1 files changed, 289 insertions, 0 deletions
diff --git a/vendor/github.com/uber/jaeger-client-go/reporter.go b/vendor/github.com/uber/jaeger-client-go/reporter.go
new file mode 100644
index 000000000..fe6288c4b
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/reporter.go
@@ -0,0 +1,289 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jaeger
+
+import (
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/opentracing/opentracing-go"
+
+	"github.com/uber/jaeger-client-go/log"
+)
+
+// Reporter is called by the tracer when a span is completed to report the span to the tracing collector.
+type Reporter interface {
+	// Report submits a new span to collectors, possibly asynchronously and/or with buffering.
+	Report(span *Span)
+
+	// Close does a clean shutdown of the reporter, flushing any traces that may be buffered in memory.
+	Close()
+}
+
+// ------------------------------
+
+type nullReporter struct{}
+
+// NewNullReporter creates a no-op reporter that ignores all reported spans.
+func NewNullReporter() Reporter {
+	return &nullReporter{}
+}
+
+// Report implements Report() method of Reporter by doing nothing.
+func (r *nullReporter) Report(span *Span) {
+	// no-op
+}
+
+// Close implements Close() method of Reporter by doing nothing.
+func (r *nullReporter) Close() {
+	// no-op
+}
+
+// ------------------------------
+
+type loggingReporter struct {
+	logger Logger
+}
+
+// NewLoggingReporter creates a reporter that logs all reported spans to provided logger.
+func NewLoggingReporter(logger Logger) Reporter {
+	return &loggingReporter{logger}
+}
+
+// Report implements Report() method of Reporter by logging the span to the logger.
+func (r *loggingReporter) Report(span *Span) {
+	r.logger.Infof("Reporting span %+v", span)
+}
+
+// Close implements Close() method of Reporter by doing nothing.
+func (r *loggingReporter) Close() {
+	// no-op
+}
+
+// ------------------------------
+
+// InMemoryReporter is used for testing, and simply collects spans in memory.
+type InMemoryReporter struct {
+	spans []opentracing.Span
+	lock  sync.Mutex
+}
+
+// NewInMemoryReporter creates a reporter that stores spans in memory.
+// NOTE: the Tracer should be created with options.PoolSpans = false.
+func NewInMemoryReporter() *InMemoryReporter {
+	return &InMemoryReporter{
+		spans: make([]opentracing.Span, 0, 10),
+	}
+}
+
+// Report implements Report() method of Reporter by storing the span in the buffer.
+func (r *InMemoryReporter) Report(span *Span) {
+	r.lock.Lock()
+	r.spans = append(r.spans, span)
+	r.lock.Unlock()
+}
+
+// Close implements Close() method of Reporter by doing nothing.
+func (r *InMemoryReporter) Close() {
+	// no-op
+}
+
+// SpansSubmitted returns the number of spans accumulated in the buffer.
+func (r *InMemoryReporter) SpansSubmitted() int {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+	return len(r.spans)
+}
+
+// GetSpans returns accumulated spans as a copy of the buffer.
+func (r *InMemoryReporter) GetSpans() []opentracing.Span {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+	copied := make([]opentracing.Span, len(r.spans))
+	copy(copied, r.spans)
+	return copied
+}
+
+// Reset clears all accumulated spans.
+func (r *InMemoryReporter) Reset() {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+	r.spans = nil
+}
+
+// ------------------------------
+
+type compositeReporter struct {
+	reporters []Reporter
+}
+
+// NewCompositeReporter creates a reporter that ignores all reported spans.
+func NewCompositeReporter(reporters ...Reporter) Reporter {
+	return &compositeReporter{reporters: reporters}
+}
+
+// Report implements Report() method of Reporter by delegating to each underlying reporter.
+func (r *compositeReporter) Report(span *Span) {
+	for _, reporter := range r.reporters {
+		reporter.Report(span)
+	}
+}
+
+// Close implements Close() method of Reporter by closing each underlying reporter.
+func (r *compositeReporter) Close() {
+	for _, reporter := range r.reporters {
+		reporter.Close()
+	}
+}
+
+// ------------- REMOTE REPORTER -----------------
+
+type reporterQueueItemType int
+
+const (
+	defaultQueueSize           = 100
+	defaultBufferFlushInterval = 1 * time.Second
+
+	reporterQueueItemSpan reporterQueueItemType = iota
+	reporterQueueItemClose
+)
+
+type reporterQueueItem struct {
+	itemType reporterQueueItemType
+	span     *Span
+	close    *sync.WaitGroup
+}
+
+type remoteReporter struct {
+	// These fields must be first in the struct because `sync/atomic` expects 64-bit alignment.
+	// Cf. https://github.com/uber/jaeger-client-go/issues/155, https://goo.gl/zW7dgq
+	queueLength int64
+	closed      int64 // 0 - not closed, 1 - closed
+
+	reporterOptions
+
+	sender Transport
+	queue  chan reporterQueueItem
+}
+
+// NewRemoteReporter creates a new reporter that sends spans out of process by means of Sender.
+// Calls to Report(Span) return immediately (side effect: if internal buffer is full the span is dropped).
+// Periodically the transport buffer is flushed even if it hasn't reached max packet size.
+// Calls to Close() block until all spans reported prior to the call to Close are flushed.
+func NewRemoteReporter(sender Transport, opts ...ReporterOption) Reporter {
+	options := reporterOptions{}
+	for _, option := range opts {
+		option(&options)
+	}
+	if options.bufferFlushInterval <= 0 {
+		options.bufferFlushInterval = defaultBufferFlushInterval
+	}
+	if options.logger == nil {
+		options.logger = log.NullLogger
+	}
+	if options.metrics == nil {
+		options.metrics = NewNullMetrics()
+	}
+	if options.queueSize <= 0 {
+		options.queueSize = defaultQueueSize
+	}
+	reporter := &remoteReporter{
+		reporterOptions: options,
+		sender:          sender,
+		queue:           make(chan reporterQueueItem, options.queueSize),
+	}
+	go reporter.processQueue()
+	return reporter
+}
+
+// Report implements Report() method of Reporter.
+// It passes the span to a background go-routine for submission to Jaeger backend.
+// If the internal queue is full, the span is dropped and metrics.ReporterDropped counter is incremented.
+// If Report() is called after the reporter has been Close()-ed, the additional spans will not be
+// sent to the backend, but the metrics.ReporterDropped counter may not reflect them correctly,
+// because some of them may still be successfully added to the queue.
+func (r *remoteReporter) Report(span *Span) {
+	select {
+	case r.queue <- reporterQueueItem{itemType: reporterQueueItemSpan, span: span}:
+		atomic.AddInt64(&r.queueLength, 1)
+	default:
+		r.metrics.ReporterDropped.Inc(1)
+	}
+}
+
+// Close implements Close() method of Reporter by waiting for the queue to be drained.
+func (r *remoteReporter) Close() {
+	if swapped := atomic.CompareAndSwapInt64(&r.closed, 0, 1); !swapped {
+		r.logger.Error("Repeated attempt to close the reporter is ignored")
+		return
+	}
+	r.sendCloseEvent()
+	r.sender.Close()
+}
+
+func (r *remoteReporter) sendCloseEvent() {
+	wg := &sync.WaitGroup{}
+	wg.Add(1)
+	item := reporterQueueItem{itemType: reporterQueueItemClose, close: wg}
+
+	r.queue <- item // if the queue is full we will block until there is space
+	atomic.AddInt64(&r.queueLength, 1)
+	wg.Wait()
+}
+
+// processQueue reads spans from the queue, converts them to Thrift, and stores them in an internal buffer.
+// When the buffer length reaches batchSize, it is flushed by submitting the accumulated spans to Jaeger.
+// Buffer also gets flushed automatically every batchFlushInterval seconds, just in case the tracer stopped
+// reporting new spans.
+func (r *remoteReporter) processQueue() {
+	// flush causes the Sender to flush its accumulated spans and clear the buffer
+	flush := func() {
+		if flushed, err := r.sender.Flush(); err != nil {
+			r.metrics.ReporterFailure.Inc(int64(flushed))
+			r.logger.Error(fmt.Sprintf("error when flushing the buffer: %s", err.Error()))
+		} else if flushed > 0 {
+			r.metrics.ReporterSuccess.Inc(int64(flushed))
+		}
+	}
+
+	timer := time.NewTicker(r.bufferFlushInterval)
+	for {
+		select {
+		case <-timer.C:
+			flush()
+		case item := <-r.queue:
+			atomic.AddInt64(&r.queueLength, -1)
+			switch item.itemType {
+			case reporterQueueItemSpan:
+				span := item.span
+				if flushed, err := r.sender.Append(span); err != nil {
+					r.metrics.ReporterFailure.Inc(int64(flushed))
+					r.logger.Error(fmt.Sprintf("error reporting span %q: %s", span.OperationName(), err.Error()))
+				} else if flushed > 0 {
+					r.metrics.ReporterSuccess.Inc(int64(flushed))
+					// to reduce the number of gauge stats, we only emit queue length on flush
+					r.metrics.ReporterQueueLength.Update(atomic.LoadInt64(&r.queueLength))
+				}
+			case reporterQueueItemClose:
+				timer.Stop()
+				flush()
+				item.close.Done()
+				return
+			}
+		}
+	}
+}