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110 lines
2.5 KiB
110 lines
2.5 KiB
/* |
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* |
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* Copyright 2018 gRPC authors. |
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* |
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* Licensed under the Apache License, Version 2.0 (the "License"); |
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* you may not use this file except in compliance with the License. |
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* You may obtain a copy of the License at |
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* |
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* http://www.apache.org/licenses/LICENSE-2.0 |
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* |
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* Unless required by applicable law or agreed to in writing, software |
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* distributed under the License is distributed on an "AS IS" BASIS, |
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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* See the License for the specific language governing permissions and |
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* limitations under the License. |
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* |
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*/ |
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// Package proto defines the protobuf codec. Importing this package will |
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// register the codec. |
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package proto |
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import ( |
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"math" |
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"sync" |
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"github.com/golang/protobuf/proto" |
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"google.golang.org/grpc/encoding" |
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) |
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// Name is the name registered for the proto compressor. |
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const Name = "proto" |
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func init() { |
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encoding.RegisterCodec(codec{}) |
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} |
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// codec is a Codec implementation with protobuf. It is the default codec for gRPC. |
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type codec struct{} |
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type cachedProtoBuffer struct { |
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lastMarshaledSize uint32 |
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proto.Buffer |
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} |
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func capToMaxInt32(val int) uint32 { |
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if val > math.MaxInt32 { |
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return uint32(math.MaxInt32) |
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} |
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return uint32(val) |
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} |
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func marshal(v interface{}, cb *cachedProtoBuffer) ([]byte, error) { |
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protoMsg := v.(proto.Message) |
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newSlice := make([]byte, 0, cb.lastMarshaledSize) |
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cb.SetBuf(newSlice) |
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cb.Reset() |
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if err := cb.Marshal(protoMsg); err != nil { |
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return nil, err |
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} |
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out := cb.Bytes() |
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cb.lastMarshaledSize = capToMaxInt32(len(out)) |
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return out, nil |
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} |
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func (codec) Marshal(v interface{}) ([]byte, error) { |
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if pm, ok := v.(proto.Marshaler); ok { |
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// object can marshal itself, no need for buffer |
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return pm.Marshal() |
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} |
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cb := protoBufferPool.Get().(*cachedProtoBuffer) |
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out, err := marshal(v, cb) |
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// put back buffer and lose the ref to the slice |
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cb.SetBuf(nil) |
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protoBufferPool.Put(cb) |
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return out, err |
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} |
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func (codec) Unmarshal(data []byte, v interface{}) error { |
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protoMsg := v.(proto.Message) |
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protoMsg.Reset() |
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if pu, ok := protoMsg.(proto.Unmarshaler); ok { |
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// object can unmarshal itself, no need for buffer |
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return pu.Unmarshal(data) |
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} |
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cb := protoBufferPool.Get().(*cachedProtoBuffer) |
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cb.SetBuf(data) |
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err := cb.Unmarshal(protoMsg) |
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cb.SetBuf(nil) |
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protoBufferPool.Put(cb) |
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return err |
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} |
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func (codec) Name() string { |
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return Name |
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} |
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var protoBufferPool = &sync.Pool{ |
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New: func() interface{} { |
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return &cachedProtoBuffer{ |
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Buffer: proto.Buffer{}, |
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lastMarshaledSize: 16, |
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} |
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}, |
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}
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