Vendor libs

vendor/github.com/alecthomas/log4go/filelog.go

@@ -0,0 +1,264 @@
+// Copyright (C) 2010, Kyle Lemons <kyle@kylelemons.net>.  All rights reserved.
+
+package log4go
+
+import (
+	"fmt"
+	"os"
+	"time"
+)
+
+// This log writer sends output to a file
+type FileLogWriter struct {
+	rec chan *LogRecord
+	rot chan bool
+
+	// The opened file
+	filename string
+	file     *os.File
+
+	// The logging format
+	format string
+
+	// File header/trailer
+	header, trailer string
+
+	// Rotate at linecount
+	maxlines          int
+	maxlines_curlines int
+
+	// Rotate at size
+	maxsize         int
+	maxsize_cursize int
+
+	// Rotate daily
+	daily          bool
+	daily_opendate int
+
+	// Keep old logfiles (.001, .002, etc)
+	rotate    bool
+	maxbackup int
+}
+
+// This is the FileLogWriter's output method
+func (w *FileLogWriter) LogWrite(rec *LogRecord) {
+	w.rec <- rec
+}
+
+func (w *FileLogWriter) Close() {
+	close(w.rec)
+	w.file.Sync()
+}
+
+// NewFileLogWriter creates a new LogWriter which writes to the given file and
+// has rotation enabled if rotate is true.
+//
+// If rotate is true, any time a new log file is opened, the old one is renamed
+// with a .### extension to preserve it.  The various Set* methods can be used
+// to configure log rotation based on lines, size, and daily.
+//
+// The standard log-line format is:
+//   [%D %T] [%L] (%S) %M
+func NewFileLogWriter(fname string, rotate bool) *FileLogWriter {
+	w := &FileLogWriter{
+		rec:       make(chan *LogRecord, LogBufferLength),
+		rot:       make(chan bool),
+		filename:  fname,
+		format:    "[%D %T] [%L] (%S) %M",
+		rotate:    rotate,
+		maxbackup: 999,
+	}
+
+	// open the file for the first time
+	if err := w.intRotate(); err != nil {
+		fmt.Fprintf(os.Stderr, "FileLogWriter(%q): %s\n", w.filename, err)
+		return nil
+	}
+
+	go func() {
+		defer func() {
+			if w.file != nil {
+				fmt.Fprint(w.file, FormatLogRecord(w.trailer, &LogRecord{Created: time.Now()}))
+				w.file.Close()
+			}
+		}()
+
+		for {
+			select {
+			case <-w.rot:
+				if err := w.intRotate(); err != nil {
+					fmt.Fprintf(os.Stderr, "FileLogWriter(%q): %s\n", w.filename, err)
+					return
+				}
+			case rec, ok := <-w.rec:
+				if !ok {
+					return
+				}
+				now := time.Now()
+				if (w.maxlines > 0 && w.maxlines_curlines >= w.maxlines) ||
+					(w.maxsize > 0 && w.maxsize_cursize >= w.maxsize) ||
+					(w.daily && now.Day() != w.daily_opendate) {
+					if err := w.intRotate(); err != nil {
+						fmt.Fprintf(os.Stderr, "FileLogWriter(%q): %s\n", w.filename, err)
+						return
+					}
+				}
+
+				// Perform the write
+				n, err := fmt.Fprint(w.file, FormatLogRecord(w.format, rec))
+				if err != nil {
+					fmt.Fprintf(os.Stderr, "FileLogWriter(%q): %s\n", w.filename, err)
+					return
+				}
+
+				// Update the counts
+				w.maxlines_curlines++
+				w.maxsize_cursize += n
+			}
+		}
+	}()
+
+	return w
+}
+
+// Request that the logs rotate
+func (w *FileLogWriter) Rotate() {
+	w.rot <- true
+}
+
+// If this is called in a threaded context, it MUST be synchronized
+func (w *FileLogWriter) intRotate() error {
+	// Close any log file that may be open
+	if w.file != nil {
+		fmt.Fprint(w.file, FormatLogRecord(w.trailer, &LogRecord{Created: time.Now()}))
+		w.file.Close()
+	}
+
+	// If we are keeping log files, move it to the next available number
+	if w.rotate {
+		_, err := os.Lstat(w.filename)
+		if err == nil { // file exists
+			// Find the next available number
+			num := 1
+			fname := ""
+			if w.daily && time.Now().Day() != w.daily_opendate {
+				yesterday := time.Now().AddDate(0, 0, -1).Format("2006-01-02")
+
+				for ; err == nil && num <= 999; num++ {
+					fname = w.filename + fmt.Sprintf(".%s.%03d", yesterday, num)
+					_, err = os.Lstat(fname)
+				}
+				// return error if the last file checked still existed
+				if err == nil {
+					return fmt.Errorf("Rotate: Cannot find free log number to rename %s\n", w.filename)
+				}
+			} else {
+				num = w.maxbackup - 1
+				for ; num >= 1; num-- {
+					fname = w.filename + fmt.Sprintf(".%d", num)
+					nfname := w.filename + fmt.Sprintf(".%d", num+1)
+					_, err = os.Lstat(fname)
+					if err == nil {
+						os.Rename(fname, nfname)
+					}
+				}
+			}
+
+			w.file.Close()
+			// Rename the file to its newfound home
+			err = os.Rename(w.filename, fname)
+			if err != nil {
+				return fmt.Errorf("Rotate: %s\n", err)
+			}
+		}
+	}
+
+	// Open the log file
+	fd, err := os.OpenFile(w.filename, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0660)
+	if err != nil {
+		return err
+	}
+	w.file = fd
+
+	now := time.Now()
+	fmt.Fprint(w.file, FormatLogRecord(w.header, &LogRecord{Created: now}))
+
+	// Set the daily open date to the current date
+	w.daily_opendate = now.Day()
+
+	// initialize rotation values
+	w.maxlines_curlines = 0
+	w.maxsize_cursize = 0
+
+	return nil
+}
+
+// Set the logging format (chainable).  Must be called before the first log
+// message is written.
+func (w *FileLogWriter) SetFormat(format string) *FileLogWriter {
+	w.format = format
+	return w
+}
+
+// Set the logfile header and footer (chainable).  Must be called before the first log
+// message is written.  These are formatted similar to the FormatLogRecord (e.g.
+// you can use %D and %T in your header/footer for date and time).
+func (w *FileLogWriter) SetHeadFoot(head, foot string) *FileLogWriter {
+	w.header, w.trailer = head, foot
+	if w.maxlines_curlines == 0 {
+		fmt.Fprint(w.file, FormatLogRecord(w.header, &LogRecord{Created: time.Now()}))
+	}
+	return w
+}
+
+// Set rotate at linecount (chainable). Must be called before the first log
+// message is written.
+func (w *FileLogWriter) SetRotateLines(maxlines int) *FileLogWriter {
+	//fmt.Fprintf(os.Stderr, "FileLogWriter.SetRotateLines: %v\n", maxlines)
+	w.maxlines = maxlines
+	return w
+}
+
+// Set rotate at size (chainable). Must be called before the first log message
+// is written.
+func (w *FileLogWriter) SetRotateSize(maxsize int) *FileLogWriter {
+	//fmt.Fprintf(os.Stderr, "FileLogWriter.SetRotateSize: %v\n", maxsize)
+	w.maxsize = maxsize
+	return w
+}
+
+// Set rotate daily (chainable). Must be called before the first log message is
+// written.
+func (w *FileLogWriter) SetRotateDaily(daily bool) *FileLogWriter {
+	//fmt.Fprintf(os.Stderr, "FileLogWriter.SetRotateDaily: %v\n", daily)
+	w.daily = daily
+	return w
+}
+
+// Set max backup files. Must be called before the first log message
+// is written.
+func (w *FileLogWriter) SetRotateMaxBackup(maxbackup int) *FileLogWriter {
+	w.maxbackup = maxbackup
+	return w
+}
+
+// SetRotate changes whether or not the old logs are kept. (chainable) Must be
+// called before the first log message is written.  If rotate is false, the
+// files are overwritten; otherwise, they are rotated to another file before the
+// new log is opened.
+func (w *FileLogWriter) SetRotate(rotate bool) *FileLogWriter {
+	//fmt.Fprintf(os.Stderr, "FileLogWriter.SetRotate: %v\n", rotate)
+	w.rotate = rotate
+	return w
+}
+
+// NewXMLLogWriter is a utility method for creating a FileLogWriter set up to
+// output XML record log messages instead of line-based ones.
+func NewXMLLogWriter(fname string, rotate bool) *FileLogWriter {
+	return NewFileLogWriter(fname, rotate).SetFormat(
+		`	<record level="%L">
+		<timestamp>%D %T</timestamp>
+		<source>%S</source>
+		<message>%M</message>
+	</record>`).SetHeadFoot("<log created=\"%D %T\">", "</log>")
+}