diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/descriptor/descriptor.proto b/vendor/github.com/golang/protobuf/protoc-gen-go/descriptor/descriptor.proto
new file mode 100644
index 0000000..8697a50
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/descriptor/descriptor.proto
@@ -0,0 +1,872 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+//
+// The messages in this file describe the definitions found in .proto files.
+// A valid .proto file can be translated directly to a FileDescriptorProto
+// without any other information (e.g. without reading its imports).
+
+
+syntax = "proto2";
+
+package google.protobuf;
+option go_package = "github.com/golang/protobuf/protoc-gen-go/descriptor;descriptor";
+option java_package = "com.google.protobuf";
+option java_outer_classname = "DescriptorProtos";
+option csharp_namespace = "Google.Protobuf.Reflection";
+option objc_class_prefix = "GPB";
+option cc_enable_arenas = true;
+
+// descriptor.proto must be optimized for speed because reflection-based
+// algorithms don't work during bootstrapping.
+option optimize_for = SPEED;
+
+// The protocol compiler can output a FileDescriptorSet containing the .proto
+// files it parses.
+message FileDescriptorSet {
+  repeated FileDescriptorProto file = 1;
+}
+
+// Describes a complete .proto file.
+message FileDescriptorProto {
+  optional string name = 1;       // file name, relative to root of source tree
+  optional string package = 2;    // e.g. "foo", "foo.bar", etc.
+
+  // Names of files imported by this file.
+  repeated string dependency = 3;
+  // Indexes of the public imported files in the dependency list above.
+  repeated int32 public_dependency = 10;
+  // Indexes of the weak imported files in the dependency list.
+  // For Google-internal migration only. Do not use.
+  repeated int32 weak_dependency = 11;
+
+  // All top-level definitions in this file.
+  repeated DescriptorProto message_type = 4;
+  repeated EnumDescriptorProto enum_type = 5;
+  repeated ServiceDescriptorProto service = 6;
+  repeated FieldDescriptorProto extension = 7;
+
+  optional FileOptions options = 8;
+
+  // This field contains optional information about the original source code.
+  // You may safely remove this entire field without harming runtime
+  // functionality of the descriptors -- the information is needed only by
+  // development tools.
+  optional SourceCodeInfo source_code_info = 9;
+
+  // The syntax of the proto file.
+  // The supported values are "proto2" and "proto3".
+  optional string syntax = 12;
+}
+
+// Describes a message type.
+message DescriptorProto {
+  optional string name = 1;
+
+  repeated FieldDescriptorProto field = 2;
+  repeated FieldDescriptorProto extension = 6;
+
+  repeated DescriptorProto nested_type = 3;
+  repeated EnumDescriptorProto enum_type = 4;
+
+  message ExtensionRange {
+    optional int32 start = 1;
+    optional int32 end = 2;
+
+    optional ExtensionRangeOptions options = 3;
+  }
+  repeated ExtensionRange extension_range = 5;
+
+  repeated OneofDescriptorProto oneof_decl = 8;
+
+  optional MessageOptions options = 7;
+
+  // Range of reserved tag numbers. Reserved tag numbers may not be used by
+  // fields or extension ranges in the same message. Reserved ranges may
+  // not overlap.
+  message ReservedRange {
+    optional int32 start = 1; // Inclusive.
+    optional int32 end = 2;   // Exclusive.
+  }
+  repeated ReservedRange reserved_range = 9;
+  // Reserved field names, which may not be used by fields in the same message.
+  // A given name may only be reserved once.
+  repeated string reserved_name = 10;
+}
+
+message ExtensionRangeOptions {
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+// Describes a field within a message.
+message FieldDescriptorProto {
+  enum Type {
+    // 0 is reserved for errors.
+    // Order is weird for historical reasons.
+    TYPE_DOUBLE         = 1;
+    TYPE_FLOAT          = 2;
+    // Not ZigZag encoded.  Negative numbers take 10 bytes.  Use TYPE_SINT64 if
+    // negative values are likely.
+    TYPE_INT64          = 3;
+    TYPE_UINT64         = 4;
+    // Not ZigZag encoded.  Negative numbers take 10 bytes.  Use TYPE_SINT32 if
+    // negative values are likely.
+    TYPE_INT32          = 5;
+    TYPE_FIXED64        = 6;
+    TYPE_FIXED32        = 7;
+    TYPE_BOOL           = 8;
+    TYPE_STRING         = 9;
+    // Tag-delimited aggregate.
+    // Group type is deprecated and not supported in proto3. However, Proto3
+    // implementations should still be able to parse the group wire format and
+    // treat group fields as unknown fields.
+    TYPE_GROUP          = 10;
+    TYPE_MESSAGE        = 11;  // Length-delimited aggregate.
+
+    // New in version 2.
+    TYPE_BYTES          = 12;
+    TYPE_UINT32         = 13;
+    TYPE_ENUM           = 14;
+    TYPE_SFIXED32       = 15;
+    TYPE_SFIXED64       = 16;
+    TYPE_SINT32         = 17;  // Uses ZigZag encoding.
+    TYPE_SINT64         = 18;  // Uses ZigZag encoding.
+  };
+
+  enum Label {
+    // 0 is reserved for errors
+    LABEL_OPTIONAL      = 1;
+    LABEL_REQUIRED      = 2;
+    LABEL_REPEATED      = 3;
+  };
+
+  optional string name = 1;
+  optional int32 number = 3;
+  optional Label label = 4;
+
+  // If type_name is set, this need not be set.  If both this and type_name
+  // are set, this must be one of TYPE_ENUM, TYPE_MESSAGE or TYPE_GROUP.
+  optional Type type = 5;
+
+  // For message and enum types, this is the name of the type.  If the name
+  // starts with a '.', it is fully-qualified.  Otherwise, C++-like scoping
+  // rules are used to find the type (i.e. first the nested types within this
+  // message are searched, then within the parent, on up to the root
+  // namespace).
+  optional string type_name = 6;
+
+  // For extensions, this is the name of the type being extended.  It is
+  // resolved in the same manner as type_name.
+  optional string extendee = 2;
+
+  // For numeric types, contains the original text representation of the value.
+  // For booleans, "true" or "false".
+  // For strings, contains the default text contents (not escaped in any way).
+  // For bytes, contains the C escaped value.  All bytes >= 128 are escaped.
+  // TODO(kenton):  Base-64 encode?
+  optional string default_value = 7;
+
+  // If set, gives the index of a oneof in the containing type's oneof_decl
+  // list.  This field is a member of that oneof.
+  optional int32 oneof_index = 9;
+
+  // JSON name of this field. The value is set by protocol compiler. If the
+  // user has set a "json_name" option on this field, that option's value
+  // will be used. Otherwise, it's deduced from the field's name by converting
+  // it to camelCase.
+  optional string json_name = 10;
+
+  optional FieldOptions options = 8;
+}
+
+// Describes a oneof.
+message OneofDescriptorProto {
+  optional string name = 1;
+  optional OneofOptions options = 2;
+}
+
+// Describes an enum type.
+message EnumDescriptorProto {
+  optional string name = 1;
+
+  repeated EnumValueDescriptorProto value = 2;
+
+  optional EnumOptions options = 3;
+
+  // Range of reserved numeric values. Reserved values may not be used by
+  // entries in the same enum. Reserved ranges may not overlap.
+  //
+  // Note that this is distinct from DescriptorProto.ReservedRange in that it
+  // is inclusive such that it can appropriately represent the entire int32
+  // domain.
+  message EnumReservedRange {
+    optional int32 start = 1; // Inclusive.
+    optional int32 end = 2;   // Inclusive.
+  }
+
+  // Range of reserved numeric values. Reserved numeric values may not be used
+  // by enum values in the same enum declaration. Reserved ranges may not
+  // overlap.
+  repeated EnumReservedRange reserved_range = 4;
+
+  // Reserved enum value names, which may not be reused. A given name may only
+  // be reserved once.
+  repeated string reserved_name = 5;
+}
+
+// Describes a value within an enum.
+message EnumValueDescriptorProto {
+  optional string name = 1;
+  optional int32 number = 2;
+
+  optional EnumValueOptions options = 3;
+}
+
+// Describes a service.
+message ServiceDescriptorProto {
+  optional string name = 1;
+  repeated MethodDescriptorProto method = 2;
+
+  optional ServiceOptions options = 3;
+}
+
+// Describes a method of a service.
+message MethodDescriptorProto {
+  optional string name = 1;
+
+  // Input and output type names.  These are resolved in the same way as
+  // FieldDescriptorProto.type_name, but must refer to a message type.
+  optional string input_type = 2;
+  optional string output_type = 3;
+
+  optional MethodOptions options = 4;
+
+  // Identifies if client streams multiple client messages
+  optional bool client_streaming = 5 [default=false];
+  // Identifies if server streams multiple server messages
+  optional bool server_streaming = 6 [default=false];
+}
+
+
+// ===================================================================
+// Options
+
+// Each of the definitions above may have "options" attached.  These are
+// just annotations which may cause code to be generated slightly differently
+// or may contain hints for code that manipulates protocol messages.
+//
+// Clients may define custom options as extensions of the *Options messages.
+// These extensions may not yet be known at parsing time, so the parser cannot
+// store the values in them.  Instead it stores them in a field in the *Options
+// message called uninterpreted_option. This field must have the same name
+// across all *Options messages. We then use this field to populate the
+// extensions when we build a descriptor, at which point all protos have been
+// parsed and so all extensions are known.
+//
+// Extension numbers for custom options may be chosen as follows:
+// * For options which will only be used within a single application or
+//   organization, or for experimental options, use field numbers 50000
+//   through 99999.  It is up to you to ensure that you do not use the
+//   same number for multiple options.
+// * For options which will be published and used publicly by multiple
+//   independent entities, e-mail protobuf-global-extension-registry@google.com
+//   to reserve extension numbers. Simply provide your project name (e.g.
+//   Objective-C plugin) and your project website (if available) -- there's no
+//   need to explain how you intend to use them. Usually you only need one
+//   extension number. You can declare multiple options with only one extension
+//   number by putting them in a sub-message. See the Custom Options section of
+//   the docs for examples:
+//   https://developers.google.com/protocol-buffers/docs/proto#options
+//   If this turns out to be popular, a web service will be set up
+//   to automatically assign option numbers.
+
+
+message FileOptions {
+
+  // Sets the Java package where classes generated from this .proto will be
+  // placed.  By default, the proto package is used, but this is often
+  // inappropriate because proto packages do not normally start with backwards
+  // domain names.
+  optional string java_package = 1;
+
+
+  // If set, all the classes from the .proto file are wrapped in a single
+  // outer class with the given name.  This applies to both Proto1
+  // (equivalent to the old "--one_java_file" option) and Proto2 (where
+  // a .proto always translates to a single class, but you may want to
+  // explicitly choose the class name).
+  optional string java_outer_classname = 8;
+
+  // If set true, then the Java code generator will generate a separate .java
+  // file for each top-level message, enum, and service defined in the .proto
+  // file.  Thus, these types will *not* be nested inside the outer class
+  // named by java_outer_classname.  However, the outer class will still be
+  // generated to contain the file's getDescriptor() method as well as any
+  // top-level extensions defined in the file.
+  optional bool java_multiple_files = 10 [default=false];
+
+  // This option does nothing.
+  optional bool java_generate_equals_and_hash = 20 [deprecated=true];
+
+  // If set true, then the Java2 code generator will generate code that
+  // throws an exception whenever an attempt is made to assign a non-UTF-8
+  // byte sequence to a string field.
+  // Message reflection will do the same.
+  // However, an extension field still accepts non-UTF-8 byte sequences.
+  // This option has no effect on when used with the lite runtime.
+  optional bool java_string_check_utf8 = 27 [default=false];
+
+
+  // Generated classes can be optimized for speed or code size.
+  enum OptimizeMode {
+    SPEED = 1;        // Generate complete code for parsing, serialization,
+                      // etc.
+    CODE_SIZE = 2;    // Use ReflectionOps to implement these methods.
+    LITE_RUNTIME = 3; // Generate code using MessageLite and the lite runtime.
+  }
+  optional OptimizeMode optimize_for = 9 [default=SPEED];
+
+  // Sets the Go package where structs generated from this .proto will be
+  // placed. If omitted, the Go package will be derived from the following:
+  //   - The basename of the package import path, if provided.
+  //   - Otherwise, the package statement in the .proto file, if present.
+  //   - Otherwise, the basename of the .proto file, without extension.
+  optional string go_package = 11;
+
+
+
+  // Should generic services be generated in each language?  "Generic" services
+  // are not specific to any particular RPC system.  They are generated by the
+  // main code generators in each language (without additional plugins).
+  // Generic services were the only kind of service generation supported by
+  // early versions of google.protobuf.
+  //
+  // Generic services are now considered deprecated in favor of using plugins
+  // that generate code specific to your particular RPC system.  Therefore,
+  // these default to false.  Old code which depends on generic services should
+  // explicitly set them to true.
+  optional bool cc_generic_services = 16 [default=false];
+  optional bool java_generic_services = 17 [default=false];
+  optional bool py_generic_services = 18 [default=false];
+  optional bool php_generic_services = 42 [default=false];
+
+  // Is this file deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for everything in the file, or it will be completely ignored; in the very
+  // least, this is a formalization for deprecating files.
+  optional bool deprecated = 23 [default=false];
+
+  // Enables the use of arenas for the proto messages in this file. This applies
+  // only to generated classes for C++.
+  optional bool cc_enable_arenas = 31 [default=false];
+
+
+  // Sets the objective c class prefix which is prepended to all objective c
+  // generated classes from this .proto. There is no default.
+  optional string objc_class_prefix = 36;
+
+  // Namespace for generated classes; defaults to the package.
+  optional string csharp_namespace = 37;
+
+  // By default Swift generators will take the proto package and CamelCase it
+  // replacing '.' with underscore and use that to prefix the types/symbols
+  // defined. When this options is provided, they will use this value instead
+  // to prefix the types/symbols defined.
+  optional string swift_prefix = 39;
+
+  // Sets the php class prefix which is prepended to all php generated classes
+  // from this .proto. Default is empty.
+  optional string php_class_prefix = 40;
+
+  // Use this option to change the namespace of php generated classes. Default
+  // is empty. When this option is empty, the package name will be used for
+  // determining the namespace.
+  optional string php_namespace = 41;
+
+  // The parser stores options it doesn't recognize here.
+  // See the documentation for the "Options" section above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message.
+  // See the documentation for the "Options" section above.
+  extensions 1000 to max;
+
+  reserved 38;
+}
+
+message MessageOptions {
+  // Set true to use the old proto1 MessageSet wire format for extensions.
+  // This is provided for backwards-compatibility with the MessageSet wire
+  // format.  You should not use this for any other reason:  It's less
+  // efficient, has fewer features, and is more complicated.
+  //
+  // The message must be defined exactly as follows:
+  //   message Foo {
+  //     option message_set_wire_format = true;
+  //     extensions 4 to max;
+  //   }
+  // Note that the message cannot have any defined fields; MessageSets only
+  // have extensions.
+  //
+  // All extensions of your type must be singular messages; e.g. they cannot
+  // be int32s, enums, or repeated messages.
+  //
+  // Because this is an option, the above two restrictions are not enforced by
+  // the protocol compiler.
+  optional bool message_set_wire_format = 1 [default=false];
+
+  // Disables the generation of the standard "descriptor()" accessor, which can
+  // conflict with a field of the same name.  This is meant to make migration
+  // from proto1 easier; new code should avoid fields named "descriptor".
+  optional bool no_standard_descriptor_accessor = 2 [default=false];
+
+  // Is this message deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the message, or it will be completely ignored; in the very least,
+  // this is a formalization for deprecating messages.
+  optional bool deprecated = 3 [default=false];
+
+  // Whether the message is an automatically generated map entry type for the
+  // maps field.
+  //
+  // For maps fields:
+  //     map<KeyType, ValueType> map_field = 1;
+  // The parsed descriptor looks like:
+  //     message MapFieldEntry {
+  //         option map_entry = true;
+  //         optional KeyType key = 1;
+  //         optional ValueType value = 2;
+  //     }
+  //     repeated MapFieldEntry map_field = 1;
+  //
+  // Implementations may choose not to generate the map_entry=true message, but
+  // use a native map in the target language to hold the keys and values.
+  // The reflection APIs in such implementions still need to work as
+  // if the field is a repeated message field.
+  //
+  // NOTE: Do not set the option in .proto files. Always use the maps syntax
+  // instead. The option should only be implicitly set by the proto compiler
+  // parser.
+  optional bool map_entry = 7;
+
+  reserved 8;  // javalite_serializable
+  reserved 9;  // javanano_as_lite
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message FieldOptions {
+  // The ctype option instructs the C++ code generator to use a different
+  // representation of the field than it normally would.  See the specific
+  // options below.  This option is not yet implemented in the open source
+  // release -- sorry, we'll try to include it in a future version!
+  optional CType ctype = 1 [default = STRING];
+  enum CType {
+    // Default mode.
+    STRING = 0;
+
+    CORD = 1;
+
+    STRING_PIECE = 2;
+  }
+  // The packed option can be enabled for repeated primitive fields to enable
+  // a more efficient representation on the wire. Rather than repeatedly
+  // writing the tag and type for each element, the entire array is encoded as
+  // a single length-delimited blob. In proto3, only explicit setting it to
+  // false will avoid using packed encoding.
+  optional bool packed = 2;
+
+  // The jstype option determines the JavaScript type used for values of the
+  // field.  The option is permitted only for 64 bit integral and fixed types
+  // (int64, uint64, sint64, fixed64, sfixed64).  A field with jstype JS_STRING
+  // is represented as JavaScript string, which avoids loss of precision that
+  // can happen when a large value is converted to a floating point JavaScript.
+  // Specifying JS_NUMBER for the jstype causes the generated JavaScript code to
+  // use the JavaScript "number" type.  The behavior of the default option
+  // JS_NORMAL is implementation dependent.
+  //
+  // This option is an enum to permit additional types to be added, e.g.
+  // goog.math.Integer.
+  optional JSType jstype = 6 [default = JS_NORMAL];
+  enum JSType {
+    // Use the default type.
+    JS_NORMAL = 0;
+
+    // Use JavaScript strings.
+    JS_STRING = 1;
+
+    // Use JavaScript numbers.
+    JS_NUMBER = 2;
+  }
+
+  // Should this field be parsed lazily?  Lazy applies only to message-type
+  // fields.  It means that when the outer message is initially parsed, the
+  // inner message's contents will not be parsed but instead stored in encoded
+  // form.  The inner message will actually be parsed when it is first accessed.
+  //
+  // This is only a hint.  Implementations are free to choose whether to use
+  // eager or lazy parsing regardless of the value of this option.  However,
+  // setting this option true suggests that the protocol author believes that
+  // using lazy parsing on this field is worth the additional bookkeeping
+  // overhead typically needed to implement it.
+  //
+  // This option does not affect the public interface of any generated code;
+  // all method signatures remain the same.  Furthermore, thread-safety of the
+  // interface is not affected by this option; const methods remain safe to
+  // call from multiple threads concurrently, while non-const methods continue
+  // to require exclusive access.
+  //
+  //
+  // Note that implementations may choose not to check required fields within
+  // a lazy sub-message.  That is, calling IsInitialized() on the outer message
+  // may return true even if the inner message has missing required fields.
+  // This is necessary because otherwise the inner message would have to be
+  // parsed in order to perform the check, defeating the purpose of lazy
+  // parsing.  An implementation which chooses not to check required fields
+  // must be consistent about it.  That is, for any particular sub-message, the
+  // implementation must either *always* check its required fields, or *never*
+  // check its required fields, regardless of whether or not the message has
+  // been parsed.
+  optional bool lazy = 5 [default=false];
+
+  // Is this field deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for accessors, or it will be completely ignored; in the very least, this
+  // is a formalization for deprecating fields.
+  optional bool deprecated = 3 [default=false];
+
+  // For Google-internal migration only. Do not use.
+  optional bool weak = 10 [default=false];
+
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+
+  reserved 4;  // removed jtype
+}
+
+message OneofOptions {
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message EnumOptions {
+
+  // Set this option to true to allow mapping different tag names to the same
+  // value.
+  optional bool allow_alias = 2;
+
+  // Is this enum deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the enum, or it will be completely ignored; in the very least, this
+  // is a formalization for deprecating enums.
+  optional bool deprecated = 3 [default=false];
+
+  reserved 5;  // javanano_as_lite
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message EnumValueOptions {
+  // Is this enum value deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the enum value, or it will be completely ignored; in the very least,
+  // this is a formalization for deprecating enum values.
+  optional bool deprecated = 1 [default=false];
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message ServiceOptions {
+
+  // Note:  Field numbers 1 through 32 are reserved for Google's internal RPC
+  //   framework.  We apologize for hoarding these numbers to ourselves, but
+  //   we were already using them long before we decided to release Protocol
+  //   Buffers.
+
+  // Is this service deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the service, or it will be completely ignored; in the very least,
+  // this is a formalization for deprecating services.
+  optional bool deprecated = 33 [default=false];
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message MethodOptions {
+
+  // Note:  Field numbers 1 through 32 are reserved for Google's internal RPC
+  //   framework.  We apologize for hoarding these numbers to ourselves, but
+  //   we were already using them long before we decided to release Protocol
+  //   Buffers.
+
+  // Is this method deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the method, or it will be completely ignored; in the very least,
+  // this is a formalization for deprecating methods.
+  optional bool deprecated = 33 [default=false];
+
+  // Is this method side-effect-free (or safe in HTTP parlance), or idempotent,
+  // or neither? HTTP based RPC implementation may choose GET verb for safe
+  // methods, and PUT verb for idempotent methods instead of the default POST.
+  enum IdempotencyLevel {
+    IDEMPOTENCY_UNKNOWN = 0;
+    NO_SIDE_EFFECTS     = 1; // implies idempotent
+    IDEMPOTENT          = 2; // idempotent, but may have side effects
+  }
+  optional IdempotencyLevel idempotency_level =
+      34 [default=IDEMPOTENCY_UNKNOWN];
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+
+// A message representing a option the parser does not recognize. This only
+// appears in options protos created by the compiler::Parser class.
+// DescriptorPool resolves these when building Descriptor objects. Therefore,
+// options protos in descriptor objects (e.g. returned by Descriptor::options(),
+// or produced by Descriptor::CopyTo()) will never have UninterpretedOptions
+// in them.
+message UninterpretedOption {
+  // The name of the uninterpreted option.  Each string represents a segment in
+  // a dot-separated name.  is_extension is true iff a segment represents an
+  // extension (denoted with parentheses in options specs in .proto files).
+  // E.g.,{ ["foo", false], ["bar.baz", true], ["qux", false] } represents
+  // "foo.(bar.baz).qux".
+  message NamePart {
+    required string name_part = 1;
+    required bool is_extension = 2;
+  }
+  repeated NamePart name = 2;
+
+  // The value of the uninterpreted option, in whatever type the tokenizer
+  // identified it as during parsing. Exactly one of these should be set.
+  optional string identifier_value = 3;
+  optional uint64 positive_int_value = 4;
+  optional int64 negative_int_value = 5;
+  optional double double_value = 6;
+  optional bytes string_value = 7;
+  optional string aggregate_value = 8;
+}
+
+// ===================================================================
+// Optional source code info
+
+// Encapsulates information about the original source file from which a
+// FileDescriptorProto was generated.
+message SourceCodeInfo {
+  // A Location identifies a piece of source code in a .proto file which
+  // corresponds to a particular definition.  This information is intended
+  // to be useful to IDEs, code indexers, documentation generators, and similar
+  // tools.
+  //
+  // For example, say we have a file like:
+  //   message Foo {
+  //     optional string foo = 1;
+  //   }
+  // Let's look at just the field definition:
+  //   optional string foo = 1;
+  //   ^       ^^     ^^  ^  ^^^
+  //   a       bc     de  f  ghi
+  // We have the following locations:
+  //   span   path               represents
+  //   [a,i)  [ 4, 0, 2, 0 ]     The whole field definition.
+  //   [a,b)  [ 4, 0, 2, 0, 4 ]  The label (optional).
+  //   [c,d)  [ 4, 0, 2, 0, 5 ]  The type (string).
+  //   [e,f)  [ 4, 0, 2, 0, 1 ]  The name (foo).
+  //   [g,h)  [ 4, 0, 2, 0, 3 ]  The number (1).
+  //
+  // Notes:
+  // - A location may refer to a repeated field itself (i.e. not to any
+  //   particular index within it).  This is used whenever a set of elements are
+  //   logically enclosed in a single code segment.  For example, an entire
+  //   extend block (possibly containing multiple extension definitions) will
+  //   have an outer location whose path refers to the "extensions" repeated
+  //   field without an index.
+  // - Multiple locations may have the same path.  This happens when a single
+  //   logical declaration is spread out across multiple places.  The most
+  //   obvious example is the "extend" block again -- there may be multiple
+  //   extend blocks in the same scope, each of which will have the same path.
+  // - A location's span is not always a subset of its parent's span.  For
+  //   example, the "extendee" of an extension declaration appears at the
+  //   beginning of the "extend" block and is shared by all extensions within
+  //   the block.
+  // - Just because a location's span is a subset of some other location's span
+  //   does not mean that it is a descendent.  For example, a "group" defines
+  //   both a type and a field in a single declaration.  Thus, the locations
+  //   corresponding to the type and field and their components will overlap.
+  // - Code which tries to interpret locations should probably be designed to
+  //   ignore those that it doesn't understand, as more types of locations could
+  //   be recorded in the future.
+  repeated Location location = 1;
+  message Location {
+    // Identifies which part of the FileDescriptorProto was defined at this
+    // location.
+    //
+    // Each element is a field number or an index.  They form a path from
+    // the root FileDescriptorProto to the place where the definition.  For
+    // example, this path:
+    //   [ 4, 3, 2, 7, 1 ]
+    // refers to:
+    //   file.message_type(3)  // 4, 3
+    //       .field(7)         // 2, 7
+    //       .name()           // 1
+    // This is because FileDescriptorProto.message_type has field number 4:
+    //   repeated DescriptorProto message_type = 4;
+    // and DescriptorProto.field has field number 2:
+    //   repeated FieldDescriptorProto field = 2;
+    // and FieldDescriptorProto.name has field number 1:
+    //   optional string name = 1;
+    //
+    // Thus, the above path gives the location of a field name.  If we removed
+    // the last element:
+    //   [ 4, 3, 2, 7 ]
+    // this path refers to the whole field declaration (from the beginning
+    // of the label to the terminating semicolon).
+    repeated int32 path = 1 [packed=true];
+
+    // Always has exactly three or four elements: start line, start column,
+    // end line (optional, otherwise assumed same as start line), end column.
+    // These are packed into a single field for efficiency.  Note that line
+    // and column numbers are zero-based -- typically you will want to add
+    // 1 to each before displaying to a user.
+    repeated int32 span = 2 [packed=true];
+
+    // If this SourceCodeInfo represents a complete declaration, these are any
+    // comments appearing before and after the declaration which appear to be
+    // attached to the declaration.
+    //
+    // A series of line comments appearing on consecutive lines, with no other
+    // tokens appearing on those lines, will be treated as a single comment.
+    //
+    // leading_detached_comments will keep paragraphs of comments that appear
+    // before (but not connected to) the current element. Each paragraph,
+    // separated by empty lines, will be one comment element in the repeated
+    // field.
+    //
+    // Only the comment content is provided; comment markers (e.g. //) are
+    // stripped out.  For block comments, leading whitespace and an asterisk
+    // will be stripped from the beginning of each line other than the first.
+    // Newlines are included in the output.
+    //
+    // Examples:
+    //
+    //   optional int32 foo = 1;  // Comment attached to foo.
+    //   // Comment attached to bar.
+    //   optional int32 bar = 2;
+    //
+    //   optional string baz = 3;
+    //   // Comment attached to baz.
+    //   // Another line attached to baz.
+    //
+    //   // Comment attached to qux.
+    //   //
+    //   // Another line attached to qux.
+    //   optional double qux = 4;
+    //
+    //   // Detached comment for corge. This is not leading or trailing comments
+    //   // to qux or corge because there are blank lines separating it from
+    //   // both.
+    //
+    //   // Detached comment for corge paragraph 2.
+    //
+    //   optional string corge = 5;
+    //   /* Block comment attached
+    //    * to corge.  Leading asterisks
+    //    * will be removed. */
+    //   /* Block comment attached to
+    //    * grault. */
+    //   optional int32 grault = 6;
+    //
+    //   // ignored detached comments.
+    optional string leading_comments = 3;
+    optional string trailing_comments = 4;
+    repeated string leading_detached_comments = 6;
+  }
+}
+
+// Describes the relationship between generated code and its original source
+// file. A GeneratedCodeInfo message is associated with only one generated
+// source file, but may contain references to different source .proto files.
+message GeneratedCodeInfo {
+  // An Annotation connects some span of text in generated code to an element
+  // of its generating .proto file.
+  repeated Annotation annotation = 1;
+  message Annotation {
+    // Identifies the element in the original source .proto file. This field
+    // is formatted the same as SourceCodeInfo.Location.path.
+    repeated int32 path = 1 [packed=true];
+
+    // Identifies the filesystem path to the original source .proto.
+    optional string source_file = 2;
+
+    // Identifies the starting offset in bytes in the generated code
+    // that relates to the identified object.
+    optional int32 begin = 3;
+
+    // Identifies the ending offset in bytes in the generated code that
+    // relates to the identified offset. The end offset should be one past
+    // the last relevant byte (so the length of the text = end - begin).
+    optional int32 end = 4;
+  }
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/doc.go b/vendor/github.com/golang/protobuf/protoc-gen-go/doc.go
new file mode 100644
index 0000000..0d6055d
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/doc.go
@@ -0,0 +1,51 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+/*
+	A plugin for the Google protocol buffer compiler to generate Go code.
+	Run it by building this program and putting it in your path with the name
+		protoc-gen-go
+	That word 'go' at the end becomes part of the option string set for the
+	protocol compiler, so once the protocol compiler (protoc) is installed
+	you can run
+		protoc --go_out=output_directory input_directory/file.proto
+	to generate Go bindings for the protocol defined by file.proto.
+	With that input, the output will be written to
+		output_directory/file.pb.go
+
+	The generated code is documented in the package comment for
+	the library.
+
+	See the README and documentation for protocol buffers to learn more:
+		https://developers.google.com/protocol-buffers/
+
+*/
+package documentation
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/generator/generator.go b/vendor/github.com/golang/protobuf/protoc-gen-go/generator/generator.go
new file mode 100644
index 0000000..c13a9f1
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/generator/generator.go
@@ -0,0 +1,3086 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+/*
+	The code generator for the plugin for the Google protocol buffer compiler.
+	It generates Go code from the protocol buffer description files read by the
+	main routine.
+*/
+package generator
+
+import (
+	"bufio"
+	"bytes"
+	"compress/gzip"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"go/build"
+	"go/parser"
+	"go/printer"
+	"go/token"
+	"log"
+	"os"
+	"path"
+	"sort"
+	"strconv"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/protoc-gen-go/generator/internal/remap"
+
+	"github.com/golang/protobuf/protoc-gen-go/descriptor"
+	plugin "github.com/golang/protobuf/protoc-gen-go/plugin"
+)
+
+// generatedCodeVersion indicates a version of the generated code.
+// It is incremented whenever an incompatibility between the generated code and
+// proto package is introduced; the generated code references
+// a constant, proto.ProtoPackageIsVersionN (where N is generatedCodeVersion).
+const generatedCodeVersion = 2
+
+// A Plugin provides functionality to add to the output during Go code generation,
+// such as to produce RPC stubs.
+type Plugin interface {
+	// Name identifies the plugin.
+	Name() string
+	// Init is called once after data structures are built but before
+	// code generation begins.
+	Init(g *Generator)
+	// Generate produces the code generated by the plugin for this file,
+	// except for the imports, by calling the generator's methods P, In, and Out.
+	Generate(file *FileDescriptor)
+	// GenerateImports produces the import declarations for this file.
+	// It is called after Generate.
+	GenerateImports(file *FileDescriptor)
+}
+
+var plugins []Plugin
+
+// RegisterPlugin installs a (second-order) plugin to be run when the Go output is generated.
+// It is typically called during initialization.
+func RegisterPlugin(p Plugin) {
+	plugins = append(plugins, p)
+}
+
+// A GoImportPath is the import path of a Go package. e.g., "google.golang.org/genproto/protobuf".
+type GoImportPath string
+
+func (p GoImportPath) String() string { return strconv.Quote(string(p)) }
+
+// A GoPackageName is the name of a Go package. e.g., "protobuf".
+type GoPackageName string
+
+// Each type we import as a protocol buffer (other than FileDescriptorProto) needs
+// a pointer to the FileDescriptorProto that represents it.  These types achieve that
+// wrapping by placing each Proto inside a struct with the pointer to its File. The
+// structs have the same names as their contents, with "Proto" removed.
+// FileDescriptor is used to store the things that it points to.
+
+// The file and package name method are common to messages and enums.
+type common struct {
+	file *FileDescriptor // File this object comes from.
+}
+
+// GoImportPath is the import path of the Go package containing the type.
+func (c *common) GoImportPath() GoImportPath {
+	return c.file.importPath
+}
+
+func (c *common) File() *FileDescriptor { return c.file }
+
+func fileIsProto3(file *descriptor.FileDescriptorProto) bool {
+	return file.GetSyntax() == "proto3"
+}
+
+func (c *common) proto3() bool { return fileIsProto3(c.file.FileDescriptorProto) }
+
+// Descriptor represents a protocol buffer message.
+type Descriptor struct {
+	common
+	*descriptor.DescriptorProto
+	parent   *Descriptor            // The containing message, if any.
+	nested   []*Descriptor          // Inner messages, if any.
+	enums    []*EnumDescriptor      // Inner enums, if any.
+	ext      []*ExtensionDescriptor // Extensions, if any.
+	typename []string               // Cached typename vector.
+	index    int                    // The index into the container, whether the file or another message.
+	path     string                 // The SourceCodeInfo path as comma-separated integers.
+	group    bool
+}
+
+// TypeName returns the elements of the dotted type name.
+// The package name is not part of this name.
+func (d *Descriptor) TypeName() []string {
+	if d.typename != nil {
+		return d.typename
+	}
+	n := 0
+	for parent := d; parent != nil; parent = parent.parent {
+		n++
+	}
+	s := make([]string, n)
+	for parent := d; parent != nil; parent = parent.parent {
+		n--
+		s[n] = parent.GetName()
+	}
+	d.typename = s
+	return s
+}
+
+// EnumDescriptor describes an enum. If it's at top level, its parent will be nil.
+// Otherwise it will be the descriptor of the message in which it is defined.
+type EnumDescriptor struct {
+	common
+	*descriptor.EnumDescriptorProto
+	parent   *Descriptor // The containing message, if any.
+	typename []string    // Cached typename vector.
+	index    int         // The index into the container, whether the file or a message.
+	path     string      // The SourceCodeInfo path as comma-separated integers.
+}
+
+// TypeName returns the elements of the dotted type name.
+// The package name is not part of this name.
+func (e *EnumDescriptor) TypeName() (s []string) {
+	if e.typename != nil {
+		return e.typename
+	}
+	name := e.GetName()
+	if e.parent == nil {
+		s = make([]string, 1)
+	} else {
+		pname := e.parent.TypeName()
+		s = make([]string, len(pname)+1)
+		copy(s, pname)
+	}
+	s[len(s)-1] = name
+	e.typename = s
+	return s
+}
+
+// Everything but the last element of the full type name, CamelCased.
+// The values of type Foo.Bar are call Foo_value1... not Foo_Bar_value1... .
+func (e *EnumDescriptor) prefix() string {
+	if e.parent == nil {
+		// If the enum is not part of a message, the prefix is just the type name.
+		return CamelCase(*e.Name) + "_"
+	}
+	typeName := e.TypeName()
+	return CamelCaseSlice(typeName[0:len(typeName)-1]) + "_"
+}
+
+// The integer value of the named constant in this enumerated type.
+func (e *EnumDescriptor) integerValueAsString(name string) string {
+	for _, c := range e.Value {
+		if c.GetName() == name {
+			return fmt.Sprint(c.GetNumber())
+		}
+	}
+	log.Fatal("cannot find value for enum constant")
+	return ""
+}
+
+// ExtensionDescriptor describes an extension. If it's at top level, its parent will be nil.
+// Otherwise it will be the descriptor of the message in which it is defined.
+type ExtensionDescriptor struct {
+	common
+	*descriptor.FieldDescriptorProto
+	parent *Descriptor // The containing message, if any.
+}
+
+// TypeName returns the elements of the dotted type name.
+// The package name is not part of this name.
+func (e *ExtensionDescriptor) TypeName() (s []string) {
+	name := e.GetName()
+	if e.parent == nil {
+		// top-level extension
+		s = make([]string, 1)
+	} else {
+		pname := e.parent.TypeName()
+		s = make([]string, len(pname)+1)
+		copy(s, pname)
+	}
+	s[len(s)-1] = name
+	return s
+}
+
+// DescName returns the variable name used for the generated descriptor.
+func (e *ExtensionDescriptor) DescName() string {
+	// The full type name.
+	typeName := e.TypeName()
+	// Each scope of the extension is individually CamelCased, and all are joined with "_" with an "E_" prefix.
+	for i, s := range typeName {
+		typeName[i] = CamelCase(s)
+	}
+	return "E_" + strings.Join(typeName, "_")
+}
+
+// ImportedDescriptor describes a type that has been publicly imported from another file.
+type ImportedDescriptor struct {
+	common
+	o Object
+}
+
+func (id *ImportedDescriptor) TypeName() []string { return id.o.TypeName() }
+
+// FileDescriptor describes an protocol buffer descriptor file (.proto).
+// It includes slices of all the messages and enums defined within it.
+// Those slices are constructed by WrapTypes.
+type FileDescriptor struct {
+	*descriptor.FileDescriptorProto
+	desc []*Descriptor          // All the messages defined in this file.
+	enum []*EnumDescriptor      // All the enums defined in this file.
+	ext  []*ExtensionDescriptor // All the top-level extensions defined in this file.
+	imp  []*ImportedDescriptor  // All types defined in files publicly imported by this file.
+
+	// Comments, stored as a map of path (comma-separated integers) to the comment.
+	comments map[string]*descriptor.SourceCodeInfo_Location
+
+	// The full list of symbols that are exported,
+	// as a map from the exported object to its symbols.
+	// This is used for supporting public imports.
+	exported map[Object][]symbol
+
+	fingerprint string        // Fingerprint of this file's contents.
+	importPath  GoImportPath  // Import path of this file's package.
+	packageName GoPackageName // Name of this file's Go package.
+
+	proto3 bool // whether to generate proto3 code for this file
+}
+
+// VarName is the variable name we'll use in the generated code to refer
+// to the compressed bytes of this descriptor. It is not exported, so
+// it is only valid inside the generated package.
+func (d *FileDescriptor) VarName() string {
+	name := strings.Map(badToUnderscore, baseName(d.GetName()))
+	return fmt.Sprintf("fileDescriptor_%s_%s", name, d.fingerprint)
+}
+
+// goPackageOption interprets the file's go_package option.
+// If there is no go_package, it returns ("", "", false).
+// If there's a simple name, it returns ("", pkg, true).
+// If the option implies an import path, it returns (impPath, pkg, true).
+func (d *FileDescriptor) goPackageOption() (impPath GoImportPath, pkg GoPackageName, ok bool) {
+	opt := d.GetOptions().GetGoPackage()
+	if opt == "" {
+		return "", "", false
+	}
+	// A semicolon-delimited suffix delimits the import path and package name.
+	sc := strings.Index(opt, ";")
+	if sc >= 0 {
+		return GoImportPath(opt[:sc]), cleanPackageName(opt[sc+1:]), true
+	}
+	// The presence of a slash implies there's an import path.
+	slash := strings.LastIndex(opt, "/")
+	if slash >= 0 {
+		return GoImportPath(opt), cleanPackageName(opt[slash+1:]), true
+	}
+	return "", cleanPackageName(opt), true
+}
+
+// goFileName returns the output name for the generated Go file.
+func (d *FileDescriptor) goFileName(pathType pathType) string {
+	name := *d.Name
+	if ext := path.Ext(name); ext == ".proto" || ext == ".protodevel" {
+		name = name[:len(name)-len(ext)]
+	}
+	name += ".pb.go"
+
+	if pathType == pathTypeSourceRelative {
+		return name
+	}
+
+	// Does the file have a "go_package" option?
+	// If it does, it may override the filename.
+	if impPath, _, ok := d.goPackageOption(); ok && impPath != "" {
+		// Replace the existing dirname with the declared import path.
+		_, name = path.Split(name)
+		name = path.Join(string(impPath), name)
+		return name
+	}
+
+	return name
+}
+
+func (d *FileDescriptor) addExport(obj Object, sym symbol) {
+	d.exported[obj] = append(d.exported[obj], sym)
+}
+
+// symbol is an interface representing an exported Go symbol.
+type symbol interface {
+	// GenerateAlias should generate an appropriate alias
+	// for the symbol from the named package.
+	GenerateAlias(g *Generator, pkg GoPackageName)
+}
+
+type messageSymbol struct {
+	sym                         string
+	hasExtensions, isMessageSet bool
+	oneofTypes                  []string
+}
+
+type getterSymbol struct {
+	name     string
+	typ      string
+	typeName string // canonical name in proto world; empty for proto.Message and similar
+	genType  bool   // whether typ contains a generated type (message/group/enum)
+}
+
+func (ms *messageSymbol) GenerateAlias(g *Generator, pkg GoPackageName) {
+	g.P("type ", ms.sym, " = ", pkg, ".", ms.sym)
+	for _, name := range ms.oneofTypes {
+		g.P("type ", name, " = ", pkg, ".", name)
+	}
+}
+
+type enumSymbol struct {
+	name   string
+	proto3 bool // Whether this came from a proto3 file.
+}
+
+func (es enumSymbol) GenerateAlias(g *Generator, pkg GoPackageName) {
+	s := es.name
+	g.P("type ", s, " = ", pkg, ".", s)
+	g.P("var ", s, "_name = ", pkg, ".", s, "_name")
+	g.P("var ", s, "_value = ", pkg, ".", s, "_value")
+}
+
+type constOrVarSymbol struct {
+	sym  string
+	typ  string // either "const" or "var"
+	cast string // if non-empty, a type cast is required (used for enums)
+}
+
+func (cs constOrVarSymbol) GenerateAlias(g *Generator, pkg GoPackageName) {
+	v := string(pkg) + "." + cs.sym
+	if cs.cast != "" {
+		v = cs.cast + "(" + v + ")"
+	}
+	g.P(cs.typ, " ", cs.sym, " = ", v)
+}
+
+// Object is an interface abstracting the abilities shared by enums, messages, extensions and imported objects.
+type Object interface {
+	GoImportPath() GoImportPath
+	TypeName() []string
+	File() *FileDescriptor
+}
+
+// Generator is the type whose methods generate the output, stored in the associated response structure.
+type Generator struct {
+	*bytes.Buffer
+
+	Request  *plugin.CodeGeneratorRequest  // The input.
+	Response *plugin.CodeGeneratorResponse // The output.
+
+	Param             map[string]string // Command-line parameters.
+	PackageImportPath string            // Go import path of the package we're generating code for
+	ImportPrefix      string            // String to prefix to imported package file names.
+	ImportMap         map[string]string // Mapping from .proto file name to import path
+
+	Pkg map[string]string // The names under which we import support packages
+
+	outputImportPath GoImportPath                   // Package we're generating code for.
+	allFiles         []*FileDescriptor              // All files in the tree
+	allFilesByName   map[string]*FileDescriptor     // All files by filename.
+	genFiles         []*FileDescriptor              // Those files we will generate output for.
+	file             *FileDescriptor                // The file we are compiling now.
+	packageNames     map[GoImportPath]GoPackageName // Imported package names in the current file.
+	usedPackages     map[GoImportPath]bool          // Packages used in current file.
+	usedPackageNames map[GoPackageName]bool         // Package names used in the current file.
+	typeNameToObject map[string]Object              // Key is a fully-qualified name in input syntax.
+	init             []string                       // Lines to emit in the init function.
+	indent           string
+	pathType         pathType // How to generate output filenames.
+	writeOutput      bool
+	annotateCode     bool                                       // whether to store annotations
+	annotations      []*descriptor.GeneratedCodeInfo_Annotation // annotations to store
+}
+
+type pathType int
+
+const (
+	pathTypeImport pathType = iota
+	pathTypeSourceRelative
+)
+
+// New creates a new generator and allocates the request and response protobufs.
+func New() *Generator {
+	g := new(Generator)
+	g.Buffer = new(bytes.Buffer)
+	g.Request = new(plugin.CodeGeneratorRequest)
+	g.Response = new(plugin.CodeGeneratorResponse)
+	return g
+}
+
+// Error reports a problem, including an error, and exits the program.
+func (g *Generator) Error(err error, msgs ...string) {
+	s := strings.Join(msgs, " ") + ":" + err.Error()
+	log.Print("protoc-gen-go: error:", s)
+	os.Exit(1)
+}
+
+// Fail reports a problem and exits the program.
+func (g *Generator) Fail(msgs ...string) {
+	s := strings.Join(msgs, " ")
+	log.Print("protoc-gen-go: error:", s)
+	os.Exit(1)
+}
+
+// CommandLineParameters breaks the comma-separated list of key=value pairs
+// in the parameter (a member of the request protobuf) into a key/value map.
+// It then sets file name mappings defined by those entries.
+func (g *Generator) CommandLineParameters(parameter string) {
+	g.Param = make(map[string]string)
+	for _, p := range strings.Split(parameter, ",") {
+		if i := strings.Index(p, "="); i < 0 {
+			g.Param[p] = ""
+		} else {
+			g.Param[p[0:i]] = p[i+1:]
+		}
+	}
+
+	g.ImportMap = make(map[string]string)
+	pluginList := "none" // Default list of plugin names to enable (empty means all).
+	for k, v := range g.Param {
+		switch k {
+		case "import_prefix":
+			g.ImportPrefix = v
+		case "import_path":
+			g.PackageImportPath = v
+		case "paths":
+			switch v {
+			case "import":
+				g.pathType = pathTypeImport
+			case "source_relative":
+				g.pathType = pathTypeSourceRelative
+			default:
+				g.Fail(fmt.Sprintf(`Unknown path type %q: want "import" or "source_relative".`, v))
+			}
+		case "plugins":
+			pluginList = v
+		case "annotate_code":
+			if v == "true" {
+				g.annotateCode = true
+			}
+		default:
+			if len(k) > 0 && k[0] == 'M' {
+				g.ImportMap[k[1:]] = v
+			}
+		}
+	}
+	if pluginList != "" {
+		// Amend the set of plugins.
+		enabled := make(map[string]bool)
+		for _, name := range strings.Split(pluginList, "+") {
+			enabled[name] = true
+		}
+		var nplugins []Plugin
+		for _, p := range plugins {
+			if enabled[p.Name()] {
+				nplugins = append(nplugins, p)
+			}
+		}
+		plugins = nplugins
+	}
+}
+
+// DefaultPackageName returns the package name printed for the object.
+// If its file is in a different package, it returns the package name we're using for this file, plus ".".
+// Otherwise it returns the empty string.
+func (g *Generator) DefaultPackageName(obj Object) string {
+	importPath := obj.GoImportPath()
+	if importPath == g.outputImportPath {
+		return ""
+	}
+	return string(g.GoPackageName(importPath)) + "."
+}
+
+// GoPackageName returns the name used for a package.
+func (g *Generator) GoPackageName(importPath GoImportPath) GoPackageName {
+	if name, ok := g.packageNames[importPath]; ok {
+		return name
+	}
+	name := cleanPackageName(baseName(string(importPath)))
+	for i, orig := 1, name; g.usedPackageNames[name]; i++ {
+		name = orig + GoPackageName(strconv.Itoa(i))
+	}
+	g.packageNames[importPath] = name
+	g.usedPackageNames[name] = true
+	return name
+}
+
+var globalPackageNames = map[GoPackageName]bool{
+	"fmt":   true,
+	"math":  true,
+	"proto": true,
+}
+
+// Create and remember a guaranteed unique package name. Pkg is the candidate name.
+// The FileDescriptor parameter is unused.
+func RegisterUniquePackageName(pkg string, f *FileDescriptor) string {
+	name := cleanPackageName(pkg)
+	for i, orig := 1, name; globalPackageNames[name]; i++ {
+		name = orig + GoPackageName(strconv.Itoa(i))
+	}
+	globalPackageNames[name] = true
+	return string(name)
+}
+
+var isGoKeyword = map[string]bool{
+	"break":       true,
+	"case":        true,
+	"chan":        true,
+	"const":       true,
+	"continue":    true,
+	"default":     true,
+	"else":        true,
+	"defer":       true,
+	"fallthrough": true,
+	"for":         true,
+	"func":        true,
+	"go":          true,
+	"goto":        true,
+	"if":          true,
+	"import":      true,
+	"interface":   true,
+	"map":         true,
+	"package":     true,
+	"range":       true,
+	"return":      true,
+	"select":      true,
+	"struct":      true,
+	"switch":      true,
+	"type":        true,
+	"var":         true,
+}
+
+func cleanPackageName(name string) GoPackageName {
+	name = strings.Map(badToUnderscore, name)
+	// Identifier must not be keyword: insert _.
+	if isGoKeyword[name] {
+		name = "_" + name
+	}
+	// Identifier must not begin with digit: insert _.
+	if r, _ := utf8.DecodeRuneInString(name); unicode.IsDigit(r) {
+		name = "_" + name
+	}
+	return GoPackageName(name)
+}
+
+// defaultGoPackage returns the package name to use,
+// derived from the import path of the package we're building code for.
+func (g *Generator) defaultGoPackage() GoPackageName {
+	p := g.PackageImportPath
+	if i := strings.LastIndex(p, "/"); i >= 0 {
+		p = p[i+1:]
+	}
+	return cleanPackageName(p)
+}
+
+// SetPackageNames sets the package name for this run.
+// The package name must agree across all files being generated.
+// It also defines unique package names for all imported files.
+func (g *Generator) SetPackageNames() {
+	g.outputImportPath = g.genFiles[0].importPath
+
+	defaultPackageNames := make(map[GoImportPath]GoPackageName)
+	for _, f := range g.genFiles {
+		if _, p, ok := f.goPackageOption(); ok {
+			defaultPackageNames[f.importPath] = p
+		}
+	}
+	for _, f := range g.genFiles {
+		if _, p, ok := f.goPackageOption(); ok {
+			// Source file: option go_package = "quux/bar";
+			f.packageName = p
+		} else if p, ok := defaultPackageNames[f.importPath]; ok {
+			// A go_package option in another file in the same package.
+			//
+			// This is a poor choice in general, since every source file should
+			// contain a go_package option. Supported mainly for historical
+			// compatibility.
+			f.packageName = p
+		} else if p := g.defaultGoPackage(); p != "" {
+			// Command-line: import_path=quux/bar.
+			//
+			// The import_path flag sets a package name for files which don't
+			// contain a go_package option.
+			f.packageName = p
+		} else if p := f.GetPackage(); p != "" {
+			// Source file: package quux.bar;
+			f.packageName = cleanPackageName(p)
+		} else {
+			// Source filename.
+			f.packageName = cleanPackageName(baseName(f.GetName()))
+		}
+	}
+
+	// Check that all files have a consistent package name and import path.
+	for _, f := range g.genFiles[1:] {
+		if a, b := g.genFiles[0].importPath, f.importPath; a != b {
+			g.Fail(fmt.Sprintf("inconsistent package import paths: %v, %v", a, b))
+		}
+		if a, b := g.genFiles[0].packageName, f.packageName; a != b {
+			g.Fail(fmt.Sprintf("inconsistent package names: %v, %v", a, b))
+		}
+	}
+
+	// Names of support packages. These never vary (if there are conflicts,
+	// we rename the conflicting package), so this could be removed someday.
+	g.Pkg = map[string]string{
+		"fmt":   "fmt",
+		"math":  "math",
+		"proto": "proto",
+	}
+}
+
+// WrapTypes walks the incoming data, wrapping DescriptorProtos, EnumDescriptorProtos
+// and FileDescriptorProtos into file-referenced objects within the Generator.
+// It also creates the list of files to generate and so should be called before GenerateAllFiles.
+func (g *Generator) WrapTypes() {
+	g.allFiles = make([]*FileDescriptor, 0, len(g.Request.ProtoFile))
+	g.allFilesByName = make(map[string]*FileDescriptor, len(g.allFiles))
+	genFileNames := make(map[string]bool)
+	for _, n := range g.Request.FileToGenerate {
+		genFileNames[n] = true
+	}
+	for _, f := range g.Request.ProtoFile {
+		fd := &FileDescriptor{
+			FileDescriptorProto: f,
+			exported:            make(map[Object][]symbol),
+			proto3:              fileIsProto3(f),
+		}
+		// The import path may be set in a number of ways.
+		if substitution, ok := g.ImportMap[f.GetName()]; ok {
+			// Command-line: M=foo.proto=quux/bar.
+			//
+			// Explicit mapping of source file to import path.
+			fd.importPath = GoImportPath(substitution)
+		} else if genFileNames[f.GetName()] && g.PackageImportPath != "" {
+			// Command-line: import_path=quux/bar.
+			//
+			// The import_path flag sets the import path for every file that
+			// we generate code for.
+			fd.importPath = GoImportPath(g.PackageImportPath)
+		} else if p, _, _ := fd.goPackageOption(); p != "" {
+			// Source file: option go_package = "quux/bar";
+			//
+			// The go_package option sets the import path. Most users should use this.
+			fd.importPath = p
+		} else {
+			// Source filename.
+			//
+			// Last resort when nothing else is available.
+			fd.importPath = GoImportPath(path.Dir(f.GetName()))
+		}
+		// We must wrap the descriptors before we wrap the enums
+		fd.desc = wrapDescriptors(fd)
+		g.buildNestedDescriptors(fd.desc)
+		fd.enum = wrapEnumDescriptors(fd, fd.desc)
+		g.buildNestedEnums(fd.desc, fd.enum)
+		fd.ext = wrapExtensions(fd)
+		extractComments(fd)
+		g.allFiles = append(g.allFiles, fd)
+		g.allFilesByName[f.GetName()] = fd
+	}
+	for _, fd := range g.allFiles {
+		fd.imp = wrapImported(fd, g)
+	}
+
+	g.genFiles = make([]*FileDescriptor, 0, len(g.Request.FileToGenerate))
+	for _, fileName := range g.Request.FileToGenerate {
+		fd := g.allFilesByName[fileName]
+		if fd == nil {
+			g.Fail("could not find file named", fileName)
+		}
+		fingerprint, err := fingerprintProto(fd.FileDescriptorProto)
+		if err != nil {
+			g.Error(err)
+		}
+		fd.fingerprint = fingerprint
+		g.genFiles = append(g.genFiles, fd)
+	}
+}
+
+// fingerprintProto returns a fingerprint for a message.
+// The fingerprint is intended to prevent conflicts between generated fileds,
+// not to provide cryptographic security.
+func fingerprintProto(m proto.Message) (string, error) {
+	b, err := proto.Marshal(m)
+	if err != nil {
+		return "", err
+	}
+	h := sha256.Sum256(b)
+	return hex.EncodeToString(h[:8]), nil
+}
+
+// Scan the descriptors in this file.  For each one, build the slice of nested descriptors
+func (g *Generator) buildNestedDescriptors(descs []*Descriptor) {
+	for _, desc := range descs {
+		if len(desc.NestedType) != 0 {
+			for _, nest := range descs {
+				if nest.parent == desc {
+					desc.nested = append(desc.nested, nest)
+				}
+			}
+			if len(desc.nested) != len(desc.NestedType) {
+				g.Fail("internal error: nesting failure for", desc.GetName())
+			}
+		}
+	}
+}
+
+func (g *Generator) buildNestedEnums(descs []*Descriptor, enums []*EnumDescriptor) {
+	for _, desc := range descs {
+		if len(desc.EnumType) != 0 {
+			for _, enum := range enums {
+				if enum.parent == desc {
+					desc.enums = append(desc.enums, enum)
+				}
+			}
+			if len(desc.enums) != len(desc.EnumType) {
+				g.Fail("internal error: enum nesting failure for", desc.GetName())
+			}
+		}
+	}
+}
+
+// Construct the Descriptor
+func newDescriptor(desc *descriptor.DescriptorProto, parent *Descriptor, file *FileDescriptor, index int) *Descriptor {
+	d := &Descriptor{
+		common:          common{file},
+		DescriptorProto: desc,
+		parent:          parent,
+		index:           index,
+	}
+	if parent == nil {
+		d.path = fmt.Sprintf("%d,%d", messagePath, index)
+	} else {
+		d.path = fmt.Sprintf("%s,%d,%d", parent.path, messageMessagePath, index)
+	}
+
+	// The only way to distinguish a group from a message is whether
+	// the containing message has a TYPE_GROUP field that matches.
+	if parent != nil {
+		parts := d.TypeName()
+		if file.Package != nil {
+			parts = append([]string{*file.Package}, parts...)
+		}
+		exp := "." + strings.Join(parts, ".")
+		for _, field := range parent.Field {
+			if field.GetType() == descriptor.FieldDescriptorProto_TYPE_GROUP && field.GetTypeName() == exp {
+				d.group = true
+				break
+			}
+		}
+	}
+
+	for _, field := range desc.Extension {
+		d.ext = append(d.ext, &ExtensionDescriptor{common{file}, field, d})
+	}
+
+	return d
+}
+
+// Return a slice of all the Descriptors defined within this file
+func wrapDescriptors(file *FileDescriptor) []*Descriptor {
+	sl := make([]*Descriptor, 0, len(file.MessageType)+10)
+	for i, desc := range file.MessageType {
+		sl = wrapThisDescriptor(sl, desc, nil, file, i)
+	}
+	return sl
+}
+
+// Wrap this Descriptor, recursively
+func wrapThisDescriptor(sl []*Descriptor, desc *descriptor.DescriptorProto, parent *Descriptor, file *FileDescriptor, index int) []*Descriptor {
+	sl = append(sl, newDescriptor(desc, parent, file, index))
+	me := sl[len(sl)-1]
+	for i, nested := range desc.NestedType {
+		sl = wrapThisDescriptor(sl, nested, me, file, i)
+	}
+	return sl
+}
+
+// Construct the EnumDescriptor
+func newEnumDescriptor(desc *descriptor.EnumDescriptorProto, parent *Descriptor, file *FileDescriptor, index int) *EnumDescriptor {
+	ed := &EnumDescriptor{
+		common:              common{file},
+		EnumDescriptorProto: desc,
+		parent:              parent,
+		index:               index,
+	}
+	if parent == nil {
+		ed.path = fmt.Sprintf("%d,%d", enumPath, index)
+	} else {
+		ed.path = fmt.Sprintf("%s,%d,%d", parent.path, messageEnumPath, index)
+	}
+	return ed
+}
+
+// Return a slice of all the EnumDescriptors defined within this file
+func wrapEnumDescriptors(file *FileDescriptor, descs []*Descriptor) []*EnumDescriptor {
+	sl := make([]*EnumDescriptor, 0, len(file.EnumType)+10)
+	// Top-level enums.
+	for i, enum := range file.EnumType {
+		sl = append(sl, newEnumDescriptor(enum, nil, file, i))
+	}
+	// Enums within messages. Enums within embedded messages appear in the outer-most message.
+	for _, nested := range descs {
+		for i, enum := range nested.EnumType {
+			sl = append(sl, newEnumDescriptor(enum, nested, file, i))
+		}
+	}
+	return sl
+}
+
+// Return a slice of all the top-level ExtensionDescriptors defined within this file.
+func wrapExtensions(file *FileDescriptor) []*ExtensionDescriptor {
+	var sl []*ExtensionDescriptor
+	for _, field := range file.Extension {
+		sl = append(sl, &ExtensionDescriptor{common{file}, field, nil})
+	}
+	return sl
+}
+
+// Return a slice of all the types that are publicly imported into this file.
+func wrapImported(file *FileDescriptor, g *Generator) (sl []*ImportedDescriptor) {
+	for _, index := range file.PublicDependency {
+		df := g.fileByName(file.Dependency[index])
+		for _, d := range df.desc {
+			if d.GetOptions().GetMapEntry() {
+				continue
+			}
+			sl = append(sl, &ImportedDescriptor{common{file}, d})
+		}
+		for _, e := range df.enum {
+			sl = append(sl, &ImportedDescriptor{common{file}, e})
+		}
+		for _, ext := range df.ext {
+			sl = append(sl, &ImportedDescriptor{common{file}, ext})
+		}
+	}
+	return
+}
+
+func extractComments(file *FileDescriptor) {
+	file.comments = make(map[string]*descriptor.SourceCodeInfo_Location)
+	for _, loc := range file.GetSourceCodeInfo().GetLocation() {
+		if loc.LeadingComments == nil {
+			continue
+		}
+		var p []string
+		for _, n := range loc.Path {
+			p = append(p, strconv.Itoa(int(n)))
+		}
+		file.comments[strings.Join(p, ",")] = loc
+	}
+}
+
+// BuildTypeNameMap builds the map from fully qualified type names to objects.
+// The key names for the map come from the input data, which puts a period at the beginning.
+// It should be called after SetPackageNames and before GenerateAllFiles.
+func (g *Generator) BuildTypeNameMap() {
+	g.typeNameToObject = make(map[string]Object)
+	for _, f := range g.allFiles {
+		// The names in this loop are defined by the proto world, not us, so the
+		// package name may be empty.  If so, the dotted package name of X will
+		// be ".X"; otherwise it will be ".pkg.X".
+		dottedPkg := "." + f.GetPackage()
+		if dottedPkg != "." {
+			dottedPkg += "."
+		}
+		for _, enum := range f.enum {
+			name := dottedPkg + dottedSlice(enum.TypeName())
+			g.typeNameToObject[name] = enum
+		}
+		for _, desc := range f.desc {
+			name := dottedPkg + dottedSlice(desc.TypeName())
+			g.typeNameToObject[name] = desc
+		}
+	}
+}
+
+// ObjectNamed, given a fully-qualified input type name as it appears in the input data,
+// returns the descriptor for the message or enum with that name.
+func (g *Generator) ObjectNamed(typeName string) Object {
+	o, ok := g.typeNameToObject[typeName]
+	if !ok {
+		g.Fail("can't find object with type", typeName)
+	}
+
+	// If the file of this object isn't a direct dependency of the current file,
+	// or in the current file, then this object has been publicly imported into
+	// a dependency of the current file.
+	// We should return the ImportedDescriptor object for it instead.
+	direct := *o.File().Name == *g.file.Name
+	if !direct {
+		for _, dep := range g.file.Dependency {
+			if *g.fileByName(dep).Name == *o.File().Name {
+				direct = true
+				break
+			}
+		}
+	}
+	if !direct {
+		found := false
+	Loop:
+		for _, dep := range g.file.Dependency {
+			df := g.fileByName(*g.fileByName(dep).Name)
+			for _, td := range df.imp {
+				if td.o == o {
+					// Found it!
+					o = td
+					found = true
+					break Loop
+				}
+			}
+		}
+		if !found {
+			log.Printf("protoc-gen-go: WARNING: failed finding publicly imported dependency for %v, used in %v", typeName, *g.file.Name)
+		}
+	}
+
+	return o
+}
+
+// AnnotatedAtoms is a list of atoms (as consumed by P) that records the file name and proto AST path from which they originated.
+type AnnotatedAtoms struct {
+	source string
+	path   string
+	atoms  []interface{}
+}
+
+// Annotate records the file name and proto AST path of a list of atoms
+// so that a later call to P can emit a link from each atom to its origin.
+func Annotate(file *FileDescriptor, path string, atoms ...interface{}) *AnnotatedAtoms {
+	return &AnnotatedAtoms{source: *file.Name, path: path, atoms: atoms}
+}
+
+// printAtom prints the (atomic, non-annotation) argument to the generated output.
+func (g *Generator) printAtom(v interface{}) {
+	switch v := v.(type) {
+	case string:
+		g.WriteString(v)
+	case *string:
+		g.WriteString(*v)
+	case bool:
+		fmt.Fprint(g, v)
+	case *bool:
+		fmt.Fprint(g, *v)
+	case int:
+		fmt.Fprint(g, v)
+	case *int32:
+		fmt.Fprint(g, *v)
+	case *int64:
+		fmt.Fprint(g, *v)
+	case float64:
+		fmt.Fprint(g, v)
+	case *float64:
+		fmt.Fprint(g, *v)
+	case GoPackageName:
+		g.WriteString(string(v))
+	case GoImportPath:
+		g.WriteString(strconv.Quote(string(v)))
+	default:
+		g.Fail(fmt.Sprintf("unknown type in printer: %T", v))
+	}
+}
+
+// P prints the arguments to the generated output.  It handles strings and int32s, plus
+// handling indirections because they may be *string, etc.  Any inputs of type AnnotatedAtoms may emit
+// annotations in a .meta file in addition to outputting the atoms themselves (if g.annotateCode
+// is true).
+func (g *Generator) P(str ...interface{}) {
+	if !g.writeOutput {
+		return
+	}
+	g.WriteString(g.indent)
+	for _, v := range str {
+		switch v := v.(type) {
+		case *AnnotatedAtoms:
+			begin := int32(g.Len())
+			for _, v := range v.atoms {
+				g.printAtom(v)
+			}
+			if g.annotateCode {
+				end := int32(g.Len())
+				var path []int32
+				for _, token := range strings.Split(v.path, ",") {
+					val, err := strconv.ParseInt(token, 10, 32)
+					if err != nil {
+						g.Fail("could not parse proto AST path: ", err.Error())
+					}
+					path = append(path, int32(val))
+				}
+				g.annotations = append(g.annotations, &descriptor.GeneratedCodeInfo_Annotation{
+					Path:       path,
+					SourceFile: &v.source,
+					Begin:      &begin,
+					End:        &end,
+				})
+			}
+		default:
+			g.printAtom(v)
+		}
+	}
+	g.WriteByte('\n')
+}
+
+// addInitf stores the given statement to be printed inside the file's init function.
+// The statement is given as a format specifier and arguments.
+func (g *Generator) addInitf(stmt string, a ...interface{}) {
+	g.init = append(g.init, fmt.Sprintf(stmt, a...))
+}
+
+// In Indents the output one tab stop.
+func (g *Generator) In() { g.indent += "\t" }
+
+// Out unindents the output one tab stop.
+func (g *Generator) Out() {
+	if len(g.indent) > 0 {
+		g.indent = g.indent[1:]
+	}
+}
+
+// GenerateAllFiles generates the output for all the files we're outputting.
+func (g *Generator) GenerateAllFiles() {
+	// Initialize the plugins
+	for _, p := range plugins {
+		p.Init(g)
+	}
+	// Generate the output. The generator runs for every file, even the files
+	// that we don't generate output for, so that we can collate the full list
+	// of exported symbols to support public imports.
+	genFileMap := make(map[*FileDescriptor]bool, len(g.genFiles))
+	for _, file := range g.genFiles {
+		genFileMap[file] = true
+	}
+	for _, file := range g.allFiles {
+		g.Reset()
+		g.annotations = nil
+		g.writeOutput = genFileMap[file]
+		g.generate(file)
+		if !g.writeOutput {
+			continue
+		}
+		fname := file.goFileName(g.pathType)
+		g.Response.File = append(g.Response.File, &plugin.CodeGeneratorResponse_File{
+			Name:    proto.String(fname),
+			Content: proto.String(g.String()),
+		})
+		if g.annotateCode {
+			// Store the generated code annotations in text, as the protoc plugin protocol requires that
+			// strings contain valid UTF-8.
+			g.Response.File = append(g.Response.File, &plugin.CodeGeneratorResponse_File{
+				Name:    proto.String(file.goFileName(g.pathType) + ".meta"),
+				Content: proto.String(proto.CompactTextString(&descriptor.GeneratedCodeInfo{Annotation: g.annotations})),
+			})
+		}
+	}
+}
+
+// Run all the plugins associated with the file.
+func (g *Generator) runPlugins(file *FileDescriptor) {
+	for _, p := range plugins {
+		p.Generate(file)
+	}
+}
+
+// Fill the response protocol buffer with the generated output for all the files we're
+// supposed to generate.
+func (g *Generator) generate(file *FileDescriptor) {
+	g.file = file
+	g.usedPackages = make(map[GoImportPath]bool)
+	g.packageNames = make(map[GoImportPath]GoPackageName)
+	g.usedPackageNames = make(map[GoPackageName]bool)
+	for name := range globalPackageNames {
+		g.usedPackageNames[name] = true
+	}
+
+	g.P("// This is a compile-time assertion to ensure that this generated file")
+	g.P("// is compatible with the proto package it is being compiled against.")
+	g.P("// A compilation error at this line likely means your copy of the")
+	g.P("// proto package needs to be updated.")
+	g.P("const _ = ", g.Pkg["proto"], ".ProtoPackageIsVersion", generatedCodeVersion, " // please upgrade the proto package")
+	g.P()
+
+	for _, td := range g.file.imp {
+		g.generateImported(td)
+	}
+	for _, enum := range g.file.enum {
+		g.generateEnum(enum)
+	}
+	for _, desc := range g.file.desc {
+		// Don't generate virtual messages for maps.
+		if desc.GetOptions().GetMapEntry() {
+			continue
+		}
+		g.generateMessage(desc)
+	}
+	for _, ext := range g.file.ext {
+		g.generateExtension(ext)
+	}
+	g.generateInitFunction()
+
+	// Run the plugins before the imports so we know which imports are necessary.
+	g.runPlugins(file)
+
+	g.generateFileDescriptor(file)
+
+	// Generate header and imports last, though they appear first in the output.
+	rem := g.Buffer
+	remAnno := g.annotations
+	g.Buffer = new(bytes.Buffer)
+	g.annotations = nil
+	g.generateHeader()
+	g.generateImports()
+	if !g.writeOutput {
+		return
+	}
+	// Adjust the offsets for annotations displaced by the header and imports.
+	for _, anno := range remAnno {
+		*anno.Begin += int32(g.Len())
+		*anno.End += int32(g.Len())
+		g.annotations = append(g.annotations, anno)
+	}
+	g.Write(rem.Bytes())
+
+	// Reformat generated code and patch annotation locations.
+	fset := token.NewFileSet()
+	original := g.Bytes()
+	if g.annotateCode {
+		// make a copy independent of g; we'll need it after Reset.
+		original = append([]byte(nil), original...)
+	}
+	ast, err := parser.ParseFile(fset, "", original, parser.ParseComments)
+	if err != nil {
+		// Print out the bad code with line numbers.
+		// This should never happen in practice, but it can while changing generated code,
+		// so consider this a debugging aid.
+		var src bytes.Buffer
+		s := bufio.NewScanner(bytes.NewReader(original))
+		for line := 1; s.Scan(); line++ {
+			fmt.Fprintf(&src, "%5d\t%s\n", line, s.Bytes())
+		}
+		g.Fail("bad Go source code was generated:", err.Error(), "\n"+src.String())
+	}
+	g.Reset()
+	err = (&printer.Config{Mode: printer.TabIndent | printer.UseSpaces, Tabwidth: 8}).Fprint(g, fset, ast)
+	if err != nil {
+		g.Fail("generated Go source code could not be reformatted:", err.Error())
+	}
+	if g.annotateCode {
+		m, err := remap.Compute(original, g.Bytes())
+		if err != nil {
+			g.Fail("formatted generated Go source code could not be mapped back to the original code:", err.Error())
+		}
+		for _, anno := range g.annotations {
+			new, ok := m.Find(int(*anno.Begin), int(*anno.End))
+			if !ok {
+				g.Fail("span in formatted generated Go source code could not be mapped back to the original code")
+			}
+			*anno.Begin = int32(new.Pos)
+			*anno.End = int32(new.End)
+		}
+	}
+}
+
+// Generate the header, including package definition
+func (g *Generator) generateHeader() {
+	g.P("// Code generated by protoc-gen-go. DO NOT EDIT.")
+	if g.file.GetOptions().GetDeprecated() {
+		g.P("// ", g.file.Name, " is a deprecated file.")
+	} else {
+		g.P("// source: ", g.file.Name)
+	}
+	g.P()
+
+	importPath, _, _ := g.file.goPackageOption()
+	if importPath == "" {
+		g.P("package ", g.file.packageName)
+	} else {
+		g.P("package ", g.file.packageName, " // import ", GoImportPath(g.ImportPrefix)+importPath)
+	}
+	g.P()
+
+	if loc, ok := g.file.comments[strconv.Itoa(packagePath)]; ok {
+		g.P("/*")
+		// not using g.PrintComments because this is a /* */ comment block.
+		text := strings.TrimSuffix(loc.GetLeadingComments(), "\n")
+		for _, line := range strings.Split(text, "\n") {
+			line = strings.TrimPrefix(line, " ")
+			// ensure we don't escape from the block comment
+			line = strings.Replace(line, "*/", "* /", -1)
+			g.P(line)
+		}
+		g.P("*/")
+		g.P()
+	}
+}
+
+// deprecationComment is the standard comment added to deprecated
+// messages, fields, enums, and enum values.
+var deprecationComment = "// Deprecated: Do not use."
+
+// PrintComments prints any comments from the source .proto file.
+// The path is a comma-separated list of integers.
+// It returns an indication of whether any comments were printed.
+// See descriptor.proto for its format.
+func (g *Generator) PrintComments(path string) bool {
+	if !g.writeOutput {
+		return false
+	}
+	if c, ok := g.makeComments(path); ok {
+		g.P(c)
+		return true
+	}
+	return false
+}
+
+// makeComments generates the comment string for the field, no "\n" at the end
+func (g *Generator) makeComments(path string) (string, bool) {
+	loc, ok := g.file.comments[path]
+	if !ok {
+		return "", false
+	}
+	w := new(bytes.Buffer)
+	nl := ""
+	for _, line := range strings.Split(strings.TrimSuffix(loc.GetLeadingComments(), "\n"), "\n") {
+		fmt.Fprintf(w, "%s// %s", nl, strings.TrimPrefix(line, " "))
+		nl = "\n"
+	}
+	return w.String(), true
+}
+
+func (g *Generator) fileByName(filename string) *FileDescriptor {
+	return g.allFilesByName[filename]
+}
+
+// weak returns whether the ith import of the current file is a weak import.
+func (g *Generator) weak(i int32) bool {
+	for _, j := range g.file.WeakDependency {
+		if j == i {
+			return true
+		}
+	}
+	return false
+}
+
+// Generate the imports
+func (g *Generator) generateImports() {
+	// We almost always need a proto import.  Rather than computing when we
+	// do, which is tricky when there's a plugin, just import it and
+	// reference it later. The same argument applies to the fmt and math packages.
+	g.P("import "+g.Pkg["proto"]+" ", GoImportPath(g.ImportPrefix)+"github.com/golang/protobuf/proto")
+	g.P("import " + g.Pkg["fmt"] + ` "fmt"`)
+	g.P("import " + g.Pkg["math"] + ` "math"`)
+	var (
+		imports       = make(map[GoImportPath]bool)
+		strongImports = make(map[GoImportPath]bool)
+		importPaths   []string
+	)
+	for i, s := range g.file.Dependency {
+		fd := g.fileByName(s)
+		importPath := fd.importPath
+		// Do not import our own package.
+		if importPath == g.file.importPath {
+			continue
+		}
+		if !imports[importPath] {
+			importPaths = append(importPaths, string(importPath))
+		}
+		imports[importPath] = true
+		if !g.weak(int32(i)) {
+			strongImports[importPath] = true
+		}
+	}
+	sort.Strings(importPaths)
+	for i := range importPaths {
+		importPath := GoImportPath(importPaths[i])
+		packageName := g.GoPackageName(importPath)
+		fullPath := GoImportPath(g.ImportPrefix) + importPath
+		// Skip weak imports.
+		if !strongImports[importPath] {
+			g.P("// skipping weak import ", packageName, " ", fullPath)
+			continue
+		}
+		// We need to import all the dependencies, even if we don't reference them,
+		// because other code and tools depend on having the full transitive closure
+		// of protocol buffer types in the binary.
+		if _, ok := g.usedPackages[importPath]; !ok {
+			packageName = "_"
+		}
+		g.P("import ", packageName, " ", fullPath)
+	}
+	g.P()
+	// TODO: may need to worry about uniqueness across plugins
+	for _, p := range plugins {
+		p.GenerateImports(g.file)
+		g.P()
+	}
+	g.P("// Reference imports to suppress errors if they are not otherwise used.")
+	g.P("var _ = ", g.Pkg["proto"], ".Marshal")
+	g.P("var _ = ", g.Pkg["fmt"], ".Errorf")
+	g.P("var _ = ", g.Pkg["math"], ".Inf")
+	g.P()
+}
+
+func (g *Generator) generateImported(id *ImportedDescriptor) {
+	tn := id.TypeName()
+	sn := tn[len(tn)-1]
+	df := id.o.File()
+	filename := *df.Name
+	if df.importPath == g.file.importPath {
+		// Don't generate type aliases for files in the same Go package as this one.
+		g.P("// Ignoring public import of ", sn, " from ", filename)
+		g.P()
+		return
+	}
+	if !supportTypeAliases {
+		g.Fail(fmt.Sprintf("%s: public imports require at least go1.9", filename))
+	}
+	g.P("// ", sn, " from public import ", filename)
+	g.usedPackages[df.importPath] = true
+
+	for _, sym := range df.exported[id.o] {
+		sym.GenerateAlias(g, g.GoPackageName(df.importPath))
+	}
+
+	g.P()
+}
+
+// Generate the enum definitions for this EnumDescriptor.
+func (g *Generator) generateEnum(enum *EnumDescriptor) {
+	// The full type name
+	typeName := enum.TypeName()
+	// The full type name, CamelCased.
+	ccTypeName := CamelCaseSlice(typeName)
+	ccPrefix := enum.prefix()
+
+	deprecatedEnum := ""
+	if enum.GetOptions().GetDeprecated() {
+		deprecatedEnum = deprecationComment
+	}
+	g.PrintComments(enum.path)
+	g.P("type ", Annotate(enum.file, enum.path, ccTypeName), " int32", deprecatedEnum)
+	g.file.addExport(enum, enumSymbol{ccTypeName, enum.proto3()})
+	g.P("const (")
+	for i, e := range enum.Value {
+		etorPath := fmt.Sprintf("%s,%d,%d", enum.path, enumValuePath, i)
+		g.PrintComments(etorPath)
+
+		deprecatedValue := ""
+		if e.GetOptions().GetDeprecated() {
+			deprecatedValue = deprecationComment
+		}
+
+		name := ccPrefix + *e.Name
+		g.P(Annotate(enum.file, etorPath, name), " ", ccTypeName, " = ", e.Number, " ", deprecatedValue)
+		g.file.addExport(enum, constOrVarSymbol{name, "const", ccTypeName})
+	}
+	g.P(")")
+	g.P("var ", ccTypeName, "_name = map[int32]string{")
+	generated := make(map[int32]bool) // avoid duplicate values
+	for _, e := range enum.Value {
+		duplicate := ""
+		if _, present := generated[*e.Number]; present {
+			duplicate = "// Duplicate value: "
+		}
+		g.P(duplicate, e.Number, ": ", strconv.Quote(*e.Name), ",")
+		generated[*e.Number] = true
+	}
+	g.P("}")
+	g.P("var ", ccTypeName, "_value = map[string]int32{")
+	for _, e := range enum.Value {
+		g.P(strconv.Quote(*e.Name), ": ", e.Number, ",")
+	}
+	g.P("}")
+
+	if !enum.proto3() {
+		g.P("func (x ", ccTypeName, ") Enum() *", ccTypeName, " {")
+		g.P("p := new(", ccTypeName, ")")
+		g.P("*p = x")
+		g.P("return p")
+		g.P("}")
+	}
+
+	g.P("func (x ", ccTypeName, ") String() string {")
+	g.P("return ", g.Pkg["proto"], ".EnumName(", ccTypeName, "_name, int32(x))")
+	g.P("}")
+
+	if !enum.proto3() {
+		g.P("func (x *", ccTypeName, ") UnmarshalJSON(data []byte) error {")
+		g.P("value, err := ", g.Pkg["proto"], ".UnmarshalJSONEnum(", ccTypeName, `_value, data, "`, ccTypeName, `")`)
+		g.P("if err != nil {")
+		g.P("return err")
+		g.P("}")
+		g.P("*x = ", ccTypeName, "(value)")
+		g.P("return nil")
+		g.P("}")
+	}
+
+	var indexes []string
+	for m := enum.parent; m != nil; m = m.parent {
+		// XXX: skip groups?
+		indexes = append([]string{strconv.Itoa(m.index)}, indexes...)
+	}
+	indexes = append(indexes, strconv.Itoa(enum.index))
+	g.P("func (", ccTypeName, ") EnumDescriptor() ([]byte, []int) {")
+	g.P("return ", g.file.VarName(), ", []int{", strings.Join(indexes, ", "), "}")
+	g.P("}")
+	if enum.file.GetPackage() == "google.protobuf" && enum.GetName() == "NullValue" {
+		g.P("func (", ccTypeName, `) XXX_WellKnownType() string { return "`, enum.GetName(), `" }`)
+	}
+
+	g.P()
+}
+
+// The tag is a string like "varint,2,opt,name=fieldname,def=7" that
+// identifies details of the field for the protocol buffer marshaling and unmarshaling
+// code.  The fields are:
+//	wire encoding
+//	protocol tag number
+//	opt,req,rep for optional, required, or repeated
+//	packed whether the encoding is "packed" (optional; repeated primitives only)
+//	name= the original declared name
+//	enum= the name of the enum type if it is an enum-typed field.
+//	proto3 if this field is in a proto3 message
+//	def= string representation of the default value, if any.
+// The default value must be in a representation that can be used at run-time
+// to generate the default value. Thus bools become 0 and 1, for instance.
+func (g *Generator) goTag(message *Descriptor, field *descriptor.FieldDescriptorProto, wiretype string) string {
+	optrepreq := ""
+	switch {
+	case isOptional(field):
+		optrepreq = "opt"
+	case isRequired(field):
+		optrepreq = "req"
+	case isRepeated(field):
+		optrepreq = "rep"
+	}
+	var defaultValue string
+	if dv := field.DefaultValue; dv != nil { // set means an explicit default
+		defaultValue = *dv
+		// Some types need tweaking.
+		switch *field.Type {
+		case descriptor.FieldDescriptorProto_TYPE_BOOL:
+			if defaultValue == "true" {
+				defaultValue = "1"
+			} else {
+				defaultValue = "0"
+			}
+		case descriptor.FieldDescriptorProto_TYPE_STRING,
+			descriptor.FieldDescriptorProto_TYPE_BYTES:
+			// Nothing to do. Quoting is done for the whole tag.
+		case descriptor.FieldDescriptorProto_TYPE_ENUM:
+			// For enums we need to provide the integer constant.
+			obj := g.ObjectNamed(field.GetTypeName())
+			if id, ok := obj.(*ImportedDescriptor); ok {
+				// It is an enum that was publicly imported.
+				// We need the underlying type.
+				obj = id.o
+			}
+			enum, ok := obj.(*EnumDescriptor)
+			if !ok {
+				log.Printf("obj is a %T", obj)
+				if id, ok := obj.(*ImportedDescriptor); ok {
+					log.Printf("id.o is a %T", id.o)
+				}
+				g.Fail("unknown enum type", CamelCaseSlice(obj.TypeName()))
+			}
+			defaultValue = enum.integerValueAsString(defaultValue)
+		}
+		defaultValue = ",def=" + defaultValue
+	}
+	enum := ""
+	if *field.Type == descriptor.FieldDescriptorProto_TYPE_ENUM {
+		// We avoid using obj.GoPackageName(), because we want to use the
+		// original (proto-world) package name.
+		obj := g.ObjectNamed(field.GetTypeName())
+		if id, ok := obj.(*ImportedDescriptor); ok {
+			obj = id.o
+		}
+		enum = ",enum="
+		if pkg := obj.File().GetPackage(); pkg != "" {
+			enum += pkg + "."
+		}
+		enum += CamelCaseSlice(obj.TypeName())
+	}
+	packed := ""
+	if (field.Options != nil && field.Options.GetPacked()) ||
+		// Per https://developers.google.com/protocol-buffers/docs/proto3#simple:
+		// "In proto3, repeated fields of scalar numeric types use packed encoding by default."
+		(message.proto3() && (field.Options == nil || field.Options.Packed == nil) &&
+			isRepeated(field) && isScalar(field)) {
+		packed = ",packed"
+	}
+	fieldName := field.GetName()
+	name := fieldName
+	if *field.Type == descriptor.FieldDescriptorProto_TYPE_GROUP {
+		// We must use the type name for groups instead of
+		// the field name to preserve capitalization.
+		// type_name in FieldDescriptorProto is fully-qualified,
+		// but we only want the local part.
+		name = *field.TypeName
+		if i := strings.LastIndex(name, "."); i >= 0 {
+			name = name[i+1:]
+		}
+	}
+	if json := field.GetJsonName(); json != "" && json != name {
+		// TODO: escaping might be needed, in which case
+		// perhaps this should be in its own "json" tag.
+		name += ",json=" + json
+	}
+	name = ",name=" + name
+	if message.proto3() {
+		name += ",proto3"
+	}
+	oneof := ""
+	if field.OneofIndex != nil {
+		oneof = ",oneof"
+	}
+	return strconv.Quote(fmt.Sprintf("%s,%d,%s%s%s%s%s%s",
+		wiretype,
+		field.GetNumber(),
+		optrepreq,
+		packed,
+		name,
+		enum,
+		oneof,
+		defaultValue))
+}
+
+func needsStar(typ descriptor.FieldDescriptorProto_Type) bool {
+	switch typ {
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		return false
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		return false
+	case descriptor.FieldDescriptorProto_TYPE_BYTES:
+		return false
+	}
+	return true
+}
+
+// TypeName is the printed name appropriate for an item. If the object is in the current file,
+// TypeName drops the package name and underscores the rest.
+// Otherwise the object is from another package; and the result is the underscored
+// package name followed by the item name.
+// The result always has an initial capital.
+func (g *Generator) TypeName(obj Object) string {
+	return g.DefaultPackageName(obj) + CamelCaseSlice(obj.TypeName())
+}
+
+// GoType returns a string representing the type name, and the wire type
+func (g *Generator) GoType(message *Descriptor, field *descriptor.FieldDescriptorProto) (typ string, wire string) {
+	// TODO: Options.
+	switch *field.Type {
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		typ, wire = "float64", "fixed64"
+	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		typ, wire = "float32", "fixed32"
+	case descriptor.FieldDescriptorProto_TYPE_INT64:
+		typ, wire = "int64", "varint"
+	case descriptor.FieldDescriptorProto_TYPE_UINT64:
+		typ, wire = "uint64", "varint"
+	case descriptor.FieldDescriptorProto_TYPE_INT32:
+		typ, wire = "int32", "varint"
+	case descriptor.FieldDescriptorProto_TYPE_UINT32:
+		typ, wire = "uint32", "varint"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED64:
+		typ, wire = "uint64", "fixed64"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED32:
+		typ, wire = "uint32", "fixed32"
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		typ, wire = "bool", "varint"
+	case descriptor.FieldDescriptorProto_TYPE_STRING:
+		typ, wire = "string", "bytes"
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		desc := g.ObjectNamed(field.GetTypeName())
+		typ, wire = "*"+g.TypeName(desc), "group"
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		desc := g.ObjectNamed(field.GetTypeName())
+		typ, wire = "*"+g.TypeName(desc), "bytes"
+	case descriptor.FieldDescriptorProto_TYPE_BYTES:
+		typ, wire = "[]byte", "bytes"
+	case descriptor.FieldDescriptorProto_TYPE_ENUM:
+		desc := g.ObjectNamed(field.GetTypeName())
+		typ, wire = g.TypeName(desc), "varint"
+	case descriptor.FieldDescriptorProto_TYPE_SFIXED32:
+		typ, wire = "int32", "fixed32"
+	case descriptor.FieldDescriptorProto_TYPE_SFIXED64:
+		typ, wire = "int64", "fixed64"
+	case descriptor.FieldDescriptorProto_TYPE_SINT32:
+		typ, wire = "int32", "zigzag32"
+	case descriptor.FieldDescriptorProto_TYPE_SINT64:
+		typ, wire = "int64", "zigzag64"
+	default:
+		g.Fail("unknown type for", field.GetName())
+	}
+	if isRepeated(field) {
+		typ = "[]" + typ
+	} else if message != nil && message.proto3() {
+		return
+	} else if field.OneofIndex != nil && message != nil {
+		return
+	} else if needsStar(*field.Type) {
+		typ = "*" + typ
+	}
+	return
+}
+
+func (g *Generator) RecordTypeUse(t string) {
+	if _, ok := g.typeNameToObject[t]; ok {
+		// Call ObjectNamed to get the true object to record the use.
+		obj := g.ObjectNamed(t)
+		g.usedPackages[obj.GoImportPath()] = true
+	}
+}
+
+// Method names that may be generated.  Fields with these names get an
+// underscore appended. Any change to this set is a potential incompatible
+// API change because it changes generated field names.
+var methodNames = [...]string{
+	"Reset",
+	"String",
+	"ProtoMessage",
+	"Marshal",
+	"Unmarshal",
+	"ExtensionRangeArray",
+	"ExtensionMap",
+	"Descriptor",
+}
+
+// Names of messages in the `google.protobuf` package for which
+// we will generate XXX_WellKnownType methods.
+var wellKnownTypes = map[string]bool{
+	"Any":       true,
+	"Duration":  true,
+	"Empty":     true,
+	"Struct":    true,
+	"Timestamp": true,
+
+	"Value":       true,
+	"ListValue":   true,
+	"DoubleValue": true,
+	"FloatValue":  true,
+	"Int64Value":  true,
+	"UInt64Value": true,
+	"Int32Value":  true,
+	"UInt32Value": true,
+	"BoolValue":   true,
+	"StringValue": true,
+	"BytesValue":  true,
+}
+
+// getterDefault finds the default value for the field to return from a getter,
+// regardless of if it's a built in default or explicit from the source. Returns e.g. "nil", `""`, "Default_MessageType_FieldName"
+func (g *Generator) getterDefault(field *descriptor.FieldDescriptorProto, goMessageType string) string {
+	if isRepeated(field) {
+		return "nil"
+	}
+	if def := field.GetDefaultValue(); def != "" {
+		defaultConstant := g.defaultConstantName(goMessageType, field.GetName())
+		if *field.Type != descriptor.FieldDescriptorProto_TYPE_BYTES {
+			return defaultConstant
+		}
+		return "append([]byte(nil), " + defaultConstant + "...)"
+	}
+	switch *field.Type {
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		return "false"
+	case descriptor.FieldDescriptorProto_TYPE_STRING:
+		return `""`
+	case descriptor.FieldDescriptorProto_TYPE_GROUP, descriptor.FieldDescriptorProto_TYPE_MESSAGE, descriptor.FieldDescriptorProto_TYPE_BYTES:
+		return "nil"
+	case descriptor.FieldDescriptorProto_TYPE_ENUM:
+		obj := g.ObjectNamed(field.GetTypeName())
+		var enum *EnumDescriptor
+		if id, ok := obj.(*ImportedDescriptor); ok {
+			// The enum type has been publicly imported.
+			enum, _ = id.o.(*EnumDescriptor)
+		} else {
+			enum, _ = obj.(*EnumDescriptor)
+		}
+		if enum == nil {
+			log.Printf("don't know how to generate getter for %s", field.GetName())
+			return "nil"
+		}
+		if len(enum.Value) == 0 {
+			return "0 // empty enum"
+		}
+		first := enum.Value[0].GetName()
+		return g.DefaultPackageName(obj) + enum.prefix() + first
+	default:
+		return "0"
+	}
+}
+
+// defaultConstantName builds the name of the default constant from the message
+// type name and the untouched field name, e.g. "Default_MessageType_FieldName"
+func (g *Generator) defaultConstantName(goMessageType, protoFieldName string) string {
+	return "Default_" + goMessageType + "_" + CamelCase(protoFieldName)
+}
+
+// The different types of fields in a message and how to actually print them
+// Most of the logic for generateMessage is in the methods of these types.
+//
+// Note that the content of the field is irrelevant, a simpleField can contain
+// anything from a scalar to a group (which is just a message).
+//
+// Extension fields (and message sets) are however handled separately.
+//
+// simpleField - a field that is neiter weak nor oneof, possibly repeated
+// oneofField - field containing list of subfields:
+// - oneofSubField - a field within the oneof
+
+// msgCtx contais the context for the generator functions.
+type msgCtx struct {
+	goName  string      // Go struct name of the message, e.g. MessageName
+	message *Descriptor // The descriptor for the message
+}
+
+// fieldCommon contains data common to all types of fields.
+type fieldCommon struct {
+	goName     string // Go name of field, e.g. "FieldName" or "Descriptor_"
+	protoName  string // Name of field in proto language, e.g. "field_name" or "descriptor"
+	getterName string // Name of the getter, e.g. "GetFieldName" or "GetDescriptor_"
+	goType     string // The Go type as a string, e.g. "*int32" or "*OtherMessage"
+	tags       string // The tag string/annotation for the type, e.g. `protobuf:"varint,8,opt,name=region_id,json=regionId"`
+	fullPath   string // The full path of the field as used by Annotate etc, e.g. "4,0,2,0"
+}
+
+// getProtoName gets the proto name of a field, e.g. "field_name" or "descriptor".
+func (f *fieldCommon) getProtoName() string {
+	return f.protoName
+}
+
+// getGoType returns the go type of the field  as a string, e.g. "*int32".
+func (f *fieldCommon) getGoType() string {
+	return f.goType
+}
+
+// simpleField is not weak, not a oneof, not an extension. Can be required, optional or repeated.
+type simpleField struct {
+	fieldCommon
+	protoTypeName string                               // Proto type name, empty if primitive, e.g. ".google.protobuf.Duration"
+	protoType     descriptor.FieldDescriptorProto_Type // Actual type enum value, e.g. descriptor.FieldDescriptorProto_TYPE_FIXED64
+	deprecated    string                               // Deprecation comment, if any, e.g. "// Deprecated: Do not use."
+	getterDef     string                               // Default for getters, e.g. "nil", `""` or "Default_MessageType_FieldName"
+	protoDef      string                               // Default value as defined in the proto file, e.g "yoshi" or "5"
+	comment       string                               // The full comment for the field, e.g. "// Useful information"
+}
+
+// decl prints the declaration of the field in the struct (if any).
+func (f *simpleField) decl(g *Generator, mc *msgCtx) {
+	g.P(f.comment, Annotate(mc.message.file, f.fullPath, f.goName), "\t", f.goType, "\t`", f.tags, "`", f.deprecated)
+}
+
+// getter prints the getter for the field.
+func (f *simpleField) getter(g *Generator, mc *msgCtx) {
+	star := ""
+	tname := f.goType
+	if needsStar(f.protoType) && tname[0] == '*' {
+		tname = tname[1:]
+		star = "*"
+	}
+	if f.deprecated != "" {
+		g.P(f.deprecated)
+	}
+	g.P("func (m *", mc.goName, ") ", Annotate(mc.message.file, f.fullPath, f.getterName), "() "+tname+" {")
+	if f.getterDef == "nil" { // Simpler getter
+		g.P("if m != nil {")
+		g.P("return m." + f.goName)
+		g.P("}")
+		g.P("return nil")
+		g.P("}")
+		g.P()
+		return
+	}
+	if mc.message.proto3() {
+		g.P("if m != nil {")
+	} else {
+		g.P("if m != nil && m." + f.goName + " != nil {")
+	}
+	g.P("return " + star + "m." + f.goName)
+	g.P("}")
+	g.P("return ", f.getterDef)
+	g.P("}")
+	g.P()
+}
+
+// setter prints the setter method of the field.
+func (f *simpleField) setter(g *Generator, mc *msgCtx) {
+	// No setter for regular fields yet
+}
+
+// getProtoDef returns the default value explicitly stated in the proto file, e.g "yoshi" or "5".
+func (f *simpleField) getProtoDef() string {
+	return f.protoDef
+}
+
+// getProtoTypeName returns the protobuf type name for the field as returned by field.GetTypeName(), e.g. ".google.protobuf.Duration".
+func (f *simpleField) getProtoTypeName() string {
+	return f.protoTypeName
+}
+
+// getProtoType returns the *field.Type value, e.g. descriptor.FieldDescriptorProto_TYPE_FIXED64.
+func (f *simpleField) getProtoType() descriptor.FieldDescriptorProto_Type {
+	return f.protoType
+}
+
+// oneofSubFields are kept slize held by each oneofField. They do not appear in the top level slize of fields for the message.
+type oneofSubField struct {
+	fieldCommon
+	protoTypeName string                               // Proto type name, empty if primitive, e.g. ".google.protobuf.Duration"
+	protoType     descriptor.FieldDescriptorProto_Type // Actual type enum value, e.g. descriptor.FieldDescriptorProto_TYPE_FIXED64
+	oneofTypeName string                               // Type name of the enclosing struct, e.g. "MessageName_FieldName"
+	fieldNumber   int                                  // Actual field number, as defined in proto, e.g. 12
+	getterDef     string                               // Default for getters, e.g. "nil", `""` or "Default_MessageType_FieldName"
+	protoDef      string                               // Default value as defined in the proto file, e.g "yoshi" or "5"
+}
+
+// wireTypeName returns a textual wire type, needed for oneof sub fields in generated code.
+func (f *oneofSubField) wireTypeName() string {
+	switch f.protoType {
+	case descriptor.FieldDescriptorProto_TYPE_FIXED64,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED64,
+		descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		return "WireFixed64"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED32,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED32,
+		descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		return "WireFixed32"
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		return "WireStartGroup"
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE,
+		descriptor.FieldDescriptorProto_TYPE_STRING,
+		descriptor.FieldDescriptorProto_TYPE_BYTES:
+		return "WireBytes"
+	default: // All others are Varints
+		return "WireVarint"
+	}
+}
+
+// typedNil prints a nil casted to the pointer to this field.
+// - for XXX_OneofFuncs
+func (f *oneofSubField) typedNil(g *Generator) {
+	g.P("(*", f.oneofTypeName, ")(nil),")
+}
+
+// marshalCase prints the case matching this oneof subfield in the marshalling code.
+func (f *oneofSubField) marshalCase(g *Generator) {
+	g.P("case *", f.oneofTypeName, ":")
+	wire := f.wireTypeName()
+	var pre, post string
+	val := "x." + f.goName // overridden for TYPE_BOOL
+	switch f.protoType {
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		pre = "b.EncodeFixed64(" + g.Pkg["math"] + ".Float64bits("
+		post = "))"
+	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		pre = "b.EncodeFixed32(uint64(" + g.Pkg["math"] + ".Float32bits("
+		post = ")))"
+	case descriptor.FieldDescriptorProto_TYPE_INT64, descriptor.FieldDescriptorProto_TYPE_UINT64:
+		pre, post = "b.EncodeVarint(uint64(", "))"
+	case descriptor.FieldDescriptorProto_TYPE_INT32, descriptor.FieldDescriptorProto_TYPE_UINT32, descriptor.FieldDescriptorProto_TYPE_ENUM:
+		pre, post = "b.EncodeVarint(uint64(", "))"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED64, descriptor.FieldDescriptorProto_TYPE_SFIXED64:
+		pre, post = "b.EncodeFixed64(uint64(", "))"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED32, descriptor.FieldDescriptorProto_TYPE_SFIXED32:
+		pre, post = "b.EncodeFixed32(uint64(", "))"
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		g.P("t := uint64(0)")
+		g.P("if ", val, " { t = 1 }")
+		val = "t"
+		pre, post = "b.EncodeVarint(", ")"
+	case descriptor.FieldDescriptorProto_TYPE_STRING:
+		pre, post = "b.EncodeStringBytes(", ")"
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		pre, post = "b.Marshal(", ")"
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		pre, post = "b.EncodeMessage(", ")"
+	case descriptor.FieldDescriptorProto_TYPE_BYTES:
+		pre, post = "b.EncodeRawBytes(", ")"
+	case descriptor.FieldDescriptorProto_TYPE_SINT32:
+		pre, post = "b.EncodeZigzag32(uint64(", "))"
+	case descriptor.FieldDescriptorProto_TYPE_SINT64:
+		pre, post = "b.EncodeZigzag64(uint64(", "))"
+	default:
+		g.Fail("unhandled oneof field type ", f.protoType.String())
+	}
+	g.P("b.EncodeVarint(", f.fieldNumber, "<<3|", g.Pkg["proto"], ".", wire, ")")
+	if t := f.protoType; t != descriptor.FieldDescriptorProto_TYPE_GROUP && t != descriptor.FieldDescriptorProto_TYPE_MESSAGE {
+		g.P(pre, val, post)
+	} else {
+		g.P("if err := ", pre, val, post, "; err != nil {")
+		g.P("return err")
+		g.P("}")
+	}
+	if f.protoType == descriptor.FieldDescriptorProto_TYPE_GROUP {
+		g.P("b.EncodeVarint(", f.fieldNumber, "<<3|", g.Pkg["proto"], ".WireEndGroup)")
+	}
+}
+
+// unmarshalCase prints the case matching this oneof subfield in the unmarshalling code.
+func (f *oneofSubField) unmarshalCase(g *Generator, origOneofName string, oneofName string) {
+	g.P("case ", f.fieldNumber, ": // ", origOneofName, ".", f.getProtoName())
+	g.P("if wire != ", g.Pkg["proto"], ".", f.wireTypeName(), " {")
+	g.P("return true, ", g.Pkg["proto"], ".ErrInternalBadWireType")
+	g.P("}")
+	lhs := "x, err" // overridden for TYPE_MESSAGE and TYPE_GROUP
+	var dec, cast, cast2 string
+	switch f.protoType {
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		dec, cast = "b.DecodeFixed64()", g.Pkg["math"]+".Float64frombits"
+	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		dec, cast, cast2 = "b.DecodeFixed32()", "uint32", g.Pkg["math"]+".Float32frombits"
+	case descriptor.FieldDescriptorProto_TYPE_INT64:
+		dec, cast = "b.DecodeVarint()", "int64"
+	case descriptor.FieldDescriptorProto_TYPE_UINT64:
+		dec = "b.DecodeVarint()"
+	case descriptor.FieldDescriptorProto_TYPE_INT32:
+		dec, cast = "b.DecodeVarint()", "int32"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED64:
+		dec = "b.DecodeFixed64()"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED32:
+		dec, cast = "b.DecodeFixed32()", "uint32"
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		dec = "b.DecodeVarint()"
+		// handled specially below
+	case descriptor.FieldDescriptorProto_TYPE_STRING:
+		dec = "b.DecodeStringBytes()"
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		g.P("msg := new(", f.goType[1:], ")") // drop star
+		lhs = "err"
+		dec = "b.DecodeGroup(msg)"
+		// handled specially below
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		g.P("msg := new(", f.goType[1:], ")") // drop star
+		lhs = "err"
+		dec = "b.DecodeMessage(msg)"
+		// handled specially below
+	case descriptor.FieldDescriptorProto_TYPE_BYTES:
+		dec = "b.DecodeRawBytes(true)"
+	case descriptor.FieldDescriptorProto_TYPE_UINT32:
+		dec, cast = "b.DecodeVarint()", "uint32"
+	case descriptor.FieldDescriptorProto_TYPE_ENUM:
+		dec, cast = "b.DecodeVarint()", f.goType
+	case descriptor.FieldDescriptorProto_TYPE_SFIXED32:
+		dec, cast = "b.DecodeFixed32()", "int32"
+	case descriptor.FieldDescriptorProto_TYPE_SFIXED64:
+		dec, cast = "b.DecodeFixed64()", "int64"
+	case descriptor.FieldDescriptorProto_TYPE_SINT32:
+		dec, cast = "b.DecodeZigzag32()", "int32"
+	case descriptor.FieldDescriptorProto_TYPE_SINT64:
+		dec, cast = "b.DecodeZigzag64()", "int64"
+	default:
+		g.Fail("unhandled oneof field type ", f.protoType.String())
+	}
+	g.P(lhs, " := ", dec)
+	val := "x"
+	if cast != "" {
+		val = cast + "(" + val + ")"
+	}
+	if cast2 != "" {
+		val = cast2 + "(" + val + ")"
+	}
+	switch f.protoType {
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		val += " != 0"
+	case descriptor.FieldDescriptorProto_TYPE_GROUP,
+		descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		val = "msg"
+	}
+	g.P("m.", oneofName, " = &", f.oneofTypeName, "{", val, "}")
+	g.P("return true, err")
+}
+
+// sizerCase prints the case matching this oneof subfield in the sizer code.
+func (f *oneofSubField) sizerCase(g *Generator) {
+	g.P("case *", f.oneofTypeName, ":")
+	val := "x." + f.goName
+	var varint, fixed string
+	switch f.protoType {
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE:
+		fixed = "8"
+	case descriptor.FieldDescriptorProto_TYPE_FLOAT:
+		fixed = "4"
+	case descriptor.FieldDescriptorProto_TYPE_INT64, descriptor.FieldDescriptorProto_TYPE_UINT64, descriptor.FieldDescriptorProto_TYPE_INT32, descriptor.FieldDescriptorProto_TYPE_UINT32, descriptor.FieldDescriptorProto_TYPE_ENUM:
+		varint = val
+	case descriptor.FieldDescriptorProto_TYPE_FIXED64, descriptor.FieldDescriptorProto_TYPE_SFIXED64:
+		fixed = "8"
+	case descriptor.FieldDescriptorProto_TYPE_FIXED32, descriptor.FieldDescriptorProto_TYPE_SFIXED32:
+		fixed = "4"
+	case descriptor.FieldDescriptorProto_TYPE_BOOL:
+		fixed = "1"
+	case descriptor.FieldDescriptorProto_TYPE_STRING:
+		fixed = "len(" + val + ")"
+		varint = fixed
+	case descriptor.FieldDescriptorProto_TYPE_GROUP:
+		fixed = g.Pkg["proto"] + ".Size(" + val + ")"
+	case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+		g.P("s := ", g.Pkg["proto"], ".Size(", val, ")")
+		fixed = "s"
+		varint = fixed
+	case descriptor.FieldDescriptorProto_TYPE_BYTES:
+		fixed = "len(" + val + ")"
+		varint = fixed
+	case descriptor.FieldDescriptorProto_TYPE_SINT32:
+		varint = "(uint32(" + val + ") << 1) ^ uint32((int32(" + val + ") >> 31))"
+	case descriptor.FieldDescriptorProto_TYPE_SINT64:
+		varint = "uint64(" + val + " << 1) ^ uint64((int64(" + val + ") >> 63))"
+	default:
+		g.Fail("unhandled oneof field type ", f.protoType.String())
+	}
+	// Tag and wire varint is known statically,
+	// so don't generate code for that part of the size computation.
+	tagAndWireSize := proto.SizeVarint(uint64(f.fieldNumber << 3)) // wire doesn't affect varint size
+	g.P("n += ", tagAndWireSize, " // tag and wire")
+	if varint != "" {
+		g.P("n += ", g.Pkg["proto"], ".SizeVarint(uint64(", varint, "))")
+	}
+	if fixed != "" {
+		g.P("n += ", fixed)
+	}
+	if f.protoType == descriptor.FieldDescriptorProto_TYPE_GROUP {
+		g.P("n += ", tagAndWireSize, " // tag and wire")
+	}
+}
+
+// getProtoDef returns the default value explicitly stated in the proto file, e.g "yoshi" or "5".
+func (f *oneofSubField) getProtoDef() string {
+	return f.protoDef
+}
+
+// getProtoTypeName returns the protobuf type name for the field as returned by field.GetTypeName(), e.g. ".google.protobuf.Duration".
+func (f *oneofSubField) getProtoTypeName() string {
+	return f.protoTypeName
+}
+
+// getProtoType returns the *field.Type value, e.g. descriptor.FieldDescriptorProto_TYPE_FIXED64.
+func (f *oneofSubField) getProtoType() descriptor.FieldDescriptorProto_Type {
+	return f.protoType
+}
+
+// oneofField represents the oneof on top level.
+// The alternative fields within the oneof are represented by oneofSubField.
+type oneofField struct {
+	fieldCommon
+	subFields []*oneofSubField // All the possible oneof fields
+	comment   string           // The full comment for the field, e.g. "// Types that are valid to be assigned to MyOneof:\n\\"
+}
+
+// decl prints the declaration of the field in the struct (if any).
+func (f *oneofField) decl(g *Generator, mc *msgCtx) {
+	comment := f.comment
+	for _, sf := range f.subFields {
+		comment += "//\t*" + sf.oneofTypeName + "\n"
+	}
+	g.P(comment, Annotate(mc.message.file, f.fullPath, f.goName), " ", f.goType, " `", f.tags, "`")
+}
+
+// getter for a oneof field will print additional discriminators and interfaces for the oneof,
+// also it prints all the getters for the sub fields.
+func (f *oneofField) getter(g *Generator, mc *msgCtx) {
+	// The discriminator type
+	g.P("type ", f.goType, " interface {")
+	g.P(f.goType, "()")
+	g.P("}")
+	g.P()
+	// The subField types, fulfilling the discriminator type contract
+	for _, sf := range f.subFields {
+		g.P("type ", Annotate(mc.message.file, sf.fullPath, sf.oneofTypeName), " struct {")
+		g.P(Annotate(mc.message.file, sf.fullPath, sf.goName), " ", sf.goType, " `", sf.tags, "`")
+		g.P("}")
+		g.P()
+	}
+	for _, sf := range f.subFields {
+		g.P("func (*", sf.oneofTypeName, ") ", f.goType, "() {}")
+		g.P()
+	}
+	// Getter for the oneof field
+	g.P("func (m *", mc.goName, ") ", Annotate(mc.message.file, f.fullPath, f.getterName), "() ", f.goType, " {")
+	g.P("if m != nil { return m.", f.goName, " }")
+	g.P("return nil")
+	g.P("}")
+	g.P()
+	// Getters for each oneof
+	for _, sf := range f.subFields {
+		g.P("func (m *", mc.goName, ") ", Annotate(mc.message.file, sf.fullPath, sf.getterName), "() "+sf.goType+" {")
+		g.P("if x, ok := m.", f.getterName, "().(*", sf.oneofTypeName, "); ok {")
+		g.P("return x.", sf.goName)
+		g.P("}")
+		g.P("return ", sf.getterDef)
+		g.P("}")
+		g.P()
+	}
+}
+
+// setter prints the setter method of the field.
+func (f *oneofField) setter(g *Generator, mc *msgCtx) {
+	// No setters for oneof yet
+}
+
+// topLevelField interface implemented by all types of fields on the top level (not oneofSubField).
+type topLevelField interface {
+	decl(g *Generator, mc *msgCtx)   // print declaration within the struct
+	getter(g *Generator, mc *msgCtx) // print getter
+	setter(g *Generator, mc *msgCtx) // print setter if applicable
+}
+
+// defField interface implemented by all types of fields that can have defaults (not oneofField, but instead oneofSubField).
+type defField interface {
+	getProtoDef() string                                // default value explicitly stated in the proto file, e.g "yoshi" or "5"
+	getProtoName() string                               // proto name of a field, e.g. "field_name" or "descriptor"
+	getGoType() string                                  // go type of the field  as a string, e.g. "*int32"
+	getProtoTypeName() string                           // protobuf type name for the field, e.g. ".google.protobuf.Duration"
+	getProtoType() descriptor.FieldDescriptorProto_Type // *field.Type value, e.g. descriptor.FieldDescriptorProto_TYPE_FIXED64
+}
+
+// generateDefaultConstants adds constants for default values if needed, which is only if the default value is.
+// explicit in the proto.
+func (g *Generator) generateDefaultConstants(mc *msgCtx, topLevelFields []topLevelField) {
+	// Collect fields that can have defaults
+	dFields := []defField{}
+	for _, pf := range topLevelFields {
+		if f, ok := pf.(*oneofField); ok {
+			for _, osf := range f.subFields {
+				dFields = append(dFields, osf)
+			}
+			continue
+		}
+		dFields = append(dFields, pf.(defField))
+	}
+	for _, df := range dFields {
+		def := df.getProtoDef()
+		if def == "" {
+			continue
+		}
+		fieldname := g.defaultConstantName(mc.goName, df.getProtoName())
+		typename := df.getGoType()
+		if typename[0] == '*' {
+			typename = typename[1:]
+		}
+		kind := "const "
+		switch {
+		case typename == "bool":
+		case typename == "string":
+			def = strconv.Quote(def)
+		case typename == "[]byte":
+			def = "[]byte(" + strconv.Quote(unescape(def)) + ")"
+			kind = "var "
+		case def == "inf", def == "-inf", def == "nan":
+			// These names are known to, and defined by, the protocol language.
+			switch def {
+			case "inf":
+				def = "math.Inf(1)"
+			case "-inf":
+				def = "math.Inf(-1)"
+			case "nan":
+				def = "math.NaN()"
+			}
+			if df.getProtoType() == descriptor.FieldDescriptorProto_TYPE_FLOAT {
+				def = "float32(" + def + ")"
+			}
+			kind = "var "
+		case df.getProtoType() == descriptor.FieldDescriptorProto_TYPE_ENUM:
+			// Must be an enum.  Need to construct the prefixed name.
+			obj := g.ObjectNamed(df.getProtoTypeName())
+			var enum *EnumDescriptor
+			if id, ok := obj.(*ImportedDescriptor); ok {
+				// The enum type has been publicly imported.
+				enum, _ = id.o.(*EnumDescriptor)
+			} else {
+				enum, _ = obj.(*EnumDescriptor)
+			}
+			if enum == nil {
+				log.Printf("don't know how to generate constant for %s", fieldname)
+				continue
+			}
+			def = g.DefaultPackageName(obj) + enum.prefix() + def
+		}
+		g.P(kind, fieldname, " ", typename, " = ", def)
+		g.file.addExport(mc.message, constOrVarSymbol{fieldname, kind, ""})
+	}
+	g.P()
+}
+
+// generateInternalStructFields just adds the XXX_<something> fields to the message struct.
+func (g *Generator) generateInternalStructFields(mc *msgCtx, topLevelFields []topLevelField) {
+	g.P("XXX_NoUnkeyedLiteral\tstruct{} `json:\"-\"`") // prevent unkeyed struct literals
+	if len(mc.message.ExtensionRange) > 0 {
+		messageset := ""
+		if opts := mc.message.Options; opts != nil && opts.GetMessageSetWireFormat() {
+			messageset = "protobuf_messageset:\"1\" "
+		}
+		g.P(g.Pkg["proto"], ".XXX_InternalExtensions `", messageset, "json:\"-\"`")
+	}
+	g.P("XXX_unrecognized\t[]byte `json:\"-\"`")
+	g.P("XXX_sizecache\tint32 `json:\"-\"`")
+
+}
+
+// generateOneofFuncs adds all the utility functions for oneof, including marshalling, unmarshalling and sizer.
+func (g *Generator) generateOneofFuncs(mc *msgCtx, topLevelFields []topLevelField) {
+	ofields := []*oneofField{}
+	for _, f := range topLevelFields {
+		if o, ok := f.(*oneofField); ok {
+			ofields = append(ofields, o)
+		}
+	}
+	if len(ofields) == 0 {
+		return
+	}
+	enc := "_" + mc.goName + "_OneofMarshaler"
+	dec := "_" + mc.goName + "_OneofUnmarshaler"
+	size := "_" + mc.goName + "_OneofSizer"
+	encSig := "(msg " + g.Pkg["proto"] + ".Message, b *" + g.Pkg["proto"] + ".Buffer) error"
+	decSig := "(msg " + g.Pkg["proto"] + ".Message, tag, wire int, b *" + g.Pkg["proto"] + ".Buffer) (bool, error)"
+	sizeSig := "(msg " + g.Pkg["proto"] + ".Message) (n int)"
+
+	// OneofFuncs
+	g.P("// XXX_OneofFuncs is for the internal use of the proto package.")
+	g.P("func (*", mc.goName, ") XXX_OneofFuncs() (func", encSig, ", func", decSig, ", func", sizeSig, ", []interface{}) {")
+	g.P("return ", enc, ", ", dec, ", ", size, ", []interface{}{")
+	for _, of := range ofields {
+		for _, sf := range of.subFields {
+			sf.typedNil(g)
+		}
+	}
+	g.P("}")
+	g.P("}")
+	g.P()
+
+	// marshaler
+	g.P("func ", enc, encSig, " {")
+	g.P("m := msg.(*", mc.goName, ")")
+	for _, of := range ofields {
+		g.P("// ", of.getProtoName())
+		g.P("switch x := m.", of.goName, ".(type) {")
+		for _, sf := range of.subFields {
+			// also fills in field.wire
+			sf.marshalCase(g)
+		}
+		g.P("case nil:")
+		g.P("default:")
+		g.P(" return ", g.Pkg["fmt"], `.Errorf("`, mc.goName, ".", of.goName, ` has unexpected type %T", x)`)
+		g.P("}")
+	}
+	g.P("return nil")
+	g.P("}")
+	g.P()
+
+	// unmarshaler
+	g.P("func ", dec, decSig, " {")
+	g.P("m := msg.(*", mc.goName, ")")
+	g.P("switch tag {")
+	for _, of := range ofields {
+		for _, sf := range of.subFields {
+			sf.unmarshalCase(g, of.getProtoName(), of.goName)
+		}
+	}
+	g.P("default:")
+	g.P("return false, nil")
+	g.P("}")
+	g.P("}")
+	g.P()
+
+	// sizer
+	g.P("func ", size, sizeSig, " {")
+	g.P("m := msg.(*", mc.goName, ")")
+	for _, of := range ofields {
+		g.P("// ", of.getProtoName())
+		g.P("switch x := m.", of.goName, ".(type) {")
+		for _, sf := range of.subFields {
+			// also fills in field.wire
+			sf.sizerCase(g)
+		}
+		g.P("case nil:")
+		g.P("default:")
+		g.P("panic(", g.Pkg["fmt"], ".Sprintf(\"proto: unexpected type %T in oneof\", x))")
+		g.P("}")
+	}
+	g.P("return n")
+	g.P("}")
+	g.P()
+}
+
+// generateMessageStruct adds the actual struct with it's members (but not methods) to the output.
+func (g *Generator) generateMessageStruct(mc *msgCtx, topLevelFields []topLevelField) {
+	comments := g.PrintComments(mc.message.path)
+
+	// Guarantee deprecation comments appear after user-provided comments.
+	if mc.message.GetOptions().GetDeprecated() {
+		if comments {
+			// Convention: Separate deprecation comments from original
+			// comments with an empty line.
+			g.P("//")
+		}
+		g.P(deprecationComment)
+	}
+
+	g.P("type ", Annotate(mc.message.file, mc.message.path, mc.goName), " struct {")
+	for _, pf := range topLevelFields {
+		pf.decl(g, mc)
+	}
+	g.generateInternalStructFields(mc, topLevelFields)
+	g.P("}")
+}
+
+// generateGetters adds getters for all fields, including oneofs and weak fields when applicable.
+func (g *Generator) generateGetters(mc *msgCtx, topLevelFields []topLevelField) {
+	for _, pf := range topLevelFields {
+		pf.getter(g, mc)
+	}
+}
+
+// generateSetters add setters for all fields, including oneofs and weak fields when applicable.
+func (g *Generator) generateSetters(mc *msgCtx, topLevelFields []topLevelField) {
+	for _, pf := range topLevelFields {
+		pf.setter(g, mc)
+	}
+}
+
+// generateCommonMethods adds methods to the message that are not on a per field basis.
+func (g *Generator) generateCommonMethods(mc *msgCtx) {
+	// Reset, String and ProtoMessage methods.
+	g.P("func (m *", mc.goName, ") Reset() { *m = ", mc.goName, "{} }")
+	g.P("func (m *", mc.goName, ") String() string { return ", g.Pkg["proto"], ".CompactTextString(m) }")
+	g.P("func (*", mc.goName, ") ProtoMessage() {}")
+	var indexes []string
+	for m := mc.message; m != nil; m = m.parent {
+		indexes = append([]string{strconv.Itoa(m.index)}, indexes...)
+	}
+	g.P("func (*", mc.goName, ") Descriptor() ([]byte, []int) {")
+	g.P("return ", g.file.VarName(), ", []int{", strings.Join(indexes, ", "), "}")
+	g.P("}")
+	// TODO: Revisit the decision to use a XXX_WellKnownType method
+	// if we change proto.MessageName to work with multiple equivalents.
+	if mc.message.file.GetPackage() == "google.protobuf" && wellKnownTypes[mc.message.GetName()] {
+		g.P("func (*", mc.goName, `) XXX_WellKnownType() string { return "`, mc.message.GetName(), `" }`)
+	}
+
+	// Extension support methods
+	if len(mc.message.ExtensionRange) > 0 {
+		// message_set_wire_format only makes sense when extensions are defined.
+		if opts := mc.message.Options; opts != nil && opts.GetMessageSetWireFormat() {
+			g.P()
+			g.P("func (m *", mc.goName, ") MarshalJSON() ([]byte, error) {")
+			g.P("return ", g.Pkg["proto"], ".MarshalMessageSetJSON(&m.XXX_InternalExtensions)")
+			g.P("}")
+			g.P("func (m *", mc.goName, ") UnmarshalJSON(buf []byte) error {")
+			g.P("return ", g.Pkg["proto"], ".UnmarshalMessageSetJSON(buf, &m.XXX_InternalExtensions)")
+			g.P("}")
+		}
+
+		g.P()
+		g.P("var extRange_", mc.goName, " = []", g.Pkg["proto"], ".ExtensionRange{")
+		for _, r := range mc.message.ExtensionRange {
+			end := fmt.Sprint(*r.End - 1) // make range inclusive on both ends
+			g.P("{Start: ", r.Start, ", End: ", end, "},")
+		}
+		g.P("}")
+		g.P("func (*", mc.goName, ") ExtensionRangeArray() []", g.Pkg["proto"], ".ExtensionRange {")
+		g.P("return extRange_", mc.goName)
+		g.P("}")
+	}
+
+	// TODO: It does not scale to keep adding another method for every
+	// operation on protos that we want to switch over to using the
+	// table-driven approach. Instead, we should only add a single method
+	// that allows getting access to the *InternalMessageInfo struct and then
+	// calling Unmarshal, Marshal, Merge, Size, and Discard directly on that.
+
+	// Wrapper for table-driven marshaling and unmarshaling.
+	g.P("func (m *", mc.goName, ") XXX_Unmarshal(b []byte) error {")
+	g.P("return xxx_messageInfo_", mc.goName, ".Unmarshal(m, b)")
+	g.P("}")
+
+	g.P("func (m *", mc.goName, ") XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {")
+	g.P("return xxx_messageInfo_", mc.goName, ".Marshal(b, m, deterministic)")
+	g.P("}")
+
+	g.P("func (dst *", mc.goName, ") XXX_Merge(src ", g.Pkg["proto"], ".Message) {")
+	g.P("xxx_messageInfo_", mc.goName, ".Merge(dst, src)")
+	g.P("}")
+
+	g.P("func (m *", mc.goName, ") XXX_Size() int {") // avoid name clash with "Size" field in some message
+	g.P("return xxx_messageInfo_", mc.goName, ".Size(m)")
+	g.P("}")
+
+	g.P("func (m *", mc.goName, ") XXX_DiscardUnknown() {")
+	g.P("xxx_messageInfo_", mc.goName, ".DiscardUnknown(m)")
+	g.P("}")
+
+	g.P("var xxx_messageInfo_", mc.goName, " ", g.Pkg["proto"], ".InternalMessageInfo")
+	g.P()
+}
+
+// Generate the type, methods and default constant definitions for this Descriptor.
+func (g *Generator) generateMessage(message *Descriptor) {
+	topLevelFields := []topLevelField{}
+	oFields := make(map[int32]*oneofField)
+	// The full type name
+	typeName := message.TypeName()
+	// The full type name, CamelCased.
+	goTypeName := CamelCaseSlice(typeName)
+
+	usedNames := make(map[string]bool)
+	for _, n := range methodNames {
+		usedNames[n] = true
+	}
+
+	// allocNames finds a conflict-free variation of the given strings,
+	// consistently mutating their suffixes.
+	// It returns the same number of strings.
+	allocNames := func(ns ...string) []string {
+	Loop:
+		for {
+			for _, n := range ns {
+				if usedNames[n] {
+					for i := range ns {
+						ns[i] += "_"
+					}
+					continue Loop
+				}
+			}
+			for _, n := range ns {
+				usedNames[n] = true
+			}
+			return ns
+		}
+	}
+
+	mapFieldTypes := make(map[*descriptor.FieldDescriptorProto]string) // keep track of the map fields to be added later
+
+	// Build a structure more suitable for generating the text in one pass
+	for i, field := range message.Field {
+		// Allocate the getter and the field at the same time so name
+		// collisions create field/method consistent names.
+		// TODO: This allocation occurs based on the order of the fields
+		// in the proto file, meaning that a change in the field
+		// ordering can change generated Method/Field names.
+		base := CamelCase(*field.Name)
+		ns := allocNames(base, "Get"+base)
+		fieldName, fieldGetterName := ns[0], ns[1]
+		typename, wiretype := g.GoType(message, field)
+		jsonName := *field.Name
+		tag := fmt.Sprintf("protobuf:%s json:%q", g.goTag(message, field, wiretype), jsonName+",omitempty")
+
+		oneof := field.OneofIndex != nil
+		if oneof && oFields[*field.OneofIndex] == nil {
+			odp := message.OneofDecl[int(*field.OneofIndex)]
+			base := CamelCase(odp.GetName())
+			names := allocNames(base, "Get"+base)
+			fname, gname := names[0], names[1]
+
+			// This is the first field of a oneof we haven't seen before.
+			// Generate the union field.
+			oneofFullPath := fmt.Sprintf("%s,%d,%d", message.path, messageOneofPath, *field.OneofIndex)
+			c, ok := g.makeComments(oneofFullPath)
+			if ok {
+				c += "\n//\n"
+			}
+			c += "// Types that are valid to be assigned to " + fname + ":\n"
+			// Generate the rest of this comment later,
+			// when we've computed any disambiguation.
+
+			dname := "is" + goTypeName + "_" + fname
+			tag := `protobuf_oneof:"` + odp.GetName() + `"`
+			of := oneofField{
+				fieldCommon: fieldCommon{
+					goName:     fname,
+					getterName: gname,
+					goType:     dname,
+					tags:       tag,
+					protoName:  odp.GetName(),
+					fullPath:   oneofFullPath,
+				},
+				comment: c,
+			}
+			topLevelFields = append(topLevelFields, &of)
+			oFields[*field.OneofIndex] = &of
+		}
+
+		if *field.Type == descriptor.FieldDescriptorProto_TYPE_MESSAGE {
+			desc := g.ObjectNamed(field.GetTypeName())
+			if d, ok := desc.(*Descriptor); ok && d.GetOptions().GetMapEntry() {
+				// Figure out the Go types and tags for the key and value types.
+				keyField, valField := d.Field[0], d.Field[1]
+				keyType, keyWire := g.GoType(d, keyField)
+				valType, valWire := g.GoType(d, valField)
+				keyTag, valTag := g.goTag(d, keyField, keyWire), g.goTag(d, valField, valWire)
+
+				// We don't use stars, except for message-typed values.
+				// Message and enum types are the only two possibly foreign types used in maps,
+				// so record their use. They are not permitted as map keys.
+				keyType = strings.TrimPrefix(keyType, "*")
+				switch *valField.Type {
+				case descriptor.FieldDescriptorProto_TYPE_ENUM:
+					valType = strings.TrimPrefix(valType, "*")
+					g.RecordTypeUse(valField.GetTypeName())
+				case descriptor.FieldDescriptorProto_TYPE_MESSAGE:
+					g.RecordTypeUse(valField.GetTypeName())
+				default:
+					valType = strings.TrimPrefix(valType, "*")
+				}
+
+				typename = fmt.Sprintf("map[%s]%s", keyType, valType)
+				mapFieldTypes[field] = typename // record for the getter generation
+
+				tag += fmt.Sprintf(" protobuf_key:%s protobuf_val:%s", keyTag, valTag)
+			}
+		}
+
+		dvalue := g.getterDefault(field, goTypeName)
+		if oneof {
+			tname := goTypeName + "_" + fieldName
+			// It is possible for this to collide with a message or enum
+			// nested in this message. Check for collisions.
+			for {
+				ok := true
+				for _, desc := range message.nested {
+					if CamelCaseSlice(desc.TypeName()) == tname {
+						ok = false
+						break
+					}
+				}
+				for _, enum := range message.enums {
+					if CamelCaseSlice(enum.TypeName()) == tname {
+						ok = false
+						break
+					}
+				}
+				if !ok {
+					tname += "_"
+					continue
+				}
+				break
+			}
+
+			oneofField := oFields[*field.OneofIndex]
+			tag := "protobuf:" + g.goTag(message, field, wiretype)
+			sf := oneofSubField{
+				fieldCommon: fieldCommon{
+					goName:     fieldName,
+					getterName: fieldGetterName,
+					goType:     typename,
+					tags:       tag,
+					protoName:  field.GetName(),
+					fullPath:   fmt.Sprintf("%s,%d,%d", message.path, messageFieldPath, i),
+				},
+				protoTypeName: field.GetTypeName(),
+				fieldNumber:   int(*field.Number),
+				protoType:     *field.Type,
+				getterDef:     dvalue,
+				protoDef:      field.GetDefaultValue(),
+				oneofTypeName: tname,
+			}
+			oneofField.subFields = append(oneofField.subFields, &sf)
+			g.RecordTypeUse(field.GetTypeName())
+			continue
+		}
+
+		fieldDeprecated := ""
+		if field.GetOptions().GetDeprecated() {
+			fieldDeprecated = deprecationComment
+		}
+
+		fieldFullPath := fmt.Sprintf("%s,%d,%d", message.path, messageFieldPath, i)
+		c, ok := g.makeComments(fieldFullPath)
+		if ok {
+			c += "\n"
+		}
+		rf := simpleField{
+			fieldCommon: fieldCommon{
+				goName:     fieldName,
+				getterName: fieldGetterName,
+				goType:     typename,
+				tags:       tag,
+				protoName:  field.GetName(),
+				fullPath:   fieldFullPath,
+			},
+			protoTypeName: field.GetTypeName(),
+			protoType:     *field.Type,
+			deprecated:    fieldDeprecated,
+			getterDef:     dvalue,
+			protoDef:      field.GetDefaultValue(),
+			comment:       c,
+		}
+		var pf topLevelField = &rf
+
+		topLevelFields = append(topLevelFields, pf)
+		g.RecordTypeUse(field.GetTypeName())
+	}
+
+	mc := &msgCtx{
+		goName:  goTypeName,
+		message: message,
+	}
+
+	g.generateMessageStruct(mc, topLevelFields)
+	g.P()
+	g.generateCommonMethods(mc)
+	g.P()
+	g.generateDefaultConstants(mc, topLevelFields)
+	g.P()
+	g.generateGetters(mc, topLevelFields)
+	g.P()
+	g.generateSetters(mc, topLevelFields)
+	g.P()
+	g.generateOneofFuncs(mc, topLevelFields)
+	g.P()
+
+	if !message.group {
+
+		var oneofTypes []string
+		for _, f := range topLevelFields {
+			if of, ok := f.(*oneofField); ok {
+				for _, osf := range of.subFields {
+					oneofTypes = append(oneofTypes, osf.oneofTypeName)
+				}
+			}
+		}
+
+		opts := message.Options
+		ms := &messageSymbol{
+			sym:           goTypeName,
+			hasExtensions: len(message.ExtensionRange) > 0,
+			isMessageSet:  opts != nil && opts.GetMessageSetWireFormat(),
+			oneofTypes:    oneofTypes,
+		}
+		g.file.addExport(message, ms)
+	}
+
+	for _, ext := range message.ext {
+		g.generateExtension(ext)
+	}
+
+	fullName := strings.Join(message.TypeName(), ".")
+	if g.file.Package != nil {
+		fullName = *g.file.Package + "." + fullName
+	}
+
+	g.addInitf("%s.RegisterType((*%s)(nil), %q)", g.Pkg["proto"], goTypeName, fullName)
+	// Register types for native map types.
+	for _, k := range mapFieldKeys(mapFieldTypes) {
+		fullName := strings.TrimPrefix(*k.TypeName, ".")
+		g.addInitf("%s.RegisterMapType((%s)(nil), %q)", g.Pkg["proto"], mapFieldTypes[k], fullName)
+	}
+
+}
+
+type byTypeName []*descriptor.FieldDescriptorProto
+
+func (a byTypeName) Len() int           { return len(a) }
+func (a byTypeName) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a byTypeName) Less(i, j int) bool { return *a[i].TypeName < *a[j].TypeName }
+
+// mapFieldKeys returns the keys of m in a consistent order.
+func mapFieldKeys(m map[*descriptor.FieldDescriptorProto]string) []*descriptor.FieldDescriptorProto {
+	keys := make([]*descriptor.FieldDescriptorProto, 0, len(m))
+	for k := range m {
+		keys = append(keys, k)
+	}
+	sort.Sort(byTypeName(keys))
+	return keys
+}
+
+var escapeChars = [256]byte{
+	'a': '\a', 'b': '\b', 'f': '\f', 'n': '\n', 'r': '\r', 't': '\t', 'v': '\v', '\\': '\\', '"': '"', '\'': '\'', '?': '?',
+}
+
+// unescape reverses the "C" escaping that protoc does for default values of bytes fields.
+// It is best effort in that it effectively ignores malformed input. Seemingly invalid escape
+// sequences are conveyed, unmodified, into the decoded result.
+func unescape(s string) string {
+	// NB: Sadly, we can't use strconv.Unquote because protoc will escape both
+	// single and double quotes, but strconv.Unquote only allows one or the
+	// other (based on actual surrounding quotes of its input argument).
+
+	var out []byte
+	for len(s) > 0 {
+		// regular character, or too short to be valid escape
+		if s[0] != '\\' || len(s) < 2 {
+			out = append(out, s[0])
+			s = s[1:]
+		} else if c := escapeChars[s[1]]; c != 0 {
+			// escape sequence
+			out = append(out, c)
+			s = s[2:]
+		} else if s[1] == 'x' || s[1] == 'X' {
+			// hex escape, e.g. "\x80
+			if len(s) < 4 {
+				// too short to be valid
+				out = append(out, s[:2]...)
+				s = s[2:]
+				continue
+			}
+			v, err := strconv.ParseUint(s[2:4], 16, 8)
+			if err != nil {
+				out = append(out, s[:4]...)
+			} else {
+				out = append(out, byte(v))
+			}
+			s = s[4:]
+		} else if '0' <= s[1] && s[1] <= '7' {
+			// octal escape, can vary from 1 to 3 octal digits; e.g., "\0" "\40" or "\164"
+			// so consume up to 2 more bytes or up to end-of-string
+			n := len(s[1:]) - len(strings.TrimLeft(s[1:], "01234567"))
+			if n > 3 {
+				n = 3
+			}
+			v, err := strconv.ParseUint(s[1:1+n], 8, 8)
+			if err != nil {
+				out = append(out, s[:1+n]...)
+			} else {
+				out = append(out, byte(v))
+			}
+			s = s[1+n:]
+		} else {
+			// bad escape, just propagate the slash as-is
+			out = append(out, s[0])
+			s = s[1:]
+		}
+	}
+
+	return string(out)
+}
+
+func (g *Generator) generateExtension(ext *ExtensionDescriptor) {
+	ccTypeName := ext.DescName()
+
+	extObj := g.ObjectNamed(*ext.Extendee)
+	var extDesc *Descriptor
+	if id, ok := extObj.(*ImportedDescriptor); ok {
+		// This is extending a publicly imported message.
+		// We need the underlying type for goTag.
+		extDesc = id.o.(*Descriptor)
+	} else {
+		extDesc = extObj.(*Descriptor)
+	}
+	extendedType := "*" + g.TypeName(extObj) // always use the original
+	field := ext.FieldDescriptorProto
+	fieldType, wireType := g.GoType(ext.parent, field)
+	tag := g.goTag(extDesc, field, wireType)
+	g.RecordTypeUse(*ext.Extendee)
+	if n := ext.FieldDescriptorProto.TypeName; n != nil {
+		// foreign extension type
+		g.RecordTypeUse(*n)
+	}
+
+	typeName := ext.TypeName()
+
+	// Special case for proto2 message sets: If this extension is extending
+	// proto2.bridge.MessageSet, and its final name component is "message_set_extension",
+	// then drop that last component.
+	//
+	// TODO: This should be implemented in the text formatter rather than the generator.
+	// In addition, the situation for when to apply this special case is implemented
+	// differently in other languages:
+	// https://github.com/google/protobuf/blob/aff10976/src/google/protobuf/text_format.cc#L1560
+	mset := false
+	if extDesc.GetOptions().GetMessageSetWireFormat() && typeName[len(typeName)-1] == "message_set_extension" {
+		typeName = typeName[:len(typeName)-1]
+		mset = true
+	}
+
+	// For text formatting, the package must be exactly what the .proto file declares,
+	// ignoring overrides such as the go_package option, and with no dot/underscore mapping.
+	extName := strings.Join(typeName, ".")
+	if g.file.Package != nil {
+		extName = *g.file.Package + "." + extName
+	}
+
+	g.P("var ", ccTypeName, " = &", g.Pkg["proto"], ".ExtensionDesc{")
+	g.P("ExtendedType: (", extendedType, ")(nil),")
+	g.P("ExtensionType: (", fieldType, ")(nil),")
+	g.P("Field: ", field.Number, ",")
+	g.P(`Name: "`, extName, `",`)
+	g.P("Tag: ", tag, ",")
+	g.P(`Filename: "`, g.file.GetName(), `",`)
+
+	g.P("}")
+	g.P()
+
+	if mset {
+		// Generate a bit more code to register with message_set.go.
+		g.addInitf("%s.RegisterMessageSetType((%s)(nil), %d, %q)", g.Pkg["proto"], fieldType, *field.Number, extName)
+	}
+
+	g.file.addExport(ext, constOrVarSymbol{ccTypeName, "var", ""})
+}
+
+func (g *Generator) generateInitFunction() {
+	for _, enum := range g.file.enum {
+		g.generateEnumRegistration(enum)
+	}
+	for _, d := range g.file.desc {
+		for _, ext := range d.ext {
+			g.generateExtensionRegistration(ext)
+		}
+	}
+	for _, ext := range g.file.ext {
+		g.generateExtensionRegistration(ext)
+	}
+	if len(g.init) == 0 {
+		return
+	}
+	g.P("func init() {")
+	for _, l := range g.init {
+		g.P(l)
+	}
+	g.P("}")
+	g.init = nil
+}
+
+func (g *Generator) generateFileDescriptor(file *FileDescriptor) {
+	// Make a copy and trim source_code_info data.
+	// TODO: Trim this more when we know exactly what we need.
+	pb := proto.Clone(file.FileDescriptorProto).(*descriptor.FileDescriptorProto)
+	pb.SourceCodeInfo = nil
+
+	b, err := proto.Marshal(pb)
+	if err != nil {
+		g.Fail(err.Error())
+	}
+
+	var buf bytes.Buffer
+	w, _ := gzip.NewWriterLevel(&buf, gzip.BestCompression)
+	w.Write(b)
+	w.Close()
+	b = buf.Bytes()
+
+	v := file.VarName()
+	g.P()
+	g.P("func init() { ", g.Pkg["proto"], ".RegisterFile(", strconv.Quote(*file.Name), ", ", v, ") }")
+	g.P("var ", v, " = []byte{")
+	g.P("// ", len(b), " bytes of a gzipped FileDescriptorProto")
+	for len(b) > 0 {
+		n := 16
+		if n > len(b) {
+			n = len(b)
+		}
+
+		s := ""
+		for _, c := range b[:n] {
+			s += fmt.Sprintf("0x%02x,", c)
+		}
+		g.P(s)
+
+		b = b[n:]
+	}
+	g.P("}")
+}
+
+func (g *Generator) generateEnumRegistration(enum *EnumDescriptor) {
+	// // We always print the full (proto-world) package name here.
+	pkg := enum.File().GetPackage()
+	if pkg != "" {
+		pkg += "."
+	}
+	// The full type name
+	typeName := enum.TypeName()
+	// The full type name, CamelCased.
+	ccTypeName := CamelCaseSlice(typeName)
+	g.addInitf("%s.RegisterEnum(%q, %[3]s_name, %[3]s_value)", g.Pkg["proto"], pkg+ccTypeName, ccTypeName)
+}
+
+func (g *Generator) generateExtensionRegistration(ext *ExtensionDescriptor) {
+	g.addInitf("%s.RegisterExtension(%s)", g.Pkg["proto"], ext.DescName())
+}
+
+// And now lots of helper functions.
+
+// Is c an ASCII lower-case letter?
+func isASCIILower(c byte) bool {
+	return 'a' <= c && c <= 'z'
+}
+
+// Is c an ASCII digit?
+func isASCIIDigit(c byte) bool {
+	return '0' <= c && c <= '9'
+}
+
+// CamelCase returns the CamelCased name.
+// If there is an interior underscore followed by a lower case letter,
+// drop the underscore and convert the letter to upper case.
+// There is a remote possibility of this rewrite causing a name collision,
+// but it's so remote we're prepared to pretend it's nonexistent - since the
+// C++ generator lowercases names, it's extremely unlikely to have two fields
+// with different capitalizations.
+// In short, _my_field_name_2 becomes XMyFieldName_2.
+func CamelCase(s string) string {
+	if s == "" {
+		return ""
+	}
+	t := make([]byte, 0, 32)
+	i := 0
+	if s[0] == '_' {
+		// Need a capital letter; drop the '_'.
+		t = append(t, 'X')
+		i++
+	}
+	// Invariant: if the next letter is lower case, it must be converted
+	// to upper case.
+	// That is, we process a word at a time, where words are marked by _ or
+	// upper case letter. Digits are treated as words.
+	for ; i < len(s); i++ {
+		c := s[i]
+		if c == '_' && i+1 < len(s) && isASCIILower(s[i+1]) {
+			continue // Skip the underscore in s.
+		}
+		if isASCIIDigit(c) {
+			t = append(t, c)
+			continue
+		}
+		// Assume we have a letter now - if not, it's a bogus identifier.
+		// The next word is a sequence of characters that must start upper case.
+		if isASCIILower(c) {
+			c ^= ' ' // Make it a capital letter.
+		}
+		t = append(t, c) // Guaranteed not lower case.
+		// Accept lower case sequence that follows.
+		for i+1 < len(s) && isASCIILower(s[i+1]) {
+			i++
+			t = append(t, s[i])
+		}
+	}
+	return string(t)
+}
+
+// CamelCaseSlice is like CamelCase, but the argument is a slice of strings to
+// be joined with "_".
+func CamelCaseSlice(elem []string) string { return CamelCase(strings.Join(elem, "_")) }
+
+// dottedSlice turns a sliced name into a dotted name.
+func dottedSlice(elem []string) string { return strings.Join(elem, ".") }
+
+// Is this field optional?
+func isOptional(field *descriptor.FieldDescriptorProto) bool {
+	return field.Label != nil && *field.Label == descriptor.FieldDescriptorProto_LABEL_OPTIONAL
+}
+
+// Is this field required?
+func isRequired(field *descriptor.FieldDescriptorProto) bool {
+	return field.Label != nil && *field.Label == descriptor.FieldDescriptorProto_LABEL_REQUIRED
+}
+
+// Is this field repeated?
+func isRepeated(field *descriptor.FieldDescriptorProto) bool {
+	return field.Label != nil && *field.Label == descriptor.FieldDescriptorProto_LABEL_REPEATED
+}
+
+// Is this field a scalar numeric type?
+func isScalar(field *descriptor.FieldDescriptorProto) bool {
+	if field.Type == nil {
+		return false
+	}
+	switch *field.Type {
+	case descriptor.FieldDescriptorProto_TYPE_DOUBLE,
+		descriptor.FieldDescriptorProto_TYPE_FLOAT,
+		descriptor.FieldDescriptorProto_TYPE_INT64,
+		descriptor.FieldDescriptorProto_TYPE_UINT64,
+		descriptor.FieldDescriptorProto_TYPE_INT32,
+		descriptor.FieldDescriptorProto_TYPE_FIXED64,
+		descriptor.FieldDescriptorProto_TYPE_FIXED32,
+		descriptor.FieldDescriptorProto_TYPE_BOOL,
+		descriptor.FieldDescriptorProto_TYPE_UINT32,
+		descriptor.FieldDescriptorProto_TYPE_ENUM,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED32,
+		descriptor.FieldDescriptorProto_TYPE_SFIXED64,
+		descriptor.FieldDescriptorProto_TYPE_SINT32,
+		descriptor.FieldDescriptorProto_TYPE_SINT64:
+		return true
+	default:
+		return false
+	}
+}
+
+// badToUnderscore is the mapping function used to generate Go names from package names,
+// which can be dotted in the input .proto file.  It replaces non-identifier characters such as
+// dot or dash with underscore.
+func badToUnderscore(r rune) rune {
+	if unicode.IsLetter(r) || unicode.IsDigit(r) || r == '_' {
+		return r
+	}
+	return '_'
+}
+
+// baseName returns the last path element of the name, with the last dotted suffix removed.
+func baseName(name string) string {
+	// First, find the last element
+	if i := strings.LastIndex(name, "/"); i >= 0 {
+		name = name[i+1:]
+	}
+	// Now drop the suffix
+	if i := strings.LastIndex(name, "."); i >= 0 {
+		name = name[0:i]
+	}
+	return name
+}
+
+// The SourceCodeInfo message describes the location of elements of a parsed
+// .proto file by way of a "path", which is a sequence of integers that
+// describe the route from a FileDescriptorProto to the relevant submessage.
+// The path alternates between a field number of a repeated field, and an index
+// into that repeated field. The constants below define the field numbers that
+// are used.
+//
+// See descriptor.proto for more information about this.
+const (
+	// tag numbers in FileDescriptorProto
+	packagePath = 2 // package
+	messagePath = 4 // message_type
+	enumPath    = 5 // enum_type
+	// tag numbers in DescriptorProto
+	messageFieldPath   = 2 // field
+	messageMessagePath = 3 // nested_type
+	messageEnumPath    = 4 // enum_type
+	messageOneofPath   = 8 // oneof_decl
+	// tag numbers in EnumDescriptorProto
+	enumValuePath = 2 // value
+)
+
+var supportTypeAliases bool
+
+func init() {
+	for _, tag := range build.Default.ReleaseTags {
+		if tag == "go1.9" {
+			supportTypeAliases = true
+			return
+		}
+	}
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/generator/internal/remap/remap.go b/vendor/github.com/golang/protobuf/protoc-gen-go/generator/internal/remap/remap.go
new file mode 100644
index 0000000..a9b6103
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/generator/internal/remap/remap.go
@@ -0,0 +1,117 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2017 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+/*
+Package remap handles tracking the locations of Go tokens in a source text
+across a rewrite by the Go formatter.
+*/
+package remap
+
+import (
+	"fmt"
+	"go/scanner"
+	"go/token"
+)
+
+// A Location represents a span of byte offsets in the source text.
+type Location struct {
+	Pos, End int // End is exclusive
+}
+
+// A Map represents a mapping between token locations in an input source text
+// and locations in the correspnding output text.
+type Map map[Location]Location
+
+// Find reports whether the specified span is recorded by m, and if so returns
+// the new location it was mapped to. If the input span was not found, the
+// returned location is the same as the input.
+func (m Map) Find(pos, end int) (Location, bool) {
+	key := Location{
+		Pos: pos,
+		End: end,
+	}
+	if loc, ok := m[key]; ok {
+		return loc, true
+	}
+	return key, false
+}
+
+func (m Map) add(opos, oend, npos, nend int) {
+	m[Location{Pos: opos, End: oend}] = Location{Pos: npos, End: nend}
+}
+
+// Compute constructs a location mapping from input to output.  An error is
+// reported if any of the tokens of output cannot be mapped.
+func Compute(input, output []byte) (Map, error) {
+	itok := tokenize(input)
+	otok := tokenize(output)
+	if len(itok) != len(otok) {
+		return nil, fmt.Errorf("wrong number of tokens, %d ≠ %d", len(itok), len(otok))
+	}
+	m := make(Map)
+	for i, ti := range itok {
+		to := otok[i]
+		if ti.Token != to.Token {
+			return nil, fmt.Errorf("token %d type mismatch: %s ≠ %s", i+1, ti, to)
+		}
+		m.add(ti.pos, ti.end, to.pos, to.end)
+	}
+	return m, nil
+}
+
+// tokinfo records the span and type of a source token.
+type tokinfo struct {
+	pos, end int
+	token.Token
+}
+
+func tokenize(src []byte) []tokinfo {
+	fs := token.NewFileSet()
+	var s scanner.Scanner
+	s.Init(fs.AddFile("src", fs.Base(), len(src)), src, nil, scanner.ScanComments)
+	var info []tokinfo
+	for {
+		pos, next, lit := s.Scan()
+		switch next {
+		case token.SEMICOLON:
+			continue
+		}
+		info = append(info, tokinfo{
+			pos:   int(pos - 1),
+			end:   int(pos + token.Pos(len(lit)) - 1),
+			Token: next,
+		})
+		if next == token.EOF {
+			break
+		}
+	}
+	return info
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/grpc/grpc.go b/vendor/github.com/golang/protobuf/protoc-gen-go/grpc/grpc.go
new file mode 100644
index 0000000..faef1ab
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/grpc/grpc.go
@@ -0,0 +1,484 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2015 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Package grpc outputs gRPC service descriptions in Go code.
+// It runs as a plugin for the Go protocol buffer compiler plugin.
+// It is linked in to protoc-gen-go.
+package grpc
+
+import (
+	"fmt"
+	"path"
+	"strconv"
+	"strings"
+
+	pb "github.com/golang/protobuf/protoc-gen-go/descriptor"
+	"github.com/golang/protobuf/protoc-gen-go/generator"
+)
+
+// generatedCodeVersion indicates a version of the generated code.
+// It is incremented whenever an incompatibility between the generated code and
+// the grpc package is introduced; the generated code references
+// a constant, grpc.SupportPackageIsVersionN (where N is generatedCodeVersion).
+const generatedCodeVersion = 4
+
+// Paths for packages used by code generated in this file,
+// relative to the import_prefix of the generator.Generator.
+const (
+	contextPkgPath = "golang.org/x/net/context"
+	grpcPkgPath    = "google.golang.org/grpc"
+)
+
+func init() {
+	generator.RegisterPlugin(new(grpc))
+}
+
+// grpc is an implementation of the Go protocol buffer compiler's
+// plugin architecture.  It generates bindings for gRPC support.
+type grpc struct {
+	gen *generator.Generator
+}
+
+// Name returns the name of this plugin, "grpc".
+func (g *grpc) Name() string {
+	return "grpc"
+}
+
+// The names for packages imported in the generated code.
+// They may vary from the final path component of the import path
+// if the name is used by other packages.
+var (
+	contextPkg string
+	grpcPkg    string
+)
+
+// Init initializes the plugin.
+func (g *grpc) Init(gen *generator.Generator) {
+	g.gen = gen
+	contextPkg = generator.RegisterUniquePackageName("context", nil)
+	grpcPkg = generator.RegisterUniquePackageName("grpc", nil)
+}
+
+// Given a type name defined in a .proto, return its object.
+// Also record that we're using it, to guarantee the associated import.
+func (g *grpc) objectNamed(name string) generator.Object {
+	g.gen.RecordTypeUse(name)
+	return g.gen.ObjectNamed(name)
+}
+
+// Given a type name defined in a .proto, return its name as we will print it.
+func (g *grpc) typeName(str string) string {
+	return g.gen.TypeName(g.objectNamed(str))
+}
+
+// P forwards to g.gen.P.
+func (g *grpc) P(args ...interface{}) { g.gen.P(args...) }
+
+// Generate generates code for the services in the given file.
+func (g *grpc) Generate(file *generator.FileDescriptor) {
+	if len(file.FileDescriptorProto.Service) == 0 {
+		return
+	}
+
+	g.P("// Reference imports to suppress errors if they are not otherwise used.")
+	g.P("var _ ", contextPkg, ".Context")
+	g.P("var _ ", grpcPkg, ".ClientConn")
+	g.P()
+
+	// Assert version compatibility.
+	g.P("// This is a compile-time assertion to ensure that this generated file")
+	g.P("// is compatible with the grpc package it is being compiled against.")
+	g.P("const _ = ", grpcPkg, ".SupportPackageIsVersion", generatedCodeVersion)
+	g.P()
+
+	for i, service := range file.FileDescriptorProto.Service {
+		g.generateService(file, service, i)
+	}
+}
+
+// GenerateImports generates the import declaration for this file.
+func (g *grpc) GenerateImports(file *generator.FileDescriptor) {
+	if len(file.FileDescriptorProto.Service) == 0 {
+		return
+	}
+	g.P("import (")
+	g.P(contextPkg, " ", generator.GoImportPath(path.Join(string(g.gen.ImportPrefix), contextPkgPath)))
+	g.P(grpcPkg, " ", generator.GoImportPath(path.Join(string(g.gen.ImportPrefix), grpcPkgPath)))
+	g.P(")")
+	g.P()
+}
+
+// reservedClientName records whether a client name is reserved on the client side.
+var reservedClientName = map[string]bool{
+	// TODO: do we need any in gRPC?
+}
+
+func unexport(s string) string { return strings.ToLower(s[:1]) + s[1:] }
+
+// deprecationComment is the standard comment added to deprecated
+// messages, fields, enums, and enum values.
+var deprecationComment = "// Deprecated: Do not use."
+
+// generateService generates all the code for the named service.
+func (g *grpc) generateService(file *generator.FileDescriptor, service *pb.ServiceDescriptorProto, index int) {
+	path := fmt.Sprintf("6,%d", index) // 6 means service.
+
+	origServName := service.GetName()
+	fullServName := origServName
+	if pkg := file.GetPackage(); pkg != "" {
+		fullServName = pkg + "." + fullServName
+	}
+	servName := generator.CamelCase(origServName)
+	deprecated := service.GetOptions().GetDeprecated()
+
+	g.P()
+	g.P(fmt.Sprintf(`// %sClient is the client API for %s service.
+//
+// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://godoc.org/google.golang.org/grpc#ClientConn.NewStream.`, servName, servName))
+
+	// Client interface.
+	if deprecated {
+		g.P("//")
+		g.P(deprecationComment)
+	}
+	g.P("type ", servName, "Client interface {")
+	for i, method := range service.Method {
+		g.gen.PrintComments(fmt.Sprintf("%s,2,%d", path, i)) // 2 means method in a service.
+		g.P(g.generateClientSignature(servName, method))
+	}
+	g.P("}")
+	g.P()
+
+	// Client structure.
+	g.P("type ", unexport(servName), "Client struct {")
+	g.P("cc *", grpcPkg, ".ClientConn")
+	g.P("}")
+	g.P()
+
+	// NewClient factory.
+	if deprecated {
+		g.P(deprecationComment)
+	}
+	g.P("func New", servName, "Client (cc *", grpcPkg, ".ClientConn) ", servName, "Client {")
+	g.P("return &", unexport(servName), "Client{cc}")
+	g.P("}")
+	g.P()
+
+	var methodIndex, streamIndex int
+	serviceDescVar := "_" + servName + "_serviceDesc"
+	// Client method implementations.
+	for _, method := range service.Method {
+		var descExpr string
+		if !method.GetServerStreaming() && !method.GetClientStreaming() {
+			// Unary RPC method
+			descExpr = fmt.Sprintf("&%s.Methods[%d]", serviceDescVar, methodIndex)
+			methodIndex++
+		} else {
+			// Streaming RPC method
+			descExpr = fmt.Sprintf("&%s.Streams[%d]", serviceDescVar, streamIndex)
+			streamIndex++
+		}
+		g.generateClientMethod(servName, fullServName, serviceDescVar, method, descExpr)
+	}
+
+	// Server interface.
+	serverType := servName + "Server"
+	g.P("// ", serverType, " is the server API for ", servName, " service.")
+	if deprecated {
+		g.P("//")
+		g.P(deprecationComment)
+	}
+	g.P("type ", serverType, " interface {")
+	for i, method := range service.Method {
+		g.gen.PrintComments(fmt.Sprintf("%s,2,%d", path, i)) // 2 means method in a service.
+		g.P(g.generateServerSignature(servName, method))
+	}
+	g.P("}")
+	g.P()
+
+	// Server registration.
+	if deprecated {
+		g.P(deprecationComment)
+	}
+	g.P("func Register", servName, "Server(s *", grpcPkg, ".Server, srv ", serverType, ") {")
+	g.P("s.RegisterService(&", serviceDescVar, `, srv)`)
+	g.P("}")
+	g.P()
+
+	// Server handler implementations.
+	var handlerNames []string
+	for _, method := range service.Method {
+		hname := g.generateServerMethod(servName, fullServName, method)
+		handlerNames = append(handlerNames, hname)
+	}
+
+	// Service descriptor.
+	g.P("var ", serviceDescVar, " = ", grpcPkg, ".ServiceDesc {")
+	g.P("ServiceName: ", strconv.Quote(fullServName), ",")
+	g.P("HandlerType: (*", serverType, ")(nil),")
+	g.P("Methods: []", grpcPkg, ".MethodDesc{")
+	for i, method := range service.Method {
+		if method.GetServerStreaming() || method.GetClientStreaming() {
+			continue
+		}
+		g.P("{")
+		g.P("MethodName: ", strconv.Quote(method.GetName()), ",")
+		g.P("Handler: ", handlerNames[i], ",")
+		g.P("},")
+	}
+	g.P("},")
+	g.P("Streams: []", grpcPkg, ".StreamDesc{")
+	for i, method := range service.Method {
+		if !method.GetServerStreaming() && !method.GetClientStreaming() {
+			continue
+		}
+		g.P("{")
+		g.P("StreamName: ", strconv.Quote(method.GetName()), ",")
+		g.P("Handler: ", handlerNames[i], ",")
+		if method.GetServerStreaming() {
+			g.P("ServerStreams: true,")
+		}
+		if method.GetClientStreaming() {
+			g.P("ClientStreams: true,")
+		}
+		g.P("},")
+	}
+	g.P("},")
+	g.P("Metadata: \"", file.GetName(), "\",")
+	g.P("}")
+	g.P()
+}
+
+// generateClientSignature returns the client-side signature for a method.
+func (g *grpc) generateClientSignature(servName string, method *pb.MethodDescriptorProto) string {
+	origMethName := method.GetName()
+	methName := generator.CamelCase(origMethName)
+	if reservedClientName[methName] {
+		methName += "_"
+	}
+	reqArg := ", in *" + g.typeName(method.GetInputType())
+	if method.GetClientStreaming() {
+		reqArg = ""
+	}
+	respName := "*" + g.typeName(method.GetOutputType())
+	if method.GetServerStreaming() || method.GetClientStreaming() {
+		respName = servName + "_" + generator.CamelCase(origMethName) + "Client"
+	}
+	return fmt.Sprintf("%s(ctx %s.Context%s, opts ...%s.CallOption) (%s, error)", methName, contextPkg, reqArg, grpcPkg, respName)
+}
+
+func (g *grpc) generateClientMethod(servName, fullServName, serviceDescVar string, method *pb.MethodDescriptorProto, descExpr string) {
+	sname := fmt.Sprintf("/%s/%s", fullServName, method.GetName())
+	methName := generator.CamelCase(method.GetName())
+	inType := g.typeName(method.GetInputType())
+	outType := g.typeName(method.GetOutputType())
+
+	if method.GetOptions().GetDeprecated() {
+		g.P(deprecationComment)
+	}
+	g.P("func (c *", unexport(servName), "Client) ", g.generateClientSignature(servName, method), "{")
+	if !method.GetServerStreaming() && !method.GetClientStreaming() {
+		g.P("out := new(", outType, ")")
+		// TODO: Pass descExpr to Invoke.
+		g.P(`err := c.cc.Invoke(ctx, "`, sname, `", in, out, opts...)`)
+		g.P("if err != nil { return nil, err }")
+		g.P("return out, nil")
+		g.P("}")
+		g.P()
+		return
+	}
+	streamType := unexport(servName) + methName + "Client"
+	g.P("stream, err := c.cc.NewStream(ctx, ", descExpr, `, "`, sname, `", opts...)`)
+	g.P("if err != nil { return nil, err }")
+	g.P("x := &", streamType, "{stream}")
+	if !method.GetClientStreaming() {
+		g.P("if err := x.ClientStream.SendMsg(in); err != nil { return nil, err }")
+		g.P("if err := x.ClientStream.CloseSend(); err != nil { return nil, err }")
+	}
+	g.P("return x, nil")
+	g.P("}")
+	g.P()
+
+	genSend := method.GetClientStreaming()
+	genRecv := method.GetServerStreaming()
+	genCloseAndRecv := !method.GetServerStreaming()
+
+	// Stream auxiliary types and methods.
+	g.P("type ", servName, "_", methName, "Client interface {")
+	if genSend {
+		g.P("Send(*", inType, ") error")
+	}
+	if genRecv {
+		g.P("Recv() (*", outType, ", error)")
+	}
+	if genCloseAndRecv {
+		g.P("CloseAndRecv() (*", outType, ", error)")
+	}
+	g.P(grpcPkg, ".ClientStream")
+	g.P("}")
+	g.P()
+
+	g.P("type ", streamType, " struct {")
+	g.P(grpcPkg, ".ClientStream")
+	g.P("}")
+	g.P()
+
+	if genSend {
+		g.P("func (x *", streamType, ") Send(m *", inType, ") error {")
+		g.P("return x.ClientStream.SendMsg(m)")
+		g.P("}")
+		g.P()
+	}
+	if genRecv {
+		g.P("func (x *", streamType, ") Recv() (*", outType, ", error) {")
+		g.P("m := new(", outType, ")")
+		g.P("if err := x.ClientStream.RecvMsg(m); err != nil { return nil, err }")
+		g.P("return m, nil")
+		g.P("}")
+		g.P()
+	}
+	if genCloseAndRecv {
+		g.P("func (x *", streamType, ") CloseAndRecv() (*", outType, ", error) {")
+		g.P("if err := x.ClientStream.CloseSend(); err != nil { return nil, err }")
+		g.P("m := new(", outType, ")")
+		g.P("if err := x.ClientStream.RecvMsg(m); err != nil { return nil, err }")
+		g.P("return m, nil")
+		g.P("}")
+		g.P()
+	}
+}
+
+// generateServerSignature returns the server-side signature for a method.
+func (g *grpc) generateServerSignature(servName string, method *pb.MethodDescriptorProto) string {
+	origMethName := method.GetName()
+	methName := generator.CamelCase(origMethName)
+	if reservedClientName[methName] {
+		methName += "_"
+	}
+
+	var reqArgs []string
+	ret := "error"
+	if !method.GetServerStreaming() && !method.GetClientStreaming() {
+		reqArgs = append(reqArgs, contextPkg+".Context")
+		ret = "(*" + g.typeName(method.GetOutputType()) + ", error)"
+	}
+	if !method.GetClientStreaming() {
+		reqArgs = append(reqArgs, "*"+g.typeName(method.GetInputType()))
+	}
+	if method.GetServerStreaming() || method.GetClientStreaming() {
+		reqArgs = append(reqArgs, servName+"_"+generator.CamelCase(origMethName)+"Server")
+	}
+
+	return methName + "(" + strings.Join(reqArgs, ", ") + ") " + ret
+}
+
+func (g *grpc) generateServerMethod(servName, fullServName string, method *pb.MethodDescriptorProto) string {
+	methName := generator.CamelCase(method.GetName())
+	hname := fmt.Sprintf("_%s_%s_Handler", servName, methName)
+	inType := g.typeName(method.GetInputType())
+	outType := g.typeName(method.GetOutputType())
+
+	if !method.GetServerStreaming() && !method.GetClientStreaming() {
+		g.P("func ", hname, "(srv interface{}, ctx ", contextPkg, ".Context, dec func(interface{}) error, interceptor ", grpcPkg, ".UnaryServerInterceptor) (interface{}, error) {")
+		g.P("in := new(", inType, ")")
+		g.P("if err := dec(in); err != nil { return nil, err }")
+		g.P("if interceptor == nil { return srv.(", servName, "Server).", methName, "(ctx, in) }")
+		g.P("info := &", grpcPkg, ".UnaryServerInfo{")
+		g.P("Server: srv,")
+		g.P("FullMethod: ", strconv.Quote(fmt.Sprintf("/%s/%s", fullServName, methName)), ",")
+		g.P("}")
+		g.P("handler := func(ctx ", contextPkg, ".Context, req interface{}) (interface{}, error) {")
+		g.P("return srv.(", servName, "Server).", methName, "(ctx, req.(*", inType, "))")
+		g.P("}")
+		g.P("return interceptor(ctx, in, info, handler)")
+		g.P("}")
+		g.P()
+		return hname
+	}
+	streamType := unexport(servName) + methName + "Server"
+	g.P("func ", hname, "(srv interface{}, stream ", grpcPkg, ".ServerStream) error {")
+	if !method.GetClientStreaming() {
+		g.P("m := new(", inType, ")")
+		g.P("if err := stream.RecvMsg(m); err != nil { return err }")
+		g.P("return srv.(", servName, "Server).", methName, "(m, &", streamType, "{stream})")
+	} else {
+		g.P("return srv.(", servName, "Server).", methName, "(&", streamType, "{stream})")
+	}
+	g.P("}")
+	g.P()
+
+	genSend := method.GetServerStreaming()
+	genSendAndClose := !method.GetServerStreaming()
+	genRecv := method.GetClientStreaming()
+
+	// Stream auxiliary types and methods.
+	g.P("type ", servName, "_", methName, "Server interface {")
+	if genSend {
+		g.P("Send(*", outType, ") error")
+	}
+	if genSendAndClose {
+		g.P("SendAndClose(*", outType, ") error")
+	}
+	if genRecv {
+		g.P("Recv() (*", inType, ", error)")
+	}
+	g.P(grpcPkg, ".ServerStream")
+	g.P("}")
+	g.P()
+
+	g.P("type ", streamType, " struct {")
+	g.P(grpcPkg, ".ServerStream")
+	g.P("}")
+	g.P()
+
+	if genSend {
+		g.P("func (x *", streamType, ") Send(m *", outType, ") error {")
+		g.P("return x.ServerStream.SendMsg(m)")
+		g.P("}")
+		g.P()
+	}
+	if genSendAndClose {
+		g.P("func (x *", streamType, ") SendAndClose(m *", outType, ") error {")
+		g.P("return x.ServerStream.SendMsg(m)")
+		g.P("}")
+		g.P()
+	}
+	if genRecv {
+		g.P("func (x *", streamType, ") Recv() (*", inType, ", error) {")
+		g.P("m := new(", inType, ")")
+		g.P("if err := x.ServerStream.RecvMsg(m); err != nil { return nil, err }")
+		g.P("return m, nil")
+		g.P("}")
+		g.P()
+	}
+
+	return hname
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/link_grpc.go b/vendor/github.com/golang/protobuf/protoc-gen-go/link_grpc.go
new file mode 100644
index 0000000..532a550
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/link_grpc.go
@@ -0,0 +1,34 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2015 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package main
+
+import _ "github.com/golang/protobuf/protoc-gen-go/grpc"
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/main.go b/vendor/github.com/golang/protobuf/protoc-gen-go/main.go
new file mode 100644
index 0000000..8e2486d
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/main.go
@@ -0,0 +1,98 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// protoc-gen-go is a plugin for the Google protocol buffer compiler to generate
+// Go code.  Run it by building this program and putting it in your path with
+// the name
+// 	protoc-gen-go
+// That word 'go' at the end becomes part of the option string set for the
+// protocol compiler, so once the protocol compiler (protoc) is installed
+// you can run
+// 	protoc --go_out=output_directory input_directory/file.proto
+// to generate Go bindings for the protocol defined by file.proto.
+// With that input, the output will be written to
+// 	output_directory/file.pb.go
+//
+// The generated code is documented in the package comment for
+// the library.
+//
+// See the README and documentation for protocol buffers to learn more:
+// 	https://developers.google.com/protocol-buffers/
+package main
+
+import (
+	"io/ioutil"
+	"os"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/protoc-gen-go/generator"
+)
+
+func main() {
+	// Begin by allocating a generator. The request and response structures are stored there
+	// so we can do error handling easily - the response structure contains the field to
+	// report failure.
+	g := generator.New()
+
+	data, err := ioutil.ReadAll(os.Stdin)
+	if err != nil {
+		g.Error(err, "reading input")
+	}
+
+	if err := proto.Unmarshal(data, g.Request); err != nil {
+		g.Error(err, "parsing input proto")
+	}
+
+	if len(g.Request.FileToGenerate) == 0 {
+		g.Fail("no files to generate")
+	}
+
+	g.CommandLineParameters(g.Request.GetParameter())
+
+	// Create a wrapped version of the Descriptors and EnumDescriptors that
+	// point to the file that defines them.
+	g.WrapTypes()
+
+	g.SetPackageNames()
+	g.BuildTypeNameMap()
+
+	g.GenerateAllFiles()
+
+	// Send back the results.
+	data, err = proto.Marshal(g.Response)
+	if err != nil {
+		g.Error(err, "failed to marshal output proto")
+	}
+	_, err = os.Stdout.Write(data)
+	if err != nil {
+		g.Error(err, "failed to write output proto")
+	}
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/plugin/plugin.pb.golden b/vendor/github.com/golang/protobuf/protoc-gen-go/plugin/plugin.pb.golden
new file mode 100644
index 0000000..8953d0f
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/plugin/plugin.pb.golden
@@ -0,0 +1,83 @@
+// Code generated by protoc-gen-go.
+// source: google/protobuf/compiler/plugin.proto
+// DO NOT EDIT!
+
+package google_protobuf_compiler
+
+import proto "github.com/golang/protobuf/proto"
+import "math"
+import google_protobuf "github.com/golang/protobuf/protoc-gen-go/descriptor"
+
+// Reference proto and math imports to suppress error if they are not otherwise used.
+var _ = proto.GetString
+var _ = math.Inf
+
+type CodeGeneratorRequest struct {
+	FileToGenerate   []string                               `protobuf:"bytes,1,rep,name=file_to_generate" json:"file_to_generate,omitempty"`
+	Parameter        *string                                `protobuf:"bytes,2,opt,name=parameter" json:"parameter,omitempty"`
+	ProtoFile        []*google_protobuf.FileDescriptorProto `protobuf:"bytes,15,rep,name=proto_file" json:"proto_file,omitempty"`
+	XXX_unrecognized []byte                                 `json:"-"`
+}
+
+func (this *CodeGeneratorRequest) Reset()         { *this = CodeGeneratorRequest{} }
+func (this *CodeGeneratorRequest) String() string { return proto.CompactTextString(this) }
+func (*CodeGeneratorRequest) ProtoMessage()       {}
+
+func (this *CodeGeneratorRequest) GetParameter() string {
+	if this != nil && this.Parameter != nil {
+		return *this.Parameter
+	}
+	return ""
+}
+
+type CodeGeneratorResponse struct {
+	Error            *string                       `protobuf:"bytes,1,opt,name=error" json:"error,omitempty"`
+	File             []*CodeGeneratorResponse_File `protobuf:"bytes,15,rep,name=file" json:"file,omitempty"`
+	XXX_unrecognized []byte                        `json:"-"`
+}
+
+func (this *CodeGeneratorResponse) Reset()         { *this = CodeGeneratorResponse{} }
+func (this *CodeGeneratorResponse) String() string { return proto.CompactTextString(this) }
+func (*CodeGeneratorResponse) ProtoMessage()       {}
+
+func (this *CodeGeneratorResponse) GetError() string {
+	if this != nil && this.Error != nil {
+		return *this.Error
+	}
+	return ""
+}
+
+type CodeGeneratorResponse_File struct {
+	Name             *string `protobuf:"bytes,1,opt,name=name" json:"name,omitempty"`
+	InsertionPoint   *string `protobuf:"bytes,2,opt,name=insertion_point" json:"insertion_point,omitempty"`
+	Content          *string `protobuf:"bytes,15,opt,name=content" json:"content,omitempty"`
+	XXX_unrecognized []byte  `json:"-"`
+}
+
+func (this *CodeGeneratorResponse_File) Reset()         { *this = CodeGeneratorResponse_File{} }
+func (this *CodeGeneratorResponse_File) String() string { return proto.CompactTextString(this) }
+func (*CodeGeneratorResponse_File) ProtoMessage()       {}
+
+func (this *CodeGeneratorResponse_File) GetName() string {
+	if this != nil && this.Name != nil {
+		return *this.Name
+	}
+	return ""
+}
+
+func (this *CodeGeneratorResponse_File) GetInsertionPoint() string {
+	if this != nil && this.InsertionPoint != nil {
+		return *this.InsertionPoint
+	}
+	return ""
+}
+
+func (this *CodeGeneratorResponse_File) GetContent() string {
+	if this != nil && this.Content != nil {
+		return *this.Content
+	}
+	return ""
+}
+
+func init() {
+}
diff --git a/vendor/github.com/golang/protobuf/protoc-gen-go/plugin/plugin.proto b/vendor/github.com/golang/protobuf/protoc-gen-go/plugin/plugin.proto
new file mode 100644
index 0000000..5b55745
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/protoc-gen-go/plugin/plugin.proto
@@ -0,0 +1,167 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//
+// WARNING:  The plugin interface is currently EXPERIMENTAL and is subject to
+//   change.
+//
+// protoc (aka the Protocol Compiler) can be extended via plugins.  A plugin is
+// just a program that reads a CodeGeneratorRequest from stdin and writes a
+// CodeGeneratorResponse to stdout.
+//
+// Plugins written using C++ can use google/protobuf/compiler/plugin.h instead
+// of dealing with the raw protocol defined here.
+//
+// A plugin executable needs only to be placed somewhere in the path.  The
+// plugin should be named "protoc-gen-$NAME", and will then be used when the
+// flag "--${NAME}_out" is passed to protoc.
+
+syntax = "proto2";
+package google.protobuf.compiler;
+option java_package = "com.google.protobuf.compiler";
+option java_outer_classname = "PluginProtos";
+
+option go_package = "github.com/golang/protobuf/protoc-gen-go/plugin;plugin_go";
+
+import "google/protobuf/descriptor.proto";
+
+// The version number of protocol compiler.
+message Version {
+  optional int32 major = 1;
+  optional int32 minor = 2;
+  optional int32 patch = 3;
+  // A suffix for alpha, beta or rc release, e.g., "alpha-1", "rc2". It should
+  // be empty for mainline stable releases.
+  optional string suffix = 4;
+}
+
+// An encoded CodeGeneratorRequest is written to the plugin's stdin.
+message CodeGeneratorRequest {
+  // The .proto files that were explicitly listed on the command-line.  The
+  // code generator should generate code only for these files.  Each file's
+  // descriptor will be included in proto_file, below.
+  repeated string file_to_generate = 1;
+
+  // The generator parameter passed on the command-line.
+  optional string parameter = 2;
+
+  // FileDescriptorProtos for all files in files_to_generate and everything
+  // they import.  The files will appear in topological order, so each file
+  // appears before any file that imports it.
+  //
+  // protoc guarantees that all proto_files will be written after
+  // the fields above, even though this is not technically guaranteed by the
+  // protobuf wire format.  This theoretically could allow a plugin to stream
+  // in the FileDescriptorProtos and handle them one by one rather than read
+  // the entire set into memory at once.  However, as of this writing, this
+  // is not similarly optimized on protoc's end -- it will store all fields in
+  // memory at once before sending them to the plugin.
+  //
+  // Type names of fields and extensions in the FileDescriptorProto are always
+  // fully qualified.
+  repeated FileDescriptorProto proto_file = 15;
+
+  // The version number of protocol compiler.
+  optional Version compiler_version = 3;
+
+}
+
+// The plugin writes an encoded CodeGeneratorResponse to stdout.
+message CodeGeneratorResponse {
+  // Error message.  If non-empty, code generation failed.  The plugin process
+  // should exit with status code zero even if it reports an error in this way.
+  //
+  // This should be used to indicate errors in .proto files which prevent the
+  // code generator from generating correct code.  Errors which indicate a
+  // problem in protoc itself -- such as the input CodeGeneratorRequest being
+  // unparseable -- should be reported by writing a message to stderr and
+  // exiting with a non-zero status code.
+  optional string error = 1;
+
+  // Represents a single generated file.
+  message File {
+    // The file name, relative to the output directory.  The name must not
+    // contain "." or ".." components and must be relative, not be absolute (so,
+    // the file cannot lie outside the output directory).  "/" must be used as
+    // the path separator, not "\".
+    //
+    // If the name is omitted, the content will be appended to the previous
+    // file.  This allows the generator to break large files into small chunks,
+    // and allows the generated text to be streamed back to protoc so that large
+    // files need not reside completely in memory at one time.  Note that as of
+    // this writing protoc does not optimize for this -- it will read the entire
+    // CodeGeneratorResponse before writing files to disk.
+    optional string name = 1;
+
+    // If non-empty, indicates that the named file should already exist, and the
+    // content here is to be inserted into that file at a defined insertion
+    // point.  This feature allows a code generator to extend the output
+    // produced by another code generator.  The original generator may provide
+    // insertion points by placing special annotations in the file that look
+    // like:
+    //   @@protoc_insertion_point(NAME)
+    // The annotation can have arbitrary text before and after it on the line,
+    // which allows it to be placed in a comment.  NAME should be replaced with
+    // an identifier naming the point -- this is what other generators will use
+    // as the insertion_point.  Code inserted at this point will be placed
+    // immediately above the line containing the insertion point (thus multiple
+    // insertions to the same point will come out in the order they were added).
+    // The double-@ is intended to make it unlikely that the generated code
+    // could contain things that look like insertion points by accident.
+    //
+    // For example, the C++ code generator places the following line in the
+    // .pb.h files that it generates:
+    //   // @@protoc_insertion_point(namespace_scope)
+    // This line appears within the scope of the file's package namespace, but
+    // outside of any particular class.  Another plugin can then specify the
+    // insertion_point "namespace_scope" to generate additional classes or
+    // other declarations that should be placed in this scope.
+    //
+    // Note that if the line containing the insertion point begins with
+    // whitespace, the same whitespace will be added to every line of the
+    // inserted text.  This is useful for languages like Python, where
+    // indentation matters.  In these languages, the insertion point comment
+    // should be indented the same amount as any inserted code will need to be
+    // in order to work correctly in that context.
+    //
+    // The code generator that generates the initial file and the one which
+    // inserts into it must both run as part of a single invocation of protoc.
+    // Code generators are executed in the order in which they appear on the
+    // command line.
+    //
+    // If |insertion_point| is present, |name| must also be present.
+    optional string insertion_point = 2;
+
+    // The file contents.
+    optional string content = 15;
+  }
+  repeated File file = 15;
+}