3bd5f335f7
Helper for another semi-typical operation: find out how big of a buffer should be allocated before decompressing. This can be useful when the stream container doesn't specify the decompressed size. Change-Id: I5f1536f809bb6f9bc6023120c024c3de7cea4269
70 lines
2.6 KiB
C
70 lines
2.6 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2021 by James Buren (libflate adaptations for RockBox)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#ifndef _INFLATE_H_
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#define _INFLATE_H_
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#include <stdint.h>
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#include <stddef.h>
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enum {
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INFLATE_RAW,
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INFLATE_ZLIB,
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INFLATE_GZIP,
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};
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struct inflate;
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typedef uint32_t (*inflate_reader) (void* block, uint32_t block_size, void* ctx);
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typedef uint32_t (*inflate_writer) (const void* block, uint32_t block_size, void* ctx);
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extern const uint32_t inflate_size;
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extern const uint32_t inflate_align;
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// 'it' must be allocated by the caller. it must be at least 'inflate_size' bytes
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// and aligned at 'inflate_align' bytes. 'st' is the type of stream to decompress;
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// see above enum for possible options.
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int inflate(struct inflate* it, int st, inflate_reader read, void* rctx, inflate_writer write, void* wctx);
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struct inflate_bufferctx {
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// initialize this with your input/output buffer.
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// the pointer is updated as data is read or written.
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void* buf;
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// buffer end marker (= buf + buf_size).
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void* end;
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};
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// reader and writer for using an in-memory buffer.
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// Use 'inflate_bufferctx' as the context argument.
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uint32_t inflate_buffer_reader(void* block, uint32_t block_size, void* ctx);
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uint32_t inflate_buffer_writer(const void* block, uint32_t block_size, void* ctx);
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// dummy writer used if you just want to figure out how big the decompressed
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// data will be. It does not actually write any data. Example usage:
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//
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// size_t size = 0;
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// inflate(it, st, read, rctx, inflate_getsize_writer, &size);
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//
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// Now 'size' will be the size of the decompressed data (assuming no errors).
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uint32_t inflate_getsize_writer(const void* block, uint32_t block_size, void* ctx);
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#endif
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