| /* |
| * |
| * Copyright 2017 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 encoding defines the interface for the compressor and the functions |
| // to register and get the compossor. |
| // This package is EXPERIMENTAL. |
| package encoding |
| |
| import ( |
| "io" |
| ) |
| |
| var registerCompressor = make(map[string]Compressor) |
| |
| // Compressor is used for compressing and decompressing when sending or receiving messages. |
| type Compressor interface { |
| // Compress writes the data written to wc to w after compressing it. If an error |
| // occurs while initializing the compressor, that error is returned instead. |
| Compress(w io.Writer) (io.WriteCloser, error) |
| // Decompress reads data from r, decompresses it, and provides the uncompressed data |
| // via the returned io.Reader. If an error occurs while initializing the decompressor, that error |
| // is returned instead. |
| Decompress(r io.Reader) (io.Reader, error) |
| // Name is the name of the compression codec and is used to set the content coding header. |
| Name() string |
| } |
| |
| // RegisterCompressor registers the compressor with gRPC by its name. It can be activated when |
| // sending an RPC via grpc.UseCompressor(). It will be automatically accessed when receiving a |
| // message based on the content coding header. Servers also use it to send a response with the |
| // same encoding as the request. |
| // |
| // NOTE: this function must only be called during initialization time (i.e. in an init() function). If |
| // multiple Compressors are registered with the same name, the one registered last will take effect. |
| func RegisterCompressor(c Compressor) { |
| registerCompressor[c.Name()] = c |
| } |
| |
| // GetCompressor returns Compressor for the given compressor name. |
| func GetCompressor(name string) Compressor { |
| return registerCompressor[name] |
| } |
| |
| // Identity specifies the optional encoding for uncompressed streams. |
| // It is intended for grpc internal use only. |
| const Identity = "identity" |