diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/transport/transport.go')
| -rw-r--r-- | vendor/google.golang.org/grpc/transport/transport.go | 771 |
1 files changed, 0 insertions, 771 deletions
diff --git a/vendor/google.golang.org/grpc/transport/transport.go b/vendor/google.golang.org/grpc/transport/transport.go deleted file mode 100644 index e0c1e343..00000000 --- a/vendor/google.golang.org/grpc/transport/transport.go +++ /dev/null @@ -1,771 +0,0 @@ -/* - * - * 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 "google.golang.org/grpc/transport" - -import ( - "fmt" - "io" - "net" - "sync" - - "golang.org/x/net/context" - "golang.org/x/net/http2" - "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" -) - -// recvMsg represents the received msg from the transport. All transport -// protocol specific info has been removed. -type recvMsg struct { - data []byte - // 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 -} - -func newRecvBuffer() *recvBuffer { - b := &recvBuffer{ - c: make(chan recvMsg, 1), - } - return b -} - -func (b *recvBuffer) put(r recvMsg) { - b.mu.Lock() - 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 { - ctx context.Context - goAway chan struct{} - recv *recvBuffer - last []byte // Stores the remaining data in the previous calls. - err error -} - -// 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 - } - n, r.err = r.read(p) - return n, r.err -} - -func (r *recvBufferReader) read(p []byte) (n int, err error) { - if r.last != nil && len(r.last) > 0 { - // Read remaining data left in last call. - copied := copy(p, r.last) - r.last = r.last[copied:] - return copied, nil - } - select { - case <-r.ctx.Done(): - return 0, ContextErr(r.ctx.Err()) - case <-r.goAway: - return 0, errStreamDrain - case m := <-r.recv.get(): - r.recv.load() - if m.err != nil { - return 0, m.err - } - copied := copy(p, m.data) - r.last = m.data[copied:] - return copied, nil - } -} - -// All items in an out of a controlBuffer should be the same type. -type item interface { - item() -} - -// controlBuffer is an unbounded channel of item. -type controlBuffer struct { - c chan item - mu sync.Mutex - backlog []item -} - -func newControlBuffer() *controlBuffer { - b := &controlBuffer{ - c: make(chan item, 1), - } - return b -} - -func (b *controlBuffer) put(r item) { - b.mu.Lock() - 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 *controlBuffer) load() { - b.mu.Lock() - if len(b.backlog) > 0 { - select { - case b.c <- b.backlog[0]: - b.backlog[0] = nil - b.backlog = b.backlog[1:] - default: - } - } - b.mu.Unlock() -} - -// get returns the channel that receives an item in the buffer. -// -// Upon receipt of an item, the caller should call load to send another -// item onto the channel if there is any. -func (b *controlBuffer) get() <-chan item { - return b.c -} - -type streamState uint8 - -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 when the final status arrives - goAway chan struct{} // closed when a GOAWAY control message is received - method string // the associated RPC method of the stream - recvCompress string - sendCompress string - buf *recvBuffer - trReader io.Reader - fc *inFlow - recvQuota uint32 - waiters waiters - - // Callback to state application's intentions to read data. This - // is used to adjust flow control, if needed. - requestRead func(int) - - sendQuotaPool *quotaPool - headerChan chan struct{} // closed to indicate the end of header metadata. - headerDone bool // set when headerChan is closed. Used to avoid closing headerChan multiple times. - header metadata.MD // the received header metadata. - trailer metadata.MD // the key-value map of trailer metadata. - - mu sync.RWMutex // guard the following - headerOk bool // becomes true from the first header is about to send - state streamState - - status *status.Status // the status error received from the server - - rstStream bool // indicates whether a RST_STREAM frame needs to be sent - rstError http2.ErrCode // the error that needs to be sent along with the RST_STREAM frame - - bytesReceived bool // indicates whether any bytes have been received on this stream - unprocessed bool // 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 -} - -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 - } - wc := s.waiters - select { - case <-wc.ctx.Done(): - return ContextErr(wc.ctx.Err()) - case <-wc.goAway: - return errStreamDrain - 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 chanel which is closed when it receives the final status -// from the server. -func (s *Stream) Done() <-chan struct{} { - return s.done -} - -// GoAway returns a channel which is closed when the server sent GoAways signal -// before this stream was initiated. -func (s *Stream) GoAway() <-chan struct{} { - return s.goAway -} - -// Header 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. -func (s *Stream) Header() (metadata.MD, error) { - err := s.waitOnHeader() - // Even if the stream is closed, header is returned if available. - select { - case <-s.headerChan: - return s.header.Copy(), nil - default: - } - return nil, err -} - -// 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. -func (s *Stream) Trailer() metadata.MD { - s.mu.RLock() - c := s.trailer.Copy() - s.mu.RUnlock() - return c -} - -// ServerTransport returns the underlying ServerTransport for the stream. -// The client side stream always returns nil. -func (s *Stream) ServerTransport() ServerTransport { - return s.st -} - -// 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. -func (s *Stream) Status() *status.Status { - return s.status -} - -// SetHeader sets the header metadata. This can be called multiple times. -// Server side only. -func (s *Stream) SetHeader(md metadata.MD) error { - s.mu.Lock() - if s.headerOk || s.state == streamDone { - s.mu.Unlock() - return ErrIllegalHeaderWrite - } - if md.Len() == 0 { - s.mu.Unlock() - return nil - } - s.header = metadata.Join(s.header, md) - s.mu.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 { - t := s.ServerTransport() - return t.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. -func (s *Stream) SetTrailer(md metadata.MD) error { - if md.Len() == 0 { - return nil - } - s.mu.Lock() - s.trailer = metadata.Join(s.trailer, md) - s.mu.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 -} - -// finish sets the stream's state and status, and closes the done channel. -// s.mu must be held by the caller. st must always be non-nil. -func (s *Stream) finish(st *status.Status) { - s.status = st - s.state = streamDone - close(s.done) -} - -// BytesReceived indicates whether any bytes have been received on this stream. -func (s *Stream) BytesReceived() bool { - s.mu.Lock() - br := s.bytesReceived - s.mu.Unlock() - return br -} - -// 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 { - s.mu.Lock() - br := s.unprocessed - s.mu.Unlock() - return br -} - -// 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 -} - -// 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 - // Authority is the :authority pseudo-header to use. This field has no effect if - // TransportCredentials is set. - Authority 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. - TransportCredentials credentials.TransportCredentials - // 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 -} - -// 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, onSuccess func()) (ClientTransport, error) { - return newHTTP2Client(connectCtx, ctx, target, opts, onSuccess) -} - -// 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 - - // Delay is a hint to the transport implementation for whether - // the data could be buffered for a batching write. The - // transport implementation may ignore the hint. - Delay 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 - - // Flush indicates whether a new stream command should be sent - // to the peer without waiting for the first data. This is - // only a hint. - // If it's true, the transport may modify the flush decision - // for performance purposes. - // If it's false, new stream will never be flushed. - Flush bool - - // 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 -} - -// 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. It stops accepting - // new RPCs and wait the completion of the pending RPCs. - GracefulClose() error - - // 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 -} - -// 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() -} - -// streamErrorf creates an StreamError with the specified error code and description. -func streamErrorf(c codes.Code, format string, a ...interface{}) StreamError { - return StreamError{ - Code: c, - Desc: fmt.Sprintf(format, a...), - } -} - -// 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 = streamErrorf(codes.Unavailable, "the connection is draining") - // 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") -) - -// TODO: See if we can replace StreamError with status package errors. - -// StreamError is an error that only affects one stream within a connection. -type StreamError struct { - Code codes.Code - Desc string -} - -func (e StreamError) Error() string { - return fmt.Sprintf("stream error: code = %s desc = %q", e.Code, e.Desc) -} - -// waiters are passed to quotaPool get methods to -// wait on in addition to waiting on quota. -type waiters struct { - ctx context.Context - tctx context.Context - done chan struct{} - goAway chan struct{} -} - -// 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 -) - -// loopyWriter is run in a separate go routine. It is the single code path that will -// write data on wire. -func loopyWriter(ctx context.Context, cbuf *controlBuffer, handler func(item) error) { - for { - select { - case i := <-cbuf.get(): - cbuf.load() - if err := handler(i); err != nil { - errorf("transport: Error while handling item. Err: %v", err) - return - } - case <-ctx.Done(): - return - } - hasData: - for { - select { - case i := <-cbuf.get(): - cbuf.load() - if err := handler(i); err != nil { - errorf("transport: Error while handling item. Err: %v", err) - return - } - case <-ctx.Done(): - return - default: - if err := handler(&flushIO{}); err != nil { - errorf("transport: Error while flushing. Err: %v", err) - return - } - break hasData - } - } - } -} |