src/tracing/console_interceptor.cc - third_party/perfetto - Git at Google

 /*
  * Copyright (C) 2020 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.
  */

 #include "perfetto/tracing/console_interceptor.h"

 #include "perfetto/ext/base/file_utils.h"
 #include "perfetto/ext/base/hash.h"
 #include "perfetto/ext/base/optional.h"
 #include "perfetto/ext/base/scoped_file.h"
 #include "perfetto/ext/base/utils.h"
 #include "perfetto/tracing/internal/track_event_internal.h"

 #include "protos/perfetto/common/interceptor_descriptor.gen.h"
 #include "protos/perfetto/config/data_source_config.gen.h"
 #include "protos/perfetto/config/interceptor_config.gen.h"
 #include "protos/perfetto/config/interceptors/console_config.pbzero.h"
 #include "protos/perfetto/trace/interned_data/interned_data.pbzero.h"
 #include "protos/perfetto/trace/trace_packet.pbzero.h"
 #include "protos/perfetto/trace/trace_packet_defaults.pbzero.h"
 #include "protos/perfetto/trace/track_event/process_descriptor.pbzero.h"
 #include "protos/perfetto/trace/track_event/thread_descriptor.pbzero.h"
 #include "protos/perfetto/trace/track_event/track_descriptor.pbzero.h"
 #include "protos/perfetto/trace/track_event/track_event.pbzero.h"

 #include <algorithm>
 #include <cmath>
 #include <tuple>

 namespace perfetto {

 // sRGB color.
 struct ConsoleColor {
   uint8_t r;
   uint8_t g;
   uint8_t b;
 };

 namespace {

 int g_output_fd_for_testing;

 // Google Turbo colormap.
 constexpr std::array<ConsoleColor, 16> kTurboColors = {{
     ConsoleColor{0x30, 0x12, 0x3b},
     ConsoleColor{0x40, 0x40, 0xa1},
     ConsoleColor{0x46, 0x6b, 0xe3},
     ConsoleColor{0x41, 0x93, 0xfe},
     ConsoleColor{0x28, 0xbb, 0xeb},
     ConsoleColor{0x17, 0xdc, 0xc2},
     ConsoleColor{0x32, 0xf1, 0x97},
     ConsoleColor{0x6d, 0xfd, 0x62},
     ConsoleColor{0xa4, 0xfc, 0x3b},
     ConsoleColor{0xcd, 0xeb, 0x34},
     ConsoleColor{0xed, 0xcf, 0x39},
     ConsoleColor{0xfd, 0xab, 0x33},
     ConsoleColor{0xfa, 0x7d, 0x20},
     ConsoleColor{0xea, 0x50, 0x0d},
     ConsoleColor{0xd0, 0x2f, 0x04},
     ConsoleColor{0xa9, 0x15, 0x01},
 }};

 constexpr size_t kHueBits = 4;
 constexpr uint32_t kMaxHue = kTurboColors.size() << kHueBits;
 constexpr uint8_t kLightness = 128u;
 constexpr ConsoleColor kWhiteColor{0xff, 0xff, 0xff};

 const char kDim[] = "\x1b[90m";
 const char kDefault[] = "\x1b[39m";
 const char kReset[] = "\x1b[0m";

 #define FMT_RGB_SET "\x1b[38;2;%d;%d;%dm"
 #define FMT_RGB_SET_BG "\x1b[48;2;%d;%d;%dm"

 ConsoleColor Mix(ConsoleColor a, ConsoleColor b, uint8_t ratio) {
   return {
       static_cast<uint8_t>(a.r + (((b.r - a.r) * ratio) >> 8)),
       static_cast<uint8_t>(a.g + (((b.g - a.g) * ratio) >> 8)),
       static_cast<uint8_t>(a.b + (((b.b - a.b) * ratio) >> 8)),
   };
 }

 ConsoleColor HueToRGB(uint32_t hue) {
   PERFETTO_DCHECK(hue < kMaxHue);
   uint32_t c1 = hue >> kHueBits;
   uint32_t c2 =
       std::min(static_cast<uint32_t>(kTurboColors.size() - 1), c1 + 1u);
   uint32_t ratio = hue & ((1 << kHueBits) - 1);
   return Mix(kTurboColors[c1], kTurboColors[c2],
              static_cast<uint8_t>(ratio | (ratio << kHueBits)));
 }

 uint32_t CounterToHue(uint32_t counter) {
   // We split the hue space into 8 segments, reversing the order of bits so
   // successive counter values will be far from each other.
   uint32_t reversed =
       ((counter & 0x7) >> 2) | ((counter & 0x3)) | ((counter & 0x1) << 2);
   return reversed * kMaxHue / 8;
 }

 }  // namespace

 class ConsoleInterceptor::Delegate : public TrackEventStateTracker::Delegate {
  public:
   explicit Delegate(InterceptorContext&);
   ~Delegate() override;

   TrackEventStateTracker::SessionState* GetSessionState() override;
   void OnTrackUpdated(TrackEventStateTracker::Track&) override;
   void OnTrackEvent(const TrackEventStateTracker::Track&,
                     const TrackEventStateTracker::ParsedTrackEvent&) override;

  private:
   using SelfHandle = LockedHandle<ConsoleInterceptor>;

   InterceptorContext& context_;
   base::Optional<SelfHandle> locked_self_;
 };

 ConsoleInterceptor::~ConsoleInterceptor() = default;

 ConsoleInterceptor::ThreadLocalState::ThreadLocalState(
     ThreadLocalStateArgs& args) {
   if (auto self = args.GetInterceptorLocked()) {
     start_time_ns = self->start_time_ns_;
     use_colors = self->use_colors_;
     fd = self->fd_;
   }
 }

 ConsoleInterceptor::ThreadLocalState::~ThreadLocalState() = default;

 ConsoleInterceptor::Delegate::Delegate(InterceptorContext& context)
     : context_(context) {}
 ConsoleInterceptor::Delegate::~Delegate() = default;

 TrackEventStateTracker::SessionState*
 ConsoleInterceptor::Delegate::GetSessionState() {
   // When the session state is retrieved for the first time, it is cached (and
   // kept locked) until we return from OnTracePacket. This avoids having to lock
   // and unlock the instance multiple times per invocation.
   if (locked_self_.has_value())
     return &locked_self_.value()->session_state_;
   locked_self_ =
       base::make_optional<SelfHandle>(context_.GetInterceptorLocked());
   return &locked_self_.value()->session_state_;
 }

 void ConsoleInterceptor::Delegate::OnTrackUpdated(
     TrackEventStateTracker::Track& track) {
   auto track_color = HueToRGB(CounterToHue(track.index));
   std::array<char, 16> title;
   if (!track.name.empty()) {
     snprintf(title.data(), title.size(), "%s", track.name.c_str());
   } else if (track.pid && track.tid) {
     snprintf(title.data(), title.size(), "%u:%u",
              static_cast<uint32_t>(track.pid),
              static_cast<uint32_t>(track.tid));
   } else if (track.pid) {
     snprintf(title.data(), title.size(), "%" PRId64, track.pid);
   } else {
     snprintf(title.data(), title.size(), "%" PRIu64, track.uuid);
   }
   int title_width = static_cast<int>(title.size());

   auto& tls = context_.GetThreadLocalState();
   std::array<char, 128> message_prefix{};
   ssize_t written = 0;
   if (tls.use_colors) {
     written = snprintf(message_prefix.data(), message_prefix.size(),
                        FMT_RGB_SET_BG " %s%s %-*.*s", track_color.r,
                        track_color.g, track_color.b, kReset, kDim, title_width,
                        title_width, title.data());
   } else {
     written = snprintf(message_prefix.data(), message_prefix.size(), "%-*.*s",
                        title_width + 2, title_width, title.data());
   }
   if (written < 0)
     written = message_prefix.size();
   track.user_data.assign(message_prefix.begin(),
                          message_prefix.begin() + written);
 }

 void ConsoleInterceptor::Delegate::OnTrackEvent(
     const TrackEventStateTracker::Track& track,
     const TrackEventStateTracker::ParsedTrackEvent& event) {
   // Start printing.
   auto& tls = context_.GetThreadLocalState();
   tls.buffer_pos = 0;

   // Print timestamp and track identifier.
   SetColor(context_, kDim);
   Printf(context_, "[%7.3lf] %.*s",
          static_cast<double>(event.timestamp_ns - tls.start_time_ns) / 1e9,
          static_cast<int>(track.user_data.size()), track.user_data.data());

   // Print category.
   Printf(context_, "%-5.*s ",
          std::min(5, static_cast<int>(event.category.size)),
          event.category.data);

   // Print stack depth.
   for (size_t i = 0; i < event.stack_depth; i++) {
     Printf(context_, "-  ");
   }

   // Print slice name.
   auto slice_color = HueToRGB(event.name_hash % kMaxHue);
   auto highlight_color = Mix(slice_color, kWhiteColor, kLightness);
   if (event.track_event.type() == protos::pbzero::TrackEvent::TYPE_SLICE_END) {
     SetColor(context_, kDefault);
     Printf(context_, "} ");
   }
   SetColor(context_, highlight_color);
   Printf(context_, "%.*s", static_cast<int>(event.name.size), event.name.data);
   SetColor(context_, kReset);
   if (event.track_event.type() ==
       protos::pbzero::TrackEvent::TYPE_SLICE_BEGIN) {
     SetColor(context_, kDefault);
     Printf(context_, " {");
   }

   // Print annotations.
   if (event.track_event.has_debug_annotations()) {
     PrintDebugAnnotations(context_, event.track_event, slice_color,
                           highlight_color);
   }

   // TODO(skyostil): Print typed arguments.

   // Print duration for longer events.
   constexpr uint64_t kNsPerMillisecond = 1000000u;
   if (event.duration_ns >= 10 * kNsPerMillisecond) {
     SetColor(context_, kDim);
     Printf(context_, " +%" PRIu64 "ms", event.duration_ns / kNsPerMillisecond);
   }
   SetColor(context_, kReset);
   Printf(context_, "\n");
 }

 // static
 void ConsoleInterceptor::Register() {
   perfetto::protos::gen::InterceptorDescriptor desc;
   desc.set_name("console");
   Interceptor<ConsoleInterceptor>::Register(desc);
 }

 // static
 void ConsoleInterceptor::SetOutputFdForTesting(int fd) {
   g_output_fd_for_testing = fd;
 }

 void ConsoleInterceptor::OnSetup(const SetupArgs& args) {
   int fd = STDOUT_FILENO;
   if (g_output_fd_for_testing)
     fd = g_output_fd_for_testing;
 #if !PERFETTO_BUILDFLAG(PERFETTO_OS_WIN) && \
     !PERFETTO_BUILDFLAG(PERFETTO_OS_WASM)
   bool use_colors = isatty(fd);
 #else
   bool use_colors = false;
 #endif
   protos::pbzero::ConsoleConfig::Decoder config(
       args.config.interceptor_config().console_config_raw());
   if (config.has_enable_colors())
     use_colors = config.enable_colors();
   if (config.output() == protos::pbzero::ConsoleConfig::OUTPUT_STDOUT) {
     fd = STDOUT_FILENO;
   } else if (config.output() == protos::pbzero::ConsoleConfig::OUTPUT_STDERR) {
     fd = STDERR_FILENO;
   }
   fd_ = fd;
   use_colors_ = use_colors;
 }

 void ConsoleInterceptor::OnStart(const StartArgs&) {
   start_time_ns_ = internal::TrackEventInternal::GetTimeNs();
 }

 void ConsoleInterceptor::OnStop(const StopArgs&) {}

 // static
 void ConsoleInterceptor::OnTracePacket(InterceptorContext context) {
   {
     auto& tls = context.GetThreadLocalState();
     Delegate delegate(context);
     perfetto::protos::pbzero::TracePacket::Decoder packet(
         context.packet_data.data, context.packet_data.size);
     TrackEventStateTracker::ProcessTracePacket(delegate, tls.sequence_state,
                                                packet);
   }  // (Potential) lock scope for session state.
   Flush(context);
 }

 // static
 void ConsoleInterceptor::Printf(InterceptorContext& context,
                                 const char* format,
                                 ...) {
   auto& tls = context.GetThreadLocalState();
   ssize_t remaining = static_cast<ssize_t>(tls.message_buffer.size()) -
                       static_cast<ssize_t>(tls.buffer_pos);
   int written = 0;
   if (remaining > 0) {
     va_list args;
     va_start(args, format);
     written = vsnprintf(&tls.message_buffer[tls.buffer_pos],
                         static_cast<size_t>(remaining), format, args);
     PERFETTO_DCHECK(written >= 0);
     va_end(args);
   }

   // In case of buffer overflow, flush to the fd and write the latest message to
   // it directly instead.
   if (remaining <= 0 || written > remaining) {
     FILE* output = (tls.fd == STDOUT_FILENO) ? stdout : stderr;
     if (g_output_fd_for_testing) {
       output = fdopen(dup(g_output_fd_for_testing), "w");
     }
     Flush(context);
     va_list args;
     va_start(args, format);
     vfprintf(output, format, args);
     va_end(args);
     if (g_output_fd_for_testing) {
       fclose(output);
     }
   } else if (written > 0) {
     tls.buffer_pos += static_cast<size_t>(written);
   }
 }

 // static
 void ConsoleInterceptor::Flush(InterceptorContext& context) {
   auto& tls = context.GetThreadLocalState();
   ssize_t res = base::WriteAll(tls.fd, &tls.message_buffer[0], tls.buffer_pos);
   PERFETTO_DCHECK(res == static_cast<ssize_t>(tls.buffer_pos));
   tls.buffer_pos = 0;
 }

 // static
 void ConsoleInterceptor::SetColor(InterceptorContext& context,
                                   const ConsoleColor& color) {
   auto& tls = context.GetThreadLocalState();
   if (!tls.use_colors)
     return;
   Printf(context, FMT_RGB_SET, color.r, color.g, color.b);
 }

 // static
 void ConsoleInterceptor::SetColor(InterceptorContext& context,
                                   const char* color) {
   auto& tls = context.GetThreadLocalState();
   if (!tls.use_colors)
     return;
   Printf(context, "%s", color);
 }

 // static
 void ConsoleInterceptor::PrintDebugAnnotations(
     InterceptorContext& context,
     const protos::pbzero::TrackEvent_Decoder& track_event,
     const ConsoleColor& slice_color,
     const ConsoleColor& highlight_color) {
   SetColor(context, slice_color);
   Printf(context, "(");

   bool is_first = true;
   for (auto it = track_event.debug_annotations(); it; it++) {
     perfetto::protos::pbzero::DebugAnnotation::Decoder annotation(*it);
     SetColor(context, slice_color);
     if (!is_first)
       Printf(context, ", ");

     PrintDebugAnnotationName(context, annotation);
     Printf(context, ":");

     SetColor(context, highlight_color);
     PrintDebugAnnotationValue(context, annotation);

     is_first = false;
   }
   SetColor(context, slice_color);
   Printf(context, ")");
 }

 // static
 void ConsoleInterceptor::PrintDebugAnnotationName(
     InterceptorContext& context,
     const perfetto::protos::pbzero::DebugAnnotation::Decoder& annotation) {
   auto& tls = context.GetThreadLocalState();
   protozero::ConstChars name{};
   if (annotation.name_iid()) {
     name.data =
         tls.sequence_state.debug_annotation_names[annotation.name_iid()].data();
     name.size =
         tls.sequence_state.debug_annotation_names[annotation.name_iid()].size();
   } else if (annotation.has_name()) {
     name.data = annotation.name().data;
     name.size = annotation.name().size;
   }
   Printf(context, "%.*s", static_cast<int>(name.size), name.data);
 }

 // static
 void ConsoleInterceptor::PrintDebugAnnotationValue(
     InterceptorContext& context,
     const perfetto::protos::pbzero::DebugAnnotation::Decoder& annotation) {
   if (annotation.has_bool_value()) {
     Printf(context, "%s", annotation.bool_value() ? "true" : "false");
   } else if (annotation.has_uint_value()) {
     Printf(context, "%" PRIu64, annotation.uint_value());
   } else if (annotation.has_int_value()) {
     Printf(context, "%" PRId64, annotation.int_value());
   } else if (annotation.has_double_value()) {
     Printf(context, "%f", annotation.double_value());
   } else if (annotation.has_string_value()) {
     Printf(context, "%.*s", static_cast<int>(annotation.string_value().size),
            annotation.string_value().data);
   } else if (annotation.has_pointer_value()) {
     Printf(context, "%p", reinterpret_cast<void*>(annotation.pointer_value()));
   } else if (annotation.has_legacy_json_value()) {
     Printf(context, "%.*s",
            static_cast<int>(annotation.legacy_json_value().size),
            annotation.legacy_json_value().data);
   } else if (annotation.has_dict_entries()) {
     Printf(context, "{");
     bool is_first = true;
     for (auto it = annotation.dict_entries(); it; ++it) {
       if (!is_first)
         Printf(context, ", ");
       perfetto::protos::pbzero::DebugAnnotation::Decoder key_value(*it);
       PrintDebugAnnotationName(context, key_value);
       Printf(context, ":");
       PrintDebugAnnotationValue(context, key_value);
       is_first = false;
     }
     Printf(context, "}");
   } else if (annotation.has_array_values()) {
     Printf(context, "[");
     bool is_first = true;
     for (auto it = annotation.array_values(); it; ++it) {
       if (!is_first)
         Printf(context, ", ");
       perfetto::protos::pbzero::DebugAnnotation::Decoder key_value(*it);
       PrintDebugAnnotationValue(context, key_value);
       is_first = false;
     }
     Printf(context, "]");
   } else {
     Printf(context, "{}");
   }
 }

 }  // namespace perfetto
	/*
	* Copyright (C) 2020 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.
	*/

	#include "perfetto/tracing/console_interceptor.h"

	#include "perfetto/ext/base/file_utils.h"
	#include "perfetto/ext/base/hash.h"
	#include "perfetto/ext/base/optional.h"
	#include "perfetto/ext/base/scoped_file.h"
	#include "perfetto/ext/base/utils.h"
	#include "perfetto/tracing/internal/track_event_internal.h"

	#include "protos/perfetto/common/interceptor_descriptor.gen.h"
	#include "protos/perfetto/config/data_source_config.gen.h"
	#include "protos/perfetto/config/interceptor_config.gen.h"
	#include "protos/perfetto/config/interceptors/console_config.pbzero.h"
	#include "protos/perfetto/trace/interned_data/interned_data.pbzero.h"
	#include "protos/perfetto/trace/trace_packet.pbzero.h"
	#include "protos/perfetto/trace/trace_packet_defaults.pbzero.h"
	#include "protos/perfetto/trace/track_event/process_descriptor.pbzero.h"
	#include "protos/perfetto/trace/track_event/thread_descriptor.pbzero.h"
	#include "protos/perfetto/trace/track_event/track_descriptor.pbzero.h"
	#include "protos/perfetto/trace/track_event/track_event.pbzero.h"

	#include <algorithm>
	#include <cmath>
	#include <tuple>

	namespace perfetto {

	// sRGB color.
	struct ConsoleColor {
	uint8_t r;
	uint8_t g;
	uint8_t b;
	};

	namespace {

	int g_output_fd_for_testing;

	// Google Turbo colormap.
	constexpr std::array<ConsoleColor, 16> kTurboColors = {{
	ConsoleColor{0x30, 0x12, 0x3b},
	ConsoleColor{0x40, 0x40, 0xa1},
	ConsoleColor{0x46, 0x6b, 0xe3},
	ConsoleColor{0x41, 0x93, 0xfe},
	ConsoleColor{0x28, 0xbb, 0xeb},
	ConsoleColor{0x17, 0xdc, 0xc2},
	ConsoleColor{0x32, 0xf1, 0x97},
	ConsoleColor{0x6d, 0xfd, 0x62},
	ConsoleColor{0xa4, 0xfc, 0x3b},
	ConsoleColor{0xcd, 0xeb, 0x34},
	ConsoleColor{0xed, 0xcf, 0x39},
	ConsoleColor{0xfd, 0xab, 0x33},
	ConsoleColor{0xfa, 0x7d, 0x20},
	ConsoleColor{0xea, 0x50, 0x0d},
	ConsoleColor{0xd0, 0x2f, 0x04},
	ConsoleColor{0xa9, 0x15, 0x01},
	}};

	constexpr size_t kHueBits = 4;
	constexpr uint32_t kMaxHue = kTurboColors.size() << kHueBits;
	constexpr uint8_t kLightness = 128u;
	constexpr ConsoleColor kWhiteColor{0xff, 0xff, 0xff};

	const char kDim[] = "\x1b[90m";
	const char kDefault[] = "\x1b[39m";
	const char kReset[] = "\x1b[0m";

	#define FMT_RGB_SET "\x1b[38;2;%d;%d;%dm"
	#define FMT_RGB_SET_BG "\x1b[48;2;%d;%d;%dm"

	ConsoleColor Mix(ConsoleColor a, ConsoleColor b, uint8_t ratio) {
	return {
	static_cast<uint8_t>(a.r + (((b.r - a.r) * ratio) >> 8)),
	static_cast<uint8_t>(a.g + (((b.g - a.g) * ratio) >> 8)),
	static_cast<uint8_t>(a.b + (((b.b - a.b) * ratio) >> 8)),
	};
	}

	ConsoleColor HueToRGB(uint32_t hue) {
	PERFETTO_DCHECK(hue < kMaxHue);
	uint32_t c1 = hue >> kHueBits;
	uint32_t c2 =
	std::min(static_cast<uint32_t>(kTurboColors.size() - 1), c1 + 1u);
	uint32_t ratio = hue & ((1 << kHueBits) - 1);
	return Mix(kTurboColors[c1], kTurboColors[c2],
	static_cast<uint8_t>(ratio \| (ratio << kHueBits)));
	}

	uint32_t CounterToHue(uint32_t counter) {
	// We split the hue space into 8 segments, reversing the order of bits so
	// successive counter values will be far from each other.
	uint32_t reversed =
	((counter & 0x7) >> 2) \| ((counter & 0x3)) \| ((counter & 0x1) << 2);
	return reversed * kMaxHue / 8;
	}

	} // namespace

	class ConsoleInterceptor::Delegate : public TrackEventStateTracker::Delegate {
	public:
	explicit Delegate(InterceptorContext&);
	~Delegate() override;

	TrackEventStateTracker::SessionState* GetSessionState() override;
	void OnTrackUpdated(TrackEventStateTracker::Track&) override;
	void OnTrackEvent(const TrackEventStateTracker::Track&,
	const TrackEventStateTracker::ParsedTrackEvent&) override;

	private:
	using SelfHandle = LockedHandle<ConsoleInterceptor>;

	InterceptorContext& context_;
	base::Optional<SelfHandle> locked_self_;
	};

	ConsoleInterceptor::~ConsoleInterceptor() = default;

	ConsoleInterceptor::ThreadLocalState::ThreadLocalState(
	ThreadLocalStateArgs& args) {
	if (auto self = args.GetInterceptorLocked()) {
	start_time_ns = self->start_time_ns_;
	use_colors = self->use_colors_;
	fd = self->fd_;
	}
	}

	ConsoleInterceptor::ThreadLocalState::~ThreadLocalState() = default;

	ConsoleInterceptor::Delegate::Delegate(InterceptorContext& context)
	: context_(context) {}
	ConsoleInterceptor::Delegate::~Delegate() = default;

	TrackEventStateTracker::SessionState*
	ConsoleInterceptor::Delegate::GetSessionState() {
	// When the session state is retrieved for the first time, it is cached (and
	// kept locked) until we return from OnTracePacket. This avoids having to lock
	// and unlock the instance multiple times per invocation.
	if (locked_self_.has_value())
	return &locked_self_.value()->session_state_;
	locked_self_ =
	base::make_optional<SelfHandle>(context_.GetInterceptorLocked());
	return &locked_self_.value()->session_state_;
	}

	void ConsoleInterceptor::Delegate::OnTrackUpdated(
	TrackEventStateTracker::Track& track) {
	auto track_color = HueToRGB(CounterToHue(track.index));
	std::array<char, 16> title;
	if (!track.name.empty()) {
	snprintf(title.data(), title.size(), "%s", track.name.c_str());
	} else if (track.pid && track.tid) {
	snprintf(title.data(), title.size(), "%u:%u",
	static_cast<uint32_t>(track.pid),
	static_cast<uint32_t>(track.tid));
	} else if (track.pid) {
	snprintf(title.data(), title.size(), "%" PRId64, track.pid);
	} else {
	snprintf(title.data(), title.size(), "%" PRIu64, track.uuid);
	}
	int title_width = static_cast<int>(title.size());

	auto& tls = context_.GetThreadLocalState();
	std::array<char, 128> message_prefix{};
	ssize_t written = 0;
	if (tls.use_colors) {
	written = snprintf(message_prefix.data(), message_prefix.size(),
	FMT_RGB_SET_BG " %s%s %-.s", track_color.r,
	track_color.g, track_color.b, kReset, kDim, title_width,
	title_width, title.data());
	} else {
	written = snprintf(message_prefix.data(), message_prefix.size(), "%-.s",
	title_width + 2, title_width, title.data());
	}
	if (written < 0)
	written = message_prefix.size();
	track.user_data.assign(message_prefix.begin(),
	message_prefix.begin() + written);
	}

	void ConsoleInterceptor::Delegate::OnTrackEvent(
	const TrackEventStateTracker::Track& track,
	const TrackEventStateTracker::ParsedTrackEvent& event) {
	// Start printing.
	auto& tls = context_.GetThreadLocalState();
	tls.buffer_pos = 0;

	// Print timestamp and track identifier.
	SetColor(context_, kDim);
	Printf(context_, "[%7.3lf] %.*s",
	static_cast<double>(event.timestamp_ns - tls.start_time_ns) / 1e9,
	static_cast<int>(track.user_data.size()), track.user_data.data());

	// Print category.
	Printf(context_, "%-5.*s ",
	std::min(5, static_cast<int>(event.category.size)),
	event.category.data);

	// Print stack depth.
	for (size_t i = 0; i < event.stack_depth; i++) {
	Printf(context_, "- ");
	}

	// Print slice name.
	auto slice_color = HueToRGB(event.name_hash % kMaxHue);
	auto highlight_color = Mix(slice_color, kWhiteColor, kLightness);
	if (event.track_event.type() == protos::pbzero::TrackEvent::TYPE_SLICE_END) {
	SetColor(context_, kDefault);
	Printf(context_, "} ");
	}
	SetColor(context_, highlight_color);
	Printf(context_, "%.*s", static_cast<int>(event.name.size), event.name.data);
	SetColor(context_, kReset);
	if (event.track_event.type() ==
	protos::pbzero::TrackEvent::TYPE_SLICE_BEGIN) {
	SetColor(context_, kDefault);
	Printf(context_, " {");
	}

	// Print annotations.
	if (event.track_event.has_debug_annotations()) {
	PrintDebugAnnotations(context_, event.track_event, slice_color,
	highlight_color);
	}

	// TODO(skyostil): Print typed arguments.

	// Print duration for longer events.
	constexpr uint64_t kNsPerMillisecond = 1000000u;
	if (event.duration_ns >= 10 * kNsPerMillisecond) {
	SetColor(context_, kDim);
	Printf(context_, " +%" PRIu64 "ms", event.duration_ns / kNsPerMillisecond);
	}
	SetColor(context_, kReset);
	Printf(context_, "\n");
	}

	// static
	void ConsoleInterceptor::Register() {
	perfetto::protos::gen::InterceptorDescriptor desc;
	desc.set_name("console");
	Interceptor<ConsoleInterceptor>::Register(desc);
	}

	// static
	void ConsoleInterceptor::SetOutputFdForTesting(int fd) {
	g_output_fd_for_testing = fd;
	}

	void ConsoleInterceptor::OnSetup(const SetupArgs& args) {
	int fd = STDOUT_FILENO;
	if (g_output_fd_for_testing)
	fd = g_output_fd_for_testing;
	#if !PERFETTO_BUILDFLAG(PERFETTO_OS_WIN) && \
	!PERFETTO_BUILDFLAG(PERFETTO_OS_WASM)
	bool use_colors = isatty(fd);
	#else
	bool use_colors = false;
	#endif
	protos::pbzero::ConsoleConfig::Decoder config(
	args.config.interceptor_config().console_config_raw());
	if (config.has_enable_colors())
	use_colors = config.enable_colors();
	if (config.output() == protos::pbzero::ConsoleConfig::OUTPUT_STDOUT) {
	fd = STDOUT_FILENO;
	} else if (config.output() == protos::pbzero::ConsoleConfig::OUTPUT_STDERR) {
	fd = STDERR_FILENO;
	}
	fd_ = fd;
	use_colors_ = use_colors;
	}

	void ConsoleInterceptor::OnStart(const StartArgs&) {
	start_time_ns_ = internal::TrackEventInternal::GetTimeNs();
	}

	void ConsoleInterceptor::OnStop(const StopArgs&) {}

	// static
	void ConsoleInterceptor::OnTracePacket(InterceptorContext context) {
	{
	auto& tls = context.GetThreadLocalState();
	Delegate delegate(context);
	perfetto::protos::pbzero::TracePacket::Decoder packet(
	context.packet_data.data, context.packet_data.size);
	TrackEventStateTracker::ProcessTracePacket(delegate, tls.sequence_state,
	packet);
	} // (Potential) lock scope for session state.
	Flush(context);
	}

	// static
	void ConsoleInterceptor::Printf(InterceptorContext& context,
	const char* format,
	...) {
	auto& tls = context.GetThreadLocalState();
	ssize_t remaining = static_cast<ssize_t>(tls.message_buffer.size()) -
	static_cast<ssize_t>(tls.buffer_pos);
	int written = 0;
	if (remaining > 0) {
	va_list args;
	va_start(args, format);
	written = vsnprintf(&tls.message_buffer[tls.buffer_pos],
	static_cast<size_t>(remaining), format, args);
	PERFETTO_DCHECK(written >= 0);
	va_end(args);
	}

	// In case of buffer overflow, flush to the fd and write the latest message to
	// it directly instead.
	if (remaining <= 0 \|\| written > remaining) {
	FILE* output = (tls.fd == STDOUT_FILENO) ? stdout : stderr;
	if (g_output_fd_for_testing) {
	output = fdopen(dup(g_output_fd_for_testing), "w");
	}
	Flush(context);
	va_list args;
	va_start(args, format);
	vfprintf(output, format, args);
	va_end(args);
	if (g_output_fd_for_testing) {
	fclose(output);
	}
	} else if (written > 0) {
	tls.buffer_pos += static_cast<size_t>(written);
	}
	}

	// static
	void ConsoleInterceptor::Flush(InterceptorContext& context) {
	auto& tls = context.GetThreadLocalState();
	ssize_t res = base::WriteAll(tls.fd, &tls.message_buffer[0], tls.buffer_pos);
	PERFETTO_DCHECK(res == static_cast<ssize_t>(tls.buffer_pos));
	tls.buffer_pos = 0;
	}

	// static
	void ConsoleInterceptor::SetColor(InterceptorContext& context,
	const ConsoleColor& color) {
	auto& tls = context.GetThreadLocalState();
	if (!tls.use_colors)
	return;
	Printf(context, FMT_RGB_SET, color.r, color.g, color.b);
	}

	// static
	void ConsoleInterceptor::SetColor(InterceptorContext& context,
	const char* color) {
	auto& tls = context.GetThreadLocalState();
	if (!tls.use_colors)
	return;
	Printf(context, "%s", color);
	}

	// static
	void ConsoleInterceptor::PrintDebugAnnotations(
	InterceptorContext& context,
	const protos::pbzero::TrackEvent_Decoder& track_event,
	const ConsoleColor& slice_color,
	const ConsoleColor& highlight_color) {
	SetColor(context, slice_color);
	Printf(context, "(");

	bool is_first = true;
	for (auto it = track_event.debug_annotations(); it; it++) {
	perfetto::protos::pbzero::DebugAnnotation::Decoder annotation(*it);
	SetColor(context, slice_color);
	if (!is_first)
	Printf(context, ", ");

	PrintDebugAnnotationName(context, annotation);
	Printf(context, ":");

	SetColor(context, highlight_color);
	PrintDebugAnnotationValue(context, annotation);

	is_first = false;
	}
	SetColor(context, slice_color);
	Printf(context, ")");
	}

	// static
	void ConsoleInterceptor::PrintDebugAnnotationName(
	InterceptorContext& context,
	const perfetto::protos::pbzero::DebugAnnotation::Decoder& annotation) {
	auto& tls = context.GetThreadLocalState();
	protozero::ConstChars name{};
	if (annotation.name_iid()) {
	name.data =
	tls.sequence_state.debug_annotation_names[annotation.name_iid()].data();
	name.size =
	tls.sequence_state.debug_annotation_names[annotation.name_iid()].size();
	} else if (annotation.has_name()) {
	name.data = annotation.name().data;
	name.size = annotation.name().size;
	}
	Printf(context, "%.*s", static_cast<int>(name.size), name.data);
	}

	// static
	void ConsoleInterceptor::PrintDebugAnnotationValue(
	InterceptorContext& context,
	const perfetto::protos::pbzero::DebugAnnotation::Decoder& annotation) {
	if (annotation.has_bool_value()) {
	Printf(context, "%s", annotation.bool_value() ? "true" : "false");
	} else if (annotation.has_uint_value()) {
	Printf(context, "%" PRIu64, annotation.uint_value());
	} else if (annotation.has_int_value()) {
	Printf(context, "%" PRId64, annotation.int_value());
	} else if (annotation.has_double_value()) {
	Printf(context, "%f", annotation.double_value());
	} else if (annotation.has_string_value()) {
	Printf(context, "%.*s", static_cast<int>(annotation.string_value().size),
	annotation.string_value().data);
	} else if (annotation.has_pointer_value()) {
	Printf(context, "%p", reinterpret_cast<void*>(annotation.pointer_value()));
	} else if (annotation.has_legacy_json_value()) {
	Printf(context, "%.*s",
	static_cast<int>(annotation.legacy_json_value().size),
	annotation.legacy_json_value().data);
	} else if (annotation.has_dict_entries()) {
	Printf(context, "{");
	bool is_first = true;
	for (auto it = annotation.dict_entries(); it; ++it) {
	if (!is_first)
	Printf(context, ", ");
	perfetto::protos::pbzero::DebugAnnotation::Decoder key_value(*it);
	PrintDebugAnnotationName(context, key_value);
	Printf(context, ":");
	PrintDebugAnnotationValue(context, key_value);
	is_first = false;
	}
	Printf(context, "}");
	} else if (annotation.has_array_values()) {
	Printf(context, "[");
	bool is_first = true;
	for (auto it = annotation.array_values(); it; ++it) {
	if (!is_first)
	Printf(context, ", ");
	perfetto::protos::pbzero::DebugAnnotation::Decoder key_value(*it);
	PrintDebugAnnotationValue(context, key_value);
	is_first = false;
	}
	Printf(context, "]");
	} else {
	Printf(context, "{}");
	}
	}

	} // namespace perfetto