Migrate Sirupsen to sirupsen.

vendor/github.com/gravitational/trace/log.go

@@ -0,0 +1,240 @@
+/*
+Copyright 2015 Gravitational, Inc.
+
+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 trace implements utility functions for capturing logs
+package trace
+
+import (
+	"bytes"
+	"fmt"
+	"regexp"
+	rundebug "runtime/debug"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+
+	"runtime"
+)
+
+const (
+	// FileField is a field with code file added to structured traces
+	FileField = "file"
+	// FunctionField is a field with function name
+	FunctionField = "func"
+	// LevelField returns logging level as set by logrus
+	LevelField = "level"
+	// Component is a field that represents component - e.g. service or
+	// function
+	Component = "trace.component"
+	// ComponentFields is a fields component
+	ComponentFields = "trace.fields"
+	// DefaultComponentPadding is a default padding for component field
+	DefaultComponentPadding = 11
+	// DefaultLevelPadding is a default padding for level field
+	DefaultLevelPadding = 4
+)
+
+// TextFormatter is logrus-compatible formatter and adds
+// file and line details to every logged entry.
+type TextFormatter struct {
+	// DisableTimestamp disables timestamp output (useful when outputting to
+	// systemd logs)
+	DisableTimestamp bool
+	// ComponentPadding is a padding to pick when displaying
+	// and formatting component field, defaults to DefaultComponentPadding
+	ComponentPadding int
+}
+
+// Format implements logrus.Formatter interface and adds file and line
+func (tf *TextFormatter) Format(e *log.Entry) (data []byte, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			data = append([]byte("panic in log formatter\n"), rundebug.Stack()...)
+			return
+		}
+	}()
+	var file string
+	if frameNo := findFrame(); frameNo != -1 {
+		t := newTrace(frameNo, nil)
+		file = t.Loc()
+	}
+
+	w := &writer{}
+
+	// time
+	if !tf.DisableTimestamp {
+		w.writeField(e.Time.Format(time.RFC3339))
+	}
+
+	// level
+	w.writeField(strings.ToUpper(padMax(e.Level.String(), DefaultLevelPadding)))
+
+	// component, always output
+	componentI, ok := e.Data[Component]
+	if !ok {
+		componentI = ""
+	}
+	component, ok := componentI.(string)
+	if !ok {
+		component = fmt.Sprintf("%v", componentI)
+	}
+	padding := DefaultComponentPadding
+	if tf.ComponentPadding != 0 {
+		padding = tf.ComponentPadding
+	}
+	if w.Len() > 0 {
+		w.WriteByte(' ')
+	}
+	if component != "" {
+		component = fmt.Sprintf("[%v]", component)
+	}
+	component = strings.ToUpper(padMax(component, padding))
+	if component[len(component)-1] != ' ' {
+		component = component[:len(component)-1] + "]"
+	}
+	w.WriteString(component)
+
+	// message
+	if e.Message != "" {
+		w.writeField(e.Message)
+	}
+
+	// rest of the fields
+	if len(e.Data) > 0 {
+		w.writeMap(e.Data)
+	}
+
+	// file, if present, always last
+	if file != "" {
+		w.writeField(file)
+	}
+
+	w.WriteByte('\n')
+	data = w.Bytes()
+	return
+}
+
+// JSONFormatter implements logrus.Formatter interface and adds file and line
+// properties to JSON entries
+type JSONFormatter struct {
+	log.JSONFormatter
+}
+
+// Format implements logrus.Formatter interface
+func (j *JSONFormatter) Format(e *log.Entry) ([]byte, error) {
+	if frameNo := findFrame(); frameNo != -1 {
+		t := newTrace(frameNo, nil)
+		new := e.WithFields(log.Fields{
+			FileField:     t.Loc(),
+			FunctionField: t.FuncName(),
+		})
+		new.Time = e.Time
+		new.Level = e.Level
+		new.Message = e.Message
+		e = new
+	}
+	return (&j.JSONFormatter).Format(e)
+}
+
+var r = regexp.MustCompile(`github\.com/(S|s)irupsen/logrus`)
+
+func findFrame() int {
+	for i := 3; i < 10; i++ {
+		_, file, _, ok := runtime.Caller(i)
+		if !ok {
+			return -1
+		}
+		if !r.MatchString(file) {
+			return i
+		}
+	}
+	return -1
+}
+
+type writer struct {
+	bytes.Buffer
+}
+
+func (w *writer) writeField(value interface{}) {
+	if w.Len() > 0 {
+		w.WriteByte(' ')
+	}
+	w.writeValue(value)
+}
+
+func (w *writer) writeValue(value interface{}) {
+	stringVal, ok := value.(string)
+	if !ok {
+		stringVal = fmt.Sprint(value)
+	}
+	if !needsQuoting(stringVal) {
+		w.WriteString(stringVal)
+	} else {
+		w.WriteString(fmt.Sprintf("%q", stringVal))
+	}
+}
+
+func (w *writer) writeKeyValue(key string, value interface{}) {
+	if w.Len() > 0 {
+		w.WriteByte(' ')
+	}
+	w.WriteString(key)
+	w.WriteByte(':')
+	w.writeValue(value)
+}
+
+func (w *writer) writeMap(m map[string]interface{}) {
+	if len(m) == 0 {
+		return
+	}
+	keys := make([]string, 0, len(m))
+	for key := range m {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+	for _, key := range keys {
+		if key == Component {
+			continue
+		}
+		switch val := m[key].(type) {
+		case log.Fields:
+			w.writeMap(val)
+		default:
+			w.writeKeyValue(key, val)
+		}
+	}
+}
+
+func needsQuoting(text string) bool {
+	for _, r := range text {
+		if !strconv.IsPrint(r) {
+			return true
+		}
+	}
+	return false
+}
+
+func padMax(in string, chars int) string {
+	switch {
+	case len(in) < chars:
+		return in + strings.Repeat(" ", chars-len(in))
+	default:
+		return in[:chars]
+	}
+}