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author | Wim <wim@42.be> | 2021-10-16 23:11:32 +0200 |
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committer | Wim <wim@42.be> | 2021-10-16 23:23:24 +0200 |
commit | 20f6c05ec50739d31f4dbe9fde0d223f2c43f6e8 (patch) | |
tree | 230edca06449a8d1755f08aabf45a03e07e6f17c /vendor/github.com/mattermost/logr/v2/target.go | |
parent | 57fce93af7f64f025cec6f3ed6088163086bc9fe (diff) | |
download | matterbridge-msglm-20f6c05ec50739d31f4dbe9fde0d223f2c43f6e8.tar.gz matterbridge-msglm-20f6c05ec50739d31f4dbe9fde0d223f2c43f6e8.tar.bz2 matterbridge-msglm-20f6c05ec50739d31f4dbe9fde0d223f2c43f6e8.zip |
Update vendor
Diffstat (limited to 'vendor/github.com/mattermost/logr/v2/target.go')
-rw-r--r-- | vendor/github.com/mattermost/logr/v2/target.go | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/vendor/github.com/mattermost/logr/v2/target.go b/vendor/github.com/mattermost/logr/v2/target.go new file mode 100644 index 00000000..fa0a9320 --- /dev/null +++ b/vendor/github.com/mattermost/logr/v2/target.go @@ -0,0 +1,304 @@ +package logr + +import ( + "context" + "errors" + "fmt" + "os" + "sync/atomic" + "time" +) + +// Target represents a destination for log records such as file, +// database, TCP socket, etc. +type Target interface { + // Init is called once to initialize the target. + Init() error + + // Write outputs to this target's destination. + Write(p []byte, rec *LogRec) (int, error) + + // Shutdown is called once to free/close any resources. + // Target queue is already drained when this is called. + Shutdown() error +} + +type targetMetrics struct { + queueSizeGauge Gauge + loggedCounter Counter + errorCounter Counter + droppedCounter Counter + blockedCounter Counter +} + +type targetHostOptions struct { + name string + filter Filter + formatter Formatter + maxQueueSize int + metrics *metrics +} + +// TargetHost hosts and manages the lifecycle of a target. +// Incoming log records are queued and formatted before +// being passed to the target. +type TargetHost struct { + target Target + name string + + filter Filter + formatter Formatter + + in chan *LogRec + quit chan struct{} // closed by Shutdown to exit read loop + done chan struct{} // closed when read loop exited + targetMetrics *targetMetrics + + shutdown int32 +} + +func newTargetHost(target Target, options targetHostOptions) (*TargetHost, error) { + host := &TargetHost{ + target: target, + name: options.name, + filter: options.filter, + formatter: options.formatter, + in: make(chan *LogRec, options.maxQueueSize), + quit: make(chan struct{}), + done: make(chan struct{}), + } + + if host.name == "" { + host.name = fmt.Sprintf("%T", target) + } + + if host.filter == nil { + host.filter = &StdFilter{Lvl: Fatal} + } + if host.formatter == nil { + host.formatter = &DefaultFormatter{} + } + + err := host.initMetrics(options.metrics) + if err != nil { + return nil, err + } + + err = target.Init() + if err != nil { + return nil, err + } + + go host.start() + + return host, nil +} + +func (h *TargetHost) initMetrics(metrics *metrics) error { + if metrics == nil { + return nil + } + + var err error + tmetrics := &targetMetrics{} + + if tmetrics.queueSizeGauge, err = metrics.collector.QueueSizeGauge(h.name); err != nil { + return err + } + if tmetrics.loggedCounter, err = metrics.collector.LoggedCounter(h.name); err != nil { + return err + } + if tmetrics.errorCounter, err = metrics.collector.ErrorCounter(h.name); err != nil { + return err + } + if tmetrics.droppedCounter, err = metrics.collector.DroppedCounter(h.name); err != nil { + return err + } + if tmetrics.blockedCounter, err = metrics.collector.BlockedCounter(h.name); err != nil { + return err + } + h.targetMetrics = tmetrics + + updateFreqMillis := metrics.updateFreqMillis + if updateFreqMillis == 0 { + updateFreqMillis = DefMetricsUpdateFreqMillis + } + if updateFreqMillis < 250 { + updateFreqMillis = 250 // don't peg the CPU + } + + go h.startMetricsUpdater(updateFreqMillis) + return nil +} + +// IsLevelEnabled returns true if this target should emit logs for the specified level. +func (h *TargetHost) IsLevelEnabled(lvl Level) (enabled bool, level Level) { + level, enabled = h.filter.GetEnabledLevel(lvl) + return enabled, level +} + +// Shutdown stops processing log records after making best +// effort to flush queue. +func (h *TargetHost) Shutdown(ctx context.Context) error { + if atomic.SwapInt32(&h.shutdown, 1) != 0 { + return errors.New("targetHost shutdown called more than once") + } + + close(h.quit) + + // No more records can be accepted; now wait for read loop to exit. + select { + case <-ctx.Done(): + case <-h.done: + } + + // b.in channel should now be drained. + return h.target.Shutdown() +} + +// Log queues a log record to be output to this target's destination. +func (h *TargetHost) Log(rec *LogRec) { + if atomic.LoadInt32(&h.shutdown) != 0 { + return + } + + lgr := rec.Logger().Logr() + select { + case h.in <- rec: + default: + handler := lgr.options.onTargetQueueFull + if handler != nil && handler(h.target, rec, cap(h.in)) { + h.incDroppedCounter() + return // drop the record + } + h.incBlockedCounter() + + select { + case <-time.After(lgr.options.enqueueTimeout): + lgr.ReportError(fmt.Errorf("target enqueue timeout for log rec [%v]", rec)) + case h.in <- rec: // block until success or timeout + } + } +} + +func (h *TargetHost) setQueueSizeGauge(val float64) { + if h.targetMetrics != nil { + h.targetMetrics.queueSizeGauge.Set(val) + } +} + +func (h *TargetHost) incLoggedCounter() { + if h.targetMetrics != nil { + h.targetMetrics.loggedCounter.Inc() + } +} + +func (h *TargetHost) incErrorCounter() { + if h.targetMetrics != nil { + h.targetMetrics.errorCounter.Inc() + } +} + +func (h *TargetHost) incDroppedCounter() { + if h.targetMetrics != nil { + h.targetMetrics.droppedCounter.Inc() + } +} + +func (h *TargetHost) incBlockedCounter() { + if h.targetMetrics != nil { + h.targetMetrics.blockedCounter.Inc() + } +} + +// String returns a name for this target. +func (h *TargetHost) String() string { + return h.name +} + +// start accepts log records via In channel and writes to the +// supplied target, until Done channel signaled. +func (h *TargetHost) start() { + defer func() { + if r := recover(); r != nil { + fmt.Fprintln(os.Stderr, "TargetHost.start -- ", r) + go h.start() + } else { + close(h.done) + } + }() + + for { + var rec *LogRec + select { + case rec = <-h.in: + if rec.flush != nil { + h.flush(rec.flush) + } else { + err := h.writeRec(rec) + if err != nil { + h.incErrorCounter() + rec.Logger().Logr().ReportError(err) + } else { + h.incLoggedCounter() + } + } + case <-h.quit: + return + } + } +} + +func (h *TargetHost) writeRec(rec *LogRec) error { + level, enabled := h.filter.GetEnabledLevel(rec.Level()) + if !enabled { + // how did we get here? + return fmt.Errorf("level %s not enabled for target %s", rec.Level().Name, h.name) + } + + buf := rec.logger.lgr.BorrowBuffer() + defer rec.logger.lgr.ReleaseBuffer(buf) + + buf, err := h.formatter.Format(rec, level, buf) + if err != nil { + return err + } + + _, err = h.target.Write(buf.Bytes(), rec) + return err +} + +// startMetricsUpdater updates the metrics for any polled values every `updateFreqMillis` seconds until +// target is shut down. +func (h *TargetHost) startMetricsUpdater(updateFreqMillis int64) { + for { + select { + case <-h.done: + return + case <-time.After(time.Duration(updateFreqMillis) * time.Millisecond): + h.setQueueSizeGauge(float64(len(h.in))) + } + } +} + +// flush drains the queue and notifies when done. +func (h *TargetHost) flush(done chan<- struct{}) { + for { + var rec *LogRec + var err error + select { + case rec = <-h.in: + // ignore any redundant flush records. + if rec.flush == nil { + err = h.writeRec(rec) + if err != nil { + h.incErrorCounter() + rec.Logger().Logr().ReportError(err) + } + } + default: + done <- struct{}{} + return + } + } +} |