Beego/pkg/logs/conn.go

// Copyright 2014 beego Author. All Rights Reserved.
//
// 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 logs

import (
	"encoding/json"
	"io"
	"net"

	"github.com/astaxie/beego/pkg/common"
)

// connWriter implements LoggerInterface.
// Writes messages in keep-live tcp connection.
type connWriter struct {
	lg              *logWriter
	innerWriter     io.WriteCloser
	customFormatter func(*LogMsg) string
	ReconnectOnMsg  bool   `json:"reconnectOnMsg"`
	Reconnect       bool   `json:"reconnect"`
	Net             string `json:"net"`
	Addr            string `json:"addr"`
	Level           int    `json:"level"`
}

// NewConn creates new ConnWrite returning as LoggerInterface.
func NewConn() Logger {
	conn := new(connWriter)
	conn.Level = LevelTrace
	return conn
}

func (c *connWriter) Format(lm *LogMsg) string {
	return lm.Msg
}

// Init initializes a connection writer with json config.
// json config only needs they "level" key
func (c *connWriter) Init(jsonConfig string, opts ...common.SimpleKV) error {

	for _, elem := range opts {
		if elem.Key == "formatter" {
			formatter, err := GetFormatter(elem)
			if err != nil {
				return err
			}
			c.customFormatter = formatter
		}
	}

	return json.Unmarshal([]byte(jsonConfig), c)
}

// WriteMsg writes message in connection.
// If connection is down, try to re-connect.
func (c *connWriter) WriteMsg(lm *LogMsg) error {
	if lm.Level > c.Level {
		return nil
	}
	if c.needToConnectOnMsg() {
		err := c.connect()
		if err != nil {
			return err
		}
	}

	if c.ReconnectOnMsg {
		defer c.innerWriter.Close()
	}

	msg := ""
	if c.customFormatter != nil {
		msg = c.customFormatter(lm)
	} else {
		msg = c.Format(lm)

	}

	_, err := c.lg.writeln(msg)
	if err != nil {
		return err
	}
	return nil
}

// Flush implementing method. empty.
func (c *connWriter) Flush() {

}

// Destroy destroy connection writer and close tcp listener.
func (c *connWriter) Destroy() {
	if c.innerWriter != nil {
		c.innerWriter.Close()
	}
}

func (c *connWriter) connect() error {
	if c.innerWriter != nil {
		c.innerWriter.Close()
		c.innerWriter = nil
	}

	conn, err := net.Dial(c.Net, c.Addr)
	if err != nil {
		return err
	}

	if tcpConn, ok := conn.(*net.TCPConn); ok {
		tcpConn.SetKeepAlive(true)
	}

	c.innerWriter = conn
	c.lg = newLogWriter(conn)
	return nil
}

func (c *connWriter) needToConnectOnMsg() bool {
	if c.Reconnect {
		return true
	}

	if c.innerWriter == nil {
		return true
	}

	return c.ReconnectOnMsg
}

func init() {
	Register(AdapterConn, NewConn)
}