memwritestream.cpp

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/* xoreos - A reimplementation of BioWare's Aurora engine
 *
 * xoreos is the legal property of its developers, whose names
 * can be found in the AUTHORS file distributed with this source
 * distribution.
 *
 * xoreos is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 *
 * xoreos is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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 *
 * You should have received a copy of the GNU General Public License
 * along with xoreos. If not, see <http://www.gnu.org/licenses/>.
 */

/* Based on ScummVM (<http://scummvm.org>) code, which is released
 * under the terms of version 2 or later of the GNU General Public
 * License.
 *
 * The original copyright note in ScummVM reads as follows:
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include <cassert>
#include <cstring>

#include "src/common/types.h"
#include "src/common/memwritestream.h"

namespace Common {

size_t MemoryWriteStream::write(const void *dataPtr, size_t dataSize) {
    assert(dataPtr);

    // Write at most as many bytes as are still available...
    if (dataSize > _bufSize - _pos)
        dataSize = _bufSize - _pos;

    std::memcpy(_ptr, dataPtr, dataSize);

    _ptr += dataSize;
    _pos += dataSize;

    return dataSize;
}

size_t MemoryWriteStream::pos() const {
    return _pos;
}

size_t MemoryWriteStream::size() const {
    return _bufSize;
}

size_t MemoryWriteStream::seek(ptrdiff_t offset, SeekableWriteStream::Origin whence) {
    assert((size_t)_pos <= _bufSize);

    const size_t oldPos = _pos;
    const size_t newPos = evalSeek(offset, whence, _pos, 0, size());
    if (newPos > _bufSize)
        throw Exception(kSeekError);

    _pos = newPos;
    _ptr = _ptr - oldPos + newPos;

    return oldPos;
}


MemoryWriteStreamDynamic::MemoryWriteStreamDynamic(bool disposeMemory, size_t capacity) :
        _data(0, disposeMemory), _ptr(0), _capacity(0), _size(0) {

    reserve(capacity);
}

MemoryWriteStreamDynamic::~MemoryWriteStreamDynamic() {
}

void MemoryWriteStreamDynamic::reserve(size_t s) {
    if (s <= _capacity)
        return;

    while (_capacity < s)
        _capacity = MAX<size_t>(2, _capacity * 2);

    byte *newData = new byte[_capacity];
    if (_data)
        memcpy(newData, _data.get(), _size);

    const size_t oldPos = pos();
    _data.dispose();
    _data.reset(newData);
    _ptr = _data.get() + oldPos;
}

void MemoryWriteStreamDynamic::ensureCapacity(size_t newLen) {
    if (newLen <= _capacity)
        return;

    reserve(newLen);
}

size_t MemoryWriteStreamDynamic::write(const void *dataPtr, size_t dataSize) {
    assert(dataPtr);

    ensureCapacity(pos() + dataSize);

    std::memcpy(_ptr, dataPtr, dataSize);

    if (pos() + dataSize > _size)
        _size = MAX(pos() + dataSize, _size);

    _ptr  += dataSize;

    return dataSize;
}

void MemoryWriteStreamDynamic::setDisposable(bool disposeMemory) {
    _data.setDisposable(disposeMemory);
}

void MemoryWriteStreamDynamic::dispose() {
    _data.dispose();

    _ptr      = 0;
    _size     = 0;
    _capacity = 0;
}

size_t MemoryWriteStreamDynamic::pos() const {
    return _ptr - _data.get();
}

size_t MemoryWriteStreamDynamic::size() const {
    return _size;
}

size_t MemoryWriteStreamDynamic::seek(ptrdiff_t offset, SeekableWriteStream::Origin whence) {
    assert((size_t)pos() <= _size);

    const size_t oldPos = pos();
    const size_t newPos = evalSeek(offset, whence, pos(), 0, size());
    if (newPos > _size)
        throw Exception(kSeekError);

    _ptr = _data.get() + newPos;

    return oldPos;
}

byte *MemoryWriteStreamDynamic::getData() {
    return _data.get();
}

} // End of namespace Common