/*

 * Copyright (C) 2014 Google Inc. All rights reserved.

 *

 * Use of this source code is governed by a BSD-style license that can be

 * found in the LICENSE file.

 */

#ifndef SkEventTracer_DEFINED

#define SkEventTracer_DEFINED

// The class in this header defines the interface between Skia's internal

// tracing macros and an external entity (e.g., Chrome) that will consume them.

// Such an entity should subclass SkEventTracer and provide an instance of

// that event to SkEventTracer::SetInstance.

// If you're looking for the tracing macros to instrument Skia itself, those

// live in src/core/SkTraceEvent.h

#include "include/core/SkTypes.h"

#include <cstdint>

class SK_API SkEventTracer {

public:

    typedef uint64_t Handle;

    /**

     * If this is the first call to SetInstance or GetInstance then the passed instance is

     * installed and true is returned. Otherwise, false is returned. In either case ownership of the

     * tracer is transferred and it will be deleted when no longer needed.

     *

     * Not deleting the tracer on process exit should not cause problems as

     * the whole heap is about to go away with the process. This can also

     * improve performance by reducing the amount of work needed.

     *

     * @param leakTracer Do not delete tracer on process exit.

     */

    static bool SetInstance(SkEventTracer*, bool leakTracer = false);

    /**

     * Gets the event tracer. If this is the first call to SetInstance or GetIntance then a default

     * event tracer is installed and returned.

     */

    static SkEventTracer* GetInstance();

    virtual ~SkEventTracer() = default;

    // The pointer returned from GetCategoryGroupEnabled() points to a

    // value with zero or more of the following bits. Used in this class only.

    // The TRACE_EVENT macros should only use the value as a bool.

    // These values must be in sync with macro values in trace_event.h in chromium.

    enum CategoryGroupEnabledFlags {

        // Category group enabled for the recording mode.

        kEnabledForRecording_CategoryGroupEnabledFlags = 1 << 0,

        // Category group enabled for the monitoring mode.

        kEnabledForMonitoring_CategoryGroupEnabledFlags = 1 << 1,

        // Category group enabled by SetEventCallbackEnabled().

        kEnabledForEventCallback_CategoryGroupEnabledFlags = 1 << 2,

    };

    virtual const uint8_t* getCategoryGroupEnabled(const char* name) = 0;

    virtual const char* getCategoryGroupName(const uint8_t* categoryEnabledFlag) = 0;

    virtual SkEventTracer::Handle

        addTraceEvent(char phase,

                      const uint8_t* categoryEnabledFlag,

                      const char* name,

                      uint64_t id,

                      int32_t numArgs,

                      const char** argNames,

                      const uint8_t* argTypes,

                      const uint64_t* argValues,

                      uint8_t flags) = 0;

    virtual void

        updateTraceEventDuration(const uint8_t* categoryEnabledFlag,

                                 const char* name,

                                 SkEventTracer::Handle handle) = 0;

    // Optional method that can be implemented to allow splitting up traces into different sections.

    virtual void newTracingSection(const char*) {}

protected:

    SkEventTracer() = default;

    SkEventTracer(const SkEventTracer&) = delete;

    SkEventTracer& operator=(const SkEventTracer&) = delete;

};

#endif // SkEventTracer_DEFINED