BizHawk/psx/mednadisc/MemoryStream.h

78 lines
2.8 KiB
C++

/* Mednafen - Multi-system Emulator
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
Notes:
For performance reasons(like in the state rewinding code), we should try to make sure map()
returns a pointer that is aligned to at least what malloc()/realloc() provides.
(And maybe forcefully align it to at least 16 bytes in the future)
*/
#ifndef __MDFN_MEMORYSTREAM_H
#define __MDFN_MEMORYSTREAM_H
#include "Stream.h"
class MemoryStream : public Stream
{
public:
MemoryStream();
MemoryStream(uint64 alloc_hint, int alloc_hint_is_size = false); // Pass -1 instead of 1 for alloc_hint_is_size to skip initialization of the memory.
MemoryStream(Stream *stream, uint64 size_limit = ~(uint64)0);
// Will create a MemoryStream equivalent of the contents of "stream", and then "delete stream".
// Will only work if stream->tell() == 0, or if "stream" is seekable.
// stream will be deleted even if this constructor throws.
//
// Will throw an exception if the initial size() of the MemoryStream would be greater than size_limit(useful for when passing
// in GZFileStream streams).
MemoryStream(const MemoryStream &zs);
MemoryStream & operator=(const MemoryStream &zs);
virtual ~MemoryStream() override;
virtual uint64 attributes(void) override;
virtual uint8 *map(void) noexcept override;
virtual uint64 map_size(void) noexcept override;
virtual void unmap(void) noexcept override;
virtual uint64 read(void *data, uint64 count, bool error_on_eos = true) override;
virtual void write(const void *data, uint64 count) override;
virtual void truncate(uint64 length) override;
virtual void seek(int64 offset, int whence) override;
virtual uint64 tell(void) override;
virtual uint64 size(void) override;
virtual void flush(void) override;
virtual void close(void) override;
virtual int get_line(std::string &str) override;
void shrink_to_fit(void) noexcept; // Minimizes alloced memory.
private:
uint8 *data_buffer;
uint64 data_buffer_size;
uint64 data_buffer_alloced;
uint64 position;
void grow_if_necessary(uint64 new_required_size, uint64 hole_end);
};
#endif