rockbox/apps/plugins/lib/buflib.h
Andrew Mahone c909878f94 Extend buflib to support shifting space out off the buffer for other use, and returning space to the buffer.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20952 a1c6a512-1295-4272-9138-f99709370657
2009-05-16 00:45:08 +00:00

63 lines
2.2 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* This is a memory allocator designed to provide reasonable management of free
* space and fast access to allocated data. More than one allocator can be used
* at a time by initializing multiple contexts.
*
* Copyright (C) 2009 Andrew Mahone
*
* 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef _BUFLIB_H_
#include <plugin.h>
union buflib_data
{
intptr_t val;
union buflib_data *ptr;
};
struct buflib_context
{
union buflib_data *handle_table;
union buflib_data *first_free_handle;
union buflib_data *last_handle;
union buflib_data *first_free_block;
union buflib_data *buf_start;
union buflib_data *alloc_end;
bool compact;
};
void buflib_init(struct buflib_context *context, void *buf, size_t size);
int buflib_alloc(struct buflib_context *context, size_t size);
void buflib_free(struct buflib_context *context, int handle);
void* buflib_buffer_out(struct buflib_context *ctx, size_t *size);
void buflib_buffer_in(struct buflib_context *ctx, int size);
/* always_inline is due to this not getting inlined when not optimizing, which
* leads to an unresolved reference since it doesn't exist as a non-inline
* function
*/
extern inline __attribute__((always_inline))
void* buflib_get_data(struct buflib_context *context, int handle)
{
return (void*)(context->handle_table[-handle].ptr);
}
#endif