mojo/public/cpp/bindings/lib/fixed_buffer.cc

   1 // Copyright 2014 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 "mojo/public/cpp/bindings/lib/fixed_buffer.h"
   6
   7 #include <stdlib.h>
   8
   9 #include <algorithm>
  10
  11 #include "mojo/public/cpp/bindings/lib/bindings_serialization.h"
  12 #include "mojo/public/cpp/environment/logging.h"
  13
  14 namespace mojo {
  15 namespace internal {
  16
  17 FixedBuffer::FixedBuffer(size_t size)
  18     : ptr_(NULL),
  19       cursor_(0),
  20       size_(internal::Align(size)) {
  21   // calloc() required to zero memory and thus avoid info leaks.
  22   ptr_ = static_cast<char*>(calloc(size_, 1));
  23 }
  24
  25 FixedBuffer::~FixedBuffer() {
  26   free(ptr_);
  27 }
  28
  29 void* FixedBuffer::Allocate(size_t delta) {
  30   delta = internal::Align(delta);
  31
  32   if (delta == 0 || delta > size_ - cursor_) {
  33     MOJO_DCHECK(false) << "Not reached";
  34     return NULL;
  35   }
  36
  37   char* result = ptr_ + cursor_;
  38   cursor_ += delta;
  39
  40   return result;
  41 }
  42
  43 void* FixedBuffer::Leak() {
  44   char* ptr = ptr_;
  45   ptr_ = NULL;
  46   cursor_ = 0;
  47   size_ = 0;
  48   return ptr;
  49 }
  50
  51 }  // namespace internal
  52 }  // namespace mojo