initial add - go fmt on grpc
Change-Id: Ib0afadd2fe5571d1456a091f94f5644458f7d3f4
diff --git a/vendor/google.golang.org/grpc/internal/transport/transport.go b/vendor/google.golang.org/grpc/internal/transport/transport.go
new file mode 100644
index 0000000..1c1d106
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/transport/transport.go
@@ -0,0 +1,816 @@
+/*
+ *
+ * Copyright 2014 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 transport defines and implements message oriented communication
+// channel to complete various transactions (e.g., an RPC). It is meant for
+// grpc-internal usage and is not intended to be imported directly by users.
+package transport
+
+import (
+ "bytes"
+ "context"
+ "errors"
+ "fmt"
+ "io"
+ "net"
+ "sync"
+ "sync/atomic"
+
+ "google.golang.org/grpc/codes"
+ "google.golang.org/grpc/credentials"
+ "google.golang.org/grpc/keepalive"
+ "google.golang.org/grpc/metadata"
+ "google.golang.org/grpc/stats"
+ "google.golang.org/grpc/status"
+ "google.golang.org/grpc/tap"
+)
+
+type bufferPool struct {
+ pool sync.Pool
+}
+
+func newBufferPool() *bufferPool {
+ return &bufferPool{
+ pool: sync.Pool{
+ New: func() interface{} {
+ return new(bytes.Buffer)
+ },
+ },
+ }
+}
+
+func (p *bufferPool) get() *bytes.Buffer {
+ return p.pool.Get().(*bytes.Buffer)
+}
+
+func (p *bufferPool) put(b *bytes.Buffer) {
+ p.pool.Put(b)
+}
+
+// recvMsg represents the received msg from the transport. All transport
+// protocol specific info has been removed.
+type recvMsg struct {
+ buffer *bytes.Buffer
+ // nil: received some data
+ // io.EOF: stream is completed. data is nil.
+ // other non-nil error: transport failure. data is nil.
+ err error
+}
+
+// recvBuffer is an unbounded channel of recvMsg structs.
+// Note recvBuffer differs from controlBuffer only in that recvBuffer
+// holds a channel of only recvMsg structs instead of objects implementing "item" interface.
+// recvBuffer is written to much more often than
+// controlBuffer and using strict recvMsg structs helps avoid allocation in "recvBuffer.put"
+type recvBuffer struct {
+ c chan recvMsg
+ mu sync.Mutex
+ backlog []recvMsg
+ err error
+}
+
+func newRecvBuffer() *recvBuffer {
+ b := &recvBuffer{
+ c: make(chan recvMsg, 1),
+ }
+ return b
+}
+
+func (b *recvBuffer) put(r recvMsg) {
+ b.mu.Lock()
+ if b.err != nil {
+ b.mu.Unlock()
+ // An error had occurred earlier, don't accept more
+ // data or errors.
+ return
+ }
+ b.err = r.err
+ if len(b.backlog) == 0 {
+ select {
+ case b.c <- r:
+ b.mu.Unlock()
+ return
+ default:
+ }
+ }
+ b.backlog = append(b.backlog, r)
+ b.mu.Unlock()
+}
+
+func (b *recvBuffer) load() {
+ b.mu.Lock()
+ if len(b.backlog) > 0 {
+ select {
+ case b.c <- b.backlog[0]:
+ b.backlog[0] = recvMsg{}
+ b.backlog = b.backlog[1:]
+ default:
+ }
+ }
+ b.mu.Unlock()
+}
+
+// get returns the channel that receives a recvMsg in the buffer.
+//
+// Upon receipt of a recvMsg, the caller should call load to send another
+// recvMsg onto the channel if there is any.
+func (b *recvBuffer) get() <-chan recvMsg {
+ return b.c
+}
+
+// recvBufferReader implements io.Reader interface to read the data from
+// recvBuffer.
+type recvBufferReader struct {
+ closeStream func(error) // Closes the client transport stream with the given error and nil trailer metadata.
+ ctx context.Context
+ ctxDone <-chan struct{} // cache of ctx.Done() (for performance).
+ recv *recvBuffer
+ last *bytes.Buffer // Stores the remaining data in the previous calls.
+ err error
+ freeBuffer func(*bytes.Buffer)
+}
+
+// Read reads the next len(p) bytes from last. If last is drained, it tries to
+// read additional data from recv. It blocks if there no additional data available
+// in recv. If Read returns any non-nil error, it will continue to return that error.
+func (r *recvBufferReader) Read(p []byte) (n int, err error) {
+ if r.err != nil {
+ return 0, r.err
+ }
+ if r.last != nil {
+ // Read remaining data left in last call.
+ copied, _ := r.last.Read(p)
+ if r.last.Len() == 0 {
+ r.freeBuffer(r.last)
+ r.last = nil
+ }
+ return copied, nil
+ }
+ if r.closeStream != nil {
+ n, r.err = r.readClient(p)
+ } else {
+ n, r.err = r.read(p)
+ }
+ return n, r.err
+}
+
+func (r *recvBufferReader) read(p []byte) (n int, err error) {
+ select {
+ case <-r.ctxDone:
+ return 0, ContextErr(r.ctx.Err())
+ case m := <-r.recv.get():
+ return r.readAdditional(m, p)
+ }
+}
+
+func (r *recvBufferReader) readClient(p []byte) (n int, err error) {
+ // If the context is canceled, then closes the stream with nil metadata.
+ // closeStream writes its error parameter to r.recv as a recvMsg.
+ // r.readAdditional acts on that message and returns the necessary error.
+ select {
+ case <-r.ctxDone:
+ // Note that this adds the ctx error to the end of recv buffer, and
+ // reads from the head. This will delay the error until recv buffer is
+ // empty, thus will delay ctx cancellation in Recv().
+ //
+ // It's done this way to fix a race between ctx cancel and trailer. The
+ // race was, stream.Recv() may return ctx error if ctxDone wins the
+ // race, but stream.Trailer() may return a non-nil md because the stream
+ // was not marked as done when trailer is received. This closeStream
+ // call will mark stream as done, thus fix the race.
+ //
+ // TODO: delaying ctx error seems like a unnecessary side effect. What
+ // we really want is to mark the stream as done, and return ctx error
+ // faster.
+ r.closeStream(ContextErr(r.ctx.Err()))
+ m := <-r.recv.get()
+ return r.readAdditional(m, p)
+ case m := <-r.recv.get():
+ return r.readAdditional(m, p)
+ }
+}
+
+func (r *recvBufferReader) readAdditional(m recvMsg, p []byte) (n int, err error) {
+ r.recv.load()
+ if m.err != nil {
+ return 0, m.err
+ }
+ copied, _ := m.buffer.Read(p)
+ if m.buffer.Len() == 0 {
+ r.freeBuffer(m.buffer)
+ r.last = nil
+ } else {
+ r.last = m.buffer
+ }
+ return copied, nil
+}
+
+type streamState uint32
+
+const (
+ streamActive streamState = iota
+ streamWriteDone // EndStream sent
+ streamReadDone // EndStream received
+ streamDone // the entire stream is finished.
+)
+
+// Stream represents an RPC in the transport layer.
+type Stream struct {
+ id uint32
+ st ServerTransport // nil for client side Stream
+ ctx context.Context // the associated context of the stream
+ cancel context.CancelFunc // always nil for client side Stream
+ done chan struct{} // closed at the end of stream to unblock writers. On the client side.
+ ctxDone <-chan struct{} // same as done chan but for server side. Cache of ctx.Done() (for performance)
+ method string // the associated RPC method of the stream
+ recvCompress string
+ sendCompress string
+ buf *recvBuffer
+ trReader io.Reader
+ fc *inFlow
+ wq *writeQuota
+
+ // Callback to state application's intentions to read data. This
+ // is used to adjust flow control, if needed.
+ requestRead func(int)
+
+ headerChan chan struct{} // closed to indicate the end of header metadata.
+ headerChanClosed uint32 // set when headerChan is closed. Used to avoid closing headerChan multiple times.
+
+ // hdrMu protects header and trailer metadata on the server-side.
+ hdrMu sync.Mutex
+ // On client side, header keeps the received header metadata.
+ //
+ // On server side, header keeps the header set by SetHeader(). The complete
+ // header will merged into this after t.WriteHeader() is called.
+ header metadata.MD
+ trailer metadata.MD // the key-value map of trailer metadata.
+
+ noHeaders bool // set if the client never received headers (set only after the stream is done).
+
+ // On the server-side, headerSent is atomically set to 1 when the headers are sent out.
+ headerSent uint32
+
+ state streamState
+
+ // On client-side it is the status error received from the server.
+ // On server-side it is unused.
+ status *status.Status
+
+ bytesReceived uint32 // indicates whether any bytes have been received on this stream
+ unprocessed uint32 // set if the server sends a refused stream or GOAWAY including this stream
+
+ // contentSubtype is the content-subtype for requests.
+ // this must be lowercase or the behavior is undefined.
+ contentSubtype string
+}
+
+// isHeaderSent is only valid on the server-side.
+func (s *Stream) isHeaderSent() bool {
+ return atomic.LoadUint32(&s.headerSent) == 1
+}
+
+// updateHeaderSent updates headerSent and returns true
+// if it was alreay set. It is valid only on server-side.
+func (s *Stream) updateHeaderSent() bool {
+ return atomic.SwapUint32(&s.headerSent, 1) == 1
+}
+
+func (s *Stream) swapState(st streamState) streamState {
+ return streamState(atomic.SwapUint32((*uint32)(&s.state), uint32(st)))
+}
+
+func (s *Stream) compareAndSwapState(oldState, newState streamState) bool {
+ return atomic.CompareAndSwapUint32((*uint32)(&s.state), uint32(oldState), uint32(newState))
+}
+
+func (s *Stream) getState() streamState {
+ return streamState(atomic.LoadUint32((*uint32)(&s.state)))
+}
+
+func (s *Stream) waitOnHeader() error {
+ if s.headerChan == nil {
+ // On the server headerChan is always nil since a stream originates
+ // only after having received headers.
+ return nil
+ }
+ select {
+ case <-s.ctx.Done():
+ // We prefer success over failure when reading messages because we delay
+ // context error in stream.Read(). To keep behavior consistent, we also
+ // prefer success here.
+ select {
+ case <-s.headerChan:
+ return nil
+ default:
+ }
+ return ContextErr(s.ctx.Err())
+ case <-s.headerChan:
+ return nil
+ }
+}
+
+// RecvCompress returns the compression algorithm applied to the inbound
+// message. It is empty string if there is no compression applied.
+func (s *Stream) RecvCompress() string {
+ if err := s.waitOnHeader(); err != nil {
+ return ""
+ }
+ return s.recvCompress
+}
+
+// SetSendCompress sets the compression algorithm to the stream.
+func (s *Stream) SetSendCompress(str string) {
+ s.sendCompress = str
+}
+
+// Done returns a channel which is closed when it receives the final status
+// from the server.
+func (s *Stream) Done() <-chan struct{} {
+ return s.done
+}
+
+// Header returns the header metadata of the stream.
+//
+// On client side, it acquires the key-value pairs of header metadata once it is
+// available. It blocks until i) the metadata is ready or ii) there is no header
+// metadata or iii) the stream is canceled/expired.
+//
+// On server side, it returns the out header after t.WriteHeader is called.
+func (s *Stream) Header() (metadata.MD, error) {
+ if s.headerChan == nil && s.header != nil {
+ // On server side, return the header in stream. It will be the out
+ // header after t.WriteHeader is called.
+ return s.header.Copy(), nil
+ }
+ err := s.waitOnHeader()
+ // Even if the stream is closed, header is returned if available.
+ select {
+ case <-s.headerChan:
+ if s.header == nil {
+ return nil, nil
+ }
+ return s.header.Copy(), nil
+ default:
+ }
+ return nil, err
+}
+
+// TrailersOnly blocks until a header or trailers-only frame is received and
+// then returns true if the stream was trailers-only. If the stream ends
+// before headers are received, returns true, nil. If a context error happens
+// first, returns it as a status error. Client-side only.
+func (s *Stream) TrailersOnly() (bool, error) {
+ err := s.waitOnHeader()
+ if err != nil {
+ return false, err
+ }
+ return s.noHeaders, nil
+}
+
+// Trailer returns the cached trailer metedata. Note that if it is not called
+// after the entire stream is done, it could return an empty MD. Client
+// side only.
+// It can be safely read only after stream has ended that is either read
+// or write have returned io.EOF.
+func (s *Stream) Trailer() metadata.MD {
+ c := s.trailer.Copy()
+ return c
+}
+
+// ContentSubtype returns the content-subtype for a request. For example, a
+// content-subtype of "proto" will result in a content-type of
+// "application/grpc+proto". This will always be lowercase. See
+// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
+// more details.
+func (s *Stream) ContentSubtype() string {
+ return s.contentSubtype
+}
+
+// Context returns the context of the stream.
+func (s *Stream) Context() context.Context {
+ return s.ctx
+}
+
+// Method returns the method for the stream.
+func (s *Stream) Method() string {
+ return s.method
+}
+
+// Status returns the status received from the server.
+// Status can be read safely only after the stream has ended,
+// that is, after Done() is closed.
+func (s *Stream) Status() *status.Status {
+ return s.status
+}
+
+// SetHeader sets the header metadata. This can be called multiple times.
+// Server side only.
+// This should not be called in parallel to other data writes.
+func (s *Stream) SetHeader(md metadata.MD) error {
+ if md.Len() == 0 {
+ return nil
+ }
+ if s.isHeaderSent() || s.getState() == streamDone {
+ return ErrIllegalHeaderWrite
+ }
+ s.hdrMu.Lock()
+ s.header = metadata.Join(s.header, md)
+ s.hdrMu.Unlock()
+ return nil
+}
+
+// SendHeader sends the given header metadata. The given metadata is
+// combined with any metadata set by previous calls to SetHeader and
+// then written to the transport stream.
+func (s *Stream) SendHeader(md metadata.MD) error {
+ return s.st.WriteHeader(s, md)
+}
+
+// SetTrailer sets the trailer metadata which will be sent with the RPC status
+// by the server. This can be called multiple times. Server side only.
+// This should not be called parallel to other data writes.
+func (s *Stream) SetTrailer(md metadata.MD) error {
+ if md.Len() == 0 {
+ return nil
+ }
+ if s.getState() == streamDone {
+ return ErrIllegalHeaderWrite
+ }
+ s.hdrMu.Lock()
+ s.trailer = metadata.Join(s.trailer, md)
+ s.hdrMu.Unlock()
+ return nil
+}
+
+func (s *Stream) write(m recvMsg) {
+ s.buf.put(m)
+}
+
+// Read reads all p bytes from the wire for this stream.
+func (s *Stream) Read(p []byte) (n int, err error) {
+ // Don't request a read if there was an error earlier
+ if er := s.trReader.(*transportReader).er; er != nil {
+ return 0, er
+ }
+ s.requestRead(len(p))
+ return io.ReadFull(s.trReader, p)
+}
+
+// tranportReader reads all the data available for this Stream from the transport and
+// passes them into the decoder, which converts them into a gRPC message stream.
+// The error is io.EOF when the stream is done or another non-nil error if
+// the stream broke.
+type transportReader struct {
+ reader io.Reader
+ // The handler to control the window update procedure for both this
+ // particular stream and the associated transport.
+ windowHandler func(int)
+ er error
+}
+
+func (t *transportReader) Read(p []byte) (n int, err error) {
+ n, err = t.reader.Read(p)
+ if err != nil {
+ t.er = err
+ return
+ }
+ t.windowHandler(n)
+ return
+}
+
+// BytesReceived indicates whether any bytes have been received on this stream.
+func (s *Stream) BytesReceived() bool {
+ return atomic.LoadUint32(&s.bytesReceived) == 1
+}
+
+// Unprocessed indicates whether the server did not process this stream --
+// i.e. it sent a refused stream or GOAWAY including this stream ID.
+func (s *Stream) Unprocessed() bool {
+ return atomic.LoadUint32(&s.unprocessed) == 1
+}
+
+// GoString is implemented by Stream so context.String() won't
+// race when printing %#v.
+func (s *Stream) GoString() string {
+ return fmt.Sprintf("<stream: %p, %v>", s, s.method)
+}
+
+// state of transport
+type transportState int
+
+const (
+ reachable transportState = iota
+ closing
+ draining
+)
+
+// ServerConfig consists of all the configurations to establish a server transport.
+type ServerConfig struct {
+ MaxStreams uint32
+ AuthInfo credentials.AuthInfo
+ InTapHandle tap.ServerInHandle
+ StatsHandler stats.Handler
+ KeepaliveParams keepalive.ServerParameters
+ KeepalivePolicy keepalive.EnforcementPolicy
+ InitialWindowSize int32
+ InitialConnWindowSize int32
+ WriteBufferSize int
+ ReadBufferSize int
+ ChannelzParentID int64
+ MaxHeaderListSize *uint32
+}
+
+// NewServerTransport creates a ServerTransport with conn or non-nil error
+// if it fails.
+func NewServerTransport(protocol string, conn net.Conn, config *ServerConfig) (ServerTransport, error) {
+ return newHTTP2Server(conn, config)
+}
+
+// ConnectOptions covers all relevant options for communicating with the server.
+type ConnectOptions struct {
+ // UserAgent is the application user agent.
+ UserAgent string
+ // Dialer specifies how to dial a network address.
+ Dialer func(context.Context, string) (net.Conn, error)
+ // FailOnNonTempDialError specifies if gRPC fails on non-temporary dial errors.
+ FailOnNonTempDialError bool
+ // PerRPCCredentials stores the PerRPCCredentials required to issue RPCs.
+ PerRPCCredentials []credentials.PerRPCCredentials
+ // TransportCredentials stores the Authenticator required to setup a client
+ // connection. Only one of TransportCredentials and CredsBundle is non-nil.
+ TransportCredentials credentials.TransportCredentials
+ // CredsBundle is the credentials bundle to be used. Only one of
+ // TransportCredentials and CredsBundle is non-nil.
+ CredsBundle credentials.Bundle
+ // KeepaliveParams stores the keepalive parameters.
+ KeepaliveParams keepalive.ClientParameters
+ // StatsHandler stores the handler for stats.
+ StatsHandler stats.Handler
+ // InitialWindowSize sets the initial window size for a stream.
+ InitialWindowSize int32
+ // InitialConnWindowSize sets the initial window size for a connection.
+ InitialConnWindowSize int32
+ // WriteBufferSize sets the size of write buffer which in turn determines how much data can be batched before it's written on the wire.
+ WriteBufferSize int
+ // ReadBufferSize sets the size of read buffer, which in turn determines how much data can be read at most for one read syscall.
+ ReadBufferSize int
+ // ChannelzParentID sets the addrConn id which initiate the creation of this client transport.
+ ChannelzParentID int64
+ // MaxHeaderListSize sets the max (uncompressed) size of header list that is prepared to be received.
+ MaxHeaderListSize *uint32
+}
+
+// TargetInfo contains the information of the target such as network address and metadata.
+type TargetInfo struct {
+ Addr string
+ Metadata interface{}
+ Authority string
+}
+
+// NewClientTransport establishes the transport with the required ConnectOptions
+// and returns it to the caller.
+func NewClientTransport(connectCtx, ctx context.Context, target TargetInfo, opts ConnectOptions, onPrefaceReceipt func(), onGoAway func(GoAwayReason), onClose func()) (ClientTransport, error) {
+ return newHTTP2Client(connectCtx, ctx, target, opts, onPrefaceReceipt, onGoAway, onClose)
+}
+
+// Options provides additional hints and information for message
+// transmission.
+type Options struct {
+ // Last indicates whether this write is the last piece for
+ // this stream.
+ Last bool
+}
+
+// CallHdr carries the information of a particular RPC.
+type CallHdr struct {
+ // Host specifies the peer's host.
+ Host string
+
+ // Method specifies the operation to perform.
+ Method string
+
+ // SendCompress specifies the compression algorithm applied on
+ // outbound message.
+ SendCompress string
+
+ // Creds specifies credentials.PerRPCCredentials for a call.
+ Creds credentials.PerRPCCredentials
+
+ // ContentSubtype specifies the content-subtype for a request. For example, a
+ // content-subtype of "proto" will result in a content-type of
+ // "application/grpc+proto". The value of ContentSubtype must be all
+ // lowercase, otherwise the behavior is undefined. See
+ // https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
+ // for more details.
+ ContentSubtype string
+
+ PreviousAttempts int // value of grpc-previous-rpc-attempts header to set
+}
+
+// ClientTransport is the common interface for all gRPC client-side transport
+// implementations.
+type ClientTransport interface {
+ // Close tears down this transport. Once it returns, the transport
+ // should not be accessed any more. The caller must make sure this
+ // is called only once.
+ Close() error
+
+ // GracefulClose starts to tear down the transport: the transport will stop
+ // accepting new RPCs and NewStream will return error. Once all streams are
+ // finished, the transport will close.
+ //
+ // It does not block.
+ GracefulClose()
+
+ // Write sends the data for the given stream. A nil stream indicates
+ // the write is to be performed on the transport as a whole.
+ Write(s *Stream, hdr []byte, data []byte, opts *Options) error
+
+ // NewStream creates a Stream for an RPC.
+ NewStream(ctx context.Context, callHdr *CallHdr) (*Stream, error)
+
+ // CloseStream clears the footprint of a stream when the stream is
+ // not needed any more. The err indicates the error incurred when
+ // CloseStream is called. Must be called when a stream is finished
+ // unless the associated transport is closing.
+ CloseStream(stream *Stream, err error)
+
+ // Error returns a channel that is closed when some I/O error
+ // happens. Typically the caller should have a goroutine to monitor
+ // this in order to take action (e.g., close the current transport
+ // and create a new one) in error case. It should not return nil
+ // once the transport is initiated.
+ Error() <-chan struct{}
+
+ // GoAway returns a channel that is closed when ClientTransport
+ // receives the draining signal from the server (e.g., GOAWAY frame in
+ // HTTP/2).
+ GoAway() <-chan struct{}
+
+ // GetGoAwayReason returns the reason why GoAway frame was received.
+ GetGoAwayReason() GoAwayReason
+
+ // RemoteAddr returns the remote network address.
+ RemoteAddr() net.Addr
+
+ // IncrMsgSent increments the number of message sent through this transport.
+ IncrMsgSent()
+
+ // IncrMsgRecv increments the number of message received through this transport.
+ IncrMsgRecv()
+}
+
+// ServerTransport is the common interface for all gRPC server-side transport
+// implementations.
+//
+// Methods may be called concurrently from multiple goroutines, but
+// Write methods for a given Stream will be called serially.
+type ServerTransport interface {
+ // HandleStreams receives incoming streams using the given handler.
+ HandleStreams(func(*Stream), func(context.Context, string) context.Context)
+
+ // WriteHeader sends the header metadata for the given stream.
+ // WriteHeader may not be called on all streams.
+ WriteHeader(s *Stream, md metadata.MD) error
+
+ // Write sends the data for the given stream.
+ // Write may not be called on all streams.
+ Write(s *Stream, hdr []byte, data []byte, opts *Options) error
+
+ // WriteStatus sends the status of a stream to the client. WriteStatus is
+ // the final call made on a stream and always occurs.
+ WriteStatus(s *Stream, st *status.Status) error
+
+ // Close tears down the transport. Once it is called, the transport
+ // should not be accessed any more. All the pending streams and their
+ // handlers will be terminated asynchronously.
+ Close() error
+
+ // RemoteAddr returns the remote network address.
+ RemoteAddr() net.Addr
+
+ // Drain notifies the client this ServerTransport stops accepting new RPCs.
+ Drain()
+
+ // IncrMsgSent increments the number of message sent through this transport.
+ IncrMsgSent()
+
+ // IncrMsgRecv increments the number of message received through this transport.
+ IncrMsgRecv()
+}
+
+// connectionErrorf creates an ConnectionError with the specified error description.
+func connectionErrorf(temp bool, e error, format string, a ...interface{}) ConnectionError {
+ return ConnectionError{
+ Desc: fmt.Sprintf(format, a...),
+ temp: temp,
+ err: e,
+ }
+}
+
+// ConnectionError is an error that results in the termination of the
+// entire connection and the retry of all the active streams.
+type ConnectionError struct {
+ Desc string
+ temp bool
+ err error
+}
+
+func (e ConnectionError) Error() string {
+ return fmt.Sprintf("connection error: desc = %q", e.Desc)
+}
+
+// Temporary indicates if this connection error is temporary or fatal.
+func (e ConnectionError) Temporary() bool {
+ return e.temp
+}
+
+// Origin returns the original error of this connection error.
+func (e ConnectionError) Origin() error {
+ // Never return nil error here.
+ // If the original error is nil, return itself.
+ if e.err == nil {
+ return e
+ }
+ return e.err
+}
+
+var (
+ // ErrConnClosing indicates that the transport is closing.
+ ErrConnClosing = connectionErrorf(true, nil, "transport is closing")
+ // errStreamDrain indicates that the stream is rejected because the
+ // connection is draining. This could be caused by goaway or balancer
+ // removing the address.
+ errStreamDrain = status.Error(codes.Unavailable, "the connection is draining")
+ // errStreamDone is returned from write at the client side to indiacte application
+ // layer of an error.
+ errStreamDone = errors.New("the stream is done")
+ // StatusGoAway indicates that the server sent a GOAWAY that included this
+ // stream's ID in unprocessed RPCs.
+ statusGoAway = status.New(codes.Unavailable, "the stream is rejected because server is draining the connection")
+)
+
+// GoAwayReason contains the reason for the GoAway frame received.
+type GoAwayReason uint8
+
+const (
+ // GoAwayInvalid indicates that no GoAway frame is received.
+ GoAwayInvalid GoAwayReason = 0
+ // GoAwayNoReason is the default value when GoAway frame is received.
+ GoAwayNoReason GoAwayReason = 1
+ // GoAwayTooManyPings indicates that a GoAway frame with
+ // ErrCodeEnhanceYourCalm was received and that the debug data said
+ // "too_many_pings".
+ GoAwayTooManyPings GoAwayReason = 2
+)
+
+// channelzData is used to store channelz related data for http2Client and http2Server.
+// These fields cannot be embedded in the original structs (e.g. http2Client), since to do atomic
+// operation on int64 variable on 32-bit machine, user is responsible to enforce memory alignment.
+// Here, by grouping those int64 fields inside a struct, we are enforcing the alignment.
+type channelzData struct {
+ kpCount int64
+ // The number of streams that have started, including already finished ones.
+ streamsStarted int64
+ // Client side: The number of streams that have ended successfully by receiving
+ // EoS bit set frame from server.
+ // Server side: The number of streams that have ended successfully by sending
+ // frame with EoS bit set.
+ streamsSucceeded int64
+ streamsFailed int64
+ // lastStreamCreatedTime stores the timestamp that the last stream gets created. It is of int64 type
+ // instead of time.Time since it's more costly to atomically update time.Time variable than int64
+ // variable. The same goes for lastMsgSentTime and lastMsgRecvTime.
+ lastStreamCreatedTime int64
+ msgSent int64
+ msgRecv int64
+ lastMsgSentTime int64
+ lastMsgRecvTime int64
+}
+
+// ContextErr converts the error from context package into a status error.
+func ContextErr(err error) error {
+ switch err {
+ case context.DeadlineExceeded:
+ return status.Error(codes.DeadlineExceeded, err.Error())
+ case context.Canceled:
+ return status.Error(codes.Canceled, err.Error())
+ }
+ return status.Errorf(codes.Internal, "Unexpected error from context packet: %v", err)
+}