blob: 579dd460ba25c102a47ed3b2eed9536f8bf14f21 [file] [log] [blame]
/*
* Copyright 2016 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "rtc_base/copyonwritebuffer.h"
namespace rtc {
CopyOnWriteBuffer::CopyOnWriteBuffer() {
RTC_DCHECK(IsConsistent());
}
CopyOnWriteBuffer::CopyOnWriteBuffer(const CopyOnWriteBuffer& buf)
: buffer_(buf.buffer_) {
}
CopyOnWriteBuffer::CopyOnWriteBuffer(CopyOnWriteBuffer&& buf)
: buffer_(std::move(buf.buffer_)) {
}
CopyOnWriteBuffer::CopyOnWriteBuffer(size_t size)
: buffer_(size > 0 ? new RefCountedObject<Buffer>(size) : nullptr) {
RTC_DCHECK(IsConsistent());
}
CopyOnWriteBuffer::CopyOnWriteBuffer(size_t size, size_t capacity)
: buffer_(size > 0 || capacity > 0
? new RefCountedObject<Buffer>(size, capacity)
: nullptr) {
RTC_DCHECK(IsConsistent());
}
CopyOnWriteBuffer::~CopyOnWriteBuffer() = default;
bool CopyOnWriteBuffer::operator==(const CopyOnWriteBuffer& buf) const {
// Must either use the same buffer internally or have the same contents.
RTC_DCHECK(IsConsistent());
RTC_DCHECK(buf.IsConsistent());
return buffer_.get() == buf.buffer_.get() ||
(buffer_.get() && buf.buffer_.get() &&
*buffer_.get() == *buf.buffer_.get());
}
void CopyOnWriteBuffer::SetSize(size_t size) {
RTC_DCHECK(IsConsistent());
if (!buffer_) {
if (size > 0) {
buffer_ = new RefCountedObject<Buffer>(size);
}
RTC_DCHECK(IsConsistent());
return;
}
// Clone data if referenced.
if (!buffer_->HasOneRef()) {
buffer_ = new RefCountedObject<Buffer>(
buffer_->data(),
std::min(buffer_->size(), size),
std::max(buffer_->capacity(), size));
}
buffer_->SetSize(size);
RTC_DCHECK(IsConsistent());
}
void CopyOnWriteBuffer::EnsureCapacity(size_t capacity) {
RTC_DCHECK(IsConsistent());
if (!buffer_) {
if (capacity > 0) {
buffer_ = new RefCountedObject<Buffer>(0, capacity);
}
RTC_DCHECK(IsConsistent());
return;
} else if (capacity <= buffer_->capacity()) {
return;
}
CloneDataIfReferenced(std::max(buffer_->capacity(), capacity));
buffer_->EnsureCapacity(capacity);
RTC_DCHECK(IsConsistent());
}
void CopyOnWriteBuffer::Clear() {
if (!buffer_)
return;
if (buffer_->HasOneRef()) {
buffer_->Clear();
} else {
buffer_ = new RefCountedObject<Buffer>(0, buffer_->capacity());
}
RTC_DCHECK(IsConsistent());
}
void CopyOnWriteBuffer::CloneDataIfReferenced(size_t new_capacity) {
if (buffer_->HasOneRef()) {
return;
}
buffer_ = new RefCountedObject<Buffer>(buffer_->data(), buffer_->size(),
new_capacity);
RTC_DCHECK(IsConsistent());
}
} // namespace rtc