net/base/io_buffer.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/base/io_buffer.h"
   6
   7 #include "base/logging.h"
   8 #include "base/numerics/safe_math.h"
   9
  10 namespace net {
  11
  12 namespace {
  13
  14 // TODO(eroman): IOBuffer is being converted to require buffer sizes and offsets
  15 // be specified as "size_t" rather than "int" (crbug.com/488553). To facilitate
  16 // this move (since LOTS of code needs to be updated), both "size_t" and "int
  17 // are being accepted. When using "size_t" this function ensures that it can be
  18 // safely converted to an "int" without truncation.
  19 void AssertValidBufferSize(size_t size) {
  20   base::CheckedNumeric<int>(size).ValueOrDie();
  21 }
  22
  23 void AssertValidBufferSize(int size) {
  24   CHECK_GE(size, 0);
  25 }
  26
  27 }  // namespace
  28
  29 IOBuffer::IOBuffer()
  30     : data_(NULL) {
  31 }
  32
  33 IOBuffer::IOBuffer(int buffer_size) {
  34   AssertValidBufferSize(buffer_size);
  35   data_ = new char[buffer_size];
  36 }
  37
  38 IOBuffer::IOBuffer(size_t buffer_size) {
  39   AssertValidBufferSize(buffer_size);
  40   data_ = new char[buffer_size];
  41 }
  42
  43 IOBuffer::IOBuffer(char* data)
  44     : data_(data) {
  45 }
  46
  47 IOBuffer::~IOBuffer() {
  48   delete[] data_;
  49   data_ = NULL;
  50 }
  51
  52 IOBufferWithSize::IOBufferWithSize(int size)
  53     : IOBuffer(size),
  54       size_(size) {
  55   AssertValidBufferSize(size);
  56 }
  57
  58 IOBufferWithSize::IOBufferWithSize(size_t size) : IOBuffer(size), size_(size) {
  59   // Note: Size check is done in superclass' constructor.
  60 }
  61
  62 IOBufferWithSize::IOBufferWithSize(char* data, int size)
  63     : IOBuffer(data),
  64       size_(size) {
  65   AssertValidBufferSize(size);
  66 }
  67
  68 IOBufferWithSize::IOBufferWithSize(char* data, size_t size)
  69     : IOBuffer(data), size_(size) {
  70   AssertValidBufferSize(size);
  71 }
  72
  73 IOBufferWithSize::~IOBufferWithSize() {
  74 }
  75
  76 StringIOBuffer::StringIOBuffer(const std::string& s)
  77     : IOBuffer(static_cast<char*>(NULL)),
  78       string_data_(s) {
  79   AssertValidBufferSize(s.size());
  80   data_ = const_cast<char*>(string_data_.data());
  81 }
  82
  83 StringIOBuffer::StringIOBuffer(scoped_ptr<std::string> s)
  84     : IOBuffer(static_cast<char*>(NULL)) {
  85   AssertValidBufferSize(s->size());
  86   string_data_.swap(*s.get());
  87   data_ = const_cast<char*>(string_data_.data());
  88 }
  89
  90 StringIOBuffer::~StringIOBuffer() {
  91   // We haven't allocated the buffer, so remove it before the base class
  92   // destructor tries to delete[] it.
  93   data_ = NULL;
  94 }
  95
  96 DrainableIOBuffer::DrainableIOBuffer(IOBuffer* base, int size)
  97     : IOBuffer(base->data()),
  98       base_(base),
  99       size_(size),
 100       used_(0) {
 101   AssertValidBufferSize(size);
 102 }
 103
 104 DrainableIOBuffer::DrainableIOBuffer(IOBuffer* base, size_t size)
 105     : IOBuffer(base->data()), base_(base), size_(size), used_(0) {
 106   AssertValidBufferSize(size);
 107 }
 108
 109 void DrainableIOBuffer::DidConsume(int bytes) {
 110   SetOffset(used_ + bytes);
 111 }
 112
 113 int DrainableIOBuffer::BytesRemaining() const {
 114   return size_ - used_;
 115 }
 116
 117 // Returns the number of consumed bytes.
 118 int DrainableIOBuffer::BytesConsumed() const {
 119   return used_;
 120 }
 121
 122 void DrainableIOBuffer::SetOffset(int bytes) {
 123   DCHECK_GE(bytes, 0);
 124   DCHECK_LE(bytes, size_);
 125   used_ = bytes;
 126   data_ = base_->data() + used_;
 127 }
 128
 129 DrainableIOBuffer::~DrainableIOBuffer() {
 130   // The buffer is owned by the |base_| instance.
 131   data_ = NULL;
 132 }
 133
 134 GrowableIOBuffer::GrowableIOBuffer()
 135     : IOBuffer(),
 136       capacity_(0),
 137       offset_(0) {
 138 }
 139
 140 void GrowableIOBuffer::SetCapacity(int capacity) {
 141   DCHECK_GE(capacity, 0);
 142   // realloc will crash if it fails.
 143   real_data_.reset(static_cast<char*>(realloc(real_data_.release(), capacity)));
 144   capacity_ = capacity;
 145   if (offset_ > capacity)
 146     set_offset(capacity);
 147   else
 148     set_offset(offset_);  // The pointer may have changed.
 149 }
 150
 151 void GrowableIOBuffer::set_offset(int offset) {
 152   DCHECK_GE(offset, 0);
 153   DCHECK_LE(offset, capacity_);
 154   offset_ = offset;
 155   data_ = real_data_.get() + offset;
 156 }
 157
 158 int GrowableIOBuffer::RemainingCapacity() {
 159   return capacity_ - offset_;
 160 }
 161
 162 char* GrowableIOBuffer::StartOfBuffer() {
 163   return real_data_.get();
 164 }
 165
 166 GrowableIOBuffer::~GrowableIOBuffer() {
 167   data_ = NULL;
 168 }
 169
 170 PickledIOBuffer::PickledIOBuffer() : IOBuffer() {
 171 }
 172
 173 void PickledIOBuffer::Done() {
 174   data_ = const_cast<char*>(static_cast<const char*>(pickle_.data()));
 175 }
 176
 177 PickledIOBuffer::~PickledIOBuffer() {
 178   data_ = NULL;
 179 }
 180
 181 WrappedIOBuffer::WrappedIOBuffer(const char* data)
 182     : IOBuffer(const_cast<char*>(data)) {
 183 }
 184
 185 WrappedIOBuffer::~WrappedIOBuffer() {
 186   data_ = NULL;
 187 }
 188
 189 }  // namespace net