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 21 namespace rtc { 22 23 static const int DEFAULT_SIZE = 4096; 24 25 ByteBuffer::ByteBuffer() { 26 Construct(NULL, DEFAULT_SIZE, ORDER_NETWORK); 27 } 28 29 ByteBuffer::ByteBuffer(ByteOrder byte_order) { 30 Construct(NULL, DEFAULT_SIZE, byte_order); 31 } 32 33 ByteBuffer::ByteBuffer(const char* bytes, size_t len) { 34 Construct(bytes, len, ORDER_NETWORK); 35 } 36 37 ByteBuffer::ByteBuffer(const char* bytes, size_t len, ByteOrder byte_order) { 38 Construct(bytes, len, byte_order); 39 } 40 41 ByteBuffer::ByteBuffer(const char* bytes) { 42 Construct(bytes, strlen(bytes), ORDER_NETWORK); 43 } 44 45 ByteBuffer::ByteBuffer(const Buffer& buf) { 46 Construct(buf.data<char>(), buf.size(), ORDER_NETWORK); 47 } 48 49 void 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 65 ByteBuffer::~ByteBuffer() { 66 delete[] bytes_; 67 } 68 69 bool ByteBuffer::ReadUInt8(uint8_t* val) { 70 if (!val) return false; 71 72 return ReadBytes(reinterpret_cast<char*>(val), 1); 73 } 74 75 bool 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 87 bool 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 } 103 104 bool 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 } 115 116 bool 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 } 127 128 bool 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 } 139 140 bool 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 } 149 150 void ByteBuffer::WriteUInt8(uint8_t val) { 151 WriteBytes(reinterpret_cast<const char*>(&val), 1); 152 } 153 154 void 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 } 158 159 void 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 } 167 168 void 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 } 172 173 void 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 } 177 178 void ByteBuffer::WriteString(const std::string& val) { 179 WriteBytes(val.c_str(), val.size()); 180 } 181 182 void ByteBuffer::WriteBytes(const char* val, size_t len) { 183 memcpy(ReserveWriteBuffer(len), val, len); 184 } 185 186 char* 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 } 194 195 void 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 } 212 213 bool ByteBuffer::Consume(size_t size) { 214 if (size > Length()) 215 return false; 216 start_ += size; 217 return true; 218 } 219 220 ByteBuffer::ReadPosition ByteBuffer::GetReadPosition() const { 221 return ReadPosition(start_, version_); 222 } 223 224 bool ByteBuffer::SetReadPosition(const ReadPosition &position) { 225 if (position.version_ != version_) { 226 return false; 227 } 228 start_ = position.start_; 229 return true; 230 } 231 232 void ByteBuffer::Clear() { 233 memset(bytes_, 0, size_); 234 start_ = end_ = 0; 235 ++version_; 236 } 237 238 } // namespace rtc 239
