Added logging

vendor/github.com/op/go-logging/log_nix.go

@@ -0,0 +1,109 @@
+// +build !windows
+
+// Copyright 2013, Örjan Persson. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package logging
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"log"
+)
+
+type color int
+
+const (
+	ColorBlack = iota + 30
+	ColorRed
+	ColorGreen
+	ColorYellow
+	ColorBlue
+	ColorMagenta
+	ColorCyan
+	ColorWhite
+)
+
+var (
+	colors = []string{
+		CRITICAL: ColorSeq(ColorMagenta),
+		ERROR:    ColorSeq(ColorRed),
+		WARNING:  ColorSeq(ColorYellow),
+		NOTICE:   ColorSeq(ColorGreen),
+		DEBUG:    ColorSeq(ColorCyan),
+	}
+	boldcolors = []string{
+		CRITICAL: ColorSeqBold(ColorMagenta),
+		ERROR:    ColorSeqBold(ColorRed),
+		WARNING:  ColorSeqBold(ColorYellow),
+		NOTICE:   ColorSeqBold(ColorGreen),
+		DEBUG:    ColorSeqBold(ColorCyan),
+	}
+)
+
+// LogBackend utilizes the standard log module.
+type LogBackend struct {
+	Logger      *log.Logger
+	Color       bool
+	ColorConfig []string
+}
+
+// NewLogBackend creates a new LogBackend.
+func NewLogBackend(out io.Writer, prefix string, flag int) *LogBackend {
+	return &LogBackend{Logger: log.New(out, prefix, flag)}
+}
+
+// Log implements the Backend interface.
+func (b *LogBackend) Log(level Level, calldepth int, rec *Record) error {
+	if b.Color {
+		col := colors[level]
+		if len(b.ColorConfig) > int(level) && b.ColorConfig[level] != "" {
+			col = b.ColorConfig[level]
+		}
+
+		buf := &bytes.Buffer{}
+		buf.Write([]byte(col))
+		buf.Write([]byte(rec.Formatted(calldepth + 1)))
+		buf.Write([]byte("\033[0m"))
+		// For some reason, the Go logger arbitrarily decided "2" was the correct
+		// call depth...
+		return b.Logger.Output(calldepth+2, buf.String())
+	}
+
+	return b.Logger.Output(calldepth+2, rec.Formatted(calldepth+1))
+}
+
+// ConvertColors takes a list of ints representing colors for log levels and
+// converts them into strings for ANSI color formatting
+func ConvertColors(colors []int, bold bool) []string {
+	converted := []string{}
+	for _, i := range colors {
+		if bold {
+			converted = append(converted, ColorSeqBold(color(i)))
+		} else {
+			converted = append(converted, ColorSeq(color(i)))
+		}
+	}
+
+	return converted
+}
+
+func ColorSeq(color color) string {
+	return fmt.Sprintf("\033[%dm", int(color))
+}
+
+func ColorSeqBold(color color) string {
+	return fmt.Sprintf("\033[%d;1m", int(color))
+}
+
+func doFmtVerbLevelColor(layout string, level Level, output io.Writer) {
+	if layout == "bold" {
+		output.Write([]byte(boldcolors[level]))
+	} else if layout == "reset" {
+		output.Write([]byte("\033[0m"))
+	} else {
+		output.Write([]byte(colors[level]))
+	}
+}