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/* ScummVM - Graphic Adventure Engine
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*
*/
#include "common/std/algorithm.h"
#include "ags/shared/util/memory_stream.h"
namespace AGS3 {
namespace AGS {
namespace Shared {
MemoryStream::MemoryStream(const uint8_t *cbuf, size_t buf_sz, DataEndianess stream_endianess)
: DataStream(stream_endianess)
, _cbuf(cbuf)
, _buf_sz(buf_sz)
, _len(buf_sz)
, _mode(kStream_Read)
, _pos(0)
, _buf(nullptr) {
}
MemoryStream::MemoryStream(uint8_t *buf, size_t buf_sz, StreamWorkMode mode, DataEndianess stream_endianess)
: DataStream(stream_endianess)
, _cbuf(nullptr)
, _buf_sz(buf_sz)
, _len(0)
, _mode(mode)
, _pos(0)
, _buf(nullptr) {
if (mode == kStream_Read) {
_cbuf = buf;
_len = buf_sz;
} else {
_buf = buf;
}
}
void MemoryStream::Close() {
_cbuf = nullptr;
_buf = nullptr;
_buf_sz = 0;
_len = 0;
_pos = 0;
}
bool MemoryStream::Flush() {
return true;
}
bool MemoryStream::IsValid() const {
return _cbuf != nullptr || _buf != nullptr;
}
bool MemoryStream::EOS() const {
return _pos >= _len;
}
soff_t MemoryStream::GetLength() const {
return _len;
}
soff_t MemoryStream::GetPosition() const {
return _pos;
}
bool MemoryStream::CanRead() const {
return (_cbuf != nullptr) && (_mode == kStream_Read);
}
bool MemoryStream::CanWrite() const {
return (_buf != nullptr) && (_mode == kStream_Write);
}
bool MemoryStream::CanSeek() const {
return true;
}
size_t MemoryStream::Read(void *buffer, size_t size) {
if (EOS()) {
return 0;
}
assert(_len > _pos);
size_t remain = _len - _pos;
size_t read_sz = MIN(remain, size);
memcpy(buffer, _cbuf + _pos, read_sz);
_pos += read_sz;
return read_sz;
}
int32_t MemoryStream::ReadByte() {
if (EOS()) {
return -1;
}
return _cbuf[_pos++];
}
soff_t MemoryStream::Seek(soff_t offset, StreamSeek origin) {
if (!CanSeek()) {
return false;
}
soff_t want_pos = -1;
switch (origin) {
case kSeekBegin: want_pos = 0 + offset; break;
case kSeekCurrent: want_pos = _pos + offset; break;
case kSeekEnd: want_pos = _len + offset; break;
default:
return -1;
}
// clamp to a valid range
_pos = static_cast<size_t>(MAX<soff_t>(0, want_pos));
_pos = std::min(_len, _pos); // clamp to EOS
return static_cast<soff_t>(_pos);
}
size_t MemoryStream::Write(const void *buffer, size_t size) {
if (!_buf || (_pos >= _buf_sz)) {
return 0;
}
size = MIN(size, _buf_sz - _pos);
memcpy(_buf + _pos, buffer, size);
_pos += size;
// will increase len if writing after eos, otherwise = overwrite at pos
_len = MAX(_len, _pos);
return size;
}
int32_t MemoryStream::WriteByte(uint8_t val) {
if (!_buf || (_pos >= _buf_sz)) {
return -1;
}
*(_buf + _pos) = val;
_pos++;
// will increase len if writing after eos, otherwise = overwrite at pos
_len = MAX(_len, _pos);
return val;
}
VectorStream::VectorStream(const std::vector<uint8_t> &cbuf, DataEndianess stream_endianess)
: MemoryStream(&cbuf.front(), cbuf.size(), stream_endianess)
, _vec(nullptr) {
}
VectorStream::VectorStream(std::vector<uint8_t> &buf, StreamWorkMode mode, DataEndianess stream_endianess)
: MemoryStream(((mode == kStream_Read) && (buf.size() > 0)) ? &buf.front() : nullptr, buf.size(), mode, stream_endianess)
, _vec(&buf) {
}
void VectorStream::Close() {
_vec = nullptr;
MemoryStream::Close();
}
bool VectorStream::CanRead() const {
return _mode == kStream_Read;
}
bool VectorStream::CanWrite() const {
return _mode == kStream_Write;
}
size_t VectorStream::Write(const void *buffer, size_t size) {
if (_pos + size > _len) {
_vec->resize(_pos + size);
_len = _pos + size;
}
memcpy(_vec->data() + _pos, buffer, size);
_pos += size;
return size;
}
int32_t VectorStream::WriteByte(uint8_t val) {
if (_pos == _len) {
_vec->push_back(val);
_len++;
} else {
(*_vec)[_pos] = val;
}
_pos++;
return val;
}
} // namespace Shared
} // namespace AGS
} // namespace AGS3
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