diff options
Diffstat (limited to 'contrib/xz/src/liblzma/lz/lz_encoder.c')
-rw-r--r-- | contrib/xz/src/liblzma/lz/lz_encoder.c | 124 |
1 files changed, 73 insertions, 51 deletions
diff --git a/contrib/xz/src/liblzma/lz/lz_encoder.c b/contrib/xz/src/liblzma/lz/lz_encoder.c index e240696..48bc487 100644 --- a/contrib/xz/src/liblzma/lz/lz_encoder.c +++ b/contrib/xz/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 @@ -76,8 +78,9 @@ move_window(lzma_mf *mf) /// This function must not be called once it has returned LZMA_STREAM_END. /// static lzma_ret -fill_window(lzma_coder *coder, lzma_allocator *allocator, const uint8_t *in, - size_t *in_pos, size_t in_size, lzma_action action) +fill_window(lzma_coder *coder, const lzma_allocator *allocator, + const uint8_t *in, size_t *in_pos, size_t in_size, + lzma_action action) { assert(coder->mf.read_pos <= coder->mf.write_pos); @@ -107,6 +110,12 @@ fill_window(lzma_coder *coder, lzma_allocator *allocator, const uint8_t *in, coder->mf.write_pos = write_pos; + // Silence Valgrind. lzma_memcmplen() can read extra bytes + // and Valgrind will give warnings if those bytes are uninitialized + // because Valgrind cannot see that the values of the uninitialized + // bytes are eventually ignored. + memzero(coder->mf.buffer + write_pos, LZMA_MEMCMPLEN_EXTRA); + // If end of stream has been reached or flushing completed, we allow // the encoder to process all the input (that is, read_pos is allowed // to reach write_pos). Otherwise we keep keep_size_after bytes @@ -130,7 +139,7 @@ fill_window(lzma_coder *coder, lzma_allocator *allocator, const uint8_t *in, && coder->mf.read_pos < coder->mf.read_limit) { // Match finder may update coder->pending and expects it to // start from zero, so use a temporary variable. - const size_t pending = coder->mf.pending; + const uint32_t pending = coder->mf.pending; coder->mf.pending = 0; // Rewind read_pos so that the match finder can hash @@ -148,7 +157,7 @@ fill_window(lzma_coder *coder, lzma_allocator *allocator, const uint8_t *in, static lzma_ret -lz_encode(lzma_coder *coder, lzma_allocator *allocator, +lz_encode(lzma_coder *coder, const 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, @@ -179,7 +188,7 @@ lz_encode(lzma_coder *coder, lzma_allocator *allocator, static bool -lz_encoder_prepare(lzma_mf *mf, lzma_allocator *allocator, +lz_encoder_prepare(lzma_mf *mf, const lzma_allocator *allocator, const lzma_lz_options *lz_options) { // For now, the dictionary size is limited to 1.5 GiB. This may grow @@ -325,25 +334,22 @@ lz_encoder_prepare(lzma_mf *mf, lzma_allocator *allocator, hs += HASH_4_SIZE; */ - // If the above code calculating hs is modified, make sure that - // this assertion stays valid (UINT32_MAX / 5 is not strictly the - // exact limit). If it doesn't, you need to calculate that - // hash_size_sum + sons_count cannot overflow. - assert(hs < UINT32_MAX / 5); - - const uint32_t old_count = mf->hash_size_sum + mf->sons_count; - mf->hash_size_sum = hs; + const uint32_t old_hash_count = mf->hash_count; + const uint32_t old_sons_count = mf->sons_count; + mf->hash_count = hs; mf->sons_count = mf->cyclic_size; if (is_bt) mf->sons_count *= 2; - const uint32_t new_count = mf->hash_size_sum + mf->sons_count; - // Deallocate the old hash array if it exists and has different size // than what is needed now. - if (old_count != new_count) { + if (old_hash_count != mf->hash_count + || old_sons_count != mf->sons_count) { lzma_free(mf->hash, allocator); mf->hash = NULL; + + lzma_free(mf->son, allocator); + mf->son = NULL; } // Maximum number of match finder cycles @@ -360,14 +366,23 @@ lz_encoder_prepare(lzma_mf *mf, lzma_allocator *allocator, static bool -lz_encoder_init(lzma_mf *mf, lzma_allocator *allocator, +lz_encoder_init(lzma_mf *mf, const lzma_allocator *allocator, const lzma_lz_options *lz_options) { // 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 @@ -381,43 +396,48 @@ lz_encoder_init(lzma_mf *mf, lzma_allocator *allocator, mf->write_pos = 0; mf->pending = 0; - // Allocate match finder's hash array. - const size_t alloc_count = mf->hash_size_sum + mf->sons_count; - #if UINT32_MAX >= SIZE_MAX / 4 // Check for integer overflow. (Huge dictionaries are not // possible on 32-bit CPU.) - if (alloc_count > SIZE_MAX / sizeof(uint32_t)) + if (mf->hash_count > SIZE_MAX / sizeof(uint32_t) + || mf->sons_count > SIZE_MAX / sizeof(uint32_t)) return true; #endif + // Allocate and initialize the hash table. Since EMPTY_HASH_VALUE + // is zero, we can use lzma_alloc_zero() or memzero() for mf->hash. + // + // We don't need to initialize mf->son, but not doing that may + // make Valgrind complain in normalization (see normalize() in + // lz_encoder_mf.c). Skipping the initialization is *very* good + // when big dictionary is used but only small amount of data gets + // actually compressed: most of the mf->son won't get actually + // allocated by the kernel, so we avoid wasting RAM and improve + // initialization speed a lot. if (mf->hash == NULL) { - mf->hash = lzma_alloc(alloc_count * sizeof(uint32_t), + mf->hash = lzma_alloc_zero(mf->hash_count * sizeof(uint32_t), + allocator); + mf->son = lzma_alloc(mf->sons_count * sizeof(uint32_t), allocator); - if (mf->hash == NULL) - return true; - } - mf->son = mf->hash + mf->hash_size_sum; - mf->cyclic_pos = 0; + if (mf->hash == NULL || mf->son == NULL) { + lzma_free(mf->hash, allocator); + mf->hash = NULL; - // Initialize the hash table. Since EMPTY_HASH_VALUE is zero, we - // can use memset(). + lzma_free(mf->son, allocator); + mf->son = NULL; + + return true; + } + } else { /* - for (uint32_t i = 0; i < hash_size_sum; ++i) - mf->hash[i] = EMPTY_HASH_VALUE; + for (uint32_t i = 0; i < mf->hash_count; ++i) + mf->hash[i] = EMPTY_HASH_VALUE; */ - memzero(mf->hash, (size_t)(mf->hash_size_sum) * sizeof(uint32_t)); + memzero(mf->hash, mf->hash_count * sizeof(uint32_t)); + } - // We don't need to initialize mf->son, but not doing that will - // make Valgrind complain in normalization (see normalize() in - // lz_encoder_mf.c). - // - // Skipping this initialization is *very* good when big dictionary is - // used but only small amount of data gets actually compressed: most - // of the mf->hash won't get actually allocated by the kernel, so - // we avoid wasting RAM and improve initialization speed a lot. - //memzero(mf->son, (size_t)(mf->sons_count) * sizeof(uint32_t)); + mf->cyclic_pos = 0; // Handle preset dictionary. if (lz_options->preset_dict != NULL @@ -445,7 +465,8 @@ lzma_lz_encoder_memusage(const lzma_lz_options *lz_options) lzma_mf mf = { .buffer = NULL, .hash = NULL, - .hash_size_sum = 0, + .son = NULL, + .hash_count = 0, .sons_count = 0, }; @@ -454,17 +475,17 @@ lzma_lz_encoder_memusage(const lzma_lz_options *lz_options) return UINT64_MAX; // Calculate the memory usage. - return (uint64_t)(mf.hash_size_sum + mf.sons_count) - * sizeof(uint32_t) - + (uint64_t)(mf.size) + sizeof(lzma_coder); + return ((uint64_t)(mf.hash_count) + mf.sons_count) * sizeof(uint32_t) + + mf.size + sizeof(lzma_coder); } static void -lz_encoder_end(lzma_coder *coder, lzma_allocator *allocator) +lz_encoder_end(lzma_coder *coder, const lzma_allocator *allocator) { lzma_next_end(&coder->next, allocator); + lzma_free(coder->mf.son, allocator); lzma_free(coder->mf.hash, allocator); lzma_free(coder->mf.buffer, allocator); @@ -479,7 +500,7 @@ lz_encoder_end(lzma_coder *coder, lzma_allocator *allocator) static lzma_ret -lz_encoder_update(lzma_coder *coder, lzma_allocator *allocator, +lz_encoder_update(lzma_coder *coder, const lzma_allocator *allocator, const lzma_filter *filters_null lzma_attribute((__unused__)), const lzma_filter *reversed_filters) { @@ -495,10 +516,10 @@ lz_encoder_update(lzma_coder *coder, lzma_allocator *allocator, extern lzma_ret -lzma_lz_encoder_init(lzma_next_coder *next, lzma_allocator *allocator, +lzma_lz_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator, const lzma_filter_info *filters, lzma_ret (*lz_init)(lzma_lz_encoder *lz, - lzma_allocator *allocator, const void *options, + const lzma_allocator *allocator, const void *options, lzma_lz_options *lz_options)) { #ifdef HAVE_SMALL @@ -522,7 +543,8 @@ lzma_lz_encoder_init(lzma_next_coder *next, lzma_allocator *allocator, next->coder->mf.buffer = NULL; next->coder->mf.hash = NULL; - next->coder->mf.hash_size_sum = 0; + next->coder->mf.son = NULL; + next->coder->mf.hash_count = 0; next->coder->mf.sons_count = 0; next->coder->next = LZMA_NEXT_CODER_INIT; |