1 files changed, 128 insertions, 0 deletions
diff --git a/vendor/go.opentelemetry.io/otel/sdk/trace/simple_span_processor.go b/vendor/go.opentelemetry.io/otel/sdk/trace/simple_span_processor.go
new file mode 100644
index 000000000..e8530a959
--- /dev/null
+++ b/vendor/go.opentelemetry.io/otel/sdk/trace/simple_span_processor.go
@@ -0,0 +1,128 @@
+// Copyright The OpenTelemetry 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 "go.opentelemetry.io/otel/sdk/trace"
+
+import (
+	"context"
+	"sync"
+
+	"go.opentelemetry.io/otel"
+)
+
+// simpleSpanProcessor is a SpanProcessor that synchronously sends all
+// completed Spans to a trace.Exporter immediately.
+type simpleSpanProcessor struct {
+	exporterMu sync.RWMutex
+	exporter   SpanExporter
+	stopOnce   sync.Once
+}
+
+var _ SpanProcessor = (*simpleSpanProcessor)(nil)
+
+// NewSimpleSpanProcessor returns a new SpanProcessor that will synchronously
+// send completed spans to the exporter immediately.
+//
+// This SpanProcessor is not recommended for production use. The synchronous
+// nature of this SpanProcessor make it good for testing, debugging, or
+// showing examples of other feature, but it will be slow and have a high
+// computation resource usage overhead. The BatchSpanProcessor is recommended
+// for production use instead.
+func NewSimpleSpanProcessor(exporter SpanExporter) SpanProcessor {
+	ssp := &simpleSpanProcessor{
+		exporter: exporter,
+	}
+	return ssp
+}
+
+// OnStart does nothing.
+func (ssp *simpleSpanProcessor) OnStart(context.Context, ReadWriteSpan) {}
+
+// OnEnd immediately exports a ReadOnlySpan.
+func (ssp *simpleSpanProcessor) OnEnd(s ReadOnlySpan) {
+	ssp.exporterMu.RLock()
+	defer ssp.exporterMu.RUnlock()
+
+	if ssp.exporter != nil && s.SpanContext().TraceFlags().IsSampled() {
+		if err := ssp.exporter.ExportSpans(context.Background(), []ReadOnlySpan{s}); err != nil {
+			otel.Handle(err)
+		}
+	}
+}
+
+// Shutdown shuts down the exporter this SimpleSpanProcessor exports to.
+func (ssp *simpleSpanProcessor) Shutdown(ctx context.Context) error {
+	var err error
+	ssp.stopOnce.Do(func() {
+		stopFunc := func(exp SpanExporter) (<-chan error, func()) {
+			done := make(chan error)
+			return done, func() { done <- exp.Shutdown(ctx) }
+		}
+
+		// The exporter field of the simpleSpanProcessor needs to be zeroed to
+		// signal it is shut down, meaning all subsequent calls to OnEnd will
+		// be gracefully ignored. This needs to be done synchronously to avoid
+		// any race condition.
+		//
+		// A closure is used to keep reference to the exporter and then the
+		// field is zeroed. This ensures the simpleSpanProcessor is shut down
+		// before the exporter. This order is important as it avoids a
+		// potential deadlock. If the exporter shut down operation generates a
+		// span, that span would need to be exported. Meaning, OnEnd would be
+		// called and try acquiring the lock that is held here.
+		ssp.exporterMu.Lock()
+		done, shutdown := stopFunc(ssp.exporter)
+		ssp.exporter = nil
+		ssp.exporterMu.Unlock()
+
+		go shutdown()
+
+		// Wait for the exporter to shut down or the deadline to expire.
+		select {
+		case err = <-done:
+		case <-ctx.Done():
+			// It is possible for the exporter to have immediately shut down
+			// and the context to be done simultaneously. In that case this
+			// outer select statement will randomly choose a case. This will
+			// result in a different returned error for similar scenarios.
+			// Instead, double check if the exporter shut down at the same
+			// time and return that error if so. This will ensure consistency
+			// as well as ensure the caller knows the exporter shut down
+			// successfully (they can already determine if the deadline is
+			// expired given they passed the context).
+			select {
+			case err = <-done:
+			default:
+				err = ctx.Err()
+			}
+		}
+	})
+	return err
+}
+
+// ForceFlush does nothing as there is no data to flush.
+func (ssp *simpleSpanProcessor) ForceFlush(context.Context) error {
+	return nil
+}
+
+// MarshalLog is the marshaling function used by the logging system to represent this Span Processor.
+func (ssp *simpleSpanProcessor) MarshalLog() interface{} {
+	return struct {
+		Type     string
+		Exporter SpanExporter
+	}{
+		Type:     "SimpleSpanProcessor",
+		Exporter: ssp.exporter,
+	}
+}