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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 21:12:04 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 21:12:04 +0000 |
commit | eac54b7c4aec25060d7bd856f7cdc290943d6aae (patch) | |
tree | 9a6d81c9f88df4698e746d63d14ddafeddd918b8 /debug/known_sizes.c | |
parent | Initial commit. (diff) | |
download | xz-utils-eac54b7c4aec25060d7bd856f7cdc290943d6aae.tar.xz xz-utils-eac54b7c4aec25060d7bd856f7cdc290943d6aae.zip |
Adding upstream version 5.4.1.upstream/5.4.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'debug/known_sizes.c')
-rw-r--r-- | debug/known_sizes.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/debug/known_sizes.c b/debug/known_sizes.c new file mode 100644 index 0000000..6c3641f --- /dev/null +++ b/debug/known_sizes.c @@ -0,0 +1,129 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file known_sizes.c +/// \brief Encodes .lzma Stream with sizes known in Block Header +/// +/// The input file is encoded in RAM, and the known Compressed Size +/// and/or Uncompressed Size values are stored in the Block Header. +/// As of writing there's no such Stream encoder in liblzma. +// +// Author: Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "sysdefs.h" +#include "lzma.h" +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/unistd.h> +#include <stdio.h> + + +// Support file sizes up to 1 MiB. We use this for output space too, so files +// close to 1 MiB had better compress at least a little or we have a buffer +// overflow. +#define BUFFER_SIZE (1U << 20) + + +int +main(void) +{ + // Allocate the buffers. + uint8_t *in = malloc(BUFFER_SIZE); + uint8_t *out = malloc(BUFFER_SIZE); + if (in == NULL || out == NULL) + return 1; + + // Fill the input buffer. + const size_t in_size = fread(in, 1, BUFFER_SIZE, stdin); + + // Filter setup + lzma_options_lzma opt_lzma; + if (lzma_lzma_preset(&opt_lzma, 1)) + return 1; + + lzma_filter filters[] = { + { + .id = LZMA_FILTER_LZMA2, + .options = &opt_lzma + }, + { + .id = LZMA_VLI_UNKNOWN + } + }; + + lzma_block block = { + .check = LZMA_CHECK_CRC32, + .compressed_size = BUFFER_SIZE, // Worst case reserve + .uncompressed_size = in_size, + .filters = filters, + }; + + lzma_stream strm = LZMA_STREAM_INIT; + if (lzma_block_encoder(&strm, &block) != LZMA_OK) + return 1; + + // Reserve space for Stream Header and Block Header. We need to + // calculate the size of the Block Header first. + if (lzma_block_header_size(&block) != LZMA_OK) + return 1; + + size_t out_size = LZMA_STREAM_HEADER_SIZE + block.header_size; + + strm.next_in = in; + strm.avail_in = in_size; + strm.next_out = out + out_size; + strm.avail_out = BUFFER_SIZE - out_size; + + if (lzma_code(&strm, LZMA_FINISH) != LZMA_STREAM_END) + return 1; + + out_size += strm.total_out; + + if (lzma_block_header_encode(&block, out + LZMA_STREAM_HEADER_SIZE) + != LZMA_OK) + return 1; + + lzma_index *idx = lzma_index_init(NULL); + if (idx == NULL) + return 1; + + if (lzma_index_append(idx, NULL, block.header_size + strm.total_out, + strm.total_in) != LZMA_OK) + return 1; + + if (lzma_index_encoder(&strm, idx) != LZMA_OK) + return 1; + + if (lzma_code(&strm, LZMA_RUN) != LZMA_STREAM_END) + return 1; + + out_size += strm.total_out; + + lzma_end(&strm); + + lzma_index_end(idx, NULL); + + // Encode the Stream Header and Stream Footer. backwards_size is + // needed only for the Stream Footer. + lzma_stream_flags sf = { + .backward_size = strm.total_out, + .check = block.check, + }; + + if (lzma_stream_header_encode(&sf, out) != LZMA_OK) + return 1; + + if (lzma_stream_footer_encode(&sf, out + out_size) != LZMA_OK) + return 1; + + out_size += LZMA_STREAM_HEADER_SIZE; + + // Write out the file. + fwrite(out, 1, out_size, stdout); + + return 0; +} |