tracing/noop_tracing.h

// Copyright 2026 Google LLC
//
// 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
//
//    https://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.
//

#ifndef THIRD_PARTY_CREDENTIO_TRACING_NOOP_TRACING_H_
#define THIRD_PARTY_CREDENTIO_TRACING_NOOP_TRACING_H_

#include <memory>

#include "absl/base/nullability.h"
#include "absl/status/status.h"
#include "absl/strings/string_view.h"
#include "tracing/span.h"
#include "tracing/tracer.h"
#include "tracing/tracer_factory.h"

namespace credentio_tracing {

// No-op implementation of Span that discards all recorded operations and
// attributes.
class NoopSpan : public Span {
 public:
  // Discards the attribute key-value pair.
  void SetAttribute(absl::string_view, AttributeValue) override {}

  // Discards the point-in-time event.
  void AddEvent(absl::string_view) override {}

  // Discards the status code update.
  void SetStatus(const absl::Status&) override {}

  // Discards span completion.
  void End() override {}
};

// No-op implementation of Tracer that creates NoopSpan instances with sub-5ns
// overhead.
class NoopTracer : public Tracer {
 public:
  using Tracer::StartSpan;

  // Returns a new NoopSpan instance.
  std::unique_ptr<Span> StartSpanImpl(
      absl::string_view span_name,
      const StartSpanOptions& options) const override;
};

// No-op implementation of TracerFactory that returns shared NoopTracer
// instances.
class NoopTracerFactory : public TracerFactory {
 public:
  // Returns a thread-safe singleton NoopTracer instance.
  absl_nonnull std::shared_ptr<Tracer> GetTracer(
      absl::string_view) const override;
};

}  // namespace credentio_tracing

#endif  // THIRD_PARTY_CREDENTIO_TRACING_NOOP_TRACING_H_