1 /*
2  * Copyright 2024 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include "InputTracingBackendInterface.h"
20 
21 #include "InputTracingPerfettoBackendConfig.h"
22 
23 #include <android/content/pm/IPackageManagerNative.h>
24 #include <ftl/flags.h>
25 #include <perfetto/tracing.h>
26 #include <mutex>
27 #include <set>
28 
29 namespace android::inputdispatcher::trace::impl {
30 
31 /**
32  * The tracing backend that writes events into ongoing Perfetto traces.
33  *
34  * Example shell command to take an input trace from Perfetto:
35  *
36  *   adb shell  perfetto \
37  *    -c - --txt \
38  *    -o /data/misc/perfetto-traces/trace.input-trace \
39  *    <<END
40  *    buffers: {
41  *      size_kb: 5000
42  *      fill_policy: RING_BUFFER
43  *    }
44  *    data_sources: {
45  *      config {
46  *          name: "android.input.inputevent"
47  *      }
48  *    }
49  *    END
50  */
51 class PerfettoBackend : public InputTracingBackendInterface {
52 public:
53     static bool sUseInProcessBackendForTest;
54     static std::function<sp<content::pm::IPackageManagerNative>()> sPackageManagerProvider;
55 
56     explicit PerfettoBackend();
57     ~PerfettoBackend() override = default;
58 
59     void traceKeyEvent(const TracedKeyEvent&, const TracedEventMetadata&) override;
60     void traceMotionEvent(const TracedMotionEvent&, const TracedEventMetadata&) override;
61     void traceWindowDispatch(const WindowDispatchArgs&, const TracedEventMetadata&) override;
62 
63 private:
64     // Implementation of the perfetto data source.
65     // Each instance of the InputEventDataSource represents a different tracing session.
66     // Its lifecycle is controlled by perfetto.
67     class InputEventDataSource : public perfetto::DataSource<InputEventDataSource> {
68     public:
69         explicit InputEventDataSource();
70 
71         void OnSetup(const SetupArgs&) override;
72         void OnStart(const StartArgs&) override;
73         void OnStop(const StopArgs&) override;
74 
75         void initializeUidMap();
76         bool shouldIgnoreTracedInputEvent(const EventType&) const;
getFlags()77         inline ftl::Flags<TraceFlag> getFlags() const { return mConfig.flags; }
78         TraceLevel resolveTraceLevel(const TracedEventMetadata&) const;
79 
80     private:
81         const int32_t mInstanceId;
82         TraceConfig mConfig;
83 
84         bool ruleMatches(const TraceRule&, const TracedEventMetadata&) const;
85 
86         std::optional<std::map<std::string, gui::Uid>> mUidMap;
87     };
88 
89     static std::once_flag sDataSourceRegistrationFlag;
90     static std::atomic<int32_t> sNextInstanceId;
91 };
92 
93 } // namespace android::inputdispatcher::trace::impl
94