ethlog: add Godoc documentation, remove README

This commit is contained in:
Felix Lange 2014-10-14 19:35:10 +02:00
parent a6265cb49a
commit e0f93c74c5
2 changed files with 70 additions and 79 deletions

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@ -1,62 +0,0 @@
## Features
- packages use tagged logger sending log messages to shared (process-wide) logging engine
- log writers (interface ethlog.LogSystem) can be added to the logging engine by wrappers/guis/clients
- shared logging engine dispatching to multiple log systems
- log level can be set separately per log system
- async logging thread: logging IO does not block main thread
- log messages are synchronously stringified to avoid incorrectly logging of changed states
- log level enum: ethlog.LogLevel: Silence, ErrorLevel, WarnLevel, InfoLevel, DebugLevel, DebugDetailLevel
## Usage
In an ethereum component package:
import "github.com/ethereum/eth-go/ethlog"
// package-wide logger using tag
var logger = ethlog.NewLogger("TAG")
Logger provides named Printf and Println style methods for all loglevels
logger.Infoln("this is info") # > [TAG] This is info
logger.Infof("this %v is info", object) # > [TAG] This object is info
Ethereum wrappers should register log systems conforming to ethlog.LogSystem
import "github.com/ethereum/eth-go/ethlog"
type CustomLogWriter struct {
logLevel ethlog.LogLevel
}
func (t *TestLogSystem) SetLogLevel(i LogLevel) {
t.level = i
}
func (t *TestLogSystem) GetLogLevel() LogLevel {
return t.level
}
func (c *CustomLogWriter) Printf(format string, v...interface{}) {
//....
}
func (c *CustomLogWriter) Println(v...interface{}) {
//....
}
ethlog.AddLogWriter(&CustomLogWriter{})
ethlog also provides constructors for that wrap io.Writers into a standard logger with a settable level:
filename := "test.log"
file, _ := os.OpenFile(filename, os.O_RDWR|os.O_CREATE, os.ModePerm)
fileLogSystem := NewStdLogSystem(file, 0, WarnLevel)
AddLogSystem(fileLogSystem)
stdOutLogSystem := NewStdLogSystem(os.Stdout, 0, WarnLevel)
AddLogSystem(stdOutLogSystem)

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@ -1,3 +1,36 @@
/*
Package ethlog implements a multi-output leveled logger.
Features
Other packages use tagged logger to send log messages to shared (process-wide) logging engine.
The shared logging engine dispatches to multiple log systems.
The log level can be set separately per log system.
Logging is asynchrounous and does not block the main thread. Message
formatting is performed by the caller goroutine to avoid incorrect
logging of mutable state.
Usage
The Logger type provides named Printf and Println style methods for
all loglevels. Each ethereum component should have its own logger with
a unique prefix.
logger.Infoln("this is info") # > [TAG] This is info
logger.Infof("this %v is info", object) # > [TAG] This object is info
ethlog also provides constructors for that wrap io.Writers into a
standard logger with a settable level:
filename := "test.log"
file, _ := os.OpenFile(filename, os.O_RDWR|os.O_CREATE, os.ModePerm)
fileLogSystem := NewStdLogSystem(file, 0, WarnLevel)
AddLogSystem(fileLogSystem)
stdOutLogSystem := NewStdLogSystem(os.Stdout, 0, WarnLevel)
AddLogSystem(stdOutLogSystem)
*/
package ethlog package ethlog
import ( import (
@ -9,6 +42,8 @@ import (
"sync/atomic" "sync/atomic"
) )
// LogSystem is implemented by log output devices.
// All methods can be called concurrently from multiple goroutines.
type LogSystem interface { type LogSystem interface {
GetLogLevel() LogLevel GetLogLevel() LogLevel
SetLogLevel(i LogLevel) SetLogLevel(i LogLevel)
@ -33,6 +68,7 @@ func newPrintfLogMessage(level LogLevel, tag string, format string, v ...interfa
type LogLevel uint8 type LogLevel uint8
const ( const (
// Standard log levels
Silence LogLevel = iota Silence LogLevel = iota
ErrorLevel ErrorLevel
WarnLevel WarnLevel
@ -102,7 +138,7 @@ func send(msg *logMessage) {
logMessages <- msg logMessages <- msg
} }
// Reset removes all registered log systems. // Reset removes all active log systems.
func Reset() { func Reset() {
mutex.Lock() mutex.Lock()
logSystems = nil logSystems = nil
@ -117,6 +153,15 @@ func Flush() {
<-waiter <-waiter
} }
// AddLogSystem starts printing messages to the given LogSystem.
func AddLogSystem(logSystem LogSystem) {
mutex.Lock()
logSystems = append(logSystems, logSystem)
mutex.Unlock()
}
// A Logger prints messages prefixed by a given tag.
// You should create one with a unique tag for each high-level component.
type Logger struct { type Logger struct {
tag string tag string
} }
@ -125,12 +170,6 @@ func NewLogger(tag string) *Logger {
return &Logger{tag} return &Logger{tag}
} }
func AddLogSystem(logSystem LogSystem) {
mutex.Lock()
logSystems = append(logSystems, logSystem)
mutex.Unlock()
}
func (logger *Logger) sendln(level LogLevel, v ...interface{}) { func (logger *Logger) sendln(level LogLevel, v ...interface{}) {
if logMessages != nil { if logMessages != nil {
msg := newPrintlnLogMessage(level, logger.tag, v...) msg := newPrintlnLogMessage(level, logger.tag, v...)
@ -145,80 +184,94 @@ func (logger *Logger) sendf(level LogLevel, format string, v ...interface{}) {
} }
} }
// Errorln writes a message with ErrorLevel.
func (logger *Logger) Errorln(v ...interface{}) { func (logger *Logger) Errorln(v ...interface{}) {
logger.sendln(ErrorLevel, v...) logger.sendln(ErrorLevel, v...)
} }
// Warnln writes a message with WarnLevel.
func (logger *Logger) Warnln(v ...interface{}) { func (logger *Logger) Warnln(v ...interface{}) {
logger.sendln(WarnLevel, v...) logger.sendln(WarnLevel, v...)
} }
// Infoln writes a message with InfoLevel.
func (logger *Logger) Infoln(v ...interface{}) { func (logger *Logger) Infoln(v ...interface{}) {
logger.sendln(InfoLevel, v...) logger.sendln(InfoLevel, v...)
} }
// Debugln writes a message with DebugLevel.
func (logger *Logger) Debugln(v ...interface{}) { func (logger *Logger) Debugln(v ...interface{}) {
logger.sendln(DebugLevel, v...) logger.sendln(DebugLevel, v...)
} }
// DebugDetailln writes a message with DebugDetailLevel.
func (logger *Logger) DebugDetailln(v ...interface{}) { func (logger *Logger) DebugDetailln(v ...interface{}) {
logger.sendln(DebugDetailLevel, v...) logger.sendln(DebugDetailLevel, v...)
} }
// Errorf writes a message with ErrorLevel.
func (logger *Logger) Errorf(format string, v ...interface{}) { func (logger *Logger) Errorf(format string, v ...interface{}) {
logger.sendf(ErrorLevel, format, v...) logger.sendf(ErrorLevel, format, v...)
} }
// Warnf writes a message with WarnLevel.
func (logger *Logger) Warnf(format string, v ...interface{}) { func (logger *Logger) Warnf(format string, v ...interface{}) {
logger.sendf(WarnLevel, format, v...) logger.sendf(WarnLevel, format, v...)
} }
// Infof writes a message with InfoLevel.
func (logger *Logger) Infof(format string, v ...interface{}) { func (logger *Logger) Infof(format string, v ...interface{}) {
logger.sendf(InfoLevel, format, v...) logger.sendf(InfoLevel, format, v...)
} }
// Debugf writes a message with DebugLevel.
func (logger *Logger) Debugf(format string, v ...interface{}) { func (logger *Logger) Debugf(format string, v ...interface{}) {
logger.sendf(DebugLevel, format, v...) logger.sendf(DebugLevel, format, v...)
} }
// DebugDetailf writes a message with DebugDetailLevel.
func (logger *Logger) DebugDetailf(format string, v ...interface{}) { func (logger *Logger) DebugDetailf(format string, v ...interface{}) {
logger.sendf(DebugDetailLevel, format, v...) logger.sendf(DebugDetailLevel, format, v...)
} }
// Fatalln writes a message with ErrorLevel and exits the program.
func (logger *Logger) Fatalln(v ...interface{}) { func (logger *Logger) Fatalln(v ...interface{}) {
logger.sendln(ErrorLevel, v...) logger.sendln(ErrorLevel, v...)
Flush() Flush()
os.Exit(0) os.Exit(0)
} }
// Fatalf writes a message with ErrorLevel and exits the program.
func (logger *Logger) Fatalf(format string, v ...interface{}) { func (logger *Logger) Fatalf(format string, v ...interface{}) {
logger.sendf(ErrorLevel, format, v...) logger.sendf(ErrorLevel, format, v...)
Flush() Flush()
os.Exit(0) os.Exit(0)
} }
type StdLogSystem struct { // NewStdLogSystem creates a LogSystem that prints to the given writer.
// The flag values are defined package log.
func NewStdLogSystem(writer io.Writer, flags int, level LogLevel) LogSystem {
logger := log.New(writer, "", flags)
return &stdLogSystem{logger, uint32(level)}
}
type stdLogSystem struct {
logger *log.Logger logger *log.Logger
level uint32 level uint32
} }
func (t *StdLogSystem) Println(v ...interface{}) { func (t *stdLogSystem) Println(v ...interface{}) {
t.logger.Println(v...) t.logger.Println(v...)
} }
func (t *StdLogSystem) Printf(format string, v ...interface{}) { func (t *stdLogSystem) Printf(format string, v ...interface{}) {
t.logger.Printf(format, v...) t.logger.Printf(format, v...)
} }
func (t *StdLogSystem) SetLogLevel(i LogLevel) { func (t *stdLogSystem) SetLogLevel(i LogLevel) {
atomic.StoreUint32(&t.level, uint32(i)) atomic.StoreUint32(&t.level, uint32(i))
} }
func (t *StdLogSystem) GetLogLevel() LogLevel { func (t *stdLogSystem) GetLogLevel() LogLevel {
return LogLevel(atomic.LoadUint32(&t.level)) return LogLevel(atomic.LoadUint32(&t.level))
} }
func NewStdLogSystem(writer io.Writer, flags int, level LogLevel) *StdLogSystem {
logger := log.New(writer, "", flags)
return &StdLogSystem{logger, uint32(level)}
}