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7d17818cec
specification. Simplify things by removing most of the support for known uncompressed size in most places. There are some miscellaneous changes here and there too. The API of liblzma has got many changes and still some more will be done soon. While most of the code has been updated, some things are not fixed (the command line tool will choke with invalid filter chain, if nothing else). Subblock filter is somewhat broken for now. It will be updated once the encoded format of the Subblock filter has been decided.
89 lines
2.4 KiB
C
89 lines
2.4 KiB
C
///////////////////////////////////////////////////////////////////////////////
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//
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/// \file stream_flags_encoder.c
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/// \brief Encodes Stream Header and Stream Footer for .lzma files
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//
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// Copyright (C) 2007 Lasse Collin
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//
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// This library is free software; you can redistribute it and/or
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// modify it under the terms of the GNU Lesser General Public
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// License as published by the Free Software Foundation; either
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// version 2.1 of the License, or (at your option) any later version.
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//
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// Lesser General Public License for more details.
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//
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///////////////////////////////////////////////////////////////////////////////
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#include "stream_common.h"
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static bool
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stream_flags_encode(const lzma_stream_flags *options, uint8_t *out)
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{
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if ((unsigned int)(options->check) > LZMA_CHECK_ID_MAX)
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return true;
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out[0] = 0x00;
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out[1] = options->check;
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return false;
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}
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extern LZMA_API lzma_ret
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lzma_stream_header_encode(const lzma_stream_flags *options, uint8_t *out)
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{
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assert(sizeof(lzma_header_magic) + LZMA_STREAM_FLAGS_SIZE
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+ 4 == LZMA_STREAM_HEADER_SIZE);
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// Magic
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memcpy(out, lzma_header_magic, sizeof(lzma_header_magic));
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// Stream Flags
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if (stream_flags_encode(options, out + sizeof(lzma_header_magic)))
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return LZMA_PROG_ERROR;
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// CRC32 of the Stream Header
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const uint32_t crc = lzma_crc32(out + sizeof(lzma_header_magic),
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LZMA_STREAM_FLAGS_SIZE, 0);
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integer_write_32(out + sizeof(lzma_header_magic)
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+ LZMA_STREAM_FLAGS_SIZE, crc);
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return LZMA_OK;
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}
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extern LZMA_API lzma_ret
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lzma_stream_footer_encode(const lzma_stream_flags *options, uint8_t *out)
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{
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assert(2 * 4 + LZMA_STREAM_FLAGS_SIZE + sizeof(lzma_footer_magic)
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== LZMA_STREAM_HEADER_SIZE);
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// Backward Size
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if (options->backward_size < LZMA_BACKWARD_SIZE_MIN
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|| options->backward_size > LZMA_BACKWARD_SIZE_MAX
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|| (options->backward_size & 3))
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return LZMA_PROG_ERROR;
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integer_write_32(out + 4, options->backward_size / 4 - 1);
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// Stream Flags
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if (stream_flags_encode(options, out + 2 * 4))
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return LZMA_PROG_ERROR;
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// CRC32
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const uint32_t crc = lzma_crc32(
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out + 4, 4 + LZMA_STREAM_FLAGS_SIZE, 0);
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integer_write_32(out, crc);
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// Magic
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memcpy(out + 2 * 4 + LZMA_STREAM_FLAGS_SIZE,
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lzma_footer_magic, sizeof(lzma_footer_magic));
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return LZMA_OK;
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}
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