chunk_alloc

chunk_alloc allows arrays (or any data) to be allocated in smaller chunks

you have to save the indices..
 variable data will have variable indices you need to
 store these as [chunk_alloc] doesn't keep track
 if you have a fixed size for each
 alloc you can do indice / sizeof(data)
 or index * sizeof(data) to convert

Lots of debug stuff still in and it needs optimization

User provides chunk_size and max_chunks
max_chunks * struct chunk will be allocated at start
with (1) chunk_size allocation initially

alloc_chunk() with size = 0 shrinks the last allocation to the size of the data used

add OOM checks on buflib_alloc -- oops

move bytes available to the header -- less memory per chunk & better alignment
keep track of the current in use chunk index -- should speed things up a bit

Now allows:
realloc chunk header
larger allocations than chunk size

reallocs smaller than existing will shrink the current array
rather than alloc a new and copy data

Comments welcome :)

Change-Id: I8ed170eef73da95da19430a80b32e5debf0c8276

firmware/include/chunk_alloc.h

@@ -0,0 +1,64 @@
+/***************************************************************************
+*             __________               __   ___.
+*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+*                     \/            \/     \/    \/            \/
+* $Id$
+*
+* Copyright (C) 2023 William Wilgus
+*
+* 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 _CHUNKALLOC_H_
+#define _CHUNKALLOC_H_
+#include <stdbool.h>
+#include <string.h>
+#include "config.h"
+#include "buflib.h"
+
+#define CHUNK_ALLOC_INVALID ((size_t)-1)
+
+struct chunk_alloc_header
+{
+    size_t chunk_bytes_total; /* total bytes in current chunk */
+    size_t chunk_bytes_free;  /* free bytes in current chunk  */
+    size_t chunk_size;        /* default chunk size    */
+    size_t count;             /* total chunks possible */
+    size_t current;           /* current chunk in use  */
+
+    struct buflib_context *context; /* buflib context for all allocations */
+    int chunk_handle; /* data handle of buflib allocated array of struct chunk */
+};
+
+void chunk_alloc_free(struct chunk_alloc_header *hdr);
+
+bool chunk_alloc_init(struct chunk_alloc_header *hdr,
+                      struct buflib_context *ctx,
+                      size_t chunk_size, size_t max_chunks);
+
+bool chunk_realloc(struct chunk_alloc_header *hdr,
+                   size_t chunk_size, size_t max_chunks);
+
+void chunk_alloc_finalize(struct chunk_alloc_header *hdr);
+
+size_t chunk_alloc(struct chunk_alloc_header *hdr, size_t size); /* Returns offset */
+
+void* chunk_get_data(struct chunk_alloc_header *hdr, size_t offset); /* Returns data */
+
+void chunk_put_data(struct chunk_alloc_header *hdr, size_t offset);
+
+static inline bool chunk_alloc_is_initialized(struct chunk_alloc_header *hdr)
+{
+    return (hdr->chunk_handle > 0);
+}
+#endif