src/trace_processor/rpc/rpc.cc - third_party/perfetto - Git at Google

 /*
  * Copyright (C) 2019 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 "src/trace_processor/rpc/rpc.h"

 #include <string.h>

 #include <vector>

 #include "perfetto/base/logging.h"
 #include "perfetto/base/time.h"
 #include "perfetto/ext/base/utils.h"
 #include "perfetto/ext/base/version.h"
 #include "perfetto/protozero/scattered_heap_buffer.h"
 #include "perfetto/protozero/scattered_stream_writer.h"
 #include "perfetto/trace_processor/trace_processor.h"
 #include "src/protozero/proto_ring_buffer.h"
 #include "src/trace_processor/rpc/query_result_serializer.h"
 #include "src/trace_processor/tp_metatrace.h"

 #include "protos/perfetto/trace_processor/trace_processor.pbzero.h"

 namespace perfetto {
 namespace trace_processor {

 namespace {
 // Writes a "Loading trace ..." update every N bytes.
 constexpr size_t kProgressUpdateBytes = 50 * 1000 * 1000;
 using TraceProcessorRpcStream = protos::pbzero::TraceProcessorRpcStream;
 using RpcProto = protos::pbzero::TraceProcessorRpc;

 // Most RPC messages are either very small or a query results.
 // QueryResultSerializer splits rows into batches of approximately 128KB. Try
 // avoid extra heap allocations for the nominal case.
 constexpr auto kSliceSize =
     QueryResultSerializer::kDefaultBatchSplitThreshold + 4096;

 // Holds a trace_processor::TraceProcessorRpc pbzero message. Avoids extra
 // copies by doing direct scattered calls from the fragmented heap buffer onto
 // the RpcResponseFunction (the receiver is expected to deal with arbitrary
 // fragmentation anyways). It also takes care of prefixing each message with
 // the proto preamble and varint size.
 class Response {
  public:
   Response(int64_t seq, int method);
   Response(const Response&) = delete;
   Response& operator=(const Response&) = delete;
   RpcProto* operator->() { return msg_; }
   void Send(Rpc::RpcResponseFunction);

  private:
   RpcProto* msg_ = nullptr;

   // The reason why we use TraceProcessorRpcStream as root message is because
   // the RPC wire protocol expects each message to be prefixed with a proto
   // preamble and varint size. This happens to be the same serialization of a
   // repeated field (this is really the same trick we use between
   // Trace and TracePacket in trace.proto)
   protozero::HeapBuffered<TraceProcessorRpcStream> buf_;
 };

 Response::Response(int64_t seq, int method) : buf_(kSliceSize, kSliceSize) {
   msg_ = buf_->add_msg();
   msg_->set_seq(seq);
   msg_->set_response(static_cast<RpcProto::TraceProcessorMethod>(method));
 }

 void Response::Send(Rpc::RpcResponseFunction send_fn) {
   buf_->Finalize();
   for (const auto& slice : buf_.GetSlices()) {
     auto range = slice.GetUsedRange();
     send_fn(range.begin, static_cast<uint32_t>(range.size()));
   }
 }

 }  // namespace

 Rpc::Rpc(std::unique_ptr<TraceProcessor> preloaded_instance)
     : trace_processor_(std::move(preloaded_instance)) {
   if (!trace_processor_)
     ResetTraceProcessor();
 }

 Rpc::Rpc() : Rpc(nullptr) {}
 Rpc::~Rpc() = default;

 void Rpc::ResetTraceProcessor() {
   trace_processor_ = TraceProcessor::CreateInstance(Config());
   bytes_parsed_ = bytes_last_progress_ = 0;
   t_parse_started_ = base::GetWallTimeNs().count();
   // Deliberately not resetting the RPC channel state (rxbuf_, {tx,rx}_seq_id_).
   // This is invoked from the same client to clear the current trace state
   // before loading a new one. The IPC channel is orthogonal to that and the
   // message numbering continues regardless of the reset.
 }

 void Rpc::OnRpcRequest(const void* data, size_t len) {
   rxbuf_.Append(data, len);
   for (;;) {
     auto msg = rxbuf_.ReadMessage();
     if (!msg.valid()) {
       if (msg.fatal_framing_error) {
         protozero::HeapBuffered<TraceProcessorRpcStream> err_msg;
         err_msg->add_msg()->set_fatal_error("RPC framing error");
         auto err = err_msg.SerializeAsArray();
         rpc_response_fn_(err.data(), static_cast<uint32_t>(err.size()));
         rpc_response_fn_(nullptr, 0);  // Disconnect.
       }
       break;
     }
     ParseRpcRequest(msg.start, msg.len);
   }
 }

 namespace {

 using ProtoEnum = protos::pbzero::MetatraceCategories;
 TraceProcessor::MetatraceCategories MetatraceCategoriesToPublicEnum(
     ProtoEnum categories) {
   switch (categories) {
     case ProtoEnum::TOPLEVEL:
       return TraceProcessor::MetatraceCategories::TOPLEVEL;
     case ProtoEnum::QUERY:
       return TraceProcessor::MetatraceCategories::QUERY;
     case ProtoEnum::FUNCTION:
       return TraceProcessor::MetatraceCategories::FUNCTION;
     case ProtoEnum::ALL:
       return TraceProcessor::MetatraceCategories::ALL;
     case ProtoEnum::NONE:
       return TraceProcessor::MetatraceCategories::NONE;
   }
   return TraceProcessor::MetatraceCategories::NONE;
 }

 }  // namespace

 // [data, len] here is a tokenized TraceProcessorRpc proto message, without the
 // size header.
 void Rpc::ParseRpcRequest(const uint8_t* data, size_t len) {
   RpcProto::Decoder req(data, len);

   // We allow restarting the sequence from 0. This happens when refreshing the
   // browser while using the external trace_processor_shell --httpd.
   if (req.seq() != 0 && rx_seq_id_ != 0 && req.seq() != rx_seq_id_ + 1) {
     char err_str[255];
     // "(ERR:rpc_seq)" is intercepted by error_dialog.ts in the UI.
     snprintf(err_str, sizeof(err_str),
              "RPC request out of order. Expected %" PRId64 ", got %" PRId64
              " (ERR:rpc_seq)",
              rx_seq_id_ + 1, req.seq());
     PERFETTO_ELOG("%s", err_str);
     protozero::HeapBuffered<TraceProcessorRpcStream> err_msg;
     err_msg->add_msg()->set_fatal_error(err_str);
     auto err = err_msg.SerializeAsArray();
     rpc_response_fn_(err.data(), static_cast<uint32_t>(err.size()));
     rpc_response_fn_(nullptr, 0);  // Disconnect.
     return;
   }
   rx_seq_id_ = req.seq();

   // The static cast is to prevent that the compiler breaks future proofness.
   const int req_type = static_cast<int>(req.request());
   static const char kErrFieldNotSet[] = "RPC error: request field not set";
   switch (req_type) {
     case RpcProto::TPM_APPEND_TRACE_DATA: {
       Response resp(tx_seq_id_++, req_type);
       auto* result = resp->set_append_result();
       if (!req.has_append_trace_data()) {
         result->set_error(kErrFieldNotSet);
       } else {
         protozero::ConstBytes byte_range = req.append_trace_data();
         util::Status res = Parse(byte_range.data, byte_range.size);
         if (!res.ok()) {
           result->set_error(res.message());
         }
       }
       resp.Send(rpc_response_fn_);
       break;
     }
     case RpcProto::TPM_FINALIZE_TRACE_DATA: {
       Response resp(tx_seq_id_++, req_type);
       NotifyEndOfFile();
       resp.Send(rpc_response_fn_);
       break;
     }
     case RpcProto::TPM_QUERY_STREAMING: {
       if (!req.has_query_args()) {
         Response resp(tx_seq_id_++, req_type);
         auto* result = resp->set_query_result();
         result->set_error(kErrFieldNotSet);
         resp.Send(rpc_response_fn_);
       } else {
         protozero::ConstBytes args = req.query_args();
         auto it = QueryInternal(args.data, args.size);
         QueryResultSerializer serializer(std::move(it));
         for (bool has_more = true; has_more;) {
           Response resp(tx_seq_id_++, req_type);
           has_more = serializer.Serialize(resp->set_query_result());
           resp.Send(rpc_response_fn_);
         }
       }
       break;
     }
     case RpcProto::TPM_COMPUTE_METRIC: {
       Response resp(tx_seq_id_++, req_type);
       auto* result = resp->set_metric_result();
       if (!req.has_compute_metric_args()) {
         result->set_error(kErrFieldNotSet);
       } else {
         protozero::ConstBytes args = req.compute_metric_args();
         ComputeMetricInternal(args.data, args.size, result);
       }
       resp.Send(rpc_response_fn_);
       break;
     }
     case RpcProto::TPM_GET_METRIC_DESCRIPTORS: {
       Response resp(tx_seq_id_++, req_type);
       auto descriptor_set = trace_processor_->GetMetricDescriptors();
       auto* result = resp->set_metric_descriptors();
       result->AppendRawProtoBytes(descriptor_set.data(), descriptor_set.size());
       resp.Send(rpc_response_fn_);
       break;
     }
     case RpcProto::TPM_RESTORE_INITIAL_TABLES: {
       trace_processor_->RestoreInitialTables();
       Response resp(tx_seq_id_++, req_type);
       resp.Send(rpc_response_fn_);
       break;
     }
     case RpcProto::TPM_ENABLE_METATRACE: {
       using protos::pbzero::MetatraceCategories;
       protozero::ConstBytes args = req.enable_metatrace_args();
       EnableMetatrace(args.data, args.size);

       Response resp(tx_seq_id_++, req_type);
       resp.Send(rpc_response_fn_);
       break;
     }
     case RpcProto::TPM_DISABLE_AND_READ_METATRACE: {
       Response resp(tx_seq_id_++, req_type);
       DisableAndReadMetatraceInternal(resp->set_metatrace());
       resp.Send(rpc_response_fn_);
       break;
     }
     case RpcProto::TPM_GET_STATUS: {
       Response resp(tx_seq_id_++, req_type);
       std::vector<uint8_t> status = GetStatus();
       resp->set_status()->AppendRawProtoBytes(status.data(), status.size());
       resp.Send(rpc_response_fn_);
       break;
     }
     default: {
       // This can legitimately happen if the client is newer. We reply with a
       // generic "unkown request" response, so the client can do feature
       // detection
       PERFETTO_DLOG("[RPC] Uknown request type (%d), size=%zu", req_type, len);
       Response resp(tx_seq_id_++, req_type);
       resp->set_invalid_request(
           static_cast<RpcProto::TraceProcessorMethod>(req_type));
       resp.Send(rpc_response_fn_);
       break;
     }
   }  // switch(req_type)
 }

 util::Status Rpc::Parse(const uint8_t* data, size_t len) {
   PERFETTO_TP_TRACE(
       metatrace::Category::TOPLEVEL, "RPC_PARSE",
       [&](metatrace::Record* r) { r->AddArg("length", std::to_string(len)); });
   if (eof_) {
     // Reset the trace processor state if another trace has been previously
     // loaded.
     ResetTraceProcessor();
   }

   eof_ = false;
   bytes_parsed_ += len;
   MaybePrintProgress();

   if (len == 0)
     return util::OkStatus();

   // TraceProcessor needs take ownership of the memory chunk.
   std::unique_ptr<uint8_t[]> data_copy(new uint8_t[len]);
   memcpy(data_copy.get(), data, len);
   return trace_processor_->Parse(std::move(data_copy), len);
 }

 void Rpc::NotifyEndOfFile() {
   PERFETTO_TP_TRACE(metatrace::Category::TOPLEVEL, "RPC_NOTIFY_END_OF_FILE");

   trace_processor_->NotifyEndOfFile();
   eof_ = true;
   MaybePrintProgress();
 }

 void Rpc::MaybePrintProgress() {
   if (eof_ || bytes_parsed_ - bytes_last_progress_ > kProgressUpdateBytes) {
     bytes_last_progress_ = bytes_parsed_;
     auto t_load_s =
         static_cast<double>(base::GetWallTimeNs().count() - t_parse_started_) /
         1e9;
     fprintf(stderr, "\rLoading trace %.2f MB (%.1f MB/s)%s",
             static_cast<double>(bytes_parsed_) / 1e6,
             static_cast<double>(bytes_parsed_) / 1e6 / t_load_s,
             (eof_ ? "\n" : ""));
     fflush(stderr);
   }
 }

 void Rpc::Query(const uint8_t* args,
                 size_t len,
                 QueryResultBatchCallback result_callback) {
   auto it = QueryInternal(args, len);
   QueryResultSerializer serializer(std::move(it));

   std::vector<uint8_t> res;
   for (bool has_more = true; has_more;) {
     has_more = serializer.Serialize(&res);
     result_callback(res.data(), res.size(), has_more);
     res.clear();
   }
 }

 Iterator Rpc::QueryInternal(const uint8_t* args, size_t len) {
   protos::pbzero::QueryArgs::Decoder query(args, len);
   std::string sql = query.sql_query().ToStdString();
   PERFETTO_DLOG("[RPC] Query < %s", sql.c_str());
   PERFETTO_TP_TRACE(metatrace::Category::TOPLEVEL, "RPC_QUERY",
                     [&](metatrace::Record* r) {
                       r->AddArg("SQL", sql);
                       if (query.has_tag()) {
                         r->AddArg("tag", query.tag());
                       }
                     });

   return trace_processor_->ExecuteQuery(sql.c_str());
 }

 void Rpc::RestoreInitialTables() {
   trace_processor_->RestoreInitialTables();
 }

 std::vector<uint8_t> Rpc::ComputeMetric(const uint8_t* args, size_t len) {
   protozero::HeapBuffered<protos::pbzero::ComputeMetricResult> result;
   ComputeMetricInternal(args, len, result.get());
   return result.SerializeAsArray();
 }

 void Rpc::ComputeMetricInternal(const uint8_t* data,
                                 size_t len,
                                 protos::pbzero::ComputeMetricResult* result) {
   protos::pbzero::ComputeMetricArgs::Decoder args(data, len);
   std::vector<std::string> metric_names;
   for (auto it = args.metric_names(); it; ++it) {
     metric_names.emplace_back(it->as_std_string());
   }

   PERFETTO_TP_TRACE(metatrace::Category::TOPLEVEL, "RPC_COMPUTE_METRIC",
                     [&](metatrace::Record* r) {
                       for (const auto& metric : metric_names) {
                         r->AddArg("Metric", metric);
                         r->AddArg("Format", std::to_string(args.format()));
                       }
                     });

   PERFETTO_DLOG("[RPC] ComputeMetrics(%zu, %s), format=%d", metric_names.size(),
                 metric_names.empty() ? "" : metric_names.front().c_str(),
                 args.format());
   switch (args.format()) {
     case protos::pbzero::ComputeMetricArgs::BINARY_PROTOBUF: {
       std::vector<uint8_t> metrics_proto;
       util::Status status =
           trace_processor_->ComputeMetric(metric_names, &metrics_proto);
       if (status.ok()) {
         result->set_metrics(metrics_proto.data(), metrics_proto.size());
       } else {
         result->set_error(status.message());
       }
       break;
     }
     case protos::pbzero::ComputeMetricArgs::TEXTPROTO: {
       std::string metrics_string;
       util::Status status = trace_processor_->ComputeMetricText(
           metric_names, TraceProcessor::MetricResultFormat::kProtoText,
           &metrics_string);
       if (status.ok()) {
         result->set_metrics_as_prototext(metrics_string);
       } else {
         result->set_error(status.message());
       }
       break;
     }
   }
 }

 void Rpc::EnableMetatrace(const uint8_t* data, size_t len) {
   using protos::pbzero::MetatraceCategories;
   TraceProcessor::MetatraceConfig config;
   protos::pbzero::EnableMetatraceArgs::Decoder args(data, len);
   config.categories = MetatraceCategoriesToPublicEnum(
       static_cast<MetatraceCategories>(args.categories()));
   trace_processor_->EnableMetatrace(config);
 }

 std::vector<uint8_t> Rpc::DisableAndReadMetatrace() {
   protozero::HeapBuffered<protos::pbzero::DisableAndReadMetatraceResult> result;
   DisableAndReadMetatraceInternal(result.get());
   return result.SerializeAsArray();
 }

 void Rpc::DisableAndReadMetatraceInternal(
     protos::pbzero::DisableAndReadMetatraceResult* result) {
   std::vector<uint8_t> trace_proto;
   util::Status status = trace_processor_->DisableAndReadMetatrace(&trace_proto);
   if (status.ok()) {
     result->set_metatrace(trace_proto.data(), trace_proto.size());
   } else {
     result->set_error(status.message());
   }
 }

 std::vector<uint8_t> Rpc::GetStatus() {
   protozero::HeapBuffered<protos::pbzero::StatusResult> status;
   status->set_loaded_trace_name(trace_processor_->GetCurrentTraceName());
   status->set_human_readable_version(base::GetVersionString());
   status->set_api_version(protos::pbzero::TRACE_PROCESSOR_CURRENT_API_VERSION);
   return status.SerializeAsArray();
 }

 }  // namespace trace_processor
 }  // namespace perfetto
	/*
	* Copyright (C) 2019 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 "src/trace_processor/rpc/rpc.h"

	#include <string.h>

	#include <vector>

	#include "perfetto/base/logging.h"
	#include "perfetto/base/time.h"
	#include "perfetto/ext/base/utils.h"
	#include "perfetto/ext/base/version.h"
	#include "perfetto/protozero/scattered_heap_buffer.h"
	#include "perfetto/protozero/scattered_stream_writer.h"
	#include "perfetto/trace_processor/trace_processor.h"
	#include "src/protozero/proto_ring_buffer.h"
	#include "src/trace_processor/rpc/query_result_serializer.h"
	#include "src/trace_processor/tp_metatrace.h"

	#include "protos/perfetto/trace_processor/trace_processor.pbzero.h"

	namespace perfetto {
	namespace trace_processor {

	namespace {
	// Writes a "Loading trace ..." update every N bytes.
	constexpr size_t kProgressUpdateBytes = 50 * 1000 * 1000;
	using TraceProcessorRpcStream = protos::pbzero::TraceProcessorRpcStream;
	using RpcProto = protos::pbzero::TraceProcessorRpc;

	// Most RPC messages are either very small or a query results.
	// QueryResultSerializer splits rows into batches of approximately 128KB. Try
	// avoid extra heap allocations for the nominal case.
	constexpr auto kSliceSize =
	QueryResultSerializer::kDefaultBatchSplitThreshold + 4096;

	// Holds a trace_processor::TraceProcessorRpc pbzero message. Avoids extra
	// copies by doing direct scattered calls from the fragmented heap buffer onto
	// the RpcResponseFunction (the receiver is expected to deal with arbitrary
	// fragmentation anyways). It also takes care of prefixing each message with
	// the proto preamble and varint size.
	class Response {
	public:
	Response(int64_t seq, int method);
	Response(const Response&) = delete;
	Response& operator=(const Response&) = delete;
	RpcProto* operator->() { return msg_; }
	void Send(Rpc::RpcResponseFunction);

	private:
	RpcProto* msg_ = nullptr;

	// The reason why we use TraceProcessorRpcStream as root message is because
	// the RPC wire protocol expects each message to be prefixed with a proto
	// preamble and varint size. This happens to be the same serialization of a
	// repeated field (this is really the same trick we use between
	// Trace and TracePacket in trace.proto)
	protozero::HeapBuffered<TraceProcessorRpcStream> buf_;
	};

	Response::Response(int64_t seq, int method) : buf_(kSliceSize, kSliceSize) {
	msg_ = buf_->add_msg();
	msg_->set_seq(seq);
	msg_->set_response(static_cast<RpcProto::TraceProcessorMethod>(method));
	}

	void Response::Send(Rpc::RpcResponseFunction send_fn) {
	buf_->Finalize();
	for (const auto& slice : buf_.GetSlices()) {
	auto range = slice.GetUsedRange();
	send_fn(range.begin, static_cast<uint32_t>(range.size()));
	}
	}

	} // namespace

	Rpc::Rpc(std::unique_ptr<TraceProcessor> preloaded_instance)
	: trace_processor_(std::move(preloaded_instance)) {
	if (!trace_processor_)
	ResetTraceProcessor();
	}

	Rpc::Rpc() : Rpc(nullptr) {}
	Rpc::~Rpc() = default;

	void Rpc::ResetTraceProcessor() {
	trace_processor_ = TraceProcessor::CreateInstance(Config());
	bytes_parsed_ = bytes_last_progress_ = 0;
	t_parse_started_ = base::GetWallTimeNs().count();
	// Deliberately not resetting the RPC channel state (rxbuf_, {tx,rx}_seq_id_).
	// This is invoked from the same client to clear the current trace state
	// before loading a new one. The IPC channel is orthogonal to that and the
	// message numbering continues regardless of the reset.
	}

	void Rpc::OnRpcRequest(const void* data, size_t len) {
	rxbuf_.Append(data, len);
	for (;;) {
	auto msg = rxbuf_.ReadMessage();
	if (!msg.valid()) {
	if (msg.fatal_framing_error) {
	protozero::HeapBuffered<TraceProcessorRpcStream> err_msg;
	err_msg->add_msg()->set_fatal_error("RPC framing error");
	auto err = err_msg.SerializeAsArray();
	rpc_response_fn_(err.data(), static_cast<uint32_t>(err.size()));
	rpc_response_fn_(nullptr, 0); // Disconnect.
	}
	break;
	}
	ParseRpcRequest(msg.start, msg.len);
	}
	}

	namespace {

	using ProtoEnum = protos::pbzero::MetatraceCategories;
	TraceProcessor::MetatraceCategories MetatraceCategoriesToPublicEnum(
	ProtoEnum categories) {
	switch (categories) {
	case ProtoEnum::TOPLEVEL:
	return TraceProcessor::MetatraceCategories::TOPLEVEL;
	case ProtoEnum::QUERY:
	return TraceProcessor::MetatraceCategories::QUERY;
	case ProtoEnum::FUNCTION:
	return TraceProcessor::MetatraceCategories::FUNCTION;
	case ProtoEnum::ALL:
	return TraceProcessor::MetatraceCategories::ALL;
	case ProtoEnum::NONE:
	return TraceProcessor::MetatraceCategories::NONE;
	}
	return TraceProcessor::MetatraceCategories::NONE;
	}

	} // namespace

	// [data, len] here is a tokenized TraceProcessorRpc proto message, without the
	// size header.
	void Rpc::ParseRpcRequest(const uint8_t* data, size_t len) {
	RpcProto::Decoder req(data, len);

	// We allow restarting the sequence from 0. This happens when refreshing the
	// browser while using the external trace_processor_shell --httpd.
	if (req.seq() != 0 && rx_seq_id_ != 0 && req.seq() != rx_seq_id_ + 1) {
	char err_str[255];
	// "(ERR:rpc_seq)" is intercepted by error_dialog.ts in the UI.
	snprintf(err_str, sizeof(err_str),
	"RPC request out of order. Expected %" PRId64 ", got %" PRId64
	" (ERR:rpc_seq)",
	rx_seq_id_ + 1, req.seq());
	PERFETTO_ELOG("%s", err_str);
	protozero::HeapBuffered<TraceProcessorRpcStream> err_msg;
	err_msg->add_msg()->set_fatal_error(err_str);
	auto err = err_msg.SerializeAsArray();
	rpc_response_fn_(err.data(), static_cast<uint32_t>(err.size()));
	rpc_response_fn_(nullptr, 0); // Disconnect.
	return;
	}
	rx_seq_id_ = req.seq();

	// The static cast is to prevent that the compiler breaks future proofness.
	const int req_type = static_cast<int>(req.request());
	static const char kErrFieldNotSet[] = "RPC error: request field not set";
	switch (req_type) {
	case RpcProto::TPM_APPEND_TRACE_DATA: {
	Response resp(tx_seq_id_++, req_type);
	auto* result = resp->set_append_result();
	if (!req.has_append_trace_data()) {
	result->set_error(kErrFieldNotSet);
	} else {
	protozero::ConstBytes byte_range = req.append_trace_data();
	util::Status res = Parse(byte_range.data, byte_range.size);
	if (!res.ok()) {
	result->set_error(res.message());
	}
	}
	resp.Send(rpc_response_fn_);
	break;
	}
	case RpcProto::TPM_FINALIZE_TRACE_DATA: {
	Response resp(tx_seq_id_++, req_type);
	NotifyEndOfFile();
	resp.Send(rpc_response_fn_);
	break;
	}
	case RpcProto::TPM_QUERY_STREAMING: {
	if (!req.has_query_args()) {
	Response resp(tx_seq_id_++, req_type);
	auto* result = resp->set_query_result();
	result->set_error(kErrFieldNotSet);
	resp.Send(rpc_response_fn_);
	} else {
	protozero::ConstBytes args = req.query_args();
	auto it = QueryInternal(args.data, args.size);
	QueryResultSerializer serializer(std::move(it));
	for (bool has_more = true; has_more;) {
	Response resp(tx_seq_id_++, req_type);
	has_more = serializer.Serialize(resp->set_query_result());
	resp.Send(rpc_response_fn_);
	}
	}
	break;
	}
	case RpcProto::TPM_COMPUTE_METRIC: {
	Response resp(tx_seq_id_++, req_type);
	auto* result = resp->set_metric_result();
	if (!req.has_compute_metric_args()) {
	result->set_error(kErrFieldNotSet);
	} else {
	protozero::ConstBytes args = req.compute_metric_args();
	ComputeMetricInternal(args.data, args.size, result);
	}
	resp.Send(rpc_response_fn_);
	break;
	}
	case RpcProto::TPM_GET_METRIC_DESCRIPTORS: {
	Response resp(tx_seq_id_++, req_type);
	auto descriptor_set = trace_processor_->GetMetricDescriptors();
	auto* result = resp->set_metric_descriptors();
	result->AppendRawProtoBytes(descriptor_set.data(), descriptor_set.size());
	resp.Send(rpc_response_fn_);
	break;
	}
	case RpcProto::TPM_RESTORE_INITIAL_TABLES: {
	trace_processor_->RestoreInitialTables();
	Response resp(tx_seq_id_++, req_type);
	resp.Send(rpc_response_fn_);
	break;
	}
	case RpcProto::TPM_ENABLE_METATRACE: {
	using protos::pbzero::MetatraceCategories;
	protozero::ConstBytes args = req.enable_metatrace_args();
	EnableMetatrace(args.data, args.size);

	Response resp(tx_seq_id_++, req_type);
	resp.Send(rpc_response_fn_);
	break;
	}
	case RpcProto::TPM_DISABLE_AND_READ_METATRACE: {
	Response resp(tx_seq_id_++, req_type);
	DisableAndReadMetatraceInternal(resp->set_metatrace());
	resp.Send(rpc_response_fn_);
	break;
	}
	case RpcProto::TPM_GET_STATUS: {
	Response resp(tx_seq_id_++, req_type);
	std::vector<uint8_t> status = GetStatus();
	resp->set_status()->AppendRawProtoBytes(status.data(), status.size());
	resp.Send(rpc_response_fn_);
	break;
	}
	default: {
	// This can legitimately happen if the client is newer. We reply with a
	// generic "unkown request" response, so the client can do feature
	// detection
	PERFETTO_DLOG("[RPC] Uknown request type (%d), size=%zu", req_type, len);
	Response resp(tx_seq_id_++, req_type);
	resp->set_invalid_request(
	static_cast<RpcProto::TraceProcessorMethod>(req_type));
	resp.Send(rpc_response_fn_);
	break;
	}
	} // switch(req_type)
	}

	util::Status Rpc::Parse(const uint8_t* data, size_t len) {
	PERFETTO_TP_TRACE(
	metatrace::Category::TOPLEVEL, "RPC_PARSE",
	[&](metatrace::Record* r) { r->AddArg("length", std::to_string(len)); });
	if (eof_) {
	// Reset the trace processor state if another trace has been previously
	// loaded.
	ResetTraceProcessor();
	}

	eof_ = false;
	bytes_parsed_ += len;
	MaybePrintProgress();

	if (len == 0)
	return util::OkStatus();

	// TraceProcessor needs take ownership of the memory chunk.
	std::unique_ptr<uint8_t[]> data_copy(new uint8_t[len]);
	memcpy(data_copy.get(), data, len);
	return trace_processor_->Parse(std::move(data_copy), len);
	}

	void Rpc::NotifyEndOfFile() {
	PERFETTO_TP_TRACE(metatrace::Category::TOPLEVEL, "RPC_NOTIFY_END_OF_FILE");

	trace_processor_->NotifyEndOfFile();
	eof_ = true;
	MaybePrintProgress();
	}

	void Rpc::MaybePrintProgress() {
	if (eof_ \|\| bytes_parsed_ - bytes_last_progress_ > kProgressUpdateBytes) {
	bytes_last_progress_ = bytes_parsed_;
	auto t_load_s =
	static_cast<double>(base::GetWallTimeNs().count() - t_parse_started_) /
	1e9;
	fprintf(stderr, "\rLoading trace %.2f MB (%.1f MB/s)%s",
	static_cast<double>(bytes_parsed_) / 1e6,
	static_cast<double>(bytes_parsed_) / 1e6 / t_load_s,
	(eof_ ? "\n" : ""));
	fflush(stderr);
	}
	}

	void Rpc::Query(const uint8_t* args,
	size_t len,
	QueryResultBatchCallback result_callback) {
	auto it = QueryInternal(args, len);
	QueryResultSerializer serializer(std::move(it));

	std::vector<uint8_t> res;
	for (bool has_more = true; has_more;) {
	has_more = serializer.Serialize(&res);
	result_callback(res.data(), res.size(), has_more);
	res.clear();
	}
	}

	Iterator Rpc::QueryInternal(const uint8_t* args, size_t len) {
	protos::pbzero::QueryArgs::Decoder query(args, len);
	std::string sql = query.sql_query().ToStdString();
	PERFETTO_DLOG("[RPC] Query < %s", sql.c_str());
	PERFETTO_TP_TRACE(metatrace::Category::TOPLEVEL, "RPC_QUERY",
	[&](metatrace::Record* r) {
	r->AddArg("SQL", sql);
	if (query.has_tag()) {
	r->AddArg("tag", query.tag());
	}
	});

	return trace_processor_->ExecuteQuery(sql.c_str());
	}

	void Rpc::RestoreInitialTables() {
	trace_processor_->RestoreInitialTables();
	}

	std::vector<uint8_t> Rpc::ComputeMetric(const uint8_t* args, size_t len) {
	protozero::HeapBuffered<protos::pbzero::ComputeMetricResult> result;
	ComputeMetricInternal(args, len, result.get());
	return result.SerializeAsArray();
	}

	void Rpc::ComputeMetricInternal(const uint8_t* data,
	size_t len,
	protos::pbzero::ComputeMetricResult* result) {
	protos::pbzero::ComputeMetricArgs::Decoder args(data, len);
	std::vector<std::string> metric_names;
	for (auto it = args.metric_names(); it; ++it) {
	metric_names.emplace_back(it->as_std_string());
	}

	PERFETTO_TP_TRACE(metatrace::Category::TOPLEVEL, "RPC_COMPUTE_METRIC",
	[&](metatrace::Record* r) {
	for (const auto& metric : metric_names) {
	r->AddArg("Metric", metric);
	r->AddArg("Format", std::to_string(args.format()));
	}
	});

	PERFETTO_DLOG("[RPC] ComputeMetrics(%zu, %s), format=%d", metric_names.size(),
	metric_names.empty() ? "" : metric_names.front().c_str(),
	args.format());
	switch (args.format()) {
	case protos::pbzero::ComputeMetricArgs::BINARY_PROTOBUF: {
	std::vector<uint8_t> metrics_proto;
	util::Status status =
	trace_processor_->ComputeMetric(metric_names, &metrics_proto);
	if (status.ok()) {
	result->set_metrics(metrics_proto.data(), metrics_proto.size());
	} else {
	result->set_error(status.message());
	}
	break;
	}
	case protos::pbzero::ComputeMetricArgs::TEXTPROTO: {
	std::string metrics_string;
	util::Status status = trace_processor_->ComputeMetricText(
	metric_names, TraceProcessor::MetricResultFormat::kProtoText,
	&metrics_string);
	if (status.ok()) {
	result->set_metrics_as_prototext(metrics_string);
	} else {
	result->set_error(status.message());
	}
	break;
	}
	}
	}

	void Rpc::EnableMetatrace(const uint8_t* data, size_t len) {
	using protos::pbzero::MetatraceCategories;
	TraceProcessor::MetatraceConfig config;
	protos::pbzero::EnableMetatraceArgs::Decoder args(data, len);
	config.categories = MetatraceCategoriesToPublicEnum(
	static_cast<MetatraceCategories>(args.categories()));
	trace_processor_->EnableMetatrace(config);
	}

	std::vector<uint8_t> Rpc::DisableAndReadMetatrace() {
	protozero::HeapBuffered<protos::pbzero::DisableAndReadMetatraceResult> result;
	DisableAndReadMetatraceInternal(result.get());
	return result.SerializeAsArray();
	}

	void Rpc::DisableAndReadMetatraceInternal(
	protos::pbzero::DisableAndReadMetatraceResult* result) {
	std::vector<uint8_t> trace_proto;
	util::Status status = trace_processor_->DisableAndReadMetatrace(&trace_proto);
	if (status.ok()) {
	result->set_metatrace(trace_proto.data(), trace_proto.size());
	} else {
	result->set_error(status.message());
	}
	}

	std::vector<uint8_t> Rpc::GetStatus() {
	protozero::HeapBuffered<protos::pbzero::StatusResult> status;
	status->set_loaded_trace_name(trace_processor_->GetCurrentTraceName());
	status->set_human_readable_version(base::GetVersionString());
	status->set_api_version(protos::pbzero::TRACE_PROCESSOR_CURRENT_API_VERSION);
	return status.SerializeAsArray();
	}

	} // namespace trace_processor
	} // namespace perfetto