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Diffstat (limited to 'vendor/google.golang.org/grpc/rpc_util.go')
-rw-r--r-- | vendor/google.golang.org/grpc/rpc_util.go | 457 |
1 files changed, 457 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/rpc_util.go b/vendor/google.golang.org/grpc/rpc_util.go new file mode 100644 index 000000000..a25eaa8a2 --- /dev/null +++ b/vendor/google.golang.org/grpc/rpc_util.go @@ -0,0 +1,457 @@ +/* + * + * Copyright 2014, Google Inc. + * All rights reserved. + * + * 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 + +import ( + "bytes" + "compress/gzip" + "encoding/binary" + "fmt" + "io" + "io/ioutil" + "math" + "os" + + "github.com/golang/protobuf/proto" + "golang.org/x/net/context" + "google.golang.org/grpc/codes" + "google.golang.org/grpc/metadata" + "google.golang.org/grpc/transport" +) + +// Codec defines the interface gRPC uses to encode and decode messages. +type Codec interface { + // Marshal returns the wire format of v. + Marshal(v interface{}) ([]byte, error) + // Unmarshal parses the wire format into v. + Unmarshal(data []byte, v interface{}) error + // String returns the name of the Codec implementation. The returned + // string will be used as part of content type in transmission. + String() string +} + +// protoCodec is a Codec implementation with protobuf. It is the default codec for gRPC. +type protoCodec struct{} + +func (protoCodec) Marshal(v interface{}) ([]byte, error) { + return proto.Marshal(v.(proto.Message)) +} + +func (protoCodec) Unmarshal(data []byte, v interface{}) error { + return proto.Unmarshal(data, v.(proto.Message)) +} + +func (protoCodec) String() string { + return "proto" +} + +// Compressor defines the interface gRPC uses to compress a message. +type Compressor interface { + // Do compresses p into w. + Do(w io.Writer, p []byte) error + // Type returns the compression algorithm the Compressor uses. + Type() string +} + +// NewGZIPCompressor creates a Compressor based on GZIP. +func NewGZIPCompressor() Compressor { + return &gzipCompressor{} +} + +type gzipCompressor struct { +} + +func (c *gzipCompressor) Do(w io.Writer, p []byte) error { + z := gzip.NewWriter(w) + if _, err := z.Write(p); err != nil { + return err + } + return z.Close() +} + +func (c *gzipCompressor) Type() string { + return "gzip" +} + +// Decompressor defines the interface gRPC uses to decompress a message. +type Decompressor interface { + // Do reads the data from r and uncompress them. + Do(r io.Reader) ([]byte, error) + // Type returns the compression algorithm the Decompressor uses. + Type() string +} + +type gzipDecompressor struct { +} + +// NewGZIPDecompressor creates a Decompressor based on GZIP. +func NewGZIPDecompressor() Decompressor { + return &gzipDecompressor{} +} + +func (d *gzipDecompressor) Do(r io.Reader) ([]byte, error) { + z, err := gzip.NewReader(r) + if err != nil { + return nil, err + } + defer z.Close() + return ioutil.ReadAll(z) +} + +func (d *gzipDecompressor) Type() string { + return "gzip" +} + +// callInfo contains all related configuration and information about an RPC. +type callInfo struct { + failFast bool + headerMD metadata.MD + trailerMD metadata.MD + traceInfo traceInfo // in trace.go +} + +var defaultCallInfo = callInfo{failFast: true} + +// CallOption configures a Call before it starts or extracts information from +// a Call after it completes. +type CallOption interface { + // before is called before the call is sent to any server. If before + // returns a non-nil error, the RPC fails with that error. + before(*callInfo) error + + // after is called after the call has completed. after cannot return an + // error, so any failures should be reported via output parameters. + after(*callInfo) +} + +type beforeCall func(c *callInfo) error + +func (o beforeCall) before(c *callInfo) error { return o(c) } +func (o beforeCall) after(c *callInfo) {} + +type afterCall func(c *callInfo) + +func (o afterCall) before(c *callInfo) error { return nil } +func (o afterCall) after(c *callInfo) { o(c) } + +// Header returns a CallOptions that retrieves the header metadata +// for a unary RPC. +func Header(md *metadata.MD) CallOption { + return afterCall(func(c *callInfo) { + *md = c.headerMD + }) +} + +// Trailer returns a CallOptions that retrieves the trailer metadata +// for a unary RPC. +func Trailer(md *metadata.MD) CallOption { + return afterCall(func(c *callInfo) { + *md = c.trailerMD + }) +} + +// FailFast configures the action to take when an RPC is attempted on broken +// connections or unreachable servers. If failfast is true, the RPC will fail +// immediately. Otherwise, the RPC client will block the call until a +// connection is available (or the call is canceled or times out) and will retry +// the call if it fails due to a transient error. Please refer to +// https://github.com/grpc/grpc/blob/master/doc/fail_fast.md +func FailFast(failFast bool) CallOption { + return beforeCall(func(c *callInfo) error { + c.failFast = failFast + return nil + }) +} + +// The format of the payload: compressed or not? +type payloadFormat uint8 + +const ( + compressionNone payloadFormat = iota // no compression + compressionMade +) + +// parser reads complete gRPC messages from the underlying reader. +type parser struct { + // r is the underlying reader. + // See the comment on recvMsg for the permissible + // error types. + r io.Reader + + // The header of a gRPC message. Find more detail + // at http://www.grpc.io/docs/guides/wire.html. + header [5]byte +} + +// recvMsg reads a complete gRPC message from the stream. +// +// It returns the message and its payload (compression/encoding) +// format. The caller owns the returned msg memory. +// +// If there is an error, possible values are: +// * io.EOF, when no messages remain +// * io.ErrUnexpectedEOF +// * of type transport.ConnectionError +// * of type transport.StreamError +// No other error values or types must be returned, which also means +// that the underlying io.Reader must not return an incompatible +// error. +func (p *parser) recvMsg(maxMsgSize int) (pf payloadFormat, msg []byte, err error) { + if _, err := io.ReadFull(p.r, p.header[:]); err != nil { + return 0, nil, err + } + + pf = payloadFormat(p.header[0]) + length := binary.BigEndian.Uint32(p.header[1:]) + + if length == 0 { + return pf, nil, nil + } + if length > uint32(maxMsgSize) { + return 0, nil, Errorf(codes.Internal, "grpc: received message length %d exceeding the max size %d", length, maxMsgSize) + } + // TODO(bradfitz,zhaoq): garbage. reuse buffer after proto decoding instead + // of making it for each message: + msg = make([]byte, int(length)) + if _, err := io.ReadFull(p.r, msg); err != nil { + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + return 0, nil, err + } + return pf, msg, nil +} + +// encode serializes msg and prepends the message header. If msg is nil, it +// generates the message header of 0 message length. +func encode(c Codec, msg interface{}, cp Compressor, cbuf *bytes.Buffer) ([]byte, error) { + var b []byte + var length uint + if msg != nil { + var err error + // TODO(zhaoq): optimize to reduce memory alloc and copying. + b, err = c.Marshal(msg) + if err != nil { + return nil, err + } + if cp != nil { + if err := cp.Do(cbuf, b); err != nil { + return nil, err + } + b = cbuf.Bytes() + } + length = uint(len(b)) + } + if length > math.MaxUint32 { + return nil, Errorf(codes.InvalidArgument, "grpc: message too large (%d bytes)", length) + } + + const ( + payloadLen = 1 + sizeLen = 4 + ) + + var buf = make([]byte, payloadLen+sizeLen+len(b)) + + // Write payload format + if cp == nil { + buf[0] = byte(compressionNone) + } else { + buf[0] = byte(compressionMade) + } + // Write length of b into buf + binary.BigEndian.PutUint32(buf[1:], uint32(length)) + // Copy encoded msg to buf + copy(buf[5:], b) + + return buf, nil +} + +func checkRecvPayload(pf payloadFormat, recvCompress string, dc Decompressor) error { + switch pf { + case compressionNone: + case compressionMade: + if dc == nil || recvCompress != dc.Type() { + return Errorf(codes.Unimplemented, "grpc: Decompressor is not installed for grpc-encoding %q", recvCompress) + } + default: + return Errorf(codes.Internal, "grpc: received unexpected payload format %d", pf) + } + return nil +} + +func recv(p *parser, c Codec, s *transport.Stream, dc Decompressor, m interface{}, maxMsgSize int) error { + pf, d, err := p.recvMsg(maxMsgSize) + if err != nil { + return err + } + if err := checkRecvPayload(pf, s.RecvCompress(), dc); err != nil { + return err + } + if pf == compressionMade { + d, err = dc.Do(bytes.NewReader(d)) + if err != nil { + return Errorf(codes.Internal, "grpc: failed to decompress the received message %v", err) + } + } + if len(d) > maxMsgSize { + // TODO: Revisit the error code. Currently keep it consistent with java + // implementation. + return Errorf(codes.Internal, "grpc: received a message of %d bytes exceeding %d limit", len(d), maxMsgSize) + } + if err := c.Unmarshal(d, m); err != nil { + return Errorf(codes.Internal, "grpc: failed to unmarshal the received message %v", err) + } + return nil +} + +// rpcError defines the status from an RPC. +type rpcError struct { + code codes.Code + desc string +} + +func (e *rpcError) Error() string { + return fmt.Sprintf("rpc error: code = %d desc = %s", e.code, e.desc) +} + +// Code returns the error code for err if it was produced by the rpc system. +// Otherwise, it returns codes.Unknown. +func Code(err error) codes.Code { + if err == nil { + return codes.OK + } + if e, ok := err.(*rpcError); ok { + return e.code + } + return codes.Unknown +} + +// ErrorDesc returns the error description of err if it was produced by the rpc system. +// Otherwise, it returns err.Error() or empty string when err is nil. +func ErrorDesc(err error) string { + if err == nil { + return "" + } + if e, ok := err.(*rpcError); ok { + return e.desc + } + return err.Error() +} + +// Errorf returns an error containing an error code and a description; +// Errorf returns nil if c is OK. +func Errorf(c codes.Code, format string, a ...interface{}) error { + if c == codes.OK { + return nil + } + return &rpcError{ + code: c, + desc: fmt.Sprintf(format, a...), + } +} + +// toRPCErr converts an error into a rpcError. +func toRPCErr(err error) error { + switch e := err.(type) { + case *rpcError: + return err + case transport.StreamError: + return &rpcError{ + code: e.Code, + desc: e.Desc, + } + case transport.ConnectionError: + return &rpcError{ + code: codes.Internal, + desc: e.Desc, + } + default: + switch err { + case context.DeadlineExceeded: + return &rpcError{ + code: codes.DeadlineExceeded, + desc: err.Error(), + } + case context.Canceled: + return &rpcError{ + code: codes.Canceled, + desc: err.Error(), + } + case ErrClientConnClosing: + return &rpcError{ + code: codes.FailedPrecondition, + desc: err.Error(), + } + } + + } + return Errorf(codes.Unknown, "%v", err) +} + +// convertCode converts a standard Go error into its canonical code. Note that +// this is only used to translate the error returned by the server applications. +func convertCode(err error) codes.Code { + switch err { + case nil: + return codes.OK + case io.EOF: + return codes.OutOfRange + case io.ErrClosedPipe, io.ErrNoProgress, io.ErrShortBuffer, io.ErrShortWrite, io.ErrUnexpectedEOF: + return codes.FailedPrecondition + case os.ErrInvalid: + return codes.InvalidArgument + case context.Canceled: + return codes.Canceled + case context.DeadlineExceeded: + return codes.DeadlineExceeded + } + switch { + case os.IsExist(err): + return codes.AlreadyExists + case os.IsNotExist(err): + return codes.NotFound + case os.IsPermission(err): + return codes.PermissionDenied + } + return codes.Unknown +} + +// SupportPackageIsVersion4 is referenced from generated protocol buffer files +// to assert that that code is compatible with this version of the grpc package. +// +// This constant may be renamed in the future if a change in the generated code +// requires a synchronised update of grpc-go and protoc-gen-go. This constant +// should not be referenced from any other code. +const SupportPackageIsVersion4 = true |