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/test/fake_packet.h"
18
19#include <ostream>
20
21#include "perfetto/base/logging.h"
22#include "perfetto/protozero/proto_utils.h"
23#include "perfetto/tracing/core/shared_memory_abi.h"
24#include "src/tracing/core/trace_buffer.h"
25
26using protozero::proto_utils::ParseVarInt;
27using protozero::proto_utils::WriteVarInt;
28
29namespace perfetto {
30
31FakePacketFragment::FakePacketFragment(size_t size, char prefix) {
32  // |size| has to be at least == 2, because one byte will be taken just by the
33  // varint header.
34  PERFETTO_CHECK(size > 1);
35
36  // Finding the |payload_size| from |size| is quite tricky:
37  // A packet with 127 bytes of payload requires:
38  //   1B header (to represent the number 127 in varint) + 127 = 128 bytes.
39  // A packet with 128 bytes payload requires:
40  //   2B header (to represent the number 128 in varint) + 128 = 130 bytes.
41  // So the only way to generate a packet of 129 bytes in total we need to
42  // generate a redundant varint header of 2 bytes + 127 bytes of payload.
43  if (size <= 128) {
44    header_[0] = static_cast<uint8_t>(size - 1);
45    header_size_ = 1;
46    payload_.resize(size - 1);
47  } else if (size == 129) {
48    header_[0] = 0x80 | 127;
49    header_size_ = 2;
50    payload_.resize(127);
51  } else {
52    WriteVarInt(size - 2, &header_[0]);
53    header_size_ = 2;
54    payload_.resize(size - 2);
55  }
56  // Fills the payload as follow: X00-X01-X02 (where X == |prefix|);
57  for (size_t i = 0; i < payload_.size(); i++) {
58    switch (i % 4) {
59      case 0:
60        payload_[i] = prefix;
61        break;
62      case 1:
63        payload_[i] = '0' + ((i / 4 / 10) % 10);
64        break;
65      case 2:
66        payload_[i] = '0' + ((i / 4) % 10);
67        break;
68      case 3:
69        payload_[i] = '-';
70        break;
71    }
72  }
73}
74
75FakePacketFragment::FakePacketFragment(const void* payload,
76                                       size_t payload_size) {
77  PERFETTO_CHECK(payload_size <= 4096 - 2);
78  payload_.assign(reinterpret_cast<const char*>(payload), payload_size);
79  uint8_t* end = WriteVarInt(payload_.size(), &header_[0]);
80  header_size_ = static_cast<size_t>(end - &header_[0]);
81}
82
83void FakePacketFragment::CopyInto(std::vector<uint8_t>* data) const {
84  data->insert(data->end(), &header_[0], &header_[0] + header_size_);
85  data->insert(data->end(), payload_.begin(), payload_.end());
86}
87
88size_t FakePacketFragment::GetSizeHeader() const {
89  uint64_t size = 0;
90  ParseVarInt(&header_[0], &header_[0] + header_size_, &size);
91  return static_cast<size_t>(size);
92}
93
94bool FakePacketFragment::operator==(const FakePacketFragment& o) const {
95  if (payload_ != o.payload_)
96    return false;
97  PERFETTO_CHECK(GetSizeHeader() == o.GetSizeHeader());
98  return true;
99}
100
101std::ostream& operator<<(std::ostream& os, const FakePacketFragment& packet) {
102  return os << "{len:" << packet.payload().size() << ", payload:\""
103            << packet.payload() << "\"}";
104}
105
106FakeChunk::FakeChunk(TraceBuffer* t, ProducerID p, WriterID w, ChunkID c)
107    : trace_buffer_{t}, producer_id{p}, writer_id{w}, chunk_id{c} {}
108
109FakeChunk& FakeChunk::AddPacket(size_t size, char seed, uint8_t packet_flag) {
110  PERFETTO_DCHECK(size <= 4096);
111  PERFETTO_CHECK(
112      !(packet_flag &
113        SharedMemoryABI::ChunkHeader::kFirstPacketContinuesFromPrevChunk) ||
114      num_packets == 0);
115  PERFETTO_CHECK(
116      !(flags & SharedMemoryABI::ChunkHeader::kLastPacketContinuesOnNextChunk));
117  flags |= packet_flag;
118  FakePacketFragment(size, seed).CopyInto(&data);
119  num_packets++;
120  return *this;
121}
122
123FakeChunk& FakeChunk::AddPacket(std::initializer_list<uint8_t> raw) {
124  data.insert(data.end(), raw.begin(), raw.end());
125  num_packets++;
126  return *this;
127}
128
129FakeChunk& FakeChunk::IncrementNumPackets() {
130  num_packets++;
131  return *this;
132}
133
134FakeChunk& FakeChunk::ClearBytes(size_t offset, size_t len) {
135  PERFETTO_DCHECK(offset + len <= data.size());
136  memset(data.data() + offset, 0, len);
137  return *this;
138}
139
140FakeChunk& FakeChunk::SetUID(uid_t u) {
141  uid = u;
142  return *this;
143}
144
145size_t FakeChunk::CopyIntoTraceBuffer() {
146  trace_buffer_->CopyChunkUntrusted(producer_id, uid, writer_id, chunk_id,
147                                    num_packets, flags, data.data(),
148                                    data.size());
149  return data.size() + TraceBuffer::InlineChunkHeaderSize;
150}
151
152}  // namespace perfetto
153