[VOL-4289] Proto changes for gRPC migration
Change-Id: I317a0a865ccf78d0c37aa229c50d293a3f66c8bb
diff --git a/vendor/google.golang.org/grpc/internal/resolver/config_selector.go b/vendor/google.golang.org/grpc/internal/resolver/config_selector.go
new file mode 100644
index 0000000..be7e13d
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/resolver/config_selector.go
@@ -0,0 +1,167 @@
+/*
+ *
+ * Copyright 2020 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+// Package resolver provides internal resolver-related functionality.
+package resolver
+
+import (
+ "context"
+ "sync"
+
+ "google.golang.org/grpc/internal/serviceconfig"
+ "google.golang.org/grpc/metadata"
+ "google.golang.org/grpc/resolver"
+)
+
+// ConfigSelector controls what configuration to use for every RPC.
+type ConfigSelector interface {
+ // Selects the configuration for the RPC, or terminates it using the error.
+ // This error will be converted by the gRPC library to a status error with
+ // code UNKNOWN if it is not returned as a status error.
+ SelectConfig(RPCInfo) (*RPCConfig, error)
+}
+
+// RPCInfo contains RPC information needed by a ConfigSelector.
+type RPCInfo struct {
+ // Context is the user's context for the RPC and contains headers and
+ // application timeout. It is passed for interception purposes and for
+ // efficiency reasons. SelectConfig should not be blocking.
+ Context context.Context
+ Method string // i.e. "/Service/Method"
+}
+
+// RPCConfig describes the configuration to use for each RPC.
+type RPCConfig struct {
+ // The context to use for the remainder of the RPC; can pass info to LB
+ // policy or affect timeout or metadata.
+ Context context.Context
+ MethodConfig serviceconfig.MethodConfig // configuration to use for this RPC
+ OnCommitted func() // Called when the RPC has been committed (retries no longer possible)
+ Interceptor ClientInterceptor
+}
+
+// ClientStream is the same as grpc.ClientStream, but defined here for circular
+// dependency reasons.
+type ClientStream interface {
+ // Header returns the header metadata received from the server if there
+ // is any. It blocks if the metadata is not ready to read.
+ Header() (metadata.MD, error)
+ // Trailer returns the trailer metadata from the server, if there is any.
+ // It must only be called after stream.CloseAndRecv has returned, or
+ // stream.Recv has returned a non-nil error (including io.EOF).
+ Trailer() metadata.MD
+ // CloseSend closes the send direction of the stream. It closes the stream
+ // when non-nil error is met. It is also not safe to call CloseSend
+ // concurrently with SendMsg.
+ CloseSend() error
+ // Context returns the context for this stream.
+ //
+ // It should not be called until after Header or RecvMsg has returned. Once
+ // called, subsequent client-side retries are disabled.
+ Context() context.Context
+ // SendMsg is generally called by generated code. On error, SendMsg aborts
+ // the stream. If the error was generated by the client, the status is
+ // returned directly; otherwise, io.EOF is returned and the status of
+ // the stream may be discovered using RecvMsg.
+ //
+ // SendMsg blocks until:
+ // - There is sufficient flow control to schedule m with the transport, or
+ // - The stream is done, or
+ // - The stream breaks.
+ //
+ // SendMsg does not wait until the message is received by the server. An
+ // untimely stream closure may result in lost messages. To ensure delivery,
+ // users should ensure the RPC completed successfully using RecvMsg.
+ //
+ // It is safe to have a goroutine calling SendMsg and another goroutine
+ // calling RecvMsg on the same stream at the same time, but it is not safe
+ // to call SendMsg on the same stream in different goroutines. It is also
+ // not safe to call CloseSend concurrently with SendMsg.
+ SendMsg(m interface{}) error
+ // RecvMsg blocks until it receives a message into m or the stream is
+ // done. It returns io.EOF when the stream completes successfully. On
+ // any other error, the stream is aborted and the error contains the RPC
+ // status.
+ //
+ // It is safe to have a goroutine calling SendMsg and another goroutine
+ // calling RecvMsg on the same stream at the same time, but it is not
+ // safe to call RecvMsg on the same stream in different goroutines.
+ RecvMsg(m interface{}) error
+}
+
+// ClientInterceptor is an interceptor for gRPC client streams.
+type ClientInterceptor interface {
+ // NewStream produces a ClientStream for an RPC which may optionally use
+ // the provided function to produce a stream for delegation. Note:
+ // RPCInfo.Context should not be used (will be nil).
+ //
+ // done is invoked when the RPC is finished using its connection, or could
+ // not be assigned a connection. RPC operations may still occur on
+ // ClientStream after done is called, since the interceptor is invoked by
+ // application-layer operations. done must never be nil when called.
+ NewStream(ctx context.Context, ri RPCInfo, done func(), newStream func(ctx context.Context, done func()) (ClientStream, error)) (ClientStream, error)
+}
+
+// ServerInterceptor is an interceptor for incoming RPC's on gRPC server side.
+type ServerInterceptor interface {
+ // AllowRPC checks if an incoming RPC is allowed to proceed based on
+ // information about connection RPC was received on, and HTTP Headers. This
+ // information will be piped into context.
+ AllowRPC(ctx context.Context) error // TODO: Make this a real interceptor for filters such as rate limiting.
+}
+
+type csKeyType string
+
+const csKey = csKeyType("grpc.internal.resolver.configSelector")
+
+// SetConfigSelector sets the config selector in state and returns the new
+// state.
+func SetConfigSelector(state resolver.State, cs ConfigSelector) resolver.State {
+ state.Attributes = state.Attributes.WithValues(csKey, cs)
+ return state
+}
+
+// GetConfigSelector retrieves the config selector from state, if present, and
+// returns it or nil if absent.
+func GetConfigSelector(state resolver.State) ConfigSelector {
+ cs, _ := state.Attributes.Value(csKey).(ConfigSelector)
+ return cs
+}
+
+// SafeConfigSelector allows for safe switching of ConfigSelector
+// implementations such that previous values are guaranteed to not be in use
+// when UpdateConfigSelector returns.
+type SafeConfigSelector struct {
+ mu sync.RWMutex
+ cs ConfigSelector
+}
+
+// UpdateConfigSelector swaps to the provided ConfigSelector and blocks until
+// all uses of the previous ConfigSelector have completed.
+func (scs *SafeConfigSelector) UpdateConfigSelector(cs ConfigSelector) {
+ scs.mu.Lock()
+ defer scs.mu.Unlock()
+ scs.cs = cs
+}
+
+// SelectConfig defers to the current ConfigSelector in scs.
+func (scs *SafeConfigSelector) SelectConfig(r RPCInfo) (*RPCConfig, error) {
+ scs.mu.RLock()
+ defer scs.mu.RUnlock()
+ return scs.cs.SelectConfig(r)
+}