diff options
Diffstat (limited to 'contrib/xz/src/liblzma/common/block_buffer_encoder.c')
| -rw-r--r-- | contrib/xz/src/liblzma/common/block_buffer_encoder.c | 98 |
1 files changed, 65 insertions, 33 deletions
diff --git a/contrib/xz/src/liblzma/common/block_buffer_encoder.c b/contrib/xz/src/liblzma/common/block_buffer_encoder.c index 519c6a684d76..39e263aa4765 100644 --- a/contrib/xz/src/liblzma/common/block_buffer_encoder.c +++ b/contrib/xz/src/liblzma/common/block_buffer_encoder.c @@ -10,6 +10,7 @@ // /////////////////////////////////////////////////////////////////////////////// +#include "block_buffer_encoder.h" #include "block_encoder.h" #include "filter_encoder.h" #include "lzma2_encoder.h" @@ -28,8 +29,8 @@ + LZMA_CHECK_SIZE_MAX + 3) & ~3) -static lzma_vli -lzma2_bound(lzma_vli uncompressed_size) +static uint64_t +lzma2_bound(uint64_t uncompressed_size) { // Prevent integer overflow in overhead calculation. if (uncompressed_size > COMPRESSED_SIZE_MAX) @@ -39,7 +40,7 @@ lzma2_bound(lzma_vli uncompressed_size) // uncompressed_size up to the next multiple of LZMA2_CHUNK_MAX, // multiply by the size of per-chunk header, and add one byte for // the end marker. - const lzma_vli overhead = ((uncompressed_size + LZMA2_CHUNK_MAX - 1) + const uint64_t overhead = ((uncompressed_size + LZMA2_CHUNK_MAX - 1) / LZMA2_CHUNK_MAX) * LZMA2_HEADER_UNCOMPRESSED + 1; @@ -51,30 +52,36 @@ lzma2_bound(lzma_vli uncompressed_size) } -extern LZMA_API(size_t) -lzma_block_buffer_bound(size_t uncompressed_size) +extern uint64_t +lzma_block_buffer_bound64(uint64_t uncompressed_size) { - // For now, if the data doesn't compress, we always use uncompressed - // chunks of LZMA2. In future we may use Subblock filter too, but - // but for simplicity we probably will still use the same bound - // calculation even though Subblock filter would have slightly less - // overhead. - lzma_vli lzma2_size = lzma2_bound(uncompressed_size); + // If the data doesn't compress, we always use uncompressed + // LZMA2 chunks. + uint64_t lzma2_size = lzma2_bound(uncompressed_size); if (lzma2_size == 0) return 0; // Take Block Padding into account. - lzma2_size = (lzma2_size + 3) & ~LZMA_VLI_C(3); + lzma2_size = (lzma2_size + 3) & ~UINT64_C(3); -#if SIZE_MAX < LZMA_VLI_MAX - // Catch the possible integer overflow on 32-bit systems. There's no - // overflow on 64-bit systems, because lzma2_bound() already takes + // No risk of integer overflow because lzma2_bound() already takes // into account the size of the headers in the Block. - if (SIZE_MAX - HEADERS_BOUND < lzma2_size) + return HEADERS_BOUND + lzma2_size; +} + + +extern LZMA_API(size_t) +lzma_block_buffer_bound(size_t uncompressed_size) +{ + uint64_t ret = lzma_block_buffer_bound64(uncompressed_size); + +#if SIZE_MAX < UINT64_MAX + // Catch the possible integer overflow on 32-bit systems. + if (ret > SIZE_MAX) return 0; #endif - return HEADERS_BOUND + lzma2_size; + return ret; } @@ -82,9 +89,6 @@ static lzma_ret block_encode_uncompressed(lzma_block *block, const uint8_t *in, size_t in_size, uint8_t *out, size_t *out_pos, size_t out_size) { - // TODO: Figure out if the last filter is LZMA2 or Subblock and use - // that filter to encode the uncompressed chunks. - // Use LZMA2 uncompressed chunks. We wouldn't need a dictionary at // all, but LZMA2 always requires a dictionary, so use the minimum // value to minimize memory usage of the decoder. @@ -160,16 +164,11 @@ block_encode_uncompressed(lzma_block *block, const uint8_t *in, size_t in_size, static lzma_ret -block_encode_normal(lzma_block *block, lzma_allocator *allocator, +block_encode_normal(lzma_block *block, const lzma_allocator *allocator, const uint8_t *in, size_t in_size, uint8_t *out, size_t *out_pos, size_t out_size) { // Find out the size of the Block Header. - block->compressed_size = lzma2_bound(in_size); - if (block->compressed_size == 0) - return LZMA_DATA_ERROR; - - block->uncompressed_size = in_size; return_if_error(lzma_block_header_size(block)); // Reserve space for the Block Header and skip it for now. @@ -221,10 +220,11 @@ block_encode_normal(lzma_block *block, lzma_allocator *allocator, } -extern LZMA_API(lzma_ret) -lzma_block_buffer_encode(lzma_block *block, lzma_allocator *allocator, +static lzma_ret +block_buffer_encode(lzma_block *block, const lzma_allocator *allocator, const uint8_t *in, size_t in_size, - uint8_t *out, size_t *out_pos, size_t out_size) + uint8_t *out, size_t *out_pos, size_t out_size, + bool try_to_compress) { // Validate the arguments. if (block == NULL || (in == NULL && in_size != 0) || out == NULL @@ -233,11 +233,11 @@ lzma_block_buffer_encode(lzma_block *block, lzma_allocator *allocator, // The contents of the structure may depend on the version so // check the version before validating the contents of *block. - if (block->version != 0) + if (block->version > 1) return LZMA_OPTIONS_ERROR; if ((unsigned int)(block->check) > LZMA_CHECK_ID_MAX - || block->filters == NULL) + || (try_to_compress && block->filters == NULL)) return LZMA_PROG_ERROR; if (!lzma_check_is_supported(block->check)) @@ -258,9 +258,19 @@ lzma_block_buffer_encode(lzma_block *block, lzma_allocator *allocator, out_size -= check_size; + // Initialize block->uncompressed_size and calculate the worst-case + // value for block->compressed_size. + block->uncompressed_size = in_size; + block->compressed_size = lzma2_bound(in_size); + if (block->compressed_size == 0) + return LZMA_DATA_ERROR; + // Do the actual compression. - const lzma_ret ret = block_encode_normal(block, allocator, - in, in_size, out, out_pos, out_size); + lzma_ret ret = LZMA_BUF_ERROR; + if (try_to_compress) + ret = block_encode_normal(block, allocator, + in, in_size, out, out_pos, out_size); + if (ret != LZMA_OK) { // If the error was something else than output buffer // becoming full, return the error now. @@ -303,3 +313,25 @@ lzma_block_buffer_encode(lzma_block *block, lzma_allocator *allocator, return LZMA_OK; } + + +extern LZMA_API(lzma_ret) +lzma_block_buffer_encode(lzma_block *block, const lzma_allocator *allocator, + const uint8_t *in, size_t in_size, + uint8_t *out, size_t *out_pos, size_t out_size) +{ + return block_buffer_encode(block, allocator, + in, in_size, out, out_pos, out_size, true); +} + + +extern LZMA_API(lzma_ret) +lzma_block_uncomp_encode(lzma_block *block, + const uint8_t *in, size_t in_size, + uint8_t *out, size_t *out_pos, size_t out_size) +{ + // It won't allocate any memory from heap so no need + // for lzma_allocator. + return block_buffer_encode(block, NULL, + in, in_size, out, out_pos, out_size, false); +} |