simplefile.go

package goolog2

import (
	"os"
	"sync"
	"sync/atomic"
)

type simpleFile struct {
	writer   FileWriter
	mutex    sync.Mutex
	sync     bool
	refcount int32
}

// Create new simple file holder
//
// Parameters:
//     filepath: name of the logging file
//     sync: if true, the stream is flushed after every message
// Returns:
//     the new file holder
// Note: the reference counter is set to 1. You have to invoke Unref()
//     to clean up the holder.
func NewSimpleFile(
	filepath string,
	sync bool,
) FileHolder {
	holder := &simpleFile{
		sync:     sync,
		refcount: 1,
	}

	// I ignore the error here - if the file cannot be opened, the logging
	// just simply doesn't work. However, if I cannot open the logging
	// file, I cannot report the error.
	file, _ := os.OpenFile(
		filepath, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644)
	holder.writer = newSimpleFileWriter(file, true)

	return holder
}

// Create new simple file holder working over an opened file handle
//
// Parameters:
//     file: the opened file
//     sync: if true, the stream is flushed after every message
// Returns:
//     the new file holder
// Note: the reference counter is set to 1. You have to invoke Unref()
//     to clean up the holder.
func NewSimpleFileHandle(
	file *os.File,
	sync bool,
) FileHolder {
	return &simpleFile{
		writer:   newSimpleFileWriter(file, false),
		sync:     sync,
		refcount: 1,
	}
}

func (this *simpleFile) AccessWriter(
	functor func(writer FileWriter),
) {
	if this.writer != nil {
		/* --  The lock avoids inter-mixing of logging lines */
		this.mutex.Lock()
		defer this.mutex.Unlock()
		functor(this.writer)
		if this.sync {
			this.writer.Sync()
		}
	}
}

func (this *simpleFile) Ref() FileHolder {
	atomic.AddInt32(&this.refcount, 1)
	return this
}

func (this *simpleFile) Unref() {
	refcount := atomic.AddInt32(&this.refcount, -1)
	if refcount == 0 && this.writer != nil {
		this.writer.Close()
		this.writer = nil
	}
}