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authorWim <wim@42.be>2020-10-19 23:40:00 +0200
committerGitHub <noreply@github.com>2020-10-19 23:40:00 +0200
commit075a84427f6332aab707d283ad770d69f8816032 (patch)
tree0ff9f56a057919f3fe968e57f6f0b1c0d1f85078 /vendor/github.com/mattermost/logr/target.go
parent950f2759bd2b20aa0bdedc3dc9a74d0dafb606d8 (diff)
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Update vendor (#1265)
Diffstat (limited to 'vendor/github.com/mattermost/logr/target.go')
-rw-r--r--vendor/github.com/mattermost/logr/target.go299
1 files changed, 299 insertions, 0 deletions
diff --git a/vendor/github.com/mattermost/logr/target.go b/vendor/github.com/mattermost/logr/target.go
new file mode 100644
index 00000000..f8e7bf75
--- /dev/null
+++ b/vendor/github.com/mattermost/logr/target.go
@@ -0,0 +1,299 @@
+package logr
+
+import (
+ "context"
+ "fmt"
+ "os"
+ "sync"
+ "time"
+)
+
+// Target represents a destination for log records such as file,
+// database, TCP socket, etc.
+type Target interface {
+ // SetName provides an optional name for the target.
+ SetName(name string)
+
+ // IsLevelEnabled returns true if this target should emit
+ // logs for the specified level. Also determines if
+ // a stack trace is required.
+ IsLevelEnabled(Level) (enabled bool, stacktrace bool)
+
+ // Formatter returns the Formatter associated with this Target.
+ Formatter() Formatter
+
+ // Log outputs the log record to this target's destination.
+ Log(rec *LogRec)
+
+ // Shutdown makes best effort to flush target queue and
+ // frees/closes all resources.
+ Shutdown(ctx context.Context) error
+}
+
+// RecordWriter can convert a LogRecord to bytes and output to some data sink.
+type RecordWriter interface {
+ Write(rec *LogRec) error
+}
+
+// Basic provides the basic functionality of a Target that can be used
+// to more easily compose your own Targets. To use, just embed Basic
+// in your target type, implement `RecordWriter`, and call `(*Basic).Start`.
+type Basic struct {
+ target Target
+
+ filter Filter
+ formatter Formatter
+
+ in chan *LogRec
+ done chan struct{}
+ w RecordWriter
+
+ mux sync.RWMutex
+ name string
+
+ metrics bool
+ queueSizeGauge Gauge
+ loggedCounter Counter
+ errorCounter Counter
+ droppedCounter Counter
+ blockedCounter Counter
+
+ metricsUpdateFreqMillis int64
+}
+
+// Start initializes this target helper and starts accepting log records for processing.
+func (b *Basic) Start(target Target, rw RecordWriter, filter Filter, formatter Formatter, maxQueued int) {
+ if filter == nil {
+ filter = &StdFilter{Lvl: Fatal}
+ }
+ if formatter == nil {
+ formatter = &DefaultFormatter{}
+ }
+
+ b.target = target
+ b.filter = filter
+ b.formatter = formatter
+ b.in = make(chan *LogRec, maxQueued)
+ b.done = make(chan struct{}, 1)
+ b.w = rw
+ go b.start()
+
+ if b.hasMetrics() {
+ go b.startMetricsUpdater()
+ }
+}
+
+func (b *Basic) SetName(name string) {
+ b.mux.Lock()
+ defer b.mux.Unlock()
+ b.name = name
+}
+
+// IsLevelEnabled returns true if this target should emit
+// logs for the specified level. Also determines if
+// a stack trace is required.
+func (b *Basic) IsLevelEnabled(lvl Level) (enabled bool, stacktrace bool) {
+ return b.filter.IsEnabled(lvl), b.filter.IsStacktraceEnabled(lvl)
+}
+
+// Formatter returns the Formatter associated with this Target.
+func (b *Basic) Formatter() Formatter {
+ return b.formatter
+}
+
+// Shutdown stops processing log records after making best
+// effort to flush queue.
+func (b *Basic) Shutdown(ctx context.Context) error {
+ // close the incoming channel and wait for read loop to exit.
+ close(b.in)
+ select {
+ case <-ctx.Done():
+ case <-b.done:
+ }
+
+ // b.in channel should now be drained.
+ return nil
+}
+
+// Log outputs the log record to this targets destination.
+func (b *Basic) Log(rec *LogRec) {
+ lgr := rec.Logger().Logr()
+ select {
+ case b.in <- rec:
+ default:
+ handler := lgr.OnTargetQueueFull
+ if handler != nil && handler(b.target, rec, cap(b.in)) {
+ b.incDroppedCounter()
+ return // drop the record
+ }
+ b.incBlockedCounter()
+
+ select {
+ case <-time.After(lgr.enqueueTimeout()):
+ lgr.ReportError(fmt.Errorf("target enqueue timeout for log rec [%v]", rec))
+ case b.in <- rec: // block until success or timeout
+ }
+ }
+}
+
+// Metrics enables metrics collection using the provided MetricsCollector.
+func (b *Basic) EnableMetrics(collector MetricsCollector, updateFreqMillis int64) error {
+ name := fmt.Sprintf("%v", b)
+
+ b.mux.Lock()
+ defer b.mux.Unlock()
+
+ b.metrics = true
+ b.metricsUpdateFreqMillis = updateFreqMillis
+
+ var err error
+
+ if b.queueSizeGauge, err = collector.QueueSizeGauge(name); err != nil {
+ return err
+ }
+ if b.loggedCounter, err = collector.LoggedCounter(name); err != nil {
+ return err
+ }
+ if b.errorCounter, err = collector.ErrorCounter(name); err != nil {
+ return err
+ }
+ if b.droppedCounter, err = collector.DroppedCounter(name); err != nil {
+ return err
+ }
+ if b.blockedCounter, err = collector.BlockedCounter(name); err != nil {
+ return err
+ }
+ return nil
+}
+
+func (b *Basic) hasMetrics() bool {
+ b.mux.RLock()
+ defer b.mux.RUnlock()
+ return b.metrics
+}
+
+func (b *Basic) setQueueSizeGauge(val float64) {
+ b.mux.RLock()
+ defer b.mux.RUnlock()
+ if b.queueSizeGauge != nil {
+ b.queueSizeGauge.Set(val)
+ }
+}
+
+func (b *Basic) incLoggedCounter() {
+ b.mux.RLock()
+ defer b.mux.RUnlock()
+ if b.loggedCounter != nil {
+ b.loggedCounter.Inc()
+ }
+}
+
+func (b *Basic) incErrorCounter() {
+ b.mux.RLock()
+ defer b.mux.RUnlock()
+ if b.errorCounter != nil {
+ b.errorCounter.Inc()
+ }
+}
+
+func (b *Basic) incDroppedCounter() {
+ b.mux.RLock()
+ defer b.mux.RUnlock()
+ if b.droppedCounter != nil {
+ b.droppedCounter.Inc()
+ }
+}
+
+func (b *Basic) incBlockedCounter() {
+ b.mux.RLock()
+ defer b.mux.RUnlock()
+ if b.blockedCounter != nil {
+ b.blockedCounter.Inc()
+ }
+}
+
+// String returns a name for this target. Use `SetName` to specify a name.
+func (b *Basic) String() string {
+ b.mux.RLock()
+ defer b.mux.RUnlock()
+
+ if b.name != "" {
+ return b.name
+ }
+ return fmt.Sprintf("%T", b.target)
+}
+
+// Start accepts log records via In channel and writes to the
+// supplied writer, until Done channel signaled.
+func (b *Basic) start() {
+ defer func() {
+ if r := recover(); r != nil {
+ fmt.Fprintln(os.Stderr, "Basic.start -- ", r)
+ go b.start()
+ }
+ }()
+
+ for rec := range b.in {
+ if rec.flush != nil {
+ b.flush(rec.flush)
+ } else {
+ err := b.w.Write(rec)
+ if err != nil {
+ b.incErrorCounter()
+ rec.Logger().Logr().ReportError(err)
+ } else {
+ b.incLoggedCounter()
+ }
+ }
+ }
+ close(b.done)
+}
+
+// startMetricsUpdater updates the metrics for any polled values every `MetricsUpdateFreqSecs` seconds until
+// target is closed.
+func (b *Basic) startMetricsUpdater() {
+ for {
+ updateFreq := b.getMetricsUpdateFreqMillis()
+ if updateFreq == 0 {
+ updateFreq = DefMetricsUpdateFreqMillis
+ }
+ if updateFreq < 250 {
+ updateFreq = 250 // don't peg the CPU
+ }
+
+ select {
+ case <-b.done:
+ return
+ case <-time.After(time.Duration(updateFreq) * time.Millisecond):
+ b.setQueueSizeGauge(float64(len(b.in)))
+ }
+ }
+}
+
+func (b *Basic) getMetricsUpdateFreqMillis() int64 {
+ b.mux.RLock()
+ defer b.mux.RUnlock()
+ return b.metricsUpdateFreqMillis
+}
+
+// flush drains the queue and notifies when done.
+func (b *Basic) flush(done chan<- struct{}) {
+ for {
+ var rec *LogRec
+ var err error
+ select {
+ case rec = <-b.in:
+ // ignore any redundant flush records.
+ if rec.flush == nil {
+ err = b.w.Write(rec)
+ if err != nil {
+ b.incErrorCounter()
+ rec.Logger().Logr().ReportError(err)
+ }
+ }
+ default:
+ done <- struct{}{}
+ return
+ }
+ }
+}