1 files changed, 124 insertions, 0 deletions
diff --git a/vendor/go.opentelemetry.io/auto/sdk/tracer.go b/vendor/go.opentelemetry.io/auto/sdk/tracer.go
new file mode 100644
index 000000000..cbcfabde3
--- /dev/null
+++ b/vendor/go.opentelemetry.io/auto/sdk/tracer.go
@@ -0,0 +1,124 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package sdk
+
+import (
+	"context"
+	"time"
+
+	"go.opentelemetry.io/otel/trace"
+	"go.opentelemetry.io/otel/trace/noop"
+
+	"go.opentelemetry.io/auto/sdk/internal/telemetry"
+)
+
+type tracer struct {
+	noop.Tracer
+
+	name, schemaURL, version string
+}
+
+var _ trace.Tracer = tracer{}
+
+func (t tracer) Start(ctx context.Context, name string, opts ...trace.SpanStartOption) (context.Context, trace.Span) {
+	var psc trace.SpanContext
+	sampled := true
+	span := new(span)
+
+	// Ask eBPF for sampling decision and span context info.
+	t.start(ctx, span, &psc, &sampled, &span.spanContext)
+
+	span.sampled.Store(sampled)
+
+	ctx = trace.ContextWithSpan(ctx, span)
+
+	if sampled {
+		// Only build traces if sampled.
+		cfg := trace.NewSpanStartConfig(opts...)
+		span.traces, span.span = t.traces(name, cfg, span.spanContext, psc)
+	}
+
+	return ctx, span
+}
+
+// Expected to be implemented in eBPF.
+//
+//go:noinline
+func (t *tracer) start(
+	ctx context.Context,
+	spanPtr *span,
+	psc *trace.SpanContext,
+	sampled *bool,
+	sc *trace.SpanContext,
+) {
+	start(ctx, spanPtr, psc, sampled, sc)
+}
+
+// start is used for testing.
+var start = func(context.Context, *span, *trace.SpanContext, *bool, *trace.SpanContext) {}
+
+func (t tracer) traces(name string, cfg trace.SpanConfig, sc, psc trace.SpanContext) (*telemetry.Traces, *telemetry.Span) {
+	span := &telemetry.Span{
+		TraceID:      telemetry.TraceID(sc.TraceID()),
+		SpanID:       telemetry.SpanID(sc.SpanID()),
+		Flags:        uint32(sc.TraceFlags()),
+		TraceState:   sc.TraceState().String(),
+		ParentSpanID: telemetry.SpanID(psc.SpanID()),
+		Name:         name,
+		Kind:         spanKind(cfg.SpanKind()),
+	}
+
+	span.Attrs, span.DroppedAttrs = convCappedAttrs(maxSpan.Attrs, cfg.Attributes())
+
+	links := cfg.Links()
+	if limit := maxSpan.Links; limit == 0 {
+		span.DroppedLinks = uint32(len(links))
+	} else {
+		if limit > 0 {
+			n := max(len(links)-limit, 0)
+			span.DroppedLinks = uint32(n)
+			links = links[n:]
+		}
+		span.Links = convLinks(links)
+	}
+
+	if t := cfg.Timestamp(); !t.IsZero() {
+		span.StartTime = cfg.Timestamp()
+	} else {
+		span.StartTime = time.Now()
+	}
+
+	return &telemetry.Traces{
+		ResourceSpans: []*telemetry.ResourceSpans{
+			{
+				ScopeSpans: []*telemetry.ScopeSpans{
+					{
+						Scope: &telemetry.Scope{
+							Name:    t.name,
+							Version: t.version,
+						},
+						Spans:     []*telemetry.Span{span},
+						SchemaURL: t.schemaURL,
+					},
+				},
+			},
+		},
+	}, span
+}
+
+func spanKind(kind trace.SpanKind) telemetry.SpanKind {
+	switch kind {
+	case trace.SpanKindInternal:
+		return telemetry.SpanKindInternal
+	case trace.SpanKindServer:
+		return telemetry.SpanKindServer
+	case trace.SpanKindClient:
+		return telemetry.SpanKindClient
+	case trace.SpanKindProducer:
+		return telemetry.SpanKindProducer
+	case trace.SpanKindConsumer:
+		return telemetry.SpanKindConsumer
+	}
+	return telemetry.SpanKind(0) // undefined.
+}