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Diffstat (limited to 'Godeps/_workspace/src/code.google.com/p/log4go/log4go.go')
| -rw-r--r-- | Godeps/_workspace/src/code.google.com/p/log4go/log4go.go | 484 |
1 files changed, 484 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/code.google.com/p/log4go/log4go.go b/Godeps/_workspace/src/code.google.com/p/log4go/log4go.go new file mode 100644 index 000000000..ab4e857f5 --- /dev/null +++ b/Godeps/_workspace/src/code.google.com/p/log4go/log4go.go @@ -0,0 +1,484 @@ +// Copyright (C) 2010, Kyle Lemons <kyle@kylelemons.net>. All rights reserved. + +// Package log4go provides level-based and highly configurable logging. +// +// Enhanced Logging +// +// This is inspired by the logging functionality in Java. Essentially, you create a Logger +// object and create output filters for it. You can send whatever you want to the Logger, +// and it will filter that based on your settings and send it to the outputs. This way, you +// can put as much debug code in your program as you want, and when you're done you can filter +// out the mundane messages so only the important ones show up. +// +// Utility functions are provided to make life easier. Here is some example code to get started: +// +// log := log4go.NewLogger() +// log.AddFilter("stdout", log4go.DEBUG, log4go.NewConsoleLogWriter()) +// log.AddFilter("log", log4go.FINE, log4go.NewFileLogWriter("example.log", true)) +// log.Info("The time is now: %s", time.LocalTime().Format("15:04:05 MST 2006/01/02")) +// +// The first two lines can be combined with the utility NewDefaultLogger: +// +// log := log4go.NewDefaultLogger(log4go.DEBUG) +// log.AddFilter("log", log4go.FINE, log4go.NewFileLogWriter("example.log", true)) +// log.Info("The time is now: %s", time.LocalTime().Format("15:04:05 MST 2006/01/02")) +// +// Usage notes: +// - The ConsoleLogWriter does not display the source of the message to standard +// output, but the FileLogWriter does. +// - The utility functions (Info, Debug, Warn, etc) derive their source from the +// calling function, and this incurs extra overhead. +// +// Changes from 2.0: +// - The external interface has remained mostly stable, but a lot of the +// internals have been changed, so if you depended on any of this or created +// your own LogWriter, then you will probably have to update your code. In +// particular, Logger is now a map and ConsoleLogWriter is now a channel +// behind-the-scenes, and the LogWrite method no longer has return values. +// +// Future work: (please let me know if you think I should work on any of these particularly) +// - Log file rotation +// - Logging configuration files ala log4j +// - Have the ability to remove filters? +// - Have GetInfoChannel, GetDebugChannel, etc return a chan string that allows +// for another method of logging +// - Add an XML filter type +package log4go + +import ( + "errors" + "os" + "fmt" + "time" + "strings" + "runtime" +) + +// Version information +const ( + L4G_VERSION = "log4go-v3.0.1" + L4G_MAJOR = 3 + L4G_MINOR = 0 + L4G_BUILD = 1 +) + +/****** Constants ******/ + +// These are the integer logging levels used by the logger +type level int + +const ( + FINEST level = iota + FINE + DEBUG + TRACE + INFO + WARNING + ERROR + CRITICAL +) + +// Logging level strings +var ( + levelStrings = [...]string{"FNST", "FINE", "DEBG", "TRAC", "INFO", "WARN", "EROR", "CRIT"} +) + +func (l level) String() string { + if l < 0 || int(l) > len(levelStrings) { + return "UNKNOWN" + } + return levelStrings[int(l)] +} + +/****** Variables ******/ +var ( + // LogBufferLength specifies how many log messages a particular log4go + // logger can buffer at a time before writing them. + LogBufferLength = 32 +) + +/****** LogRecord ******/ + +// A LogRecord contains all of the pertinent information for each message +type LogRecord struct { + Level level // The log level + Created time.Time // The time at which the log message was created (nanoseconds) + Source string // The message source + Message string // The log message +} + +/****** LogWriter ******/ + +// This is an interface for anything that should be able to write logs +type LogWriter interface { + // This will be called to log a LogRecord message. + LogWrite(rec *LogRecord) + + // This should clean up anything lingering about the LogWriter, as it is called before + // the LogWriter is removed. LogWrite should not be called after Close. + Close() +} + +/****** Logger ******/ + +// A Filter represents the log level below which no log records are written to +// the associated LogWriter. +type Filter struct { + Level level + LogWriter +} + +// A Logger represents a collection of Filters through which log messages are +// written. +type Logger map[string]*Filter + +// Create a new logger. +// +// DEPRECATED: Use make(Logger) instead. +func NewLogger() Logger { + os.Stderr.WriteString("warning: use of deprecated NewLogger\n") + return make(Logger) +} + +// Create a new logger with a "stdout" filter configured to send log messages at +// or above lvl to standard output. +// +// DEPRECATED: use NewDefaultLogger instead. +func NewConsoleLogger(lvl level) Logger { + os.Stderr.WriteString("warning: use of deprecated NewConsoleLogger\n") + return Logger{ + "stdout": &Filter{lvl, NewConsoleLogWriter()}, + } +} + +// Create a new logger with a "stdout" filter configured to send log messages at +// or above lvl to standard output. +func NewDefaultLogger(lvl level) Logger { + return Logger{ + "stdout": &Filter{lvl, NewConsoleLogWriter()}, + } +} + +// Closes all log writers in preparation for exiting the program or a +// reconfiguration of logging. Calling this is not really imperative, unless +// you want to guarantee that all log messages are written. Close removes +// all filters (and thus all LogWriters) from the logger. +func (log Logger) Close() { + // Close all open loggers + for name, filt := range log { + filt.Close() + delete(log, name) + } +} + +// Add a new LogWriter to the Logger which will only log messages at lvl or +// higher. This function should not be called from multiple goroutines. +// Returns the logger for chaining. +func (log Logger) AddFilter(name string, lvl level, writer LogWriter) Logger { + log[name] = &Filter{lvl, writer} + return log +} + +/******* Logging *******/ +// Send a formatted log message internally +func (log Logger) intLogf(lvl level, format string, args ...interface{}) { + skip := true + + // Determine if any logging will be done + for _, filt := range log { + if lvl >= filt.Level { + skip = false + break + } + } + if skip { + return + } + + // Determine caller func + pc, _, lineno, ok := runtime.Caller(2) + src := "" + if ok { + src = fmt.Sprintf("%s:%d", runtime.FuncForPC(pc).Name(), lineno) + } + + msg := format + if len(args) > 0 { + msg = fmt.Sprintf(format, args...) + } + + // Make the log record + rec := &LogRecord{ + Level: lvl, + Created: time.Now(), + Source: src, + Message: msg, + } + + // Dispatch the logs + for _, filt := range log { + if lvl < filt.Level { + continue + } + filt.LogWrite(rec) + } +} + +// Send a closure log message internally +func (log Logger) intLogc(lvl level, closure func() string) { + skip := true + + // Determine if any logging will be done + for _, filt := range log { + if lvl >= filt.Level { + skip = false + break + } + } + if skip { + return + } + + // Determine caller func + pc, _, lineno, ok := runtime.Caller(2) + src := "" + if ok { + src = fmt.Sprintf("%s:%d", runtime.FuncForPC(pc).Name(), lineno) + } + + // Make the log record + rec := &LogRecord{ + Level: lvl, + Created: time.Now(), + Source: src, + Message: closure(), + } + + // Dispatch the logs + for _, filt := range log { + if lvl < filt.Level { + continue + } + filt.LogWrite(rec) + } +} + +// Send a log message with manual level, source, and message. +func (log Logger) Log(lvl level, source, message string) { + skip := true + + // Determine if any logging will be done + for _, filt := range log { + if lvl >= filt.Level { + skip = false + break + } + } + if skip { + return + } + + // Make the log record + rec := &LogRecord{ + Level: lvl, + Created: time.Now(), + Source: source, + Message: message, + } + + // Dispatch the logs + for _, filt := range log { + if lvl < filt.Level { + continue + } + filt.LogWrite(rec) + } +} + +// Logf logs a formatted log message at the given log level, using the caller as +// its source. +func (log Logger) Logf(lvl level, format string, args ...interface{}) { + log.intLogf(lvl, format, args...) +} + +// Logc logs a string returned by the closure at the given log level, using the caller as +// its source. If no log message would be written, the closure is never called. +func (log Logger) Logc(lvl level, closure func() string) { + log.intLogc(lvl, closure) +} + +// Finest logs a message at the finest log level. +// See Debug for an explanation of the arguments. +func (log Logger) Finest(arg0 interface{}, args ...interface{}) { + const ( + lvl = FINEST + ) + switch first := arg0.(type) { + case string: + // Use the string as a format string + log.intLogf(lvl, first, args...) + case func() string: + // Log the closure (no other arguments used) + log.intLogc(lvl, first) + default: + // Build a format string so that it will be similar to Sprint + log.intLogf(lvl, fmt.Sprint(arg0)+strings.Repeat(" %v", len(args)), args...) + } +} + +// Fine logs a message at the fine log level. +// See Debug for an explanation of the arguments. +func (log Logger) Fine(arg0 interface{}, args ...interface{}) { + const ( + lvl = FINE + ) + switch first := arg0.(type) { + case string: + // Use the string as a format string + log.intLogf(lvl, first, args...) + case func() string: + // Log the closure (no other arguments used) + log.intLogc(lvl, first) + default: + // Build a format string so that it will be similar to Sprint + log.intLogf(lvl, fmt.Sprint(arg0)+strings.Repeat(" %v", len(args)), args...) + } +} + +// Debug is a utility method for debug log messages. +// The behavior of Debug depends on the first argument: +// - arg0 is a string +// When given a string as the first argument, this behaves like Logf but with +// the DEBUG log level: the first argument is interpreted as a format for the +// latter arguments. +// - arg0 is a func()string +// When given a closure of type func()string, this logs the string returned by +// the closure iff it will be logged. The closure runs at most one time. +// - arg0 is interface{} +// When given anything else, the log message will be each of the arguments +// formatted with %v and separated by spaces (ala Sprint). +func (log Logger) Debug(arg0 interface{}, args ...interface{}) { + const ( + lvl = DEBUG + ) + switch first := arg0.(type) { + case string: + // Use the string as a format string + log.intLogf(lvl, first, args...) + case func() string: + // Log the closure (no other arguments used) + log.intLogc(lvl, first) + default: + // Build a format string so that it will be similar to Sprint + log.intLogf(lvl, fmt.Sprint(arg0)+strings.Repeat(" %v", len(args)), args...) + } +} + +// Trace logs a message at the trace log level. +// See Debug for an explanation of the arguments. +func (log Logger) Trace(arg0 interface{}, args ...interface{}) { + const ( + lvl = TRACE + ) + switch first := arg0.(type) { + case string: + // Use the string as a format string + log.intLogf(lvl, first, args...) + case func() string: + // Log the closure (no other arguments used) + log.intLogc(lvl, first) + default: + // Build a format string so that it will be similar to Sprint + log.intLogf(lvl, fmt.Sprint(arg0)+strings.Repeat(" %v", len(args)), args...) + } +} + +// Info logs a message at the info log level. +// See Debug for an explanation of the arguments. +func (log Logger) Info(arg0 interface{}, args ...interface{}) { + const ( + lvl = INFO + ) + switch first := arg0.(type) { + case string: + // Use the string as a format string + log.intLogf(lvl, first, args...) + case func() string: + // Log the closure (no other arguments used) + log.intLogc(lvl, first) + default: + // Build a format string so that it will be similar to Sprint + log.intLogf(lvl, fmt.Sprint(arg0)+strings.Repeat(" %v", len(args)), args...) + } +} + +// Warn logs a message at the warning log level and returns the formatted error. +// At the warning level and higher, there is no performance benefit if the +// message is not actually logged, because all formats are processed and all +// closures are executed to format the error message. +// See Debug for further explanation of the arguments. +func (log Logger) Warn(arg0 interface{}, args ...interface{}) error { + const ( + lvl = WARNING + ) + var msg string + switch first := arg0.(type) { + case string: + // Use the string as a format string + msg = fmt.Sprintf(first, args...) + case func() string: + // Log the closure (no other arguments used) + msg = first() + default: + // Build a format string so that it will be similar to Sprint + msg = fmt.Sprintf(fmt.Sprint(first)+strings.Repeat(" %v", len(args)), args...) + } + log.intLogf(lvl, msg) + return errors.New(msg) +} + +// Error logs a message at the error log level and returns the formatted error, +// See Warn for an explanation of the performance and Debug for an explanation +// of the parameters. +func (log Logger) Error(arg0 interface{}, args ...interface{}) error { + const ( + lvl = ERROR + ) + var msg string + switch first := arg0.(type) { + case string: + // Use the string as a format string + msg = fmt.Sprintf(first, args...) + case func() string: + // Log the closure (no other arguments used) + msg = first() + default: + // Build a format string so that it will be similar to Sprint + msg = fmt.Sprintf(fmt.Sprint(first)+strings.Repeat(" %v", len(args)), args...) + } + log.intLogf(lvl, msg) + return errors.New(msg) +} + +// Critical logs a message at the critical log level and returns the formatted error, +// See Warn for an explanation of the performance and Debug for an explanation +// of the parameters. +func (log Logger) Critical(arg0 interface{}, args ...interface{}) error { + const ( + lvl = CRITICAL + ) + var msg string + switch first := arg0.(type) { + case string: + // Use the string as a format string + msg = fmt.Sprintf(first, args...) + case func() string: + // Log the closure (no other arguments used) + msg = first() + default: + // Build a format string so that it will be similar to Sprint + msg = fmt.Sprintf(fmt.Sprint(first)+strings.Repeat(" %v", len(args)), args...) + } + log.intLogf(lvl, msg) + return errors.New(msg) +} |