FS#9916 buflib plugin memory allocator

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20202 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 58 insertions, 0 deletions

diff --git a/apps/plugins/lib/buflib.h b/apps/plugins/lib/buflib.h
new file mode 100644
index 0000000000..ddadb1b9a9
--- /dev/null
+++ b/apps/plugins/lib/buflib.h
@@ -0,0 +1,58 @@
+/***************************************************************************
+*             __________               __   ___.
+*   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 *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);
+
+/* 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