Initial commit

vendor/github.com/hyperhq/hypercli/daemon/logger/copier.go

@@ -0,0 +1,86 @@
+package logger
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"sync"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+)
+
+// Copier can copy logs from specified sources to Logger and attach
+// ContainerID and Timestamp.
+// Writes are concurrent, so you need implement some sync in your logger
+type Copier struct {
+	// cid is the container id for which we are copying logs
+	cid string
+	// srcs is map of name -> reader pairs, for example "stdout", "stderr"
+	srcs     map[string]io.Reader
+	dst      Logger
+	copyJobs sync.WaitGroup
+	closed   chan struct{}
+}
+
+// NewCopier creates a new Copier
+func NewCopier(cid string, srcs map[string]io.Reader, dst Logger) *Copier {
+	return &Copier{
+		cid:    cid,
+		srcs:   srcs,
+		dst:    dst,
+		closed: make(chan struct{}),
+	}
+}
+
+// Run starts logs copying
+func (c *Copier) Run() {
+	for src, w := range c.srcs {
+		c.copyJobs.Add(1)
+		go c.copySrc(src, w)
+	}
+}
+
+func (c *Copier) copySrc(name string, src io.Reader) {
+	defer c.copyJobs.Done()
+	reader := bufio.NewReader(src)
+
+	for {
+		select {
+		case <-c.closed:
+			return
+		default:
+			line, err := reader.ReadBytes('\n')
+			line = bytes.TrimSuffix(line, []byte{'\n'})
+
+			// ReadBytes can return full or partial output even when it failed.
+			// e.g. it can return a full entry and EOF.
+			if err == nil || len(line) > 0 {
+				if logErr := c.dst.Log(&Message{ContainerID: c.cid, Line: line, Source: name, Timestamp: time.Now().UTC()}); logErr != nil {
+					logrus.Errorf("Failed to log msg %q for logger %s: %s", line, c.dst.Name(), logErr)
+				}
+			}
+
+			if err != nil {
+				if err != io.EOF {
+					logrus.Errorf("Error scanning log stream: %s", err)
+				}
+				return
+			}
+		}
+	}
+}
+
+// Wait waits until all copying is done
+func (c *Copier) Wait() {
+	c.copyJobs.Wait()
+}
+
+// Close closes the copier
+func (c *Copier) Close() {
+	select {
+	case <-c.closed:
+	default:
+		close(c.closed)
+	}
+}