Commit missing file: log.go

psiphon/server/log.go

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2016, Psiphon Inc.
+ * All rights reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package server
+
+import (
+	"io"
+	"os"
+
+	"github.com/Psiphon-Inc/logrus"
+	"github.com/Psiphon-Labs/psiphon-tunnel-core/psiphon"
+)
+
+// ContextLogger adds context logging functionality to the
+// underlying logging packages.
+type ContextLogger struct {
+	*logrus.Logger
+}
+
+// LogFields is an alias for the field struct in the
+// underlying logging package.
+type LogFields logrus.Fields
+
+// WithContext adds a "context" field containing the caller's
+// function name and source file line number. Use this function
+// when the log has no fields.
+func (logger *ContextLogger) WithContext() *logrus.Entry {
+	return logrus.WithFields(
+		logrus.Fields{
+			"context": psiphon.GetParentContext(),
+		})
+}
+
+// WithContextFields adds a "context" field containing the caller's
+// function name and source file line number. Use this function
+// when the log has fields. Note that any existing "context" field
+// will be renamed to "field.context".
+func (logger *ContextLogger) WithContextFields(fields LogFields) *logrus.Entry {
+	_, ok := fields["context"]
+	if ok {
+		fields["fields.context"] = fields["context"]
+	}
+	fields["context"] = psiphon.GetParentContext()
+	return log.WithFields(logrus.Fields(fields))
+}
+
+// NewLogWriter returns an io.PipeWriter that can be used to write
+// to the global logger. Caller must Close() the writer.
+func NewLogWriter() *io.PipeWriter {
+	return log.Writer()
+}
+
+var log *ContextLogger
+
+func init() {
+	log = &ContextLogger{
+		&logrus.Logger{
+			Out:       os.Stderr,
+			Formatter: new(logrus.TextFormatter),
+			Hooks:     make(logrus.LevelHooks),
+			Level:     logrus.DebugLevel,
+		},
+	}
+}