syncthing/vendor/github.com/sirupsen/logrus/logger.go
Jakob Borg 916ec63af6 cmd/stdiscosrv: New discovery server (fixes #4618)
This is a new revision of the discovery server. Relevant changes and
non-changes:

- Protocol towards clients is unchanged.

- Recommended large scale design is still to be deployed nehind nginx (I
  tested, and it's still a lot faster at terminating TLS).

- Database backend is leveldb again, only. It scales enough, is easy to
  setup, and we don't need any backend to take care of.

- Server supports replication. This is a simple TCP channel - protect it
  with a firewall when deploying over the internet. (We deploy this within
  the same datacenter, and with firewall.) Any incoming client announces
  are sent over the replication channel(s) to other peer discosrvs.
  Incoming replication changes are applied to the database as if they came
  from clients, but without the TLS/certificate overhead.

- Metrics are exposed using the prometheus library, when enabled.

- The database values and replication protocol is protobuf, because JSON
  was quite CPU intensive when I tried that and benchmarked it.

- The "Retry-After" value for failed lookups gets slowly increased from
  a default of 120 seconds, by 5 seconds for each failed lookup,
  independently by each discosrv. This lowers the query load over time for
  clients that are never seen. The Retry-After maxes out at 3600 after a
  couple of weeks of this increase. The number of failed lookups is
  stored in the database, now and then (avoiding making each lookup a
  database put).

All in all this means clients can be pointed towards a cluster using
just multiple A / AAAA records to gain both load sharing and redundancy
(if one is down, clients will talk to the remaining ones).

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4648
2018-01-14 08:52:31 +00:00

324 lines
7.9 KiB
Go

package logrus
import (
"io"
"os"
"sync"
"sync/atomic"
)
type Logger struct {
// The logs are `io.Copy`'d to this in a mutex. It's common to set this to a
// file, or leave it default which is `os.Stderr`. You can also set this to
// something more adventorous, such as logging to Kafka.
Out io.Writer
// Hooks for the logger instance. These allow firing events based on logging
// levels and log entries. For example, to send errors to an error tracking
// service, log to StatsD or dump the core on fatal errors.
Hooks LevelHooks
// All log entries pass through the formatter before logged to Out. The
// included formatters are `TextFormatter` and `JSONFormatter` for which
// TextFormatter is the default. In development (when a TTY is attached) it
// logs with colors, but to a file it wouldn't. You can easily implement your
// own that implements the `Formatter` interface, see the `README` or included
// formatters for examples.
Formatter Formatter
// The logging level the logger should log at. This is typically (and defaults
// to) `logrus.Info`, which allows Info(), Warn(), Error() and Fatal() to be
// logged.
Level Level
// Used to sync writing to the log. Locking is enabled by Default
mu MutexWrap
// Reusable empty entry
entryPool sync.Pool
}
type MutexWrap struct {
lock sync.Mutex
disabled bool
}
func (mw *MutexWrap) Lock() {
if !mw.disabled {
mw.lock.Lock()
}
}
func (mw *MutexWrap) Unlock() {
if !mw.disabled {
mw.lock.Unlock()
}
}
func (mw *MutexWrap) Disable() {
mw.disabled = true
}
// Creates a new logger. Configuration should be set by changing `Formatter`,
// `Out` and `Hooks` directly on the default logger instance. You can also just
// instantiate your own:
//
// var log = &Logger{
// Out: os.Stderr,
// Formatter: new(JSONFormatter),
// Hooks: make(LevelHooks),
// Level: logrus.DebugLevel,
// }
//
// It's recommended to make this a global instance called `log`.
func New() *Logger {
return &Logger{
Out: os.Stderr,
Formatter: new(TextFormatter),
Hooks: make(LevelHooks),
Level: InfoLevel,
}
}
func (logger *Logger) newEntry() *Entry {
entry, ok := logger.entryPool.Get().(*Entry)
if ok {
return entry
}
return NewEntry(logger)
}
func (logger *Logger) releaseEntry(entry *Entry) {
logger.entryPool.Put(entry)
}
// Adds a field to the log entry, note that it doesn't log until you call
// Debug, Print, Info, Warn, Fatal or Panic. It only creates a log entry.
// If you want multiple fields, use `WithFields`.
func (logger *Logger) WithField(key string, value interface{}) *Entry {
entry := logger.newEntry()
defer logger.releaseEntry(entry)
return entry.WithField(key, value)
}
// Adds a struct of fields to the log entry. All it does is call `WithField` for
// each `Field`.
func (logger *Logger) WithFields(fields Fields) *Entry {
entry := logger.newEntry()
defer logger.releaseEntry(entry)
return entry.WithFields(fields)
}
// Add an error as single field to the log entry. All it does is call
// `WithError` for the given `error`.
func (logger *Logger) WithError(err error) *Entry {
entry := logger.newEntry()
defer logger.releaseEntry(entry)
return entry.WithError(err)
}
func (logger *Logger) Debugf(format string, args ...interface{}) {
if logger.level() >= DebugLevel {
entry := logger.newEntry()
entry.Debugf(format, args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Infof(format string, args ...interface{}) {
if logger.level() >= InfoLevel {
entry := logger.newEntry()
entry.Infof(format, args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Printf(format string, args ...interface{}) {
entry := logger.newEntry()
entry.Printf(format, args...)
logger.releaseEntry(entry)
}
func (logger *Logger) Warnf(format string, args ...interface{}) {
if logger.level() >= WarnLevel {
entry := logger.newEntry()
entry.Warnf(format, args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Warningf(format string, args ...interface{}) {
if logger.level() >= WarnLevel {
entry := logger.newEntry()
entry.Warnf(format, args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Errorf(format string, args ...interface{}) {
if logger.level() >= ErrorLevel {
entry := logger.newEntry()
entry.Errorf(format, args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Fatalf(format string, args ...interface{}) {
if logger.level() >= FatalLevel {
entry := logger.newEntry()
entry.Fatalf(format, args...)
logger.releaseEntry(entry)
}
Exit(1)
}
func (logger *Logger) Panicf(format string, args ...interface{}) {
if logger.level() >= PanicLevel {
entry := logger.newEntry()
entry.Panicf(format, args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Debug(args ...interface{}) {
if logger.level() >= DebugLevel {
entry := logger.newEntry()
entry.Debug(args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Info(args ...interface{}) {
if logger.level() >= InfoLevel {
entry := logger.newEntry()
entry.Info(args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Print(args ...interface{}) {
entry := logger.newEntry()
entry.Info(args...)
logger.releaseEntry(entry)
}
func (logger *Logger) Warn(args ...interface{}) {
if logger.level() >= WarnLevel {
entry := logger.newEntry()
entry.Warn(args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Warning(args ...interface{}) {
if logger.level() >= WarnLevel {
entry := logger.newEntry()
entry.Warn(args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Error(args ...interface{}) {
if logger.level() >= ErrorLevel {
entry := logger.newEntry()
entry.Error(args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Fatal(args ...interface{}) {
if logger.level() >= FatalLevel {
entry := logger.newEntry()
entry.Fatal(args...)
logger.releaseEntry(entry)
}
Exit(1)
}
func (logger *Logger) Panic(args ...interface{}) {
if logger.level() >= PanicLevel {
entry := logger.newEntry()
entry.Panic(args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Debugln(args ...interface{}) {
if logger.level() >= DebugLevel {
entry := logger.newEntry()
entry.Debugln(args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Infoln(args ...interface{}) {
if logger.level() >= InfoLevel {
entry := logger.newEntry()
entry.Infoln(args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Println(args ...interface{}) {
entry := logger.newEntry()
entry.Println(args...)
logger.releaseEntry(entry)
}
func (logger *Logger) Warnln(args ...interface{}) {
if logger.level() >= WarnLevel {
entry := logger.newEntry()
entry.Warnln(args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Warningln(args ...interface{}) {
if logger.level() >= WarnLevel {
entry := logger.newEntry()
entry.Warnln(args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Errorln(args ...interface{}) {
if logger.level() >= ErrorLevel {
entry := logger.newEntry()
entry.Errorln(args...)
logger.releaseEntry(entry)
}
}
func (logger *Logger) Fatalln(args ...interface{}) {
if logger.level() >= FatalLevel {
entry := logger.newEntry()
entry.Fatalln(args...)
logger.releaseEntry(entry)
}
Exit(1)
}
func (logger *Logger) Panicln(args ...interface{}) {
if logger.level() >= PanicLevel {
entry := logger.newEntry()
entry.Panicln(args...)
logger.releaseEntry(entry)
}
}
//When file is opened with appending mode, it's safe to
//write concurrently to a file (within 4k message on Linux).
//In these cases user can choose to disable the lock.
func (logger *Logger) SetNoLock() {
logger.mu.Disable()
}
func (logger *Logger) level() Level {
return Level(atomic.LoadUint32((*uint32)(&logger.Level)))
}
func (logger *Logger) SetLevel(level Level) {
atomic.StoreUint32((*uint32)(&logger.Level), uint32(level))
}
func (logger *Logger) AddHook(hook Hook) {
logger.mu.Lock()
defer logger.mu.Unlock()
logger.Hooks.Add(hook)
}