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/*
* Copyright 2018 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/memory_stream.h"
#include <errno.h>
#include <string.h>
#include <algorithm>
#include "rtc_base/checks.h"
namespace rtc {
StreamState MemoryStream::GetState() const {
return SS_OPEN;
}
StreamResult MemoryStream::Read(void* buffer,
size_t bytes,
size_t* bytes_read,
int* error) {
if (seek_position_ >= data_length_) {
return SR_EOS;
}
size_t available = data_length_ - seek_position_;
if (bytes > available) {
// Read partial buffer
bytes = available;
}
memcpy(buffer, &buffer_[seek_position_], bytes);
seek_position_ += bytes;
if (bytes_read) {
*bytes_read = bytes;
}
return SR_SUCCESS;
}
StreamResult MemoryStream::Write(const void* buffer,
size_t bytes,
size_t* bytes_written,
int* error) {
size_t available = buffer_length_ - seek_position_;
if (0 == available) {
// Increase buffer size to the larger of:
// a) new position rounded up to next 256 bytes
// b) double the previous length
size_t new_buffer_length =
std::max(((seek_position_ + bytes) | 0xFF) + 1, buffer_length_ * 2);
StreamResult result = DoReserve(new_buffer_length, error);
if (SR_SUCCESS != result) {
return result;
}
RTC_DCHECK(buffer_length_ >= new_buffer_length);
available = buffer_length_ - seek_position_;
}
if (bytes > available) {
bytes = available;
}
memcpy(&buffer_[seek_position_], buffer, bytes);
seek_position_ += bytes;
if (data_length_ < seek_position_) {
data_length_ = seek_position_;
}
if (bytes_written) {
*bytes_written = bytes;
}
return SR_SUCCESS;
}
void MemoryStream::Close() {
// nothing to do
}
bool MemoryStream::SetPosition(size_t position) {
if (position > data_length_)
return false;
seek_position_ = position;
return true;
}
bool MemoryStream::GetPosition(size_t* position) const {
if (position)
*position = seek_position_;
return true;
}
void MemoryStream::Rewind() {
seek_position_ = 0;
}
bool MemoryStream::GetSize(size_t* size) const {
if (size)
*size = data_length_;
return true;
}
bool MemoryStream::ReserveSize(size_t size) {
return (SR_SUCCESS == DoReserve(size, nullptr));
}
///////////////////////////////////////////////////////////////////////////////
MemoryStream::MemoryStream() {}
MemoryStream::~MemoryStream() {
delete[] buffer_;
}
void MemoryStream::SetData(const void* data, size_t length) {
data_length_ = buffer_length_ = length;
delete[] buffer_;
buffer_ = new char[buffer_length_];
memcpy(buffer_, data, data_length_);
seek_position_ = 0;
}
StreamResult MemoryStream::DoReserve(size_t size, int* error) {
if (buffer_length_ >= size)
return SR_SUCCESS;
if (char* new_buffer = new char[size]) {
memcpy(new_buffer, buffer_, data_length_);
delete[] buffer_;
buffer_ = new_buffer;
buffer_length_ = size;
return SR_SUCCESS;
}
if (error) {
*error = ENOMEM;
}
return SR_ERROR;
}
} // namespace rtc
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