1 files changed, 85 insertions, 0 deletions
diff --git a/pkg/log/glog.go b/pkg/log/glog.go
new file mode 100644
index 000000000..f57c4427b
--- /dev/null
+++ b/pkg/log/glog.go
@@ -0,0 +1,85 @@
+// Copyright 2018 The gVisor 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 log
+
+import (
+	"fmt"
+	"os"
+	"runtime"
+	"strings"
+	"time"
+)
+
+// GoogleEmitter is a wrapper that emits logs in a format compatible with
+// package github.com/golang/glog.
+type GoogleEmitter struct {
+	*Writer
+}
+
+// pid is used for the threadid component of the header.
+var pid = os.Getpid()
+
+// Emit emits the message, google-style.
+//
+// Log lines have this form:
+//   Lmmdd hh:mm:ss.uuuuuu threadid file:line] msg...
+//
+// where the fields are defined as follows:
+//   L                A single character, representing the log level (eg 'I' for INFO)
+//   mm               The month (zero padded; ie May is '05')
+//   dd               The day (zero padded)
+//   hh:mm:ss.uuuuuu  Time in hours, minutes and fractional seconds
+//   threadid         The space-padded thread ID as returned by GetTID()
+//   file             The file name
+//   line             The line number
+//   msg              The user-supplied message
+//
+func (g GoogleEmitter) Emit(depth int, level Level, timestamp time.Time, format string, args ...interface{}) {
+	// Log level.
+	prefix := byte('?')
+	switch level {
+	case Debug:
+		prefix = byte('D')
+	case Info:
+		prefix = byte('I')
+	case Warning:
+		prefix = byte('W')
+	}
+
+	// Timestamp.
+	_, month, day := timestamp.Date()
+	hour, minute, second := timestamp.Clock()
+	microsecond := int(timestamp.Nanosecond() / 1000)
+
+	// 0 = this frame.
+	_, file, line, ok := runtime.Caller(depth + 1)
+	if ok {
+		// Trim any directory path from the file.
+		slash := strings.LastIndexByte(file, byte('/'))
+		if slash >= 0 {
+			file = file[slash+1:]
+		}
+	} else {
+		// We don't have a filename.
+		file = "???"
+		line = 0
+	}
+
+	// Generate the message.
+	message := fmt.Sprintf(format, args...)
+
+	// Emit the formatted result.
+	fmt.Fprintf(g.Writer, "%c%02d%02d %02d:%02d:%02d.%06d % 7d %s:%d] %s\n", prefix, int(month), day, hour, minute, second, microsecond, pid, file, line, message)
+}