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// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "mojo/public/bindings/lib/buffer.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <algorithm>
#include "mojo/public/bindings/lib/bindings_serialization.h"
namespace mojo {
//-----------------------------------------------------------------------------
ScratchBuffer::ScratchBuffer()
: overflow_(NULL) {
fixed_.next = NULL;
fixed_.cursor = fixed_data_;
fixed_.end = fixed_data_ + kMinSegmentSize;
}
ScratchBuffer::~ScratchBuffer() {
while (overflow_) {
Segment* doomed = overflow_;
overflow_ = overflow_->next;
free(doomed);
}
}
void* ScratchBuffer::Allocate(size_t delta) {
delta = internal::Align(delta);
void* result =
AllocateInSegment((overflow_ != NULL) ? overflow_ : &fixed_, delta);
if (result)
return result;
AddOverflowSegment(delta);
return Allocate(delta);
}
void* ScratchBuffer::AllocateInSegment(Segment* segment, size_t delta) {
void* result;
if (static_cast<size_t>(segment->end - segment->cursor) >= delta) {
result = segment->cursor;
memset(result, 0, delta);
segment->cursor += delta;
} else {
result = NULL;
}
return result;
}
void ScratchBuffer::AddOverflowSegment(size_t delta) {
if (delta < kMinSegmentSize)
delta = kMinSegmentSize;
Segment* segment = static_cast<Segment*>(malloc(sizeof(Segment) + delta));
segment->next = overflow_;
segment->cursor = reinterpret_cast<char*>(segment + 1);
segment->end = segment->cursor + delta;
overflow_ = segment;
}
//-----------------------------------------------------------------------------
FixedBuffer::FixedBuffer(size_t size)
: ptr_(NULL),
cursor_(0),
size_(internal::Align(size)) {
ptr_ = static_cast<char*>(calloc(size_, 1));
}
FixedBuffer::~FixedBuffer() {
free(ptr_);
}
void* FixedBuffer::Allocate(size_t delta) {
delta = internal::Align(delta);
// TODO(darin): Using <assert.h> is probably not going to cut it.
assert(delta > 0);
assert(cursor_ + delta <= size_);
if (cursor_ + delta > size_)
return NULL;
char* result = ptr_ + cursor_;
cursor_ += delta;
return result;
}
void* FixedBuffer::Leak() {
char* ptr = ptr_;
ptr_ = NULL;
cursor_ = 0;
size_ = 0;
return ptr;
}
} // namespace mojo
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