eliasdb/ecal/logging.go

/*
 * EliasDB
 *
 * Copyright 2016 Matthias Ladkau. All rights reserved.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/*
Package ecal contains the main API for the event condition language ECAL.
*/
package ecal

import (
	"fmt"
	"log"

	"devt.de/krotik/common/datautil"
)

// Logging
// =======

/*
Logger is an interface for log message consumers.
*/
type Logger interface {

	/*
	   LogError adds a new error log message.
	*/
	LogError(p *Processor, v ...interface{})

	/*
	   LogInfo adds a new info log message.
	*/
	LogInfo(p *Processor, v ...interface{})

	/*
	   LogDebug adds a new debug log message.
	*/
	LogDebug(p *Processor, v ...interface{})
}

/*
MemoryLogger collects log messages in a RingBuffer in memory.
*/
type MemoryLogger struct {
	*datautil.RingBuffer
}

/*
NewMemoryLogger returns a new memory logger instance.
*/
func NewMemoryLogger(size int) *MemoryLogger {
	return &MemoryLogger{datautil.NewRingBuffer(size)}
}

/*
LogError adds a new error log message.
*/
func (ml *MemoryLogger) LogError(p *Processor, m ...interface{}) {
	ml.RingBuffer.Add(fmt.Sprintf("error: %v", fmt.Sprint(m...)))
}

/*
LogInfo adds a new info log message.
*/
func (ml *MemoryLogger) LogInfo(p *Processor, m ...interface{}) {
	ml.RingBuffer.Add(fmt.Sprintf("info: %v", fmt.Sprint(m...)))
}

/*
LogDebug adds a new debug log message.
*/
func (ml *MemoryLogger) LogDebug(p *Processor, m ...interface{}) {
	ml.RingBuffer.Add(fmt.Sprintf("debug: %v", fmt.Sprint(m...)))
}

/*
Slice returns the contents of the current log as a slice.
*/
func (ml *MemoryLogger) Slice() []string {
	sl := ml.RingBuffer.Slice()
	ret := make([]string, len(sl))
	for i, lm := range sl {
		ret[i] = lm.(string)
	}
	return ret
}

/*
Reset resets the current log.
*/
func (ml *MemoryLogger) Reset() {
	ml.RingBuffer.Reset()
}

/*
Size returns the current log size.
*/
func (ml *MemoryLogger) Size() int {
	return ml.RingBuffer.Size()
}

/*
String returns the current log as a string.
*/
func (ml *MemoryLogger) String() string {
	return ml.RingBuffer.String()
}

/*
StdOutLogger writes log messages to stdout.
*/
type StdOutLogger struct {
	stdlog func(v ...interface{})
}

/*
NewStdOutLogger returns a stdout logger instance.
*/
func NewStdOutLogger() Logger {
	return &StdOutLogger{log.Print}
}

/*
LogError adds a new error log message.
*/
func (sl *StdOutLogger) LogError(p *Processor, m ...interface{}) {
	sl.stdlog(fmt.Sprintf("error: %v", fmt.Sprint(m...)))
}

/*
LogInfo adds a new info log message.
*/
func (sl *StdOutLogger) LogInfo(p *Processor, m ...interface{}) {
	sl.stdlog(fmt.Sprintf("error: %v", fmt.Sprint(m...)))
}

/*
LogDebug adds a new debug log message.
*/
func (sl *StdOutLogger) LogDebug(p *Processor, m ...interface{}) {
	sl.stdlog(fmt.Sprintf("error: %v", fmt.Sprint(m...)))
}

/*
NullLogger discards log messages.
*/
type NullLogger struct {
}

/*
NewNullLogger returns a null logger instance.
*/
func NewNullLogger() Logger {
	return &NullLogger{}
}

/*
LogError adds a new error log message.
*/
func (nl *NullLogger) LogError(p *Processor, m ...interface{}) {
}

/*
LogInfo adds a new info log message.
*/
func (nl *NullLogger) LogInfo(p *Processor, m ...interface{}) {
}

/*
LogDebug adds a new debug log message.
*/
func (nl *NullLogger) LogDebug(p *Processor, m ...interface{}) {
}