Add libtracing_perfetto for tracing using Perfetto SDK

libtracing_perfetto internally uses the Perfetto SDK or
libcutils based on an aconfig flag.

Test: atest libtracing_perfetto_tests
Bug: 303199244
Ignore-AOSP-First: Internal feature
Change-Id: I9922d11607051ff22777e3df12b8f877a765dfa7
diff --git a/libs/tracing_perfetto/tests/utils.cpp b/libs/tracing_perfetto/tests/utils.cpp
new file mode 100644
index 0000000..9c42028
--- /dev/null
+++ b/libs/tracing_perfetto/tests/utils.cpp
@@ -0,0 +1,219 @@
+/*
+ * 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.
+ */
+
+// Copied from //external/perfetto/src/shared_lib/test/utils.cc
+
+#include "utils.h"
+
+#include "perfetto/public/abi/heap_buffer.h"
+#include "perfetto/public/pb_msg.h"
+#include "perfetto/public/pb_utils.h"
+#include "perfetto/public/protos/config/data_source_config.pzc.h"
+#include "perfetto/public/protos/config/trace_config.pzc.h"
+#include "perfetto/public/protos/config/track_event/track_event_config.pzc.h"
+#include "perfetto/public/tracing_session.h"
+
+namespace perfetto {
+namespace shlib {
+namespace test_utils {
+namespace {
+
+std::string ToHexChars(uint8_t val) {
+  std::string ret;
+  uint8_t high_nibble = (val & 0xF0) >> 4;
+  uint8_t low_nibble = (val & 0xF);
+  static const char hex_chars[] = "0123456789ABCDEF";
+  ret.push_back(hex_chars[high_nibble]);
+  ret.push_back(hex_chars[low_nibble]);
+  return ret;
+}
+
+}  // namespace
+
+TracingSession TracingSession::Builder::Build() {
+  struct PerfettoPbMsgWriter writer;
+  struct PerfettoHeapBuffer* hb = PerfettoHeapBufferCreate(&writer.writer);
+
+  struct perfetto_protos_TraceConfig cfg;
+  PerfettoPbMsgInit(&cfg.msg, &writer);
+
+  {
+    struct perfetto_protos_TraceConfig_BufferConfig buffers;
+    perfetto_protos_TraceConfig_begin_buffers(&cfg, &buffers);
+
+    perfetto_protos_TraceConfig_BufferConfig_set_size_kb(&buffers, 1024);
+
+    perfetto_protos_TraceConfig_end_buffers(&cfg, &buffers);
+  }
+
+  {
+    struct perfetto_protos_TraceConfig_DataSource data_sources;
+    perfetto_protos_TraceConfig_begin_data_sources(&cfg, &data_sources);
+
+    {
+      struct perfetto_protos_DataSourceConfig ds_cfg;
+      perfetto_protos_TraceConfig_DataSource_begin_config(&data_sources,
+                                                          &ds_cfg);
+
+      perfetto_protos_DataSourceConfig_set_cstr_name(&ds_cfg,
+                                                     data_source_name_.c_str());
+      if (!enabled_categories_.empty() && !disabled_categories_.empty()) {
+        perfetto_protos_TrackEventConfig te_cfg;
+        perfetto_protos_DataSourceConfig_begin_track_event_config(&ds_cfg,
+                                                                  &te_cfg);
+        for (const std::string& cat : enabled_categories_) {
+          perfetto_protos_TrackEventConfig_set_enabled_categories(
+              &te_cfg, cat.data(), cat.size());
+        }
+        for (const std::string& cat : disabled_categories_) {
+          perfetto_protos_TrackEventConfig_set_disabled_categories(
+              &te_cfg, cat.data(), cat.size());
+        }
+        perfetto_protos_DataSourceConfig_end_track_event_config(&ds_cfg,
+                                                                &te_cfg);
+      }
+
+      perfetto_protos_TraceConfig_DataSource_end_config(&data_sources, &ds_cfg);
+    }
+
+    perfetto_protos_TraceConfig_end_data_sources(&cfg, &data_sources);
+  }
+  size_t cfg_size = PerfettoStreamWriterGetWrittenSize(&writer.writer);
+  std::unique_ptr<uint8_t[]> ser(new uint8_t[cfg_size]);
+  PerfettoHeapBufferCopyInto(hb, &writer.writer, ser.get(), cfg_size);
+  PerfettoHeapBufferDestroy(hb, &writer.writer);
+
+  struct PerfettoTracingSessionImpl* ts =
+      PerfettoTracingSessionCreate(PERFETTO_BACKEND_IN_PROCESS);
+
+  PerfettoTracingSessionSetup(ts, ser.get(), cfg_size);
+
+  PerfettoTracingSessionStartBlocking(ts);
+
+  return TracingSession::Adopt(ts);
+}
+
+TracingSession TracingSession::Adopt(struct PerfettoTracingSessionImpl* session) {
+  TracingSession ret;
+  ret.session_ = session;
+  ret.stopped_ = std::make_unique<WaitableEvent>();
+  PerfettoTracingSessionSetStopCb(
+      ret.session_,
+      [](struct PerfettoTracingSessionImpl*, void* arg) {
+        static_cast<WaitableEvent*>(arg)->Notify();
+      },
+      ret.stopped_.get());
+  return ret;
+}
+
+TracingSession::TracingSession(TracingSession&& other) noexcept {
+  session_ = other.session_;
+  other.session_ = nullptr;
+  stopped_ = std::move(other.stopped_);
+  other.stopped_ = nullptr;
+}
+
+TracingSession::~TracingSession() {
+  if (!session_) {
+    return;
+  }
+  if (!stopped_->IsNotified()) {
+    PerfettoTracingSessionStopBlocking(session_);
+    stopped_->WaitForNotification();
+  }
+  PerfettoTracingSessionDestroy(session_);
+}
+
+bool TracingSession::FlushBlocking(uint32_t timeout_ms) {
+  WaitableEvent notification;
+  bool result;
+  auto* cb = new std::function<void(bool)>([&](bool success) {
+    result = success;
+    notification.Notify();
+  });
+  PerfettoTracingSessionFlushAsync(
+      session_, timeout_ms,
+      [](PerfettoTracingSessionImpl*, bool success, void* user_arg) {
+        auto* f = reinterpret_cast<std::function<void(bool)>*>(user_arg);
+        (*f)(success);
+        delete f;
+      },
+      cb);
+  notification.WaitForNotification();
+  return result;
+}
+
+void TracingSession::WaitForStopped() {
+  stopped_->WaitForNotification();
+}
+
+void TracingSession::StopBlocking() {
+  PerfettoTracingSessionStopBlocking(session_);
+}
+
+std::vector<uint8_t> TracingSession::ReadBlocking() {
+  std::vector<uint8_t> data;
+  PerfettoTracingSessionReadTraceBlocking(
+      session_,
+      [](struct PerfettoTracingSessionImpl*, const void* trace_data,
+         size_t size, bool, void* user_arg) {
+        auto& dst = *static_cast<std::vector<uint8_t>*>(user_arg);
+        auto* src = static_cast<const uint8_t*>(trace_data);
+        dst.insert(dst.end(), src, src + size);
+      },
+      &data);
+  return data;
+}
+
+}  // namespace test_utils
+}  // namespace shlib
+}  // namespace perfetto
+
+void PrintTo(const PerfettoPbDecoderField& field, std::ostream* pos) {
+  std::ostream& os = *pos;
+  PerfettoPbDecoderStatus status =
+      static_cast<PerfettoPbDecoderStatus>(field.status);
+  switch (status) {
+    case PERFETTO_PB_DECODER_ERROR:
+      os << "MALFORMED PROTOBUF";
+      break;
+    case PERFETTO_PB_DECODER_DONE:
+      os << "DECODER DONE";
+      break;
+    case PERFETTO_PB_DECODER_OK:
+      switch (field.wire_type) {
+        case PERFETTO_PB_WIRE_TYPE_DELIMITED:
+          os << "\"";
+          for (size_t i = 0; i < field.value.delimited.len; i++) {
+            os << perfetto::shlib::test_utils::ToHexChars(
+                      field.value.delimited.start[i])
+               << " ";
+          }
+          os << "\"";
+          break;
+        case PERFETTO_PB_WIRE_TYPE_VARINT:
+          os << "varint: " << field.value.integer64;
+          break;
+        case PERFETTO_PB_WIRE_TYPE_FIXED32:
+          os << "fixed32: " << field.value.integer32;
+          break;
+        case PERFETTO_PB_WIRE_TYPE_FIXED64:
+          os << "fixed64: " << field.value.integer64;
+          break;
+      }
+      break;
+  }
+}