From 5db75054e900fa06ef5ade5f2c21dffdd5d16141 Mon Sep 17 00:00:00 2001 From: Lasse Collin Date: Fri, 25 Jul 2014 21:15:07 +0300 Subject: [PATCH] liblzma: Use lzma_memcmplen() in the match finders. This doesn't change the match finder output. --- src/liblzma/lz/lz_encoder.c | 13 ++++++++++++- src/liblzma/lz/lz_encoder_mf.c | 33 +++++++++++---------------------- 2 files changed, 23 insertions(+), 23 deletions(-) diff --git a/src/liblzma/lz/lz_encoder.c b/src/liblzma/lz/lz_encoder.c index 76954e4d..2033844f 100644 --- a/src/liblzma/lz/lz_encoder.c +++ b/src/liblzma/lz/lz_encoder.c @@ -20,6 +20,8 @@ # include "lz_encoder_hash_table.h" #endif +#include "memcmplen.h" + struct lzma_coder_s { /// LZ-based encoder e.g. LZMA @@ -363,9 +365,18 @@ lz_encoder_init(lzma_mf *mf, const lzma_allocator *allocator, { // Allocate the history buffer. if (mf->buffer == NULL) { - mf->buffer = lzma_alloc(mf->size, allocator); + // lzma_memcmplen() is used for the dictionary buffer + // so we need to allocate a few extra bytes to prevent + // it from reading past the end of the buffer. + mf->buffer = lzma_alloc(mf->size + LZMA_MEMCMPLEN_EXTRA, + allocator); if (mf->buffer == NULL) return true; + + // Keep Valgrind happy with lzma_memcmplen() and initialize + // the extra bytes whose value may get read but which will + // effectively get ignored. + memzero(mf->buffer + mf->size, LZMA_MEMCMPLEN_EXTRA); } // Use cyclic_size as initial mf->offset. This allows diff --git a/src/liblzma/lz/lz_encoder_mf.c b/src/liblzma/lz/lz_encoder_mf.c index bf787f45..6dc39f4a 100644 --- a/src/liblzma/lz/lz_encoder_mf.c +++ b/src/liblzma/lz/lz_encoder_mf.c @@ -13,6 +13,7 @@ #include "lz_encoder.h" #include "lz_encoder_hash.h" +#include "memcmplen.h" /// \brief Find matches starting from the current byte @@ -65,9 +66,7 @@ lzma_mf_find(lzma_mf *mf, uint32_t *count_ptr, lzma_match *matches) // here because the match distances are zero based. const uint8_t *p2 = p1 - matches[count - 1].dist - 1; - while (len_best < limit - && p1[len_best] == p2[len_best]) - ++len_best; + len_best = lzma_memcmplen(p1, p2, len_best, limit); } } @@ -272,10 +271,7 @@ hc_find_func( + (delta > cyclic_pos ? cyclic_size : 0)]; if (pb[len_best] == cur[len_best] && pb[0] == cur[0]) { - uint32_t len = 0; - while (++len != len_limit) - if (pb[len] != cur[len]) - break; + uint32_t len = lzma_memcmplen(pb, cur, 1, len_limit); if (len_best < len) { len_best = len; @@ -321,9 +317,8 @@ lzma_mf_hc3_find(lzma_mf *mf, lzma_match *matches) uint32_t len_best = 2; if (delta2 < mf->cyclic_size && *(cur - delta2) == *cur) { - for ( ; len_best != len_limit; ++len_best) - if (*(cur + len_best - delta2) != cur[len_best]) - break; + len_best = lzma_memcmplen(cur - delta2, cur, + len_best, len_limit); matches[0].len = len_best; matches[0].dist = delta2 - 1; @@ -400,9 +395,8 @@ lzma_mf_hc4_find(lzma_mf *mf, lzma_match *matches) } if (matches_count != 0) { - for ( ; len_best != len_limit; ++len_best) - if (*(cur + len_best - delta2) != cur[len_best]) - break; + len_best = lzma_memcmplen(cur - delta2, cur, + len_best, len_limit); matches[matches_count - 1].len = len_best; @@ -487,9 +481,7 @@ bt_find_func( uint32_t len = my_min(len0, len1); if (pb[len] == cur[len]) { - while (++len != len_limit) - if (pb[len] != cur[len]) - break; + len = lzma_memcmplen(pb, cur, len + 1, len_limit); if (len_best < len) { len_best = len; @@ -552,9 +544,7 @@ bt_skip_func( uint32_t len = my_min(len0, len1); if (pb[len] == cur[len]) { - while (++len != len_limit) - if (pb[len] != cur[len]) - break; + len = lzma_memcmplen(pb, cur, len + 1, len_limit); if (len == len_limit) { *ptr1 = pair[0]; @@ -715,9 +705,8 @@ lzma_mf_bt4_find(lzma_mf *mf, lzma_match *matches) } if (matches_count != 0) { - for ( ; len_best != len_limit; ++len_best) - if (*(cur + len_best - delta2) != cur[len_best]) - break; + len_best = lzma_memcmplen( + cur, cur - delta2, len_best, len_limit); matches[matches_count - 1].len = len_best; -- 2.11.4.GIT