Repo created

TMessagesProj/jni/voip/webrtc/base/profiler/profile_builder.h

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+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_PROFILER_PROFILE_BUILDER_H_
+#define BASE_PROFILER_PROFILE_BUILDER_H_
+
+#include <memory>
+
+#include "base/base_export.h"
+#include "base/optional.h"
+#include "base/profiler/frame.h"
+#include "base/profiler/module_cache.h"
+#include "base/time/time.h"
+
+namespace base {
+
+// The ProfileBuilder interface allows the user to record profile information on
+// the fly in whatever format is desired. Functions are invoked by the profiler
+// on its own thread so must not block or perform expensive operations.
+class BASE_EXPORT ProfileBuilder {
+ public:
+  ProfileBuilder() = default;
+  virtual ~ProfileBuilder() = default;
+
+  // Gets the ModuleCache to be used by the StackSamplingProfiler when looking
+  // up modules from addresses.
+  virtual ModuleCache* GetModuleCache() = 0;
+
+  struct BASE_EXPORT MetadataItem {
+    MetadataItem(uint64_t name_hash, Optional<int64_t> key, int64_t value);
+    MetadataItem();
+
+    MetadataItem(const MetadataItem& other);
+    MetadataItem& operator=(const MetadataItem& other);
+
+    // The hash of the metadata name, as produced by HashMetricName().
+    uint64_t name_hash;
+    // The key if specified when setting the item.
+    Optional<int64_t> key;
+    // The value of the metadata item.
+    int64_t value;
+  };
+
+  static constexpr size_t MAX_METADATA_COUNT = 50;
+  typedef std::array<MetadataItem, MAX_METADATA_COUNT> MetadataItemArray;
+
+  class MetadataProvider {
+   public:
+    MetadataProvider() = default;
+    virtual ~MetadataProvider() = default;
+
+    virtual size_t GetItems(ProfileBuilder::MetadataItemArray* const items) = 0;
+  };
+
+  // Records metadata to be associated with the current sample. To avoid
+  // deadlock on locks taken by the suspended profiled thread, implementations
+  // of this method must not execute any code that could take a lock, including
+  // heap allocation or use of CHECK/DCHECK/LOG statements. Generally
+  // implementations should simply atomically copy metadata state to be
+  // associated with the sample.
+  virtual void RecordMetadata(MetadataProvider* metadata_provider) {}
+
+  // Applies the specified metadata |item| to samples collected in the range
+  // [period_start, period_end), iff the profile already captured execution that
+  // covers that range entirely. This restriction avoids bias in the results
+  // towards samples in the middle of the period, at the expense of excluding
+  // periods overlapping the start or end of the profile. |period_end| must be
+  // <= TimeTicks::Now().
+  virtual void ApplyMetadataRetrospectively(TimeTicks period_start,
+                                            TimeTicks period_end,
+                                            const MetadataItem& item) {}
+
+  // Records a new set of frames. Invoked when sampling a sample completes.
+  virtual void OnSampleCompleted(std::vector<Frame> frames,
+                                 TimeTicks sample_timestamp) = 0;
+
+  // Finishes the profile construction with |profile_duration| and
+  // |sampling_period|. Invoked when sampling a profile completes.
+  virtual void OnProfileCompleted(TimeDelta profile_duration,
+                                  TimeDelta sampling_period) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ProfileBuilder);
+};
+
+}  // namespace base
+
+#endif  // BASE_PROFILER_PROFILE_BUILDER_H_