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/*
* Copyright (C) 2018 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/proto_trace_tokenizer.h"
#include <string>
#include "perfetto/base/logging.h"
#include "perfetto/base/utils.h"
#include "perfetto/protozero/proto_decoder.h"
#include "perfetto/protozero/proto_utils.h"
#include "src/trace_processor/process_tracker.h"
#include "src/trace_processor/sched_tracker.h"
#include "src/trace_processor/trace_blob_view.h"
#include "src/trace_processor/trace_sorter.h"
#include "perfetto/trace/trace.pb.h"
#include "perfetto/trace/trace_packet.pb.h"
namespace perfetto {
namespace trace_processor {
using protozero::ProtoDecoder;
using protozero::proto_utils::kFieldTypeLengthDelimited;
using protozero::proto_utils::MakeTagLengthDelimited;
using protozero::proto_utils::MakeTagVarInt;
using protozero::proto_utils::ParseVarInt;
ProtoTraceTokenizer::ProtoTraceTokenizer(TraceProcessorContext* ctx)
: trace_sorter_(ctx->sorter.get()) {}
ProtoTraceTokenizer::~ProtoTraceTokenizer() = default;
bool ProtoTraceTokenizer::Parse(std::unique_ptr<uint8_t[]> owned_buf,
size_t size) {
uint8_t* data = &owned_buf[0];
if (!partial_buf_.empty()) {
// It takes ~5 bytes for a proto preamble + the varint size.
const size_t kHeaderBytes = 5;
if (PERFETTO_UNLIKELY(partial_buf_.size() < kHeaderBytes)) {
size_t missing_len = std::min(kHeaderBytes - partial_buf_.size(), size);
partial_buf_.insert(partial_buf_.end(), &data[0], &data[missing_len]);
if (partial_buf_.size() < kHeaderBytes)
return true;
data += missing_len;
size -= missing_len;
}
// At this point we have enough data in partial_buf_ to read at least the
// field header and know the size of the next TracePacket.
constexpr uint8_t kTracePacketTag =
MakeTagLengthDelimited(protos::Trace::kPacketFieldNumber);
const uint8_t* pos = &partial_buf_[0];
uint8_t proto_field_tag = *pos;
uint64_t field_size = 0;
const uint8_t* next = ParseVarInt(++pos, &*partial_buf_.end(), &field_size);
bool parse_failed = next == pos;
pos = next;
if (proto_field_tag != kTracePacketTag || field_size == 0 || parse_failed) {
PERFETTO_ELOG("Failed parsing a TracePacket from the partial buffer");
return false; // Unrecoverable error, stop parsing.
}
// At this point we know how big the TracePacket is.
size_t hdr_size = static_cast<size_t>(pos - &partial_buf_[0]);
size_t size_incl_header = static_cast<size_t>(field_size + hdr_size);
PERFETTO_DCHECK(size_incl_header > partial_buf_.size());
// There is a good chance that between the |partial_buf_| and the new |data|
// of the current call we have enough bytes to parse a TracePacket.
if (partial_buf_.size() + size >= size_incl_header) {
// Create a new buffer for the whole TracePacket and copy into that:
// 1) The beginning of the TracePacket (including the proto header) from
// the partial buffer.
// 2) The rest of the TracePacket from the current |data| buffer (note
// that we might have consumed already a few bytes form |data| earlier
// in this function, hence we need to keep |off| into account).
std::unique_ptr<uint8_t[]> buf(new uint8_t[size_incl_header]);
memcpy(&buf[0], partial_buf_.data(), partial_buf_.size());
// |size_missing| is the number of bytes for the rest of the TracePacket
// in |data|.
size_t size_missing = size_incl_header - partial_buf_.size();
memcpy(&buf[partial_buf_.size()], &data[0], size_missing);
data += size_missing;
size -= size_missing;
partial_buf_.clear();
uint8_t* buf_start = &buf[0]; // Note that buf is std::moved below.
ParseInternal(std::move(buf), buf_start, size_incl_header);
} else {
partial_buf_.insert(partial_buf_.end(), data, &data[size]);
return true;
}
}
ParseInternal(std::move(owned_buf), data, size);
return true;
}
void ProtoTraceTokenizer::ParseInternal(std::unique_ptr<uint8_t[]> owned_buf,
uint8_t* data,
size_t size) {
PERFETTO_DCHECK(data >= &owned_buf[0]);
const uint8_t* start = &owned_buf[0];
const size_t data_off = static_cast<size_t>(data - start);
TraceBlobView whole_buf(std::move(owned_buf), data_off, size);
ProtoDecoder decoder(data, size);
for (auto fld = decoder.ReadField(); fld.id != 0; fld = decoder.ReadField()) {
if (fld.id != protos::Trace::kPacketFieldNumber) {
PERFETTO_ELOG("Non-trace packet field found in root Trace proto");
continue;
}
size_t field_offset = static_cast<size_t>(fld.data() - start);
ParsePacket(whole_buf.slice(field_offset, fld.size()));
}
const size_t leftover = static_cast<size_t>(size - decoder.offset());
if (leftover > 0) {
PERFETTO_DCHECK(partial_buf_.empty());
partial_buf_.insert(partial_buf_.end(), &data[decoder.offset()],
&data[decoder.offset() + leftover]);
}
}
void ProtoTraceTokenizer::ParsePacket(TraceBlobView packet) {
constexpr auto kTimestampFieldNumber =
protos::TracePacket::kTimestampFieldNumber;
ProtoDecoder decoder(packet.data(), packet.length());
uint64_t timestamp = 0;
bool timestamp_found = false;
// Speculate on the fact that the timestamp is often the 1st field of the
// packet.
constexpr auto timestampFieldTag = MakeTagVarInt(kTimestampFieldNumber);
if (PERFETTO_LIKELY(packet.length() > 10 &&
packet.data()[0] == timestampFieldTag)) {
// Fastpath.
const uint8_t* next =
ParseVarInt(packet.data() + 1, packet.data() + 11, &timestamp);
timestamp_found = next != packet.data() + 1;
decoder.Reset(next);
} else {
// Slowpath.
timestamp_found = decoder.FindIntField<kTimestampFieldNumber>(&timestamp);
}
if (timestamp_found)
last_timestamp_ = timestamp;
// TODO(primiano): this can be optimized for the ftrace case.
for (auto fld = decoder.ReadField(); fld.id != 0; fld = decoder.ReadField()) {
if (fld.id == protos::TracePacket::kTrustedUidFieldNumber)
continue;
if (fld.id == protos::TracePacket::kFtraceEventsFieldNumber) {
const size_t fld_off = packet.offset_of(fld.data());
ParseFtraceBundle(packet.slice(fld_off, fld.size()));
return;
}
}
// Use parent data and length because we want to parse this again
// later to get the exact type of the packet.
trace_sorter_->PushTracePacket(last_timestamp_, std::move(packet));
PERFETTO_DCHECK(decoder.IsEndOfBuffer());
}
PERFETTO_ALWAYS_INLINE
void ProtoTraceTokenizer::ParseFtraceBundle(TraceBlobView bundle) {
constexpr auto kCpuFieldNumber = protos::FtraceEventBundle::kCpuFieldNumber;
constexpr auto kCpuFieldTag = MakeTagVarInt(kCpuFieldNumber);
const uint8_t* data = bundle.data();
const size_t length = bundle.length();
ProtoDecoder decoder(data, length);
// For speed we speculate on the location and size (<128) of the cpu field.
// In P+ cpu is pushed as the first field.
// In P cpu is pushed as the 2nd last field.
uint64_t cpu = 0;
if (length > 2 && data[0] == kCpuFieldTag && data[1] < 0x80) {
cpu = data[1];
} else if (PERFETTO_LIKELY(length > 4 && data[length - 4] == kCpuFieldTag) &&
data[length - 3] < 0x80) {
cpu = data[length - 3];
} else {
if (!PERFETTO_LIKELY((decoder.FindIntField<kCpuFieldNumber>(&cpu)))) {
PERFETTO_ELOG("CPU field not found in FtraceEventBundle");
return;
}
}
for (auto fld = decoder.ReadField(); fld.id != 0; fld = decoder.ReadField()) {
switch (fld.id) {
case protos::FtraceEventBundle::kEventFieldNumber: {
const size_t fld_off = bundle.offset_of(fld.data());
auto cpu_32 = static_cast<uint32_t>(cpu);
ParseFtraceEvent(cpu_32, bundle.slice(fld_off, fld.size()));
break;
}
default:
break;
}
}
PERFETTO_DCHECK(decoder.IsEndOfBuffer());
}
PERFETTO_ALWAYS_INLINE
void ProtoTraceTokenizer::ParseFtraceEvent(uint32_t cpu, TraceBlobView event) {
constexpr auto kTimestampFieldNumber =
protos::FtraceEvent::kTimestampFieldNumber;
const uint8_t* data = event.data();
const size_t length = event.length();
ProtoDecoder decoder(data, length);
uint64_t timestamp;
bool timestamp_found = false;
// Speculate on the fact that the timestamp is often the 1st field of the
// event.
constexpr auto timestampFieldTag = MakeTagVarInt(kTimestampFieldNumber);
if (PERFETTO_LIKELY(length > 10 && data[0] == timestampFieldTag)) {
// Fastpath.
const uint8_t* next = ParseVarInt(data + 1, data + 11, &timestamp);
timestamp_found = next != data + 1;
decoder.Reset(next);
} else {
// Slowpath.
timestamp_found = decoder.FindIntField<kTimestampFieldNumber>(&timestamp);
}
if (PERFETTO_UNLIKELY(!timestamp_found)) {
PERFETTO_ELOG("Timestamp field not found in FtraceEvent");
return;
}
last_timestamp_ = timestamp;
// We don't need to parse this packet, just push it to be sorted with
// the timestamp.
trace_sorter_->PushFtracePacket(cpu, timestamp, std::move(event));
}
} // namespace trace_processor
} // namespace perfetto