| /* |
| * |
| * 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 ( |
| "math" |
| "sync" |
| |
| "github.com/golang/protobuf/proto" |
| ) |
| |
| // Codec defines the interface gRPC uses to encode and decode messages. |
| // Note that implementations of this interface must be thread safe; |
| // a Codec's methods can be called from concurrent goroutines. |
| 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 { |
| } |
| |
| type cachedProtoBuffer struct { |
| lastMarshaledSize uint32 |
| proto.Buffer |
| } |
| |
| func capToMaxInt32(val int) uint32 { |
| if val > math.MaxInt32 { |
| return uint32(math.MaxInt32) |
| } |
| return uint32(val) |
| } |
| |
| func (p protoCodec) marshal(v interface{}, cb *cachedProtoBuffer) ([]byte, error) { |
| protoMsg := v.(proto.Message) |
| newSlice := make([]byte, 0, cb.lastMarshaledSize) |
| |
| cb.SetBuf(newSlice) |
| cb.Reset() |
| if err := cb.Marshal(protoMsg); err != nil { |
| return nil, err |
| } |
| out := cb.Bytes() |
| cb.lastMarshaledSize = capToMaxInt32(len(out)) |
| return out, nil |
| } |
| |
| func (p protoCodec) Marshal(v interface{}) ([]byte, error) { |
| cb := protoBufferPool.Get().(*cachedProtoBuffer) |
| out, err := p.marshal(v, cb) |
| |
| // put back buffer and lose the ref to the slice |
| cb.SetBuf(nil) |
| protoBufferPool.Put(cb) |
| return out, err |
| } |
| |
| func (p protoCodec) Unmarshal(data []byte, v interface{}) error { |
| cb := protoBufferPool.Get().(*cachedProtoBuffer) |
| cb.SetBuf(data) |
| v.(proto.Message).Reset() |
| err := cb.Unmarshal(v.(proto.Message)) |
| cb.SetBuf(nil) |
| protoBufferPool.Put(cb) |
| return err |
| } |
| |
| func (protoCodec) String() string { |
| return "proto" |
| } |
| |
| var ( |
| protoBufferPool = &sync.Pool{ |
| New: func() interface{} { |
| return &cachedProtoBuffer{ |
| Buffer: proto.Buffer{}, |
| lastMarshaledSize: 16, |
| } |
| }, |
| } |
| ) |
