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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 
ByteBuffer()41 ByteBuffer::ByteBuffer() {
42   start_ = 0;
43   end_   = 0;
44   size_  = DEFAULT_SIZE;
45   bytes_ = new char[size_];
46 }
47 
ByteBuffer(const char * bytes,size_t len)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 
ByteBuffer(const char * bytes)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 
~ByteBuffer()64 ByteBuffer::~ByteBuffer() {
65   delete[] bytes_;
66 }
67 
ReadUInt8(uint8 * val)68 bool ByteBuffer::ReadUInt8(uint8* val) {
69   if (!val) return false;
70 
71   return ReadBytes(reinterpret_cast<char*>(val), 1);
72 }
73 
ReadUInt16(uint16 * val)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 
ReadUInt24(uint32 * val)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 
ReadUInt32(uint32 * val)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 
ReadUInt64(uint64 * val)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 
ReadString(std::string * val,size_t len)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 
ReadBytes(char * val,size_t len)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 
WriteUInt8(uint8 val)144 void ByteBuffer::WriteUInt8(uint8 val) {
145   WriteBytes(reinterpret_cast<const char*>(&val), 1);
146 }
147 
WriteUInt16(uint16 val)148 void ByteBuffer::WriteUInt16(uint16 val) {
149   uint16 v = HostToNetwork16(val);
150   WriteBytes(reinterpret_cast<const char*>(&v), 2);
151 }
152 
WriteUInt24(uint32 val)153 void ByteBuffer::WriteUInt24(uint32 val) {
154   uint32 v = HostToNetwork32(val);
155   WriteBytes(reinterpret_cast<const char*>(&v) + 1, 3);
156 }
157 
WriteUInt32(uint32 val)158 void ByteBuffer::WriteUInt32(uint32 val) {
159   uint32 v = HostToNetwork32(val);
160   WriteBytes(reinterpret_cast<const char*>(&v), 4);
161 }
162 
WriteUInt64(uint64 val)163 void ByteBuffer::WriteUInt64(uint64 val) {
164   uint64 v = HostToNetwork64(val);
165   WriteBytes(reinterpret_cast<const char*>(&v), 8);
166 }
167 
WriteString(const std::string & val)168 void ByteBuffer::WriteString(const std::string& val) {
169   WriteBytes(val.c_str(), val.size());
170 }
171 
WriteBytes(const char * val,size_t len)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 
Resize(size_t size)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 
Consume(size_t size)195 void ByteBuffer::Consume(size_t size) {
196   if (size > Length())
197     return;
198 
199   start_ += size;
200 }
201 
Shift(size_t size)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