1 files changed, 664 insertions, 0 deletions
diff --git a/vendor/github.com/mattermost/logr/logr.go b/vendor/github.com/mattermost/logr/logr.go
new file mode 100644
index 00000000..631366a5
--- /dev/null
+++ b/vendor/github.com/mattermost/logr/logr.go
@@ -0,0 +1,664 @@
+package logr
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"sync"
+	"time"
+
+	"github.com/wiggin77/cfg"
+	"github.com/wiggin77/merror"
+)
+
+// Logr maintains a list of log targets and accepts incoming
+// log records.
+type Logr struct {
+	tmux    sync.RWMutex // target mutex
+	targets []Target
+
+	mux                sync.RWMutex
+	maxQueueSizeActual int
+	in                 chan *LogRec
+	done               chan struct{}
+	once               sync.Once
+	shutdown           bool
+	lvlCache           levelCache
+
+	metricsInitOnce  sync.Once
+	metricsCloseOnce sync.Once
+	metricsDone      chan struct{}
+	metrics          MetricsCollector
+	queueSizeGauge   Gauge
+	loggedCounter    Counter
+	errorCounter     Counter
+
+	bufferPool sync.Pool
+
+	// MaxQueueSize is the maximum number of log records that can be queued.
+	// If exceeded, `OnQueueFull` is called which determines if the log
+	// record will be dropped or block until add is successful.
+	// If this is modified, it must be done before `Configure` or
+	// `AddTarget`.  Defaults to DefaultMaxQueueSize.
+	MaxQueueSize int
+
+	// OnLoggerError, when not nil, is called any time an internal
+	// logging error occurs. For example, this can happen when a
+	// target cannot connect to its data sink.
+	OnLoggerError func(error)
+
+	// OnQueueFull, when not nil, is called on an attempt to add
+	// a log record to a full Logr queue.
+	// `MaxQueueSize` can be used to modify the maximum queue size.
+	// This function should return quickly, with a bool indicating whether
+	// the log record should be dropped (true) or block until the log record
+	// is successfully added (false). If nil then blocking (false) is assumed.
+	OnQueueFull func(rec *LogRec, maxQueueSize int) bool
+
+	// OnTargetQueueFull, when not nil, is called on an attempt to add
+	// a log record to a full target queue provided the target supports reporting
+	// this condition.
+	// This function should return quickly, with a bool indicating whether
+	// the log record should be dropped (true) or block until the log record
+	// is successfully added (false). If nil then blocking (false) is assumed.
+	OnTargetQueueFull func(target Target, rec *LogRec, maxQueueSize int) bool
+
+	// OnExit, when not nil, is called when a FatalXXX style log API is called.
+	// When nil, then the default behavior is to cleanly shut down this Logr and
+	// call `os.Exit(code)`.
+	OnExit func(code int)
+
+	// OnPanic, when not nil, is called when a PanicXXX style log API is called.
+	// When nil, then the default behavior is to cleanly shut down this Logr and
+	// call `panic(err)`.
+	OnPanic func(err interface{})
+
+	// EnqueueTimeout is the amount of time a log record can take to be queued.
+	// This only applies to blocking enqueue which happen after `logr.OnQueueFull`
+	// is called and returns false.
+	EnqueueTimeout time.Duration
+
+	// ShutdownTimeout is the amount of time `logr.Shutdown` can execute before
+	// timing out.
+	ShutdownTimeout time.Duration
+
+	// FlushTimeout is the amount of time `logr.Flush` can execute before
+	// timing out.
+	FlushTimeout time.Duration
+
+	// UseSyncMapLevelCache can be set to true before the first target is added
+	// when high concurrency (e.g. >32 cores) is expected. This may improve
+	// performance with large numbers of cores - benchmark for your use case.
+	UseSyncMapLevelCache bool
+
+	// MaxPooledFormatBuffer determines the maximum size of a buffer that can be
+	// pooled. To reduce allocations, the buffers needed during formatting (etc)
+	// are pooled. A very large log item will grow a buffer that could stay in
+	// memory indefinitely. This settings lets you control how big a pooled buffer
+	// can be - anything larger will be garbage collected after use.
+	// Defaults to 1MB.
+	MaxPooledBuffer int
+
+	// DisableBufferPool when true disables the buffer pool. See MaxPooledBuffer.
+	DisableBufferPool bool
+
+	// MetricsUpdateFreqMillis determines how often polled metrics are updated
+	// when metrics are enabled.
+	MetricsUpdateFreqMillis int64
+}
+
+// Configure adds/removes targets via the supplied `Config`.
+func (logr *Logr) Configure(config *cfg.Config) error {
+	// TODO
+	return fmt.Errorf("not implemented yet")
+}
+
+func (logr *Logr) ensureInit() {
+	logr.once.Do(func() {
+		defer func() {
+			go logr.start()
+		}()
+
+		logr.mux.Lock()
+		defer logr.mux.Unlock()
+
+		logr.maxQueueSizeActual = logr.MaxQueueSize
+		if logr.maxQueueSizeActual == 0 {
+			logr.maxQueueSizeActual = DefaultMaxQueueSize
+		}
+
+		if logr.maxQueueSizeActual < 0 {
+			logr.maxQueueSizeActual = 0
+		}
+
+		logr.in = make(chan *LogRec, logr.maxQueueSizeActual)
+		logr.done = make(chan struct{})
+
+		if logr.UseSyncMapLevelCache {
+			logr.lvlCache = &syncMapLevelCache{}
+		} else {
+			logr.lvlCache = &arrayLevelCache{}
+		}
+
+		if logr.MaxPooledBuffer == 0 {
+			logr.MaxPooledBuffer = DefaultMaxPooledBuffer
+		}
+		logr.bufferPool = sync.Pool{
+			New: func() interface{} {
+				return new(bytes.Buffer)
+			},
+		}
+
+		logr.lvlCache.setup()
+	})
+}
+
+// AddTarget adds one or more targets to the logger which will receive
+// log records for outputting.
+func (logr *Logr) AddTarget(targets ...Target) error {
+	if logr.IsShutdown() {
+		return fmt.Errorf("AddTarget called after Logr shut down")
+	}
+
+	logr.ensureInit()
+	metrics := logr.getMetricsCollector()
+	defer logr.ResetLevelCache() // call this after tmux is released
+
+	logr.tmux.Lock()
+	defer logr.tmux.Unlock()
+
+	errs := merror.New()
+	for _, t := range targets {
+		if t == nil {
+			continue
+		}
+
+		logr.targets = append(logr.targets, t)
+		if metrics != nil {
+			if tm, ok := t.(TargetWithMetrics); ok {
+				if err := tm.EnableMetrics(metrics, logr.MetricsUpdateFreqMillis); err != nil {
+					errs.Append(err)
+				}
+			}
+		}
+	}
+	return errs.ErrorOrNil()
+}
+
+// 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 (logr *Logr) NewLogger() Logger {
+	logger := Logger{logr: logr}
+	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 (logr *Logr) IsLevelEnabled(lvl Level) LevelStatus {
+	status, ok := logr.isLevelEnabledFromCache(lvl)
+	if ok {
+		return status
+	}
+
+	// Check each target.
+	logr.tmux.RLock()
+	for _, t := range logr.targets {
+		e, s := t.IsLevelEnabled(lvl)
+		if e {
+			status.Enabled = true
+			if s {
+				status.Stacktrace = true
+				break // if both enabled then no sense checking more targets
+			}
+		}
+	}
+	logr.tmux.RUnlock()
+
+	// Cache and return the result.
+	if err := logr.updateLevelCache(lvl.ID, status); err != nil {
+		logr.ReportError(err)
+		return LevelStatus{}
+	}
+	return status
+}
+
+func (logr *Logr) isLevelEnabledFromCache(lvl Level) (LevelStatus, bool) {
+	logr.mux.RLock()
+	defer logr.mux.RUnlock()
+
+	// Don't accept new log records after shutdown.
+	if logr.shutdown {
+		return levelStatusDisabled, true
+	}
+
+	// Check cache. lvlCache may still be nil if no targets added.
+	if logr.lvlCache == nil {
+		return levelStatusDisabled, true
+	}
+	status, ok := logr.lvlCache.get(lvl.ID)
+	if ok {
+		return status, true
+	}
+	return LevelStatus{}, false
+}
+
+func (logr *Logr) updateLevelCache(id LevelID, status LevelStatus) error {
+	logr.mux.RLock()
+	defer logr.mux.RUnlock()
+	if logr.lvlCache != nil {
+		return logr.lvlCache.put(id, status)
+	}
+	return nil
+}
+
+// HasTargets returns true only if at least one target exists within the Logr.
+func (logr *Logr) HasTargets() bool {
+	logr.tmux.RLock()
+	defer logr.tmux.RUnlock()
+	return len(logr.targets) > 0
+}
+
+// TargetInfo provides name and type for a Target.
+type TargetInfo struct {
+	Name string
+	Type string
+}
+
+// TargetInfos enumerates all the targets added to this Logr.
+// The resulting slice represents a snapshot at time of calling.
+func (logr *Logr) TargetInfos() []TargetInfo {
+	logr.tmux.RLock()
+	defer logr.tmux.RUnlock()
+
+	infos := make([]TargetInfo, 0)
+
+	for _, t := range logr.targets {
+		inf := TargetInfo{
+			Name: fmt.Sprintf("%v", t),
+			Type: fmt.Sprintf("%T", t),
+		}
+		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 (logr *Logr) RemoveTargets(cxt context.Context, f func(ti TargetInfo) bool) error {
+	var removed bool
+	defer func() {
+		if removed {
+			// call this after tmux is released since
+			// it will lock mux and we don't want to
+			// introduce possible deadlock.
+			logr.ResetLevelCache()
+		}
+	}()
+
+	errs := merror.New()
+
+	logr.tmux.Lock()
+	defer logr.tmux.Unlock()
+
+	cp := make([]Target, 0)
+
+	for _, t := range logr.targets {
+		inf := TargetInfo{
+			Name: fmt.Sprintf("%v", t),
+			Type: fmt.Sprintf("%T", t),
+		}
+		if f(inf) {
+			if err := t.Shutdown(cxt); err != nil {
+				errs.Append(err)
+			}
+			removed = true
+		} else {
+			cp = append(cp, t)
+		}
+	}
+	logr.targets = cp
+	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 (logr *Logr) ResetLevelCache() {
+	// Write lock so that new cache entries cannot be stored while we
+	// clear the cache.
+	logr.mux.Lock()
+	defer logr.mux.Unlock()
+	logr.resetLevelCache()
+}
+
+// resetLevelCache empties the level cache without locking.
+// mux.Lock must be held before calling this function.
+func (logr *Logr) resetLevelCache() {
+	// lvlCache may still be nil if no targets added.
+	if logr.lvlCache != nil {
+		logr.lvlCache.clear()
+	}
+}
+
+// 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 (logr *Logr) enqueue(rec *LogRec) {
+	if logr.in == nil {
+		logr.ReportError(fmt.Errorf("AddTarget or Configure must be called before enqueue"))
+	}
+
+	select {
+	case logr.in <- rec:
+	default:
+		if logr.OnQueueFull != nil && logr.OnQueueFull(rec, logr.maxQueueSizeActual) {
+			return // drop the record
+		}
+		select {
+		case <-time.After(logr.enqueueTimeout()):
+			logr.ReportError(fmt.Errorf("enqueue timed out for log rec [%v]", rec))
+		case logr.in <- rec: // block until success or timeout
+		}
+	}
+}
+
+// exit is called by one of the FatalXXX style APIS. If `logr.OnExit` is not nil
+// then that method is called, otherwise the default behavior is to shut down this
+// Logr cleanly then call `os.Exit(code)`.
+func (logr *Logr) exit(code int) {
+	if logr.OnExit != nil {
+		logr.OnExit(code)
+		return
+	}
+
+	if err := logr.Shutdown(); err != nil {
+		logr.ReportError(err)
+	}
+	os.Exit(code)
+}
+
+// panic is called by one of the PanicXXX style APIS. If `logr.OnPanic` is not nil
+// then that method is called, otherwise the default behavior is to shut down this
+// Logr cleanly then call `panic(err)`.
+func (logr *Logr) panic(err interface{}) {
+	if logr.OnPanic != nil {
+		logr.OnPanic(err)
+		return
+	}
+
+	if err := logr.Shutdown(); err != nil {
+		logr.ReportError(err)
+	}
+	panic(err)
+}
+
+// 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 (logr *Logr) Flush() error {
+	ctx, cancel := context.WithTimeout(context.Background(), logr.flushTimeout())
+	defer cancel()
+	return logr.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 (logr *Logr) FlushWithTimeout(ctx context.Context) error {
+	if !logr.HasTargets() {
+		return nil
+	}
+
+	if logr.IsShutdown() {
+		return errors.New("Flush called on shut down Logr")
+	}
+
+	rec := newFlushLogRec(logr.NewLogger())
+	logr.enqueue(rec)
+
+	select {
+	case <-ctx.Done():
+		return newTimeoutError("logr queue shutdown 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 (logr *Logr) IsShutdown() bool {
+	logr.mux.Lock()
+	defer logr.mux.Unlock()
+	return logr.shutdown
+}
+
+// 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 (logr *Logr) Shutdown() error {
+	ctx, cancel := context.WithTimeout(context.Background(), logr.shutdownTimeout())
+	defer cancel()
+	return logr.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 (logr *Logr) ShutdownWithTimeout(ctx context.Context) error {
+	logr.mux.Lock()
+	if logr.shutdown {
+		logr.mux.Unlock()
+		return errors.New("Shutdown called again after shut down")
+	}
+	logr.shutdown = true
+	logr.resetLevelCache()
+	logr.mux.Unlock()
+
+	logr.metricsCloseOnce.Do(func() {
+		if logr.metricsDone != nil {
+			close(logr.metricsDone)
+		}
+	})
+
+	errs := merror.New()
+
+	// close the incoming channel and wait for read loop to exit.
+	if logr.in != nil {
+		close(logr.in)
+		select {
+		case <-ctx.Done():
+			errs.Append(newTimeoutError("logr queue shutdown timeout"))
+		case <-logr.done:
+		}
+	}
+
+	// logr.in channel should now be drained to targets and no more log records
+	// can be added.
+	logr.tmux.RLock()
+	defer logr.tmux.RUnlock()
+	for _, t := range logr.targets {
+		err := t.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 (logr *Logr) ReportError(err interface{}) {
+	logr.incErrorCounter()
+
+	if logr.OnLoggerError == nil {
+		fmt.Fprintln(os.Stderr, err)
+		return
+	}
+	logr.OnLoggerError(fmt.Errorf("%v", err))
+}
+
+// BorrowBuffer borrows a buffer from the pool. Release the buffer to reduce garbage collection.
+func (logr *Logr) BorrowBuffer() *bytes.Buffer {
+	if logr.DisableBufferPool {
+		return &bytes.Buffer{}
+	}
+	return logr.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 (logr *Logr) ReleaseBuffer(buf *bytes.Buffer) {
+	if !logr.DisableBufferPool && buf.Cap() < logr.MaxPooledBuffer {
+		buf.Reset()
+		logr.bufferPool.Put(buf)
+	}
+}
+
+// enqueueTimeout returns amount of time a log record can take to be queued.
+// This only applies to blocking enqueue which happen after `logr.OnQueueFull` is called
+// and returns false.
+func (logr *Logr) enqueueTimeout() time.Duration {
+	if logr.EnqueueTimeout == 0 {
+		return DefaultEnqueueTimeout
+	}
+	return logr.EnqueueTimeout
+}
+
+// shutdownTimeout returns the timeout duration for `logr.Shutdown`.
+func (logr *Logr) shutdownTimeout() time.Duration {
+	if logr.ShutdownTimeout == 0 {
+		return DefaultShutdownTimeout
+	}
+	return logr.ShutdownTimeout
+}
+
+// flushTimeout returns the timeout duration for `logr.Flush`.
+func (logr *Logr) flushTimeout() time.Duration {
+	if logr.FlushTimeout == 0 {
+		return DefaultFlushTimeout
+	}
+	return logr.FlushTimeout
+}
+
+// start selects on incoming log records until done channel signals.
+// Incoming log records are fanned out to all log targets.
+func (logr *Logr) start() {
+	defer func() {
+		if r := recover(); r != nil {
+			logr.ReportError(r)
+			go logr.start()
+		}
+	}()
+
+	for rec := range logr.in {
+		if rec.flush != nil {
+			logr.flush(rec.flush)
+		} else {
+			rec.prep()
+			logr.fanout(rec)
+		}
+	}
+	close(logr.done)
+}
+
+// startMetricsUpdater updates the metrics for any polled values every `MetricsUpdateFreqSecs` seconds until
+// logr is closed.
+func (logr *Logr) startMetricsUpdater() {
+	for {
+		updateFreq := logr.getMetricsUpdateFreqMillis()
+		if updateFreq == 0 {
+			updateFreq = DefMetricsUpdateFreqMillis
+		}
+		if updateFreq < 250 {
+			updateFreq = 250 // don't peg the CPU
+		}
+
+		select {
+		case <-logr.metricsDone:
+			return
+		case <-time.After(time.Duration(updateFreq) * time.Millisecond):
+			logr.setQueueSizeGauge(float64(len(logr.in)))
+		}
+	}
+}
+
+func (logr *Logr) getMetricsUpdateFreqMillis() int64 {
+	logr.mux.RLock()
+	defer logr.mux.RUnlock()
+	return logr.MetricsUpdateFreqMillis
+}
+
+// fanout pushes a LogRec to all targets.
+func (logr *Logr) fanout(rec *LogRec) {
+	var target Target
+	defer func() {
+		if r := recover(); r != nil {
+			logr.ReportError(fmt.Errorf("fanout failed for target %s, %v", target, r))
+		}
+	}()
+
+	var logged bool
+	defer func() {
+		if logged {
+			logr.incLoggedCounter() // call this after tmux is released
+		}
+	}()
+
+	logr.tmux.RLock()
+	defer logr.tmux.RUnlock()
+	for _, target = range logr.targets {
+		if enabled, _ := target.IsLevelEnabled(rec.Level()); enabled {
+			target.Log(rec)
+			logged = true
+		}
+	}
+}
+
+// flush drains the queue and notifies when done.
+func (logr *Logr) flush(done chan<- struct{}) {
+	// first drain the logr queue.
+loop:
+	for {
+		var rec *LogRec
+		select {
+		case rec = <-logr.in:
+			if rec.flush == nil {
+				rec.prep()
+				logr.fanout(rec)
+			}
+		default:
+			break loop
+		}
+	}
+
+	logger := logr.NewLogger()
+
+	// drain all the targets; block until finished.
+	logr.tmux.RLock()
+	defer logr.tmux.RUnlock()
+	for _, target := range logr.targets {
+		rec := newFlushLogRec(logger)
+		target.Log(rec)
+		<-rec.flush
+	}
+	done <- struct{}{}
+}