diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/encoding/encoding.go')
-rw-r--r-- | vendor/google.golang.org/grpc/encoding/encoding.go | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/encoding/encoding.go b/vendor/google.golang.org/grpc/encoding/encoding.go new file mode 100644 index 000000000..ade8b7cec --- /dev/null +++ b/vendor/google.golang.org/grpc/encoding/encoding.go @@ -0,0 +1,118 @@ +/* + * + * 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 codec, and +// functions to register and retrieve compressors and codecs. +// +// This package is EXPERIMENTAL. +package encoding + +import ( + "io" + "strings" +) + +// Identity specifies the optional encoding for uncompressed streams. +// It is intended for grpc internal use only. +const Identity = "identity" + +// 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. The result must be static; the result cannot change + // between calls. + Name() string +} + +var registeredCompressor = make(map[string]Compressor) + +// 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), and is not thread-safe. If multiple Compressors are +// registered with the same name, the one registered last will take effect. +func RegisterCompressor(c Compressor) { + registeredCompressor[c.Name()] = c +} + +// GetCompressor returns Compressor for the given compressor name. +func GetCompressor(name string) Compressor { + return registeredCompressor[name] +} + +// 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 + // Name returns the name of the Codec implementation. The returned string + // will be used as part of content type in transmission. The result must be + // static; the result cannot change between calls. + Name() string +} + +var registeredCodecs = make(map[string]Codec) + +// RegisterCodec registers the provided Codec for use with all gRPC clients and +// servers. +// +// The Codec will be stored and looked up by result of its Name() method, which +// should match the content-subtype of the encoding handled by the Codec. This +// is case-insensitive, and is stored and looked up as lowercase. If the +// result of calling Name() is an empty string, RegisterCodec will panic. See +// Content-Type on +// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for +// more details. +// +// NOTE: this function must only be called during initialization time (i.e. in +// an init() function), and is not thread-safe. If multiple Compressors are +// registered with the same name, the one registered last will take effect. +func RegisterCodec(codec Codec) { + if codec == nil { + panic("cannot register a nil Codec") + } + contentSubtype := strings.ToLower(codec.Name()) + if contentSubtype == "" { + panic("cannot register Codec with empty string result for String()") + } + registeredCodecs[contentSubtype] = codec +} + +// GetCodec gets a registered Codec by content-subtype, or nil if no Codec is +// registered for the content-subtype. +// +// The content-subtype is expected to be lowercase. +func GetCodec(contentSubtype string) Codec { + return registeredCodecs[contentSubtype] +} |