VOL-1867 move simulated olt from voltha-go to voltha-simolt-adapter
Sourced from voltha-go commit 251a11c0ffe60512318a644cd6ce0dc4e12f4018
Change-Id: I8e7ee4da1fed739b3c461917301d2729a79307f5
diff --git a/vendor/google.golang.org/grpc/internal/binarylog/sink.go b/vendor/google.golang.org/grpc/internal/binarylog/sink.go
new file mode 100644
index 0000000..20d044f
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/binarylog/sink.go
@@ -0,0 +1,162 @@
+/*
+ *
+ * Copyright 2018 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 binarylog
+
+import (
+ "bufio"
+ "encoding/binary"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "sync"
+ "time"
+
+ "github.com/golang/protobuf/proto"
+ pb "google.golang.org/grpc/binarylog/grpc_binarylog_v1"
+ "google.golang.org/grpc/grpclog"
+)
+
+var (
+ defaultSink Sink = &noopSink{} // TODO(blog): change this default (file in /tmp).
+)
+
+// SetDefaultSink sets the sink where binary logs will be written to.
+//
+// Not thread safe. Only set during initialization.
+func SetDefaultSink(s Sink) {
+ if defaultSink != nil {
+ defaultSink.Close()
+ }
+ defaultSink = s
+}
+
+// Sink writes log entry into the binary log sink.
+type Sink interface {
+ // Write will be called to write the log entry into the sink.
+ //
+ // It should be thread-safe so it can be called in parallel.
+ Write(*pb.GrpcLogEntry) error
+ // Close will be called when the Sink is replaced by a new Sink.
+ Close() error
+}
+
+type noopSink struct{}
+
+func (ns *noopSink) Write(*pb.GrpcLogEntry) error { return nil }
+func (ns *noopSink) Close() error { return nil }
+
+// newWriterSink creates a binary log sink with the given writer.
+//
+// Write() marshalls the proto message and writes it to the given writer. Each
+// message is prefixed with a 4 byte big endian unsigned integer as the length.
+//
+// No buffer is done, Close() doesn't try to close the writer.
+func newWriterSink(w io.Writer) *writerSink {
+ return &writerSink{out: w}
+}
+
+type writerSink struct {
+ out io.Writer
+}
+
+func (ws *writerSink) Write(e *pb.GrpcLogEntry) error {
+ b, err := proto.Marshal(e)
+ if err != nil {
+ grpclog.Infof("binary logging: failed to marshal proto message: %v", err)
+ }
+ hdr := make([]byte, 4)
+ binary.BigEndian.PutUint32(hdr, uint32(len(b)))
+ if _, err := ws.out.Write(hdr); err != nil {
+ return err
+ }
+ if _, err := ws.out.Write(b); err != nil {
+ return err
+ }
+ return nil
+}
+
+func (ws *writerSink) Close() error { return nil }
+
+type bufWriteCloserSink struct {
+ mu sync.Mutex
+ closer io.Closer
+ out *writerSink // out is built on buf.
+ buf *bufio.Writer // buf is kept for flush.
+
+ writeStartOnce sync.Once
+ writeTicker *time.Ticker
+}
+
+func (fs *bufWriteCloserSink) Write(e *pb.GrpcLogEntry) error {
+ // Start the write loop when Write is called.
+ fs.writeStartOnce.Do(fs.startFlushGoroutine)
+ fs.mu.Lock()
+ if err := fs.out.Write(e); err != nil {
+ fs.mu.Unlock()
+ return err
+ }
+ fs.mu.Unlock()
+ return nil
+}
+
+const (
+ bufFlushDuration = 60 * time.Second
+)
+
+func (fs *bufWriteCloserSink) startFlushGoroutine() {
+ fs.writeTicker = time.NewTicker(bufFlushDuration)
+ go func() {
+ for range fs.writeTicker.C {
+ fs.mu.Lock()
+ fs.buf.Flush()
+ fs.mu.Unlock()
+ }
+ }()
+}
+
+func (fs *bufWriteCloserSink) Close() error {
+ if fs.writeTicker != nil {
+ fs.writeTicker.Stop()
+ }
+ fs.mu.Lock()
+ fs.buf.Flush()
+ fs.closer.Close()
+ fs.out.Close()
+ fs.mu.Unlock()
+ return nil
+}
+
+func newBufWriteCloserSink(o io.WriteCloser) Sink {
+ bufW := bufio.NewWriter(o)
+ return &bufWriteCloserSink{
+ closer: o,
+ out: newWriterSink(bufW),
+ buf: bufW,
+ }
+}
+
+// NewTempFileSink creates a temp file and returns a Sink that writes to this
+// file.
+func NewTempFileSink() (Sink, error) {
+ tempFile, err := ioutil.TempFile("/tmp", "grpcgo_binarylog_*.txt")
+ if err != nil {
+ return nil, fmt.Errorf("failed to create temp file: %v", err)
+ }
+ return newBufWriteCloserSink(tempFile), nil
+}