Elia Battiston | be9edc1 | 2022-03-09 11:35:58 +0100 | [diff] [blame] | 1 | /* |
| 2 | * |
| 3 | * Copyright 2018 gRPC authors. |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | * you may not use this file except in compliance with the License. |
| 7 | * You may obtain a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | * |
| 17 | */ |
| 18 | |
| 19 | package binarylog |
| 20 | |
| 21 | import ( |
| 22 | "bufio" |
| 23 | "encoding/binary" |
| 24 | "fmt" |
| 25 | "io" |
| 26 | "io/ioutil" |
| 27 | "sync" |
| 28 | "time" |
| 29 | |
| 30 | "github.com/golang/protobuf/proto" |
| 31 | pb "google.golang.org/grpc/binarylog/grpc_binarylog_v1" |
| 32 | "google.golang.org/grpc/grpclog" |
| 33 | ) |
| 34 | |
| 35 | var ( |
| 36 | defaultSink Sink = &noopSink{} // TODO(blog): change this default (file in /tmp). |
| 37 | ) |
| 38 | |
| 39 | // SetDefaultSink sets the sink where binary logs will be written to. |
| 40 | // |
| 41 | // Not thread safe. Only set during initialization. |
| 42 | func SetDefaultSink(s Sink) { |
| 43 | if defaultSink != nil { |
| 44 | defaultSink.Close() |
| 45 | } |
| 46 | defaultSink = s |
| 47 | } |
| 48 | |
| 49 | // Sink writes log entry into the binary log sink. |
| 50 | type Sink interface { |
| 51 | // Write will be called to write the log entry into the sink. |
| 52 | // |
| 53 | // It should be thread-safe so it can be called in parallel. |
| 54 | Write(*pb.GrpcLogEntry) error |
| 55 | // Close will be called when the Sink is replaced by a new Sink. |
| 56 | Close() error |
| 57 | } |
| 58 | |
| 59 | type noopSink struct{} |
| 60 | |
| 61 | func (ns *noopSink) Write(*pb.GrpcLogEntry) error { return nil } |
| 62 | func (ns *noopSink) Close() error { return nil } |
| 63 | |
| 64 | // newWriterSink creates a binary log sink with the given writer. |
| 65 | // |
| 66 | // Write() marshals the proto message and writes it to the given writer. Each |
| 67 | // message is prefixed with a 4 byte big endian unsigned integer as the length. |
| 68 | // |
| 69 | // No buffer is done, Close() doesn't try to close the writer. |
| 70 | func newWriterSink(w io.Writer) *writerSink { |
| 71 | return &writerSink{out: w} |
| 72 | } |
| 73 | |
| 74 | type writerSink struct { |
| 75 | out io.Writer |
| 76 | } |
| 77 | |
| 78 | func (ws *writerSink) Write(e *pb.GrpcLogEntry) error { |
| 79 | b, err := proto.Marshal(e) |
| 80 | if err != nil { |
| 81 | grpclog.Infof("binary logging: failed to marshal proto message: %v", err) |
| 82 | } |
| 83 | hdr := make([]byte, 4) |
| 84 | binary.BigEndian.PutUint32(hdr, uint32(len(b))) |
| 85 | if _, err := ws.out.Write(hdr); err != nil { |
| 86 | return err |
| 87 | } |
| 88 | if _, err := ws.out.Write(b); err != nil { |
| 89 | return err |
| 90 | } |
| 91 | return nil |
| 92 | } |
| 93 | |
| 94 | func (ws *writerSink) Close() error { return nil } |
| 95 | |
| 96 | type bufWriteCloserSink struct { |
| 97 | mu sync.Mutex |
| 98 | closer io.Closer |
| 99 | out *writerSink // out is built on buf. |
| 100 | buf *bufio.Writer // buf is kept for flush. |
| 101 | |
| 102 | writeStartOnce sync.Once |
| 103 | writeTicker *time.Ticker |
| 104 | } |
| 105 | |
| 106 | func (fs *bufWriteCloserSink) Write(e *pb.GrpcLogEntry) error { |
| 107 | // Start the write loop when Write is called. |
| 108 | fs.writeStartOnce.Do(fs.startFlushGoroutine) |
| 109 | fs.mu.Lock() |
| 110 | if err := fs.out.Write(e); err != nil { |
| 111 | fs.mu.Unlock() |
| 112 | return err |
| 113 | } |
| 114 | fs.mu.Unlock() |
| 115 | return nil |
| 116 | } |
| 117 | |
| 118 | const ( |
| 119 | bufFlushDuration = 60 * time.Second |
| 120 | ) |
| 121 | |
| 122 | func (fs *bufWriteCloserSink) startFlushGoroutine() { |
| 123 | fs.writeTicker = time.NewTicker(bufFlushDuration) |
| 124 | go func() { |
| 125 | for range fs.writeTicker.C { |
| 126 | fs.mu.Lock() |
| 127 | fs.buf.Flush() |
| 128 | fs.mu.Unlock() |
| 129 | } |
| 130 | }() |
| 131 | } |
| 132 | |
| 133 | func (fs *bufWriteCloserSink) Close() error { |
| 134 | if fs.writeTicker != nil { |
| 135 | fs.writeTicker.Stop() |
| 136 | } |
| 137 | fs.mu.Lock() |
| 138 | fs.buf.Flush() |
| 139 | fs.closer.Close() |
| 140 | fs.out.Close() |
| 141 | fs.mu.Unlock() |
| 142 | return nil |
| 143 | } |
| 144 | |
| 145 | func newBufWriteCloserSink(o io.WriteCloser) Sink { |
| 146 | bufW := bufio.NewWriter(o) |
| 147 | return &bufWriteCloserSink{ |
| 148 | closer: o, |
| 149 | out: newWriterSink(bufW), |
| 150 | buf: bufW, |
| 151 | } |
| 152 | } |
| 153 | |
| 154 | // NewTempFileSink creates a temp file and returns a Sink that writes to this |
| 155 | // file. |
| 156 | func NewTempFileSink() (Sink, error) { |
| 157 | tempFile, err := ioutil.TempFile("/tmp", "grpcgo_binarylog_*.txt") |
| 158 | if err != nil { |
| 159 | return nil, fmt.Errorf("failed to create temp file: %v", err) |
| 160 | } |
| 161 | return newBufWriteCloserSink(tempFile), nil |
| 162 | } |