1 files changed, 471 insertions, 0 deletions
diff --git a/vendor/github.com/mattermost/logr/v2/logr.go b/vendor/github.com/mattermost/logr/v2/logr.go
new file mode 100644
index 00000000..82b2a835
--- /dev/null
+++ b/vendor/github.com/mattermost/logr/v2/logr.go
@@ -0,0 +1,471 @@
+package logr
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/wiggin77/merror"
+)
+
+// Logr maintains a list of log targets and accepts incoming
+// log records.  Use `New` to create instances.
+type Logr struct {
+	tmux        sync.RWMutex // targetHosts mutex
+	targetHosts []*TargetHost
+
+	in         chan *LogRec
+	quit       chan struct{} // closed by Shutdown to exit read loop
+	done       chan struct{} // closed when read loop exited
+	lvlCache   levelCache
+	bufferPool sync.Pool
+	options    *options
+
+	metricsMux sync.RWMutex
+	metrics    *metrics
+
+	shutdown int32
+}
+
+// New creates a new Logr instance with one or more options specified.
+// Some options with invalid values can cause an error to be returned,
+// however `logr.New()` using just defaults never errors.
+func New(opts ...Option) (*Logr, error) {
+	options := &options{
+		maxQueueSize:    DefaultMaxQueueSize,
+		enqueueTimeout:  DefaultEnqueueTimeout,
+		shutdownTimeout: DefaultShutdownTimeout,
+		flushTimeout:    DefaultFlushTimeout,
+		maxPooledBuffer: DefaultMaxPooledBuffer,
+	}
+
+	lgr := &Logr{options: options}
+
+	// apply the options
+	for _, opt := range opts {
+		if err := opt(lgr); err != nil {
+			return nil, err
+		}
+	}
+	pkgName := GetLogrPackageName()
+	if pkgName != "" {
+		opt := StackFilter(pkgName, pkgName+"/targets", pkgName+"/formatters")
+		_ = opt(lgr)
+	}
+
+	lgr.in = make(chan *LogRec, lgr.options.maxQueueSize)
+	lgr.quit = make(chan struct{})
+	lgr.done = make(chan struct{})
+
+	if lgr.options.useSyncMapLevelCache {
+		lgr.lvlCache = &syncMapLevelCache{}
+	} else {
+		lgr.lvlCache = &arrayLevelCache{}
+	}
+	lgr.lvlCache.setup()
+
+	lgr.bufferPool = sync.Pool{
+		New: func() interface{} {
+			return new(bytes.Buffer)
+		},
+	}
+
+	lgr.initMetrics(lgr.options.metricsCollector, lgr.options.metricsUpdateFreqMillis)
+
+	go lgr.start()
+
+	return lgr, nil
+}
+
+// AddTarget adds a target to the logger which will receive
+// log records for outputting.
+func (lgr *Logr) AddTarget(target Target, name string, filter Filter, formatter Formatter, maxQueueSize int) error {
+	if lgr.IsShutdown() {
+		return fmt.Errorf("AddTarget called after Logr shut down")
+	}
+
+	lgr.metricsMux.RLock()
+	metrics := lgr.metrics
+	lgr.metricsMux.RUnlock()
+
+	hostOpts := targetHostOptions{
+		name:         name,
+		filter:       filter,
+		formatter:    formatter,
+		maxQueueSize: maxQueueSize,
+		metrics:      metrics,
+	}
+
+	host, err := newTargetHost(target, hostOpts)
+	if err != nil {
+		return err
+	}
+
+	lgr.tmux.Lock()
+	defer lgr.tmux.Unlock()
+
+	lgr.targetHosts = append(lgr.targetHosts, host)
+
+	lgr.ResetLevelCache()
+
+	return nil
+}
+
+// NewLogger creates a Logger using defaults. A `Logger` is light-weight
+// enough to create on-demand, but typically one or more Loggers are
+// created and re-used.
+func (lgr *Logr) NewLogger() Logger {
+	logger := Logger{lgr: lgr}
+	return logger
+}
+
+var levelStatusDisabled = LevelStatus{}
+
+// IsLevelEnabled returns true if at least one target has the specified
+// level enabled. The result is cached so that subsequent checks are fast.
+func (lgr *Logr) IsLevelEnabled(lvl Level) LevelStatus {
+	// No levels enabled after shutdown
+	if atomic.LoadInt32(&lgr.shutdown) != 0 {
+		return levelStatusDisabled
+	}
+
+	// Check cache.
+	status, ok := lgr.lvlCache.get(lvl.ID)
+	if ok {
+		return status
+	}
+
+	status = LevelStatus{}
+
+	// Cache miss; check each target.
+	lgr.tmux.RLock()
+	defer lgr.tmux.RUnlock()
+	for _, host := range lgr.targetHosts {
+		enabled, level := host.IsLevelEnabled(lvl)
+		if enabled {
+			status.Enabled = true
+			if level.Stacktrace || host.formatter.IsStacktraceNeeded() {
+				status.Stacktrace = true
+				break // if both level and stacktrace enabled then no sense checking more targets
+			}
+		}
+	}
+
+	// Cache and return the result.
+	if err := lgr.lvlCache.put(lvl.ID, status); err != nil {
+		lgr.ReportError(err)
+		return LevelStatus{}
+	}
+	return status
+}
+
+// HasTargets returns true only if at least one target exists within the lgr.
+func (lgr *Logr) HasTargets() bool {
+	lgr.tmux.RLock()
+	defer lgr.tmux.RUnlock()
+	return len(lgr.targetHosts) > 0
+}
+
+// TargetInfo provides name and type for a Target.
+type TargetInfo struct {
+	Name string
+	Type string
+}
+
+// TargetInfos enumerates all the targets added to this lgr.
+// The resulting slice represents a snapshot at time of calling.
+func (lgr *Logr) TargetInfos() []TargetInfo {
+	infos := make([]TargetInfo, 0)
+
+	lgr.tmux.RLock()
+	defer lgr.tmux.RUnlock()
+
+	for _, host := range lgr.targetHosts {
+		inf := TargetInfo{
+			Name: host.String(),
+			Type: fmt.Sprintf("%T", host.target),
+		}
+		infos = append(infos, inf)
+	}
+	return infos
+}
+
+// RemoveTargets safely removes one or more targets based on the filtering method.
+// f should return true to delete the target, false to keep it.
+// When removing a target, best effort is made to write any queued log records before
+// closing, with cxt determining how much time can be spent in total.
+// Note, keep the timeout short since this method blocks certain logging operations.
+func (lgr *Logr) RemoveTargets(cxt context.Context, f func(ti TargetInfo) bool) error {
+	errs := merror.New()
+	hosts := make([]*TargetHost, 0)
+
+	lgr.tmux.Lock()
+	defer lgr.tmux.Unlock()
+
+	for _, host := range lgr.targetHosts {
+		inf := TargetInfo{
+			Name: host.String(),
+			Type: fmt.Sprintf("%T", host.target),
+		}
+		if f(inf) {
+			if err := host.Shutdown(cxt); err != nil {
+				errs.Append(err)
+			}
+		} else {
+			hosts = append(hosts, host)
+		}
+	}
+
+	lgr.targetHosts = hosts
+	lgr.ResetLevelCache()
+
+	return errs.ErrorOrNil()
+}
+
+// ResetLevelCache resets the cached results of `IsLevelEnabled`. This is
+// called any time a Target is added or a target's level is changed.
+func (lgr *Logr) ResetLevelCache() {
+	lgr.lvlCache.clear()
+}
+
+// SetMetricsCollector sets (or resets) the metrics collector to be used for gathering
+// metrics for all targets. Only targets added after this call will use the collector.
+//
+// To ensure all targets use a collector, use the `SetMetricsCollector` option when
+// creating the Logr instead, or configure/reconfigure the Logr after calling this method.
+func (lgr *Logr) SetMetricsCollector(collector MetricsCollector, updateFreqMillis int64) {
+	lgr.initMetrics(collector, updateFreqMillis)
+}
+
+// enqueue adds a log record to the logr queue. If the queue is full then
+// this function either blocks or the log record is dropped, depending on
+// the result of calling `OnQueueFull`.
+func (lgr *Logr) enqueue(rec *LogRec) {
+	select {
+	case lgr.in <- rec:
+	default:
+		if lgr.options.onQueueFull != nil && lgr.options.onQueueFull(rec, cap(lgr.in)) {
+			return // drop the record
+		}
+		select {
+		case <-time.After(lgr.options.enqueueTimeout):
+			lgr.ReportError(fmt.Errorf("enqueue timed out for log rec [%v]", rec))
+		case lgr.in <- rec: // block until success or timeout
+		}
+	}
+}
+
+// Flush blocks while flushing the logr queue and all target queues, by
+// writing existing log records to valid targets.
+// Any attempts to add new log records will block until flush is complete.
+// `logr.FlushTimeout` determines how long flush can execute before
+// timing out. Use `IsTimeoutError` to determine if the returned error is
+// due to a timeout.
+func (lgr *Logr) Flush() error {
+	ctx, cancel := context.WithTimeout(context.Background(), lgr.options.flushTimeout)
+	defer cancel()
+	return lgr.FlushWithTimeout(ctx)
+}
+
+// Flush blocks while flushing the logr queue and all target queues, by
+// writing existing log records to valid targets.
+// Any attempts to add new log records will block until flush is complete.
+// Use `IsTimeoutError` to determine if the returned error is
+// due to a timeout.
+func (lgr *Logr) FlushWithTimeout(ctx context.Context) error {
+	if !lgr.HasTargets() {
+		return nil
+	}
+
+	if lgr.IsShutdown() {
+		return errors.New("Flush called on shut down Logr")
+	}
+
+	rec := newFlushLogRec(lgr.NewLogger())
+	lgr.enqueue(rec)
+
+	select {
+	case <-ctx.Done():
+		return newTimeoutError("logr queue flush timeout")
+	case <-rec.flush:
+	}
+	return nil
+}
+
+// IsShutdown returns true if this Logr instance has been shut down.
+// No further log records can be enqueued and no targets added after
+// shutdown.
+func (lgr *Logr) IsShutdown() bool {
+	return atomic.LoadInt32(&lgr.shutdown) != 0
+}
+
+// Shutdown cleanly stops the logging engine after making best efforts
+// to flush all targets. Call this function right before application
+// exit - logr cannot be restarted once shut down.
+// `logr.ShutdownTimeout` determines how long shutdown can execute before
+// timing out. Use `IsTimeoutError` to determine if the returned error is
+// due to a timeout.
+func (lgr *Logr) Shutdown() error {
+	ctx, cancel := context.WithTimeout(context.Background(), lgr.options.shutdownTimeout)
+	defer cancel()
+	return lgr.ShutdownWithTimeout(ctx)
+}
+
+// Shutdown cleanly stops the logging engine after making best efforts
+// to flush all targets. Call this function right before application
+// exit - logr cannot be restarted once shut down.
+// Use `IsTimeoutError` to determine if the returned error is due to a
+// timeout.
+func (lgr *Logr) ShutdownWithTimeout(ctx context.Context) error {
+	if err := lgr.FlushWithTimeout(ctx); err != nil {
+		return err
+	}
+
+	if atomic.SwapInt32(&lgr.shutdown, 1) != 0 {
+		return errors.New("Shutdown called again after shut down")
+	}
+
+	lgr.ResetLevelCache()
+	lgr.stopMetricsUpdater()
+
+	close(lgr.quit)
+
+	errs := merror.New()
+
+	// Wait for read loop to exit
+	select {
+	case <-ctx.Done():
+		errs.Append(newTimeoutError("logr queue shutdown timeout"))
+	case <-lgr.done:
+	}
+
+	// logr.in channel should now be drained to targets and no more log records
+	// can be added.
+	lgr.tmux.RLock()
+	defer lgr.tmux.RUnlock()
+	for _, host := range lgr.targetHosts {
+		err := host.Shutdown(ctx)
+		if err != nil {
+			errs.Append(err)
+		}
+	}
+	return errs.ErrorOrNil()
+}
+
+// ReportError is used to notify the host application of any internal logging errors.
+// If `OnLoggerError` is not nil, it is called with the error, otherwise the error is
+// output to `os.Stderr`.
+func (lgr *Logr) ReportError(err interface{}) {
+	lgr.incErrorCounter()
+
+	if lgr.options.onLoggerError == nil {
+		fmt.Fprintln(os.Stderr, err)
+		return
+	}
+	lgr.options.onLoggerError(fmt.Errorf("%v", err))
+}
+
+// BorrowBuffer borrows a buffer from the pool. Release the buffer to reduce garbage collection.
+func (lgr *Logr) BorrowBuffer() *bytes.Buffer {
+	if lgr.options.disableBufferPool {
+		return &bytes.Buffer{}
+	}
+	return lgr.bufferPool.Get().(*bytes.Buffer)
+}
+
+// ReleaseBuffer returns a buffer to the pool to reduce garbage collection. The buffer is only
+// retained if less than MaxPooledBuffer.
+func (lgr *Logr) ReleaseBuffer(buf *bytes.Buffer) {
+	if !lgr.options.disableBufferPool && buf.Cap() < lgr.options.maxPooledBuffer {
+		buf.Reset()
+		lgr.bufferPool.Put(buf)
+	}
+}
+
+// start selects on incoming log records until shutdown record is received.
+// Incoming log records are fanned out to all log targets.
+func (lgr *Logr) start() {
+	defer func() {
+		if r := recover(); r != nil {
+			lgr.ReportError(r)
+			go lgr.start()
+		} else {
+			close(lgr.done)
+		}
+	}()
+
+	for {
+		var rec *LogRec
+		select {
+		case rec = <-lgr.in:
+			if rec.flush != nil {
+				lgr.flush(rec.flush)
+			} else {
+				rec.prep()
+				lgr.fanout(rec)
+			}
+		case <-lgr.quit:
+			return
+		}
+	}
+}
+
+// fanout pushes a LogRec to all targets.
+func (lgr *Logr) fanout(rec *LogRec) {
+	var host *TargetHost
+	defer func() {
+		if r := recover(); r != nil {
+			lgr.ReportError(fmt.Errorf("fanout failed for target %s, %v", host.String(), r))
+		}
+	}()
+
+	var logged bool
+
+	lgr.tmux.RLock()
+	defer lgr.tmux.RUnlock()
+	for _, host = range lgr.targetHosts {
+		if enabled, _ := host.IsLevelEnabled(rec.Level()); enabled {
+			host.Log(rec)
+			logged = true
+		}
+	}
+
+	if logged {
+		lgr.incLoggedCounter()
+	}
+}
+
+// flush drains the queue and notifies when done.
+func (lgr *Logr) flush(done chan<- struct{}) {
+	// first drain the logr queue.
+loop:
+	for {
+		var rec *LogRec
+		select {
+		case rec = <-lgr.in:
+			if rec.flush == nil {
+				rec.prep()
+				lgr.fanout(rec)
+			}
+		default:
+			break loop
+		}
+	}
+
+	logger := lgr.NewLogger()
+
+	// drain all the targets; block until finished.
+	lgr.tmux.RLock()
+	defer lgr.tmux.RUnlock()
+	for _, host := range lgr.targetHosts {
+		rec := newFlushLogRec(logger)
+		host.Log(rec)
+		<-rec.flush
+	}
+	done <- struct{}{}
+}