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author | mm <mm@FreeBSD.org> | 2010-05-10 06:59:50 +0000 |
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committer | mm <mm@FreeBSD.org> | 2010-05-10 06:59:50 +0000 |
commit | 5c358d45429b654efa9c8177ecd370a7965ec1a7 (patch) | |
tree | d2d916954c6a66a3168ee356b5f24da01c2017d6 /contrib/xz/src/liblzma/delta/delta_encoder.c | |
parent | 3e09decd1986826f54af1a47be97bb87c1220783 (diff) | |
parent | 1008b7c6744a190c5b15aaf8cab1054671e4c7c3 (diff) | |
download | FreeBSD-src-5c358d45429b654efa9c8177ecd370a7965ec1a7.zip FreeBSD-src-5c358d45429b654efa9c8177ecd370a7965ec1a7.tar.gz |
Import of liblzma, xz, xzdec, lzmainfo from vendor branch
Add support for xz and lzma to lesspipe.sh (xzless, lzless)
Bump __FreeBSD_version
Approved by: delphij (mentor)
MFC after: 2 weeks
Diffstat (limited to 'contrib/xz/src/liblzma/delta/delta_encoder.c')
-rw-r--r-- | contrib/xz/src/liblzma/delta/delta_encoder.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/contrib/xz/src/liblzma/delta/delta_encoder.c b/contrib/xz/src/liblzma/delta/delta_encoder.c new file mode 100644 index 0000000..80d0d17 --- /dev/null +++ b/contrib/xz/src/liblzma/delta/delta_encoder.c @@ -0,0 +1,121 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file delta_encoder.c +/// \brief Delta filter encoder +// +// Author: Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "delta_encoder.h" +#include "delta_private.h" + + +/// Copies and encodes the data at the same time. This is used when Delta +/// is the first filter in the chain (and thus the last filter in the +/// encoder's filter stack). +static void +copy_and_encode(lzma_coder *coder, + const uint8_t *restrict in, uint8_t *restrict out, size_t size) +{ + const size_t distance = coder->distance; + + for (size_t i = 0; i < size; ++i) { + const uint8_t tmp = coder->history[ + (distance + coder->pos) & 0xFF]; + coder->history[coder->pos-- & 0xFF] = in[i]; + out[i] = in[i] - tmp; + } +} + + +/// Encodes the data in place. This is used when we are the last filter +/// in the chain (and thus non-last filter in the encoder's filter stack). +static void +encode_in_place(lzma_coder *coder, uint8_t *buffer, size_t size) +{ + const size_t distance = coder->distance; + + for (size_t i = 0; i < size; ++i) { + const uint8_t tmp = coder->history[ + (distance + coder->pos) & 0xFF]; + coder->history[coder->pos-- & 0xFF] = buffer[i]; + buffer[i] -= tmp; + } +} + + +static lzma_ret +delta_encode(lzma_coder *coder, lzma_allocator *allocator, + const uint8_t *restrict in, size_t *restrict in_pos, + size_t in_size, uint8_t *restrict out, + size_t *restrict out_pos, size_t out_size, lzma_action action) +{ + lzma_ret ret; + + if (coder->next.code == NULL) { + const size_t in_avail = in_size - *in_pos; + const size_t out_avail = out_size - *out_pos; + const size_t size = MIN(in_avail, out_avail); + + copy_and_encode(coder, in + *in_pos, out + *out_pos, size); + + *in_pos += size; + *out_pos += size; + + ret = action != LZMA_RUN && *in_pos == in_size + ? LZMA_STREAM_END : LZMA_OK; + + } else { + const size_t out_start = *out_pos; + + ret = coder->next.code(coder->next.coder, allocator, + in, in_pos, in_size, out, out_pos, out_size, + action); + + encode_in_place(coder, out + out_start, *out_pos - out_start); + } + + return ret; +} + + +static lzma_ret +delta_encoder_update(lzma_coder *coder, lzma_allocator *allocator, + const lzma_filter *filters_null lzma_attribute((unused)), + const lzma_filter *reversed_filters) +{ + // Delta doesn't and will never support changing the options in + // the middle of encoding. If the app tries to change them, we + // simply ignore them. + return lzma_next_filter_update( + &coder->next, allocator, reversed_filters + 1); +} + + +extern lzma_ret +lzma_delta_encoder_init(lzma_next_coder *next, lzma_allocator *allocator, + const lzma_filter_info *filters) +{ + next->code = &delta_encode; + next->update = &delta_encoder_update; + return lzma_delta_coder_init(next, allocator, filters); +} + + +extern lzma_ret +lzma_delta_props_encode(const void *options, uint8_t *out) +{ + // The caller must have already validated the options, so it's + // LZMA_PROG_ERROR if they are invalid. + if (lzma_delta_coder_memusage(options) == UINT64_MAX) + return LZMA_PROG_ERROR; + + const lzma_options_delta *opt = options; + out[0] = opt->dist - LZMA_DELTA_DIST_MIN; + + return LZMA_OK; +} |