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      1 /*
      2  * libjingle
      3  * Copyright 2004--2005, Google Inc.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  *  1. Redistributions of source code must retain the above copyright notice,
      9  *     this list of conditions and the following disclaimer.
     10  *  2. Redistributions in binary form must reproduce the above copyright notice,
     11  *     this list of conditions and the following disclaimer in the documentation
     12  *     and/or other materials provided with the distribution.
     13  *  3. The name of the author may not be used to endorse or promote products
     14  *     derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include "talk/base/bytebuffer.h"
     29 
     30 #include <algorithm>
     31 #include <cassert>
     32 #include <cstring>
     33 
     34 #include "talk/base/basictypes.h"
     35 #include "talk/base/byteorder.h"
     36 
     37 namespace talk_base {
     38 
     39 static const int DEFAULT_SIZE = 4096;
     40 
     41 ByteBuffer::ByteBuffer() {
     42   start_ = 0;
     43   end_   = 0;
     44   size_  = DEFAULT_SIZE;
     45   bytes_ = new char[size_];
     46 }
     47 
     48 ByteBuffer::ByteBuffer(const char* bytes, size_t len) {
     49   start_ = 0;
     50   end_   = len;
     51   size_  = len;
     52   bytes_ = new char[size_];
     53   memcpy(bytes_, bytes, end_);
     54 }
     55 
     56 ByteBuffer::ByteBuffer(const char* bytes) {
     57   start_ = 0;
     58   end_   = strlen(bytes);
     59   size_  = end_;
     60   bytes_ = new char[size_];
     61   memcpy(bytes_, bytes, end_);
     62 }
     63 
     64 ByteBuffer::~ByteBuffer() {
     65   delete[] bytes_;
     66 }
     67 
     68 bool ByteBuffer::ReadUInt8(uint8* val) {
     69   if (!val) return false;
     70 
     71   return ReadBytes(reinterpret_cast<char*>(val), 1);
     72 }
     73 
     74 bool ByteBuffer::ReadUInt16(uint16* val) {
     75   if (!val) return false;
     76 
     77   uint16 v;
     78   if (!ReadBytes(reinterpret_cast<char*>(&v), 2)) {
     79     return false;
     80   } else {
     81     *val = NetworkToHost16(v);
     82     return true;
     83   }
     84 }
     85 
     86 bool ByteBuffer::ReadUInt24(uint32* val) {
     87   if (!val) return false;
     88 
     89   uint32 v = 0;
     90   if (!ReadBytes(reinterpret_cast<char*>(&v) + 1, 3)) {
     91     return false;
     92   } else {
     93     *val = NetworkToHost32(v);
     94     return true;
     95   }
     96 }
     97 
     98 bool ByteBuffer::ReadUInt32(uint32* val) {
     99   if (!val) return false;
    100 
    101   uint32 v;
    102   if (!ReadBytes(reinterpret_cast<char*>(&v), 4)) {
    103     return false;
    104   } else {
    105     *val = NetworkToHost32(v);
    106     return true;
    107   }
    108 }
    109 
    110 bool ByteBuffer::ReadUInt64(uint64* val) {
    111   if (!val) return false;
    112 
    113   uint64 v;
    114   if (!ReadBytes(reinterpret_cast<char*>(&v), 8)) {
    115     return false;
    116   } else {
    117     *val = NetworkToHost64(v);
    118     return true;
    119   }
    120 }
    121 
    122 bool ByteBuffer::ReadString(std::string* val, size_t len) {
    123   if (!val) return false;
    124 
    125   if (len > Length()) {
    126     return false;
    127   } else {
    128     val->append(bytes_ + start_, len);
    129     start_ += len;
    130     return true;
    131   }
    132 }
    133 
    134 bool ByteBuffer::ReadBytes(char* val, size_t len) {
    135   if (len > Length()) {
    136     return false;
    137   } else {
    138     memcpy(val, bytes_ + start_, len);
    139     start_ += len;
    140     return true;
    141   }
    142 }
    143 
    144 void ByteBuffer::WriteUInt8(uint8 val) {
    145   WriteBytes(reinterpret_cast<const char*>(&val), 1);
    146 }
    147 
    148 void ByteBuffer::WriteUInt16(uint16 val) {
    149   uint16 v = HostToNetwork16(val);
    150   WriteBytes(reinterpret_cast<const char*>(&v), 2);
    151 }
    152 
    153 void ByteBuffer::WriteUInt24(uint32 val) {
    154   uint32 v = HostToNetwork32(val);
    155   WriteBytes(reinterpret_cast<const char*>(&v) + 1, 3);
    156 }
    157 
    158 void ByteBuffer::WriteUInt32(uint32 val) {
    159   uint32 v = HostToNetwork32(val);
    160   WriteBytes(reinterpret_cast<const char*>(&v), 4);
    161 }
    162 
    163 void ByteBuffer::WriteUInt64(uint64 val) {
    164   uint64 v = HostToNetwork64(val);
    165   WriteBytes(reinterpret_cast<const char*>(&v), 8);
    166 }
    167 
    168 void ByteBuffer::WriteString(const std::string& val) {
    169   WriteBytes(val.c_str(), val.size());
    170 }
    171 
    172 void ByteBuffer::WriteBytes(const char* val, size_t len) {
    173   if (Length() + len > Capacity())
    174     Resize(Length() + len);
    175 
    176   memcpy(bytes_ + end_, val, len);
    177   end_ += len;
    178 }
    179 
    180 void ByteBuffer::Resize(size_t size) {
    181   if (size > size_)
    182     size = _max(size, 3 * size_ / 2);
    183 
    184   size_t len = _min(end_ - start_, size);
    185   char* new_bytes = new char[size];
    186   memcpy(new_bytes, bytes_ + start_, len);
    187   delete [] bytes_;
    188 
    189   start_ = 0;
    190   end_   = len;
    191   size_  = size;
    192   bytes_ = new_bytes;
    193 }
    194 
    195 void ByteBuffer::Consume(size_t size) {
    196   if (size > Length())
    197     return;
    198 
    199   start_ += size;
    200 }
    201 
    202 void ByteBuffer::Shift(size_t size) {
    203   if (size > Length())
    204     return;
    205 
    206   end_ = Length() - size;
    207   memmove(bytes_, bytes_ + start_ + size, end_);
    208   start_ = 0;
    209 }
    210 
    211 }  // namespace talk_base
    212