From 3599dba9570a6972a16b6398d6c838e9b420e985 Mon Sep 17 00:00:00 2001 From: Lasse Collin Date: Mon, 14 Jan 2008 11:54:56 +0200 Subject: More fixes to LZMA decoder's flush marker handling. --- src/liblzma/lzma/lzma_decoder.c | 52 ++++++++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 22 deletions(-) diff --git a/src/liblzma/lzma/lzma_decoder.c b/src/liblzma/lzma/lzma_decoder.c index fd57ac82..04fae74e 100644 --- a/src/liblzma/lzma/lzma_decoder.c +++ b/src/liblzma/lzma/lzma_decoder.c @@ -425,13 +425,7 @@ decode_real(lzma_coder *restrict coder, const uint8_t *restrict in, // Not a repeated match // // We will decode a new distance and store - // the value to rep0. - - // The latest three match distances are kept in - // memory in case there are repeated matches. - rep3 = rep2; - rep2 = rep1; - rep1 = rep0; + // the value to distance. // Decode the length of the match. length_decode(len, coder->len_decoder, pos_state); @@ -447,36 +441,36 @@ decode_real(lzma_coder *restrict coder, const uint8_t *restrict in, if (pos_slot >= START_POS_MODEL_INDEX) { uint32_t direct_bits = (pos_slot >> 1) - 1; assert(direct_bits >= 1 && direct_bits <= 30); - rep0 = 2 | (pos_slot & 1); + uint32_t distance = 2 | (pos_slot & 1); if (pos_slot < END_POS_MODEL_INDEX) { assert(direct_bits <= 5); - rep0 <<= direct_bits; - assert(rep0 <= 96); + distance <<= direct_bits; + assert(distance <= 96); // -1 is fine, because // bittree_reverse_decode() // starts from table index [1] // (not [0]). - assert((int32_t)(rep0 - pos_slot - 1) >= -1); - assert((int32_t)(rep0 - pos_slot - 1) <= 82); - // We add the result to rep0, so rep0 + assert((int32_t)(distance - pos_slot - 1) >= -1); + assert((int32_t)(distance - pos_slot - 1) <= 82); + // We add the result to distance, so distance // must not be part of second argument // of the macro. - const int32_t offset = rep0 - pos_slot - 1; - bittree_reverse_decode(rep0, coder->pos_decoders + offset, + const int32_t offset = distance - pos_slot - 1; + bittree_reverse_decode(distance, coder->pos_decoders + offset, direct_bits); } else { assert(pos_slot >= 14); assert(direct_bits >= 6); direct_bits -= ALIGN_BITS; assert(direct_bits >= 2); - rc_decode_direct(rep0, direct_bits); - rep0 <<= ALIGN_BITS; + rc_decode_direct(distance, direct_bits); + distance <<= ALIGN_BITS; - bittree_reverse_decode(rep0, coder->pos_align_decoder, + bittree_reverse_decode(distance, coder->pos_align_decoder, ALIGN_BITS); - if (rep0 == UINT32_MAX) { + if (distance == UINT32_MAX) { if (len == LEN_SPECIAL_EOPM) { // End of Payload Marker found. coder->lz.eopm_detected = true; @@ -501,16 +495,31 @@ decode_real(lzma_coder *restrict coder, const uint8_t *restrict in, rc_reset(rc); // If we don't have enough input here, we jump - // out of the loop without calling rc_normalize(). + // out of the loop. Note that while there is a + // useless call to rc_normalize(), it does nothing + // since we have just reset the range decoder. if (!rc_read_init(&rc, in, &in_pos_local, in_size)) - goto out; + break; + + continue; } else { return true; } } } + + // The latest three match distances are kept in + // memory in case there are repeated matches. + rep3 = rep2; + rep2 = rep1; + rep1 = rep0; + rep0 = distance; + } else { + rep3 = rep2; + rep2 = rep1; + rep1 = rep0; rep0 = pos_slot; } @@ -630,7 +639,6 @@ decode_real(lzma_coder *restrict coder, const uint8_t *restrict in, // Update the *data structure. // ///////////////////////////////// -out: // Range decoder rc_from_local(coder->rc); -- cgit v1.2.3