1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
|
// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef COMPONENTS_UI_DEVTOOLS_TRACING_AGENT_H_
#define COMPONENTS_UI_DEVTOOLS_TRACING_AGENT_H_
#include <memory>
#include <string>
#include <utility>
#include "base/functional/callback.h"
#include "base/memory/weak_ptr.h"
#include "base/trace_event/trace_config.h"
#include "components/ui_devtools/devtools_base_agent.h"
#include "components/ui_devtools/tracing.h"
namespace base {
class RepeatingTimer;
}
namespace ui_devtools {
class ConnectorDelegate;
// This class is used for tracing in the ui_devtools performance panel.
// A lot of the code is based on TracingHandler from
// content/browser/devtools/protocol/tracing_handler.h.
class UI_DEVTOOLS_EXPORT TracingAgent
: public UiDevToolsBaseAgent<protocol::Tracing::Metainfo> {
public:
explicit TracingAgent(std::unique_ptr<ConnectorDelegate> connector);
TracingAgent(const TracingAgent&) = delete;
TracingAgent& operator=(const TracingAgent&) = delete;
~TracingAgent() override;
void set_gpu_pid(base::ProcessId pid) { gpu_pid_ = pid; }
// Sends the Tracing JSON data in the form of CBOR to the frontend.
void OnTraceDataCollected(std::unique_ptr<std::string> trace_fragment);
// Signals that tracing is complete and notifies any data loss to the
// frontend.
void OnTraceComplete();
// Tracing::Backend:
void start(std::optional<std::string> categories,
std::optional<std::string> options,
std::optional<double> buffer_usage_reporting_interval,
std::unique_ptr<StartCallback> callback) override;
protocol::Response end() override;
private:
class DevToolsTraceEndpointProxy;
class PerfettoTracingSession;
struct TraceDataBufferState {
public:
std::string data;
size_t pos = 0;
int open_braces = 0;
bool in_string = false;
bool slashed = false;
size_t offset = 0;
};
// Returns the longest prefix of |trace_fragment| that is a valid list and
// stores the rest (tail) to be used in subsequent calls. This returns the
// longest prefix of the tail prepended to |trace_fragment| next time. Assumes
// that the input is a potentially incomplete string representation of a comma
// separated list of JSON objects.
std::string UpdateTraceDataBuffer(const std::string& trace_fragment);
// Sets TraceConfig to only collect trace events for the specified processes
// in this method. Currently, only the browser process is specified. Starts
// tracing by attempting to enable tracing via perfetto.
void StartTracing(std::unique_ptr<StartCallback>);
// Called when we have successfully started tracing with Perfetto session.
void OnRecordingEnabled(std::unique_ptr<StartCallback> callback);
// Edits tracing data to use the normal devtools frontend logic to display
// the performance metrics. Without this, it will use the devtools generic
// trace logic to display the performance metrics.
void EditTraceDataForFrontend();
// Sets up repeating timer to request the trace buffer status from the
// perfetto tracing session. If usage_reporting_interval is too small, it will
// be clipped to a minimum value.
void SetupTimer(double usage_reporting_interval);
// Sends frontend information on buffer usage such as how much of the buffer
// is used and the approximate number of events in the trace log.
void OnBufferUsage(float percent_full, size_t approximate_event_count);
// Gets updated buffer usage from the perfetto tracing session.
void UpdateBufferUsage();
// Resets buffer usage and passes the trace data to the trace data endpoint
// consumer.
void StopTracing(const scoped_refptr<DevToolsTraceEndpointProxy>& endpoint,
const std::string& agent_label);
std::unique_ptr<base::RepeatingTimer> buffer_usage_poll_timer_;
std::unique_ptr<ConnectorDelegate> connector_;
base::ProcessId gpu_pid_ = base::kNullProcessId;
bool did_initiate_recording_ = false;
double buffer_usage_reporting_interval_ = 0;
base::trace_event::TraceConfig trace_config_;
std::unique_ptr<PerfettoTracingSession> perfetto_session_;
TraceDataBufferState trace_data_buffer_state_;
base::WeakPtrFactory<TracingAgent> weak_factory_{this};
};
} // namespace ui_devtools
#endif // COMPONENTS_UI_DEVTOOLS_TRACING_AGENT_H_
|
