1/*
2 *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include "webrtc/base/bytebuffer.h"
12
13#include <assert.h>
14#include <string.h>
15
16#include <algorithm>
17
18#include "webrtc/base/basictypes.h"
19#include "webrtc/base/byteorder.h"
20
21namespace rtc {
22
23static const int DEFAULT_SIZE = 4096;
24
25ByteBuffer::ByteBuffer() {
26  Construct(NULL, DEFAULT_SIZE, ORDER_NETWORK);
27}
28
29ByteBuffer::ByteBuffer(ByteOrder byte_order) {
30  Construct(NULL, DEFAULT_SIZE, byte_order);
31}
32
33ByteBuffer::ByteBuffer(const char* bytes, size_t len) {
34  Construct(bytes, len, ORDER_NETWORK);
35}
36
37ByteBuffer::ByteBuffer(const char* bytes, size_t len, ByteOrder byte_order) {
38  Construct(bytes, len, byte_order);
39}
40
41ByteBuffer::ByteBuffer(const char* bytes) {
42  Construct(bytes, strlen(bytes), ORDER_NETWORK);
43}
44
45ByteBuffer::ByteBuffer(const Buffer& buf) {
46  Construct(buf.data<char>(), buf.size(), ORDER_NETWORK);
47}
48
49void ByteBuffer::Construct(const char* bytes, size_t len,
50                           ByteOrder byte_order) {
51  version_ = 0;
52  start_ = 0;
53  size_ = len;
54  byte_order_ = byte_order;
55  bytes_ = new char[size_];
56
57  if (bytes) {
58    end_ = len;
59    memcpy(bytes_, bytes, end_);
60  } else {
61    end_ = 0;
62  }
63}
64
65ByteBuffer::~ByteBuffer() {
66  delete[] bytes_;
67}
68
69bool ByteBuffer::ReadUInt8(uint8_t* val) {
70  if (!val) return false;
71
72  return ReadBytes(reinterpret_cast<char*>(val), 1);
73}
74
75bool ByteBuffer::ReadUInt16(uint16_t* val) {
76  if (!val) return false;
77
78  uint16_t v;
79  if (!ReadBytes(reinterpret_cast<char*>(&v), 2)) {
80    return false;
81  } else {
82    *val = (byte_order_ == ORDER_NETWORK) ? NetworkToHost16(v) : v;
83    return true;
84  }
85}
86
87bool ByteBuffer::ReadUInt24(uint32_t* val) {
88  if (!val) return false;
89
90  uint32_t v = 0;
91  char* read_into = reinterpret_cast<char*>(&v);
92  if (byte_order_ == ORDER_NETWORK || IsHostBigEndian()) {
93    ++read_into;
94  }
95
96  if (!ReadBytes(read_into, 3)) {
97    return false;
98  } else {
99    *val = (byte_order_ == ORDER_NETWORK) ? NetworkToHost32(v) : v;
100    return true;
101  }
102}
103
104bool ByteBuffer::ReadUInt32(uint32_t* val) {
105  if (!val) return false;
106
107  uint32_t v;
108  if (!ReadBytes(reinterpret_cast<char*>(&v), 4)) {
109    return false;
110  } else {
111    *val = (byte_order_ == ORDER_NETWORK) ? NetworkToHost32(v) : v;
112    return true;
113  }
114}
115
116bool ByteBuffer::ReadUInt64(uint64_t* val) {
117  if (!val) return false;
118
119  uint64_t v;
120  if (!ReadBytes(reinterpret_cast<char*>(&v), 8)) {
121    return false;
122  } else {
123    *val = (byte_order_ == ORDER_NETWORK) ? NetworkToHost64(v) : v;
124    return true;
125  }
126}
127
128bool ByteBuffer::ReadString(std::string* val, size_t len) {
129  if (!val) return false;
130
131  if (len > Length()) {
132    return false;
133  } else {
134    val->append(bytes_ + start_, len);
135    start_ += len;
136    return true;
137  }
138}
139
140bool ByteBuffer::ReadBytes(char* val, size_t len) {
141  if (len > Length()) {
142    return false;
143  } else {
144    memcpy(val, bytes_ + start_, len);
145    start_ += len;
146    return true;
147  }
148}
149
150void ByteBuffer::WriteUInt8(uint8_t val) {
151  WriteBytes(reinterpret_cast<const char*>(&val), 1);
152}
153
154void ByteBuffer::WriteUInt16(uint16_t val) {
155  uint16_t v = (byte_order_ == ORDER_NETWORK) ? HostToNetwork16(val) : val;
156  WriteBytes(reinterpret_cast<const char*>(&v), 2);
157}
158
159void ByteBuffer::WriteUInt24(uint32_t val) {
160  uint32_t v = (byte_order_ == ORDER_NETWORK) ? HostToNetwork32(val) : val;
161  char* start = reinterpret_cast<char*>(&v);
162  if (byte_order_ == ORDER_NETWORK || IsHostBigEndian()) {
163    ++start;
164  }
165  WriteBytes(start, 3);
166}
167
168void ByteBuffer::WriteUInt32(uint32_t val) {
169  uint32_t v = (byte_order_ == ORDER_NETWORK) ? HostToNetwork32(val) : val;
170  WriteBytes(reinterpret_cast<const char*>(&v), 4);
171}
172
173void ByteBuffer::WriteUInt64(uint64_t val) {
174  uint64_t v = (byte_order_ == ORDER_NETWORK) ? HostToNetwork64(val) : val;
175  WriteBytes(reinterpret_cast<const char*>(&v), 8);
176}
177
178void ByteBuffer::WriteString(const std::string& val) {
179  WriteBytes(val.c_str(), val.size());
180}
181
182void ByteBuffer::WriteBytes(const char* val, size_t len) {
183  memcpy(ReserveWriteBuffer(len), val, len);
184}
185
186char* ByteBuffer::ReserveWriteBuffer(size_t len) {
187  if (Length() + len > Capacity())
188    Resize(Length() + len);
189
190  char* start = bytes_ + end_;
191  end_ += len;
192  return start;
193}
194
195void ByteBuffer::Resize(size_t size) {
196  size_t len = std::min(end_ - start_, size);
197  if (size <= size_) {
198    // Don't reallocate, just move data backwards
199    memmove(bytes_, bytes_ + start_, len);
200  } else {
201    // Reallocate a larger buffer.
202    size_ = std::max(size, 3 * size_ / 2);
203    char* new_bytes = new char[size_];
204    memcpy(new_bytes, bytes_ + start_, len);
205    delete [] bytes_;
206    bytes_ = new_bytes;
207  }
208  start_ = 0;
209  end_ = len;
210  ++version_;
211}
212
213bool ByteBuffer::Consume(size_t size) {
214  if (size > Length())
215    return false;
216  start_ += size;
217  return true;
218}
219
220ByteBuffer::ReadPosition ByteBuffer::GetReadPosition() const {
221  return ReadPosition(start_, version_);
222}
223
224bool ByteBuffer::SetReadPosition(const ReadPosition &position) {
225  if (position.version_ != version_) {
226    return false;
227  }
228  start_ = position.start_;
229  return true;
230}
231
232void ByteBuffer::Clear() {
233  memset(bytes_, 0, size_);
234  start_ = end_ = 0;
235  ++version_;
236}
237
238}  // namespace rtc
239