apps/plugins/lib/buflib.h

   1 /***************************************************************************
   2 *             __________               __   ___.
   3 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7 *                     \/            \/     \/    \/            \/
   8 * $Id$
   9 *
  10 * This is a memory allocator designed to provide reasonable management of free
  11 * space and fast access to allocated data. More than one allocator can be used
  12 * at a time by initializing multiple contexts.
  13 *
  14 * Copyright (C) 2009 Andrew Mahone
  15 *
  16 * This program is free software; you can redistribute it and/or
  17 * modify it under the terms of the GNU General Public License
  18 * as published by the Free Software Foundation; either version 2
  19 * of the License, or (at your option) any later version.
  20 *
  21 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  22 * KIND, either express or implied.
  23 *
  24 ****************************************************************************/
  25
  26 #ifndef _BUFLIB_H_
  27 #include <plugin.h>
  28
  29 union buflib_data
  30 {
  31     intptr_t val;
  32     union buflib_data *ptr;
  33 };
  34
  35 struct buflib_context
  36 {
  37     union buflib_data *handle_table;
  38     union buflib_data *first_free_handle;
  39     union buflib_data *last_handle;
  40     union buflib_data *first_free_block;
  41     union buflib_data *buf_start;
  42     union buflib_data *alloc_end;
  43     bool compact;
  44 };
  45
  46 void buflib_init(struct buflib_context *context, void *buf, size_t size);
  47 int buflib_alloc(struct buflib_context *context, size_t size);
  48 void buflib_free(struct buflib_context *context, int handle);
  49 void* buflib_buffer_out(struct buflib_context *ctx, size_t *size);
  50 void buflib_buffer_in(struct buflib_context *ctx, int size);
  51
  52
  53
  54 static inline void* buflib_get_data(struct buflib_context *context, int handle)
  55 {
  56     return (void*)(context->handle_table[-handle].ptr);
  57 }
  58 #endif