Initial

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

vendor/go.opencensus.io/trace/export.go

@@ -0,0 +1,97 @@
+// Copyright 2017, OpenCensus Authors
+//
+// 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 trace
+
+import (
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+// Exporter is a type for functions that receive sampled trace spans.
+//
+// The ExportSpan method should be safe for concurrent use and should return
+// quickly; if an Exporter takes a significant amount of time to process a
+// SpanData, that work should be done on another goroutine.
+//
+// The SpanData should not be modified, but a pointer to it can be kept.
+type Exporter interface {
+	ExportSpan(s *SpanData)
+}
+
+type exportersMap map[Exporter]struct{}
+
+var (
+	exporterMu sync.Mutex
+	exporters  atomic.Value
+)
+
+// RegisterExporter adds to the list of Exporters that will receive sampled
+// trace spans.
+//
+// Binaries can register exporters, libraries shouldn't register exporters.
+func RegisterExporter(e Exporter) {
+	exporterMu.Lock()
+	new := make(exportersMap)
+	if old, ok := exporters.Load().(exportersMap); ok {
+		for k, v := range old {
+			new[k] = v
+		}
+	}
+	new[e] = struct{}{}
+	exporters.Store(new)
+	exporterMu.Unlock()
+}
+
+// UnregisterExporter removes from the list of Exporters the Exporter that was
+// registered with the given name.
+func UnregisterExporter(e Exporter) {
+	exporterMu.Lock()
+	new := make(exportersMap)
+	if old, ok := exporters.Load().(exportersMap); ok {
+		for k, v := range old {
+			new[k] = v
+		}
+	}
+	delete(new, e)
+	exporters.Store(new)
+	exporterMu.Unlock()
+}
+
+// SpanData contains all the information collected by a Span.
+type SpanData struct {
+	SpanContext
+	ParentSpanID SpanID
+	SpanKind     int
+	Name         string
+	StartTime    time.Time
+	// The wall clock time of EndTime will be adjusted to always be offset
+	// from StartTime by the duration of the span.
+	EndTime time.Time
+	// The values of Attributes each have type string, bool, or int64.
+	Attributes    map[string]interface{}
+	Annotations   []Annotation
+	MessageEvents []MessageEvent
+	Status
+	Links                    []Link
+	HasRemoteParent          bool
+	DroppedAttributeCount    int
+	DroppedAnnotationCount   int
+	DroppedMessageEventCount int
+	DroppedLinkCount         int
+
+	// ChildSpanCount holds the number of child span created for this span.
+	ChildSpanCount int
+}