1 /*
2 * Copyright (C) 2018 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "src/tracing/core/trace_writer_for_testing.h"
18
19 #include "perfetto/base/logging.h"
20 #include "perfetto/ext/base/utils.h"
21 #include "perfetto/protozero/message.h"
22 #include "protos/perfetto/trace/trace.pbzero.h"
23 #include "protos/perfetto/trace/trace_packet.pbzero.h"
24
25 namespace perfetto {
26
TraceWriterForTesting()27 TraceWriterForTesting::TraceWriterForTesting()
28 : delegate_(static_cast<size_t>(base::kPageSize),
29 static_cast<size_t>(base::kPageSize)),
30 stream_(&delegate_) {
31 delegate_.set_writer(&stream_);
32 cur_packet_.reset(new protos::pbzero::TracePacket());
33 cur_packet_->Finalize(); // To avoid the DCHECK in NewTracePacket().
34 }
35
~TraceWriterForTesting()36 TraceWriterForTesting::~TraceWriterForTesting() {}
37
Flush(std::function<void ()> callback)38 void TraceWriterForTesting::Flush(std::function<void()> callback) {
39 // Flush() cannot be called in the middle of a TracePacket.
40 PERFETTO_CHECK(cur_packet_->is_finalized());
41
42 if (callback)
43 callback();
44 }
45
46 std::vector<protos::gen::TracePacket>
GetAllTracePackets()47 TraceWriterForTesting::GetAllTracePackets() {
48 PERFETTO_CHECK(cur_packet_->is_finalized());
49
50 std::vector<uint8_t> buffer = delegate_.StitchSlices();
51 protozero::ProtoDecoder trace(buffer.data(), buffer.size());
52 std::vector<protos::gen::TracePacket> ret;
53 for (auto fld = trace.ReadField(); fld.valid(); fld = trace.ReadField()) {
54 PERFETTO_CHECK(fld.id() == protos::pbzero::Trace::kPacketFieldNumber);
55 protos::gen::TracePacket packet;
56 packet.ParseFromArray(fld.data(), fld.size());
57 ret.emplace_back(std::move(packet));
58 }
59 PERFETTO_CHECK(trace.bytes_left() == 0);
60 return ret;
61 }
62
GetOnlyTracePacket()63 protos::gen::TracePacket TraceWriterForTesting::GetOnlyTracePacket() {
64 auto packets = GetAllTracePackets();
65 PERFETTO_CHECK(packets.size() == 1);
66 return packets[0];
67 }
68
69 TraceWriterForTesting::TracePacketHandle
NewTracePacket()70 TraceWriterForTesting::NewTracePacket() {
71 // If we hit this, the caller is calling NewTracePacket() without having
72 // finalized the previous packet.
73 PERFETTO_DCHECK(cur_packet_->is_finalized());
74 cur_packet_->Reset(&stream_);
75
76 // Instead of storing the contents of the TracePacket directly in the backing
77 // buffer like the real trace writers, we prepend the proto preamble to make
78 // the buffer contents parsable as a sequence of TracePacket protos.
79
80 uint8_t data[protozero::proto_utils::kMaxTagEncodedSize];
81 uint8_t* data_end = protozero::proto_utils::WriteVarInt(
82 protozero::proto_utils::MakeTagLengthDelimited(
83 protos::pbzero::Trace::kPacketFieldNumber),
84 data);
85 stream_.WriteBytes(data, static_cast<uint32_t>(data_end - data));
86
87 auto packet = TraceWriter::TracePacketHandle(cur_packet_.get());
88 packet->set_size_field(
89 stream_.ReserveBytes(protozero::proto_utils::kMessageLengthFieldSize));
90 return packet;
91 }
92
writer_id() const93 WriterID TraceWriterForTesting::writer_id() const {
94 return 0;
95 }
96
written() const97 uint64_t TraceWriterForTesting::written() const {
98 return 0;
99 }
100
101 } // namespace perfetto
102