InputTracer: Read trace configuration from perfetto

Bug: 210460522
Test: manual with perfetto
Change-Id: I5eba37fd2dbf76f92c91504fed403642761cdb1d
diff --git a/services/inputflinger/dispatcher/trace/AndroidInputEventProtoConverter.cpp b/services/inputflinger/dispatcher/trace/AndroidInputEventProtoConverter.cpp
index cee741c..ddc4cb3 100644
--- a/services/inputflinger/dispatcher/trace/AndroidInputEventProtoConverter.cpp
+++ b/services/inputflinger/dispatcher/trace/AndroidInputEventProtoConverter.cpp
@@ -21,6 +21,23 @@
 
 namespace android::inputdispatcher::trace {
 
+namespace {
+
+using namespace ftl::flag_operators;
+
+// The trace config to use for maximal tracing.
+const impl::TraceConfig CONFIG_TRACE_ALL{
+        .flags = impl::TraceFlag::TRACE_DISPATCHER_INPUT_EVENTS |
+                impl::TraceFlag::TRACE_DISPATCHER_WINDOW_DISPATCH,
+        .rules = {impl::TraceRule{.level = impl::TraceLevel::TRACE_LEVEL_COMPLETE,
+                                  .matchAllPackages = {},
+                                  .matchAnyPackages = {},
+                                  .matchSecure{},
+                                  .matchImeConnectionActive = {}}},
+};
+
+} // namespace
+
 void AndroidInputEventProtoConverter::toProtoMotionEvent(const TracedMotionEvent& event,
                                                          proto::AndroidMotionEvent& outProto) {
     outProto.set_event_id(event.id);
@@ -105,4 +122,65 @@
     }
 }
 
+impl::TraceConfig AndroidInputEventProtoConverter::parseConfig(
+        proto::AndroidInputEventConfig::Decoder& protoConfig) {
+    if (protoConfig.has_mode() &&
+        protoConfig.mode() == proto::AndroidInputEventConfig::TRACE_MODE_TRACE_ALL) {
+        // User has requested the preset for maximal tracing
+        return CONFIG_TRACE_ALL;
+    }
+
+    impl::TraceConfig config;
+
+    // Parse trace flags
+    if (protoConfig.has_trace_dispatcher_input_events() &&
+        protoConfig.trace_dispatcher_input_events()) {
+        config.flags |= impl::TraceFlag::TRACE_DISPATCHER_INPUT_EVENTS;
+    }
+    if (protoConfig.has_trace_dispatcher_window_dispatch() &&
+        protoConfig.trace_dispatcher_window_dispatch()) {
+        config.flags |= impl::TraceFlag::TRACE_DISPATCHER_WINDOW_DISPATCH;
+    }
+
+    // Parse trace rules
+    auto rulesIt = protoConfig.rules();
+    while (rulesIt) {
+        proto::AndroidInputEventConfig::TraceRule::Decoder protoRule{rulesIt->as_bytes()};
+        config.rules.emplace_back();
+        auto& rule = config.rules.back();
+
+        rule.level = protoRule.has_trace_level()
+                ? static_cast<impl::TraceLevel>(protoRule.trace_level())
+                : impl::TraceLevel::TRACE_LEVEL_NONE;
+
+        if (protoRule.has_match_all_packages()) {
+            auto pkgIt = protoRule.match_all_packages();
+            while (pkgIt) {
+                rule.matchAllPackages.emplace_back(pkgIt->as_std_string());
+                pkgIt++;
+            }
+        }
+
+        if (protoRule.has_match_any_packages()) {
+            auto pkgIt = protoRule.match_any_packages();
+            while (pkgIt) {
+                rule.matchAnyPackages.emplace_back(pkgIt->as_std_string());
+                pkgIt++;
+            }
+        }
+
+        if (protoRule.has_match_secure()) {
+            rule.matchSecure = protoRule.match_secure();
+        }
+
+        if (protoRule.has_match_ime_connection_active()) {
+            rule.matchImeConnectionActive = protoRule.match_ime_connection_active();
+        }
+
+        rulesIt++;
+    }
+
+    return config;
+}
+
 } // namespace android::inputdispatcher::trace
diff --git a/services/inputflinger/dispatcher/trace/AndroidInputEventProtoConverter.h b/services/inputflinger/dispatcher/trace/AndroidInputEventProtoConverter.h
index ab5f9ca..bab1701 100644
--- a/services/inputflinger/dispatcher/trace/AndroidInputEventProtoConverter.h
+++ b/services/inputflinger/dispatcher/trace/AndroidInputEventProtoConverter.h
@@ -16,9 +16,11 @@
 
 #pragma once
 
+#include <perfetto/config/android/android_input_event_config.pbzero.h>
 #include <perfetto/trace/android/android_input_event.pbzero.h>
 
 #include "InputTracingBackendInterface.h"
+#include "InputTracingPerfettoBackendConfig.h"
 
 namespace proto = perfetto::protos::pbzero;
 
@@ -34,6 +36,8 @@
     static void toProtoKeyEvent(const TracedKeyEvent& event, proto::AndroidKeyEvent& outProto);
     static void toProtoWindowDispatchEvent(const WindowDispatchArgs&,
                                            proto::AndroidWindowInputDispatchEvent& outProto);
+
+    static impl::TraceConfig parseConfig(proto::AndroidInputEventConfig::Decoder& protoConfig);
 };
 
 } // namespace android::inputdispatcher::trace
diff --git a/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.cpp b/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.cpp
index 8ef9ca5..e8d89e0 100644
--- a/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.cpp
+++ b/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.cpp
@@ -33,12 +33,25 @@
 
 // --- PerfettoBackend::InputEventDataSource ---
 
-void PerfettoBackend::InputEventDataSource::OnStart(const perfetto::DataSourceBase::StartArgs&) {
-    LOG(INFO) << "Starting perfetto trace for: " << INPUT_EVENT_TRACE_DATA_SOURCE_NAME;
+PerfettoBackend::InputEventDataSource::InputEventDataSource() : mInstanceId(sNextInstanceId++) {}
+
+void PerfettoBackend::InputEventDataSource::OnSetup(const InputEventDataSource::SetupArgs& args) {
+    LOG(INFO) << "Setting up perfetto trace for: " << INPUT_EVENT_TRACE_DATA_SOURCE_NAME
+              << ", instanceId: " << mInstanceId;
+    const auto rawConfig = args.config->android_input_event_config_raw();
+    auto protoConfig = perfetto::protos::pbzero::AndroidInputEventConfig::Decoder{rawConfig};
+
+    mConfig = AndroidInputEventProtoConverter::parseConfig(protoConfig);
 }
 
-void PerfettoBackend::InputEventDataSource::OnStop(const perfetto::DataSourceBase::StopArgs&) {
-    LOG(INFO) << "Stopping perfetto trace for: " << INPUT_EVENT_TRACE_DATA_SOURCE_NAME;
+void PerfettoBackend::InputEventDataSource::OnStart(const InputEventDataSource::StartArgs&) {
+    LOG(INFO) << "Starting perfetto trace for: " << INPUT_EVENT_TRACE_DATA_SOURCE_NAME
+              << ", instanceId: " << mInstanceId;
+}
+
+void PerfettoBackend::InputEventDataSource::OnStop(const InputEventDataSource::StopArgs&) {
+    LOG(INFO) << "Stopping perfetto trace for: " << INPUT_EVENT_TRACE_DATA_SOURCE_NAME
+              << ", instanceId: " << mInstanceId;
     InputEventDataSource::Trace([&](InputEventDataSource::TraceContext ctx) { ctx.Flush(); });
 }
 
@@ -46,6 +59,8 @@
 
 std::once_flag PerfettoBackend::sDataSourceRegistrationFlag{};
 
+std::atomic<int32_t> PerfettoBackend::sNextInstanceId{1};
+
 PerfettoBackend::PerfettoBackend() {
     // Use a once-flag to ensure that the data source is only registered once per boot, since
     // we never unregister the InputEventDataSource.
diff --git a/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.h b/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.h
index d455375..7e1e36a 100644
--- a/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.h
+++ b/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.h
@@ -18,6 +18,8 @@
 
 #include "InputTracingBackendInterface.h"
 
+#include "InputTracingPerfettoBackendConfig.h"
+
 #include <perfetto/tracing.h>
 #include <mutex>
 
@@ -52,15 +54,24 @@
     void traceMotionEvent(const TracedMotionEvent&, const TracedEventArgs&) override;
     void traceWindowDispatch(const WindowDispatchArgs&, const TracedEventArgs&) override;
 
+private:
+    // Implementation of the perfetto data source.
+    // Each instance of the InputEventDataSource represents a different tracing session.
     class InputEventDataSource : public perfetto::DataSource<InputEventDataSource> {
     public:
-        void OnSetup(const SetupArgs&) override {}
+        explicit InputEventDataSource();
+
+        void OnSetup(const SetupArgs&) override;
         void OnStart(const StartArgs&) override;
         void OnStop(const StopArgs&) override;
+
+    private:
+        const int32_t mInstanceId;
+        TraceConfig mConfig;
     };
 
-private:
     static std::once_flag sDataSourceRegistrationFlag;
+    static std::atomic<int32_t> sNextInstanceId;
 };
 
 } // namespace android::inputdispatcher::trace::impl
diff --git a/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackendConfig.h b/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackendConfig.h
new file mode 100644
index 0000000..536e32b
--- /dev/null
+++ b/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackendConfig.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * 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
+ *
+ *      http://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.
+ */
+
+#pragma once
+
+#include <ftl/enum.h>
+#include <ftl/flags.h>
+#include <perfetto/config/android/android_input_event_config.pbzero.h>
+#include <vector>
+
+namespace android::inputdispatcher::trace::impl {
+
+/** Flags representing the configurations that are enabled in the trace. */
+enum class TraceFlag : uint32_t {
+    // Trace details about input events processed by InputDispatcher.
+    TRACE_DISPATCHER_INPUT_EVENTS = 0x1,
+    // Trace details about an event being sent to a window by InputDispatcher.
+    TRACE_DISPATCHER_WINDOW_DISPATCH = 0x2,
+
+    ftl_last = TRACE_DISPATCHER_WINDOW_DISPATCH,
+};
+
+/** Representation of AndroidInputEventConfig::TraceLevel. */
+using TraceLevel = perfetto::protos::pbzero::AndroidInputEventConfig::TraceLevel;
+
+/** Representation of AndroidInputEventConfig::TraceRule. */
+struct TraceRule {
+    TraceLevel level;
+
+    std::vector<std::string> matchAllPackages;
+    std::vector<std::string> matchAnyPackages;
+    std::optional<bool> matchSecure;
+    std::optional<bool> matchImeConnectionActive;
+};
+
+/**
+ * A complete configuration for a tracing session.
+ *
+ * The trace rules are applied as documented in the perfetto config:
+ *   /external/perfetto/protos/perfetto/config/android/android_input_event_config.proto
+ */
+struct TraceConfig {
+    ftl::Flags<TraceFlag> flags;
+    std::vector<TraceRule> rules;
+};
+
+} // namespace android::inputdispatcher::trace::impl