diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/liblzma/api/lzma/block.h | 57 | ||||
| -rw-r--r-- | src/liblzma/api/lzma/container.h | 56 | ||||
| -rw-r--r-- | src/liblzma/api/lzma/index.h | 70 | ||||
| -rw-r--r-- | src/liblzma/common/Makefile.am | 2 | ||||
| -rw-r--r-- | src/liblzma/common/block_buffer_encoder.c | 305 | ||||
| -rw-r--r-- | src/liblzma/common/index_decoder.c | 83 | ||||
| -rw-r--r-- | src/liblzma/common/index_encoder.c | 59 | ||||
| -rw-r--r-- | src/liblzma/common/stream_buffer_encoder.c | 138 |
8 files changed, 744 insertions, 26 deletions
diff --git a/src/liblzma/api/lzma/block.h b/src/liblzma/api/lzma/block.h index a747b145..3a49be3a 100644 --- a/src/liblzma/api/lzma/block.h +++ b/src/liblzma/api/lzma/block.h @@ -55,6 +55,7 @@ typedef struct { * - lzma_block_total_size() * - lzma_block_encoder() * - lzma_block_decoder() + * - lzma_block_buffer_encode() * * Written by: * - lzma_block_header_decode() @@ -76,6 +77,7 @@ typedef struct { * * Written by: * - lzma_block_header_size() + * - lzma_block_buffer_encode() */ uint32_t header_size; # define LZMA_BLOCK_HEADER_SIZE_MIN 8 @@ -95,6 +97,7 @@ typedef struct { * - lzma_block_total_size() * - lzma_block_encoder() * - lzma_block_decoder() + * - lzma_block_buffer_encode() */ lzma_check check; @@ -147,6 +150,7 @@ typedef struct { * - lzma_block_compressed_size() * - lzma_block_encoder() * - lzma_block_decoder() + * - lzma_block_buffer_encode() */ lzma_vli compressed_size; @@ -168,6 +172,7 @@ typedef struct { * - lzma_block_header_decode() * - lzma_block_encoder() * - lzma_block_decoder() + * - lzma_block_buffer_encode() */ lzma_vli uncompressed_size; @@ -182,6 +187,7 @@ typedef struct { * - lzma_block_header_encode() * - lzma_block_encoder() * - lzma_block_decoder() + * - lzma_block_buffer_encode() * * Written by: * - lzma_block_header_decode(): Note that this does NOT free() @@ -415,3 +421,54 @@ extern lzma_ret lzma_block_encoder(lzma_stream *strm, lzma_block *block) */ extern lzma_ret lzma_block_decoder(lzma_stream *strm, lzma_block *block) lzma_attr_warn_unused_result; + + +/** + * \brief Calculate maximum output buffer size for single-call encoding + * + * This is equivalent to lzma_stream_buffer_bound() but for .xz Blocks. + * See the documentation of lzma_stream_buffer_bound(). + */ +extern size_t lzma_block_buffer_bound(size_t uncompressed_size); + + +/** + * \brief Single-call .xz Block encoder + * + * In contrast to the multi-call encoder initialized with + * lzma_block_encoder(), this function encodes also the Block Header. This + * is required to make it possible to write appropriate Block Header also + * in case the data isn't compressible, and different filter chain has to be + * used to encode the data in uncompressed form using uncompressed chunks + * of the LZMA2 filter. + * + * When the data isn't compressible, header_size, compressed_size, and + * uncompressed_size are set just like when the data was compressible, but + * it is possible that header_size is too small to hold the filter chain + * specified in block->filters, because that isn't necessarily the filter + * chain that was actually used to encode the data. lzma_block_unpadded_size() + * still works normally, because it doesn't read the filters array. + * + * \param block Block options: block->version, block->check, + * and block->filters must be initialized. + * \param allocator lzma_allocator for custom allocator functions. + * Set to NULL to use malloc() and free(). + * \param in Beginning of the input buffer + * \param in_size Size of the input buffer + * \param out Beginning of the output buffer + * \param out_pos The next byte will be written to out[*out_pos]. + * *out_pos is updated only if encoding succeeds. + * \param out_size Size of the out buffer; the first byte into + * which no data is written to is out[out_size]. + * + * \return - LZMA_OK: Encoding was successful. + * - LZMA_BUF_ERROR: Not enough output buffer space. + * - LZMA_OPTIONS_ERROR + * - LZMA_MEM_ERROR + * - LZMA_DATA_ERROR + * - LZMA_PROG_ERROR + */ +extern lzma_ret lzma_block_buffer_encode( + lzma_block *block, lzma_allocator *allocator, + const uint8_t *in, size_t in_size, + uint8_t *out, size_t *out_pos, size_t out_size); diff --git a/src/liblzma/api/lzma/container.h b/src/liblzma/api/lzma/container.h index f5c0e7ab..240d5dfb 100644 --- a/src/liblzma/api/lzma/container.h +++ b/src/liblzma/api/lzma/container.h @@ -169,6 +169,62 @@ extern lzma_ret lzma_alone_encoder( lzma_attr_warn_unused_result; +/** + * \brief Calculate output buffer size for single-call Stream encoder + * + * When trying to compress uncompressible data, the encoded size will be + * slightly bigger than the input data. This function calculates how much + * output buffer space is required to be sure that lzma_stream_buffer_encode() + * doesn't return LZMA_BUF_ERROR. + * + * The calculated value is not exact, but it is guaranteed to be big enough. + * The actual maximum output space required may be slightly smaller (up to + * about 100 bytes). This should not be a problem in practice. + * + * If the calculated maximum size doesn't fit into size_t or would make the + * Stream grow past LZMA_VLI_MAX (which should never happen in practice), + * zero is returned to indicate the error. + * + * \note The limit calculated by this function applies only to + * single-call encoding. Multi-call encoding may (and probably + * will) have larger maximum expansion when encoding + * uncompressible data. Currently there is no function to + * calculate the maximum expansion of multi-call encoding. + */ +extern size_t lzma_stream_buffer_bound(size_t uncompressed_size); + + +/** + * \brief Single-call Stream encoder + * + * \param filters Array of filters. This must be terminated with + * filters[n].id = LZMA_VLI_UNKNOWN. See filter.h + * for more information. + * \param check Type of the integrity check to calculate from + * uncompressed data. + * \param allocator lzma_allocator for custom allocator functions. + * Set to NULL to use malloc() and free(). + * \param in Beginning of the input buffer + * \param in_size Size of the input buffer + * \param out Beginning of the output buffer + * \param out_pos The next byte will be written to out[*out_pos]. + * *out_pos is updated only if encoding succeeds. + * \param out_size Size of the out buffer; the first byte into + * which no data is written to is out[out_size]. + * + * \return - LZMA_OK: Encoding was successful. + * - LZMA_BUF_ERROR: Not enough output buffer space. + * - LZMA_OPTIONS_ERROR + * - LZMA_MEM_ERROR + * - LZMA_DATA_ERROR + * - LZMA_PROG_ERROR + */ +extern lzma_ret lzma_stream_buffer_encode( + lzma_filter *filters, lzma_check check, + lzma_allocator *allocator, const uint8_t *in, size_t in_size, + uint8_t *out, size_t *out_pos, size_t out_size); + + /************ * Decoding * ************/ diff --git a/src/liblzma/api/lzma/index.h b/src/liblzma/api/lzma/index.h index 9d6b7550..9af296dd 100644 --- a/src/liblzma/api/lzma/index.h +++ b/src/liblzma/api/lzma/index.h @@ -255,7 +255,7 @@ extern lzma_ret lzma_index_cat(lzma_index *lzma_restrict dest, /** - * \brief Duplicates an Index list + * \brief Duplicate an Index list * * Makes an identical copy of the Index. Also the read position is copied. * @@ -267,7 +267,7 @@ extern lzma_index *lzma_index_dup( /** - * \brief Compares if two Index lists are identical + * \brief Compare if two Index lists are identical * * \return True if *a and *b are equal, false otherwise. */ @@ -276,7 +276,7 @@ extern lzma_bool lzma_index_equal(const lzma_index *a, const lzma_index *b) /** - * \brief Initializes Index encoder + * \brief Initialize Index encoder * * \param strm Pointer to properly prepared lzma_stream * \param i Pointer to lzma_index which should be encoded. @@ -294,14 +294,15 @@ extern lzma_ret lzma_index_encoder(lzma_stream *strm, lzma_index *i) /** - * \brief Initializes Index decoder + * \brief Initialize Index decoder * * \param strm Pointer to properly prepared lzma_stream * \param i Pointer to a pointer that will be made to point * to the final decoded Index once lzma_code() has * returned LZMA_STREAM_END. That is, - * lzma_index_decoder() takes care of allocating - * a new lzma_index structure. + * lzma_index_decoder() always takes care of + * allocating a new lzma_index structure, and *i + * doesn't need to be initialized by the caller. * \param memlimit How much memory the resulting Index is allowed * to require. * @@ -321,3 +322,60 @@ extern lzma_ret lzma_index_encoder(lzma_stream *strm, lzma_index *i) extern lzma_ret lzma_index_decoder( lzma_stream *strm, lzma_index **i, uint64_t memlimit) lzma_attr_warn_unused_result; + + +/** + * \brief Single-call Index encoder + * + * \param i Index to be encoded. The read position will be at + * the end of the Index if encoding succeeds, or at + * unspecified position in case an error occurs. + * \param out Beginning of the output buffer + * \param out_pos The next byte will be written to out[*out_pos]. + * *out_pos is updated only if encoding succeeds. + * \param out_size Size of the out buffer; the first byte into + * which no data is written to is out[out_size]. + * + * \return - LZMA_OK: Encoding was successful. + * - LZMA_BUF_ERROR: Output buffer is too small. Use + * lzma_index_size() to find out how much output + * space is needed. + * - LZMA_PROG_ERROR + * + * \note This function doesn't take allocator argument since all + * the internal data is allocated on stack. + */ +extern lzma_ret lzma_index_buffer_encode(lzma_index *i, + uint8_t *out, size_t *out_pos, size_t out_size); + + +/** + * \brief Single-call Index decoder + * + * \param i Pointer to a pointer that will be made to point + * to the final decoded Index if decoding is + * successful. That is, lzma_index_buffer_decode() + * always takes care of allocating a new + * lzma_index structure, and *i doesn't need to be + * initialized by the caller. + * \param memlimit Pointer to how much memory the resulting Index + * is allowed to require. The value pointed by + * this pointer is modified if and only if + * LZMA_MEMLIMIT_ERROR is returned. + * \param allocator Pointer to lzma_allocator, or NULL to use malloc() + * \param in Beginning of the input buffer + * \param in_pos The next byte will be read from in[*in_pos]. + * *in_pos is updated only if decoding succeeds. + * \param in_size Size of the input buffer; the first byte that + * won't be read is in[in_size]. + * + * \return - LZMA_OK: Decoding was successful. + * - LZMA_MEM_ERROR + * - LZMA_MEMLIMIT_ERROR: Memory usage limit was reached. + * The minimum required memlimit value was stored to *memlimit. + * - LZMA_DATA_ERROR + * - LZMA_PROG_ERROR + */ +extern lzma_ret lzma_index_buffer_decode( + lzma_index **i, uint64_t *memlimit, lzma_allocator *allocator, + const uint8_t *in, size_t *in_pos, size_t in_size); diff --git a/src/liblzma/common/Makefile.am b/src/liblzma/common/Makefile.am index f64abdf5..1fa845a4 100644 --- a/src/liblzma/common/Makefile.am +++ b/src/liblzma/common/Makefile.am @@ -39,6 +39,7 @@ libcommon_la_SOURCES = \ if COND_MAIN_ENCODER libcommon_la_SOURCES += \ alone_encoder.c \ + block_buffer_encoder.c \ block_encoder.c \ block_encoder.h \ block_header_encoder.c \ @@ -48,6 +49,7 @@ libcommon_la_SOURCES += \ filter_flags_encoder.c \ index_encoder.c \ index_encoder.h \ + stream_buffer_encoder.c \ stream_encoder.c \ stream_encoder.h \ stream_flags_encoder.c \ diff --git a/src/liblzma/common/block_buffer_encoder.c b/src/liblzma/common/block_buffer_encoder.c new file mode 100644 index 00000000..67412a7d --- /dev/null +++ b/src/liblzma/common/block_buffer_encoder.c @@ -0,0 +1,305 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file block_buffer_encoder.c +/// \brief Single-call .xz Block encoder +// +// Copyright (C) 2009 Lasse Collin +// +// This library is free software; you can redistribute it and/or +// modify it under the terms of the GNU Lesser General Public +// License as published by the Free Software Foundation; either +// version 2.1 of the License, or (at your option) any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +// Lesser General Public License for more details. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "block_encoder.h" +#include "filter_encoder.h" +#include "lzma2_encoder.h" +#include "check.h" + + +/// Estimate the maximum size of the Block Header and Check fields for +/// a Block that uses LZMA2 uncompressed chunks. We could use +/// lzma_block_header_size() but this is simpler. +/// +/// Block Header Size + Block Flags + Compressed Size +/// + Uncompressed Size + Filter Flags for LZMA2 + CRC32 + Check +/// and round up to the next multiple of four to take Header Padding +/// into account. +#define HEADERS_BOUND ((1 + 1 + 2 * LZMA_VLI_BYTES_MAX + 3 + 4 \ + + LZMA_CHECK_SIZE_MAX + 3) & ~3) + + +static lzma_vli +lzma2_bound(lzma_vli uncompressed_size) +{ + // Prevent integer overflow in overhead calculation. + if (uncompressed_size > COMPRESSED_SIZE_MAX) + return 0; + + // Calculate the exact overhead of the LZMA2 headers: Round + // 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) + / LZMA2_CHUNK_MAX) + * LZMA2_HEADER_UNCOMPRESSED + 1; + + // Catch the possible integer overflow. + if (COMPRESSED_SIZE_MAX - overhead < uncompressed_size) + return 0; + + return uncompressed_size + overhead; +} + + +extern LZMA_API size_t +lzma_block_buffer_bound(size_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 (lzma2_size == 0) + return 0; + + // Take Block Padding into account. + lzma2_size = (lzma2_size + 3) & ~LZMA_VLI_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 + // into account the size of the headers in the Block. + if (SIZE_MAX - HEADERS_BOUND < lzma2_size) + return 0; +#endif + + return HEADERS_BOUND + lzma2_size; +} + + +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. + lzma_options_lzma lzma2 = { + .dict_size = LZMA_DICT_SIZE_MIN, + }; + + lzma_filter filters[2]; + filters[0].id = LZMA_FILTER_LZMA2; + filters[0].options = &lzma2; + filters[1].id = LZMA_VLI_UNKNOWN; + + // Set the above filter options to *block temporarily so that we can + // encode the Block Header. + lzma_filter *filters_orig = block->filters; + block->filters = filters; + + if (lzma_block_header_size(block) != LZMA_OK) { + block->filters = filters_orig; + return LZMA_PROG_ERROR; + } + + // Check that there's enough output space. The caller has already + // set block->compressed_size to what lzma2_bound() has returned, + // so we can reuse that value. We know that compressed_size is a + // known valid VLI and header_size is a small value so their sum + // will never overflow. + assert(block->compressed_size == lzma2_bound(in_size)); + if (out_size - *out_pos + < block->header_size + block->compressed_size) { + block->filters = filters_orig; + return LZMA_BUF_ERROR; + } + + if (lzma_block_header_encode(block, out + *out_pos) != LZMA_OK) { + block->filters = filters_orig; + return LZMA_PROG_ERROR; + } + + block->filters = filters_orig; + *out_pos += block->header_size; + + // Encode the data using LZMA2 uncompressed chunks. + size_t in_pos = 0; + uint8_t control = 0x01; // Dictionary reset + + while (in_pos < in_size) { + // Control byte: Indicate uncompressed chunk, of which + // the first resets the dictionary. + out[(*out_pos)++] = control; + control = 0x02; // No dictionary reset + + // Size of the uncompressed chunk + const size_t copy_size + = MIN(in_size - in_pos, LZMA2_CHUNK_MAX); + out[(*out_pos)++] = (copy_size - 1) >> 8; + out[(*out_pos)++] = (copy_size - 1) & 0xFF; + + // The actual data + assert(*out_pos + copy_size <= out_size); + memcpy(out + *out_pos, in + in_pos, copy_size); + + in_pos += copy_size; + *out_pos += copy_size; + } + + // End marker + out[(*out_pos)++] = 0x00; + assert(*out_pos <= out_size); + + return LZMA_OK; +} + + +static lzma_ret +block_encode_normal(lzma_block *block, 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. + if (out_size - *out_pos <= block->header_size) + return LZMA_BUF_ERROR; + + const size_t out_start = *out_pos; + *out_pos += block->header_size; + + // Limit out_size so that we stop encoding if the output would grow + // bigger than what uncompressed Block would be. + if (out_size - *out_pos > block->compressed_size) + out_size = *out_pos + block->compressed_size; + + // TODO: In many common cases this could be optimized to use + // significantly less memory. + lzma_next_coder raw_encoder = LZMA_NEXT_CODER_INIT; + lzma_ret ret = lzma_raw_encoder_init( + &raw_encoder, allocator, block->filters); + + if (ret == LZMA_OK) { + size_t in_pos = 0; + ret = raw_encoder.code(raw_encoder.coder, allocator, + in, &in_pos, in_size, out, out_pos, out_size, + LZMA_FINISH); + } + + // NOTE: This needs to be run even if lzma_raw_encoder_init() failed. + lzma_next_end(&raw_encoder, allocator); + + if (ret == LZMA_STREAM_END) { + // Compression was successful. Write the Block Header. + block->compressed_size + = *out_pos - (out_start + block->header_size); + ret = lzma_block_header_encode(block, out + out_start); + if (ret != LZMA_OK) + ret = LZMA_PROG_ERROR; + + } else if (ret == LZMA_OK) { + // Output buffer became full. + ret = LZMA_BUF_ERROR; + } + + // Reset *out_pos if something went wrong. + if (ret != LZMA_OK) + *out_pos = out_start; + + return ret; +} + + +extern LZMA_API lzma_ret +lzma_block_buffer_encode(lzma_block *block, lzma_allocator *allocator, + const uint8_t *in, size_t in_size, + uint8_t *out, size_t *out_pos, size_t out_size) +{ + // Sanity checks + if (block == NULL || block->filters == NULL + || (in == NULL && in_size != 0) || out == NULL + || out_pos == NULL || *out_pos > out_size) + return LZMA_PROG_ERROR; + + // Check the version field. + if (block->version != 0) + return LZMA_OPTIONS_ERROR; + + // Size of a Block has to be a multiple of four, so limit the size + // here already. This way we don't need to check it again when adding + // Block Padding. + out_size -= (out_size - *out_pos) & 3; + + // Get the size of the Check field. + const size_t check_size = lzma_check_size(block->check); + if (check_size == UINT32_MAX) + return LZMA_PROG_ERROR; + + // Reserve space for the Check field. + if (out_size - *out_pos <= check_size) + return LZMA_BUF_ERROR; + + out_size -= check_size; + + // Do the actual compression. + const lzma_ret 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. + if (ret != LZMA_BUF_ERROR) + return ret; + + // The data was uncompressible (at least with the options + // given to us) or the output buffer was too small. Use the + // uncompressed chunks of LZMA2 to wrap the data into a valid + // Block. If we haven't been given enough output space, even + // this may fail. + return_if_error(block_encode_uncompressed(block, in, in_size, + out, out_pos, out_size)); + } + + assert(*out_pos <= out_size); + + // Block Padding. No buffer overflow here, because we already adjusted + // out_size so that (out_size - out_start) is a multiple of four. + // Thus, if the buffer is full, the loop body can never run. + for (size_t i = (size_t)(block->compressed_size); i & 3; ++i) { + assert(*out_pos < out_size); + out[(*out_pos)++] = 0x00; + } + + // If there's no Check field, we are done now. + if (check_size > 0) { + // Calculate the integrity check. We reserved space for + // the Check field earlier so we don't need to check for + // available output space here. + lzma_check_state check; + lzma_check_init(&check, block->check); + lzma_check_update(&check, block->check, in, in_size); + lzma_check_finish(&check, block->check); + + memcpy(out + *out_pos, check.buffer.u8, check_size); + *out_pos += check_size; + } + + return LZMA_OK; +} diff --git a/src/liblzma/common/index_decoder.c b/src/liblzma/common/index_decoder.c index e29e0b0d..de507978 100644 --- a/src/liblzma/common/index_decoder.c +++ b/src/liblzma/common/index_decoder.c @@ -226,6 +226,27 @@ index_decoder_memconfig(lzma_coder *coder, uint64_t *memusage, static lzma_ret +index_decoder_reset(lzma_coder *coder, lzma_allocator *allocator, + lzma_index **i, uint64_t memlimit) +{ + // We always allocate a new lzma_index. + *i = lzma_index_init(NULL, allocator); + if (*i == NULL) + return LZMA_MEM_ERROR; + + // Initialize the rest. + coder->sequence = SEQ_INDICATOR; + coder->memlimit = memlimit; + coder->index = *i; + coder->count = 0; // Needs to be initialized due to _memconfig(). + coder->pos = 0; + coder->crc32 = 0; + + return LZMA_OK; +} + + +static lzma_ret index_decoder_init(lzma_next_coder *next, lzma_allocator *allocator, lzma_index **i, uint64_t memlimit) { @@ -247,20 +268,7 @@ index_decoder_init(lzma_next_coder *next, lzma_allocator *allocator, lzma_index_end(next->coder->index, allocator); } - // We always allocate a new lzma_index. - *i = lzma_index_init(NULL, allocator); - if (*i == NULL) - return LZMA_MEM_ERROR; - - // Initialize the rest. - next->coder->sequence = SEQ_INDICATOR; - next->coder->memlimit = memlimit; - next->coder->index = *i; - next->coder->count = 0; // Needs to be initialized due to _memconfig(). - next->coder->pos = 0; - next->coder->crc32 = 0; - - return LZMA_OK; + return index_decoder_reset(next->coder, allocator, i, memlimit); } @@ -273,3 +281,50 @@ lzma_index_decoder(lzma_stream *strm, lzma_index **i, uint64_t memlimit) return LZMA_OK; } + + +extern LZMA_API lzma_ret +lzma_index_buffer_decode( + lzma_index **i, uint64_t *memlimit, lzma_allocator *allocator, + const uint8_t *in, size_t *in_pos, size_t in_size) +{ + // Sanity checks + if (i == NULL || in == NULL || in_pos == NULL || *in_pos > in_size) + return LZMA_PROG_ERROR; + + // Initialize the decoder. + lzma_coder coder; + return_if_error(index_decoder_reset(&coder, allocator, i, *memlimit)); + + // Store the input start position so that we can restore it in case + // of an error. + const size_t in_start = *in_pos; + + // Do the actual decoding. + lzma_ret ret = index_decode(&coder, allocator, in, in_pos, in_size, + NULL, NULL, 0, LZMA_RUN); + + if (ret == LZMA_STREAM_END) { + ret = LZMA_OK; + } else { + // Something went wrong, free the Index structure and restore + // the input position. + lzma_index_end(*i, allocator); + *i = NULL; + *in_pos = in_start; + + if (ret == LZMA_OK) { + // The input is truncated or otherwise corrupt. + // Use LZMA_DATA_ERROR instead of LZMA_BUF_ERROR + // like lzma_vli_decode() does in single-call mode. + ret = LZMA_DATA_ERROR; + + } else if (ret == LZMA_MEMLIMIT_ERROR) { + // Tell the caller how much memory would have + // been needed. + *memlimit = lzma_index_memusage(coder.count); + } + } + + return ret; +} diff --git a/src/liblzma/common/index_encoder.c b/src/liblzma/common/index_encoder.c index 522dbb53..17a0806a 100644 --- a/src/liblzma/common/index_encoder.c +++ b/src/liblzma/common/index_encoder.c @@ -178,6 +178,20 @@ index_encoder_end(lzma_coder *coder, lzma_allocator *allocator) } +static void +index_encoder_reset(lzma_coder *coder, lzma_index *i) +{ + lzma_index_rewind(i); + + coder->sequence = SEQ_INDICATOR; + coder->index = i; + coder->pos = 0; + coder->crc32 = 0; + + return; +} + + extern lzma_ret lzma_index_encoder_init(lzma_next_coder *next, lzma_allocator *allocator, lzma_index *i) @@ -196,12 +210,7 @@ lzma_index_encoder_init(lzma_next_coder *next, lzma_allocator *allocator, next->end = &index_encoder_end; } - lzma_index_rewind(i); - - next->coder->sequence = SEQ_INDICATOR; - next->coder->index = i; - next->coder->pos = 0; - next->coder->crc32 = 0; + index_encoder_reset(next->coder, i); return LZMA_OK; } @@ -216,3 +225,41 @@ lzma_index_encoder(lzma_stream *strm, lzma_index *i) return LZMA_OK; } + + +extern LZMA_API lzma_ret +lzma_index_buffer_encode(lzma_index *i, + uint8_t *out, size_t *out_pos, size_t out_size) +{ + // Validate the arugments. + if (i == NULL || out == NULL || out_pos == NULL || *out_pos > out_size) + return LZMA_PROG_ERROR; + + // Don't try to encode if there's not enough output space. + if (out_size - *out_pos < lzma_index_size(i)) + return LZMA_BUF_ERROR; + + // The Index encoder needs just one small data structure so we can + // allocate it on stack. + lzma_coder coder; + index_encoder_reset(&coder, i); + + // Do the actual encoding. This should never fail, but store + // the original *out_pos just in case. + const size_t out_start = *out_pos; + lzma_ret ret = index_encode(&coder, NULL, NULL, NULL, 0, + out, out_pos, out_size, LZMA_RUN); + + if (ret == LZMA_STREAM_END) { + ret = LZMA_OK; + } else { + // We should never get here, but just in case, restore the + // output position and set the error accordingly if something + // goes wrong and debugging isn't enabled. + assert(0); + *out_pos = out_start; + ret = LZMA_PROG_ERROR; + } + + return ret; +} diff --git a/src/liblzma/common/stream_buffer_encoder.c b/src/liblzma/common/stream_buffer_encoder.c new file mode 100644 index 00000000..29588365 --- /dev/null +++ b/src/liblzma/common/stream_buffer_encoder.c @@ -0,0 +1,138 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file stream_buffer_encoder.c +/// \brief Single-call .xz Stream encoder +// +// Copyright (C) 2009 Lasse Collin +// +// This library is free software; you can redistribute it and/or +// modify it under the terms of the GNU Lesser General Public +// License as published by the Free Software Foundation; either +// version 2.1 of the License, or (at your option) any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +// Lesser General Public License for more details. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "index.h" + + +/// Maximum size of Index that has exactly one Record. +/// Index Indicator + Number of Records + Record + CRC32 rounded up to +/// the next multiple of four. +#define INDEX_BOUND ((1 + 1 + 2 * LZMA_VLI_BYTES_MAX + 4 + 3) & ~3) + +/// Stream Header, Stream Footer, and Index +#define HEADERS_BOUND (2 * LZMA_STREAM_HEADER_SIZE + INDEX_BOUND) + + +extern LZMA_API size_t +lzma_stream_buffer_bound(size_t uncompressed_size) +{ + // Get the maximum possible size of a Block. + const size_t block_bound = lzma_block_buffer_bound(uncompressed_size); + if (block_bound == 0) + return 0; + + // Catch the possible integer overflow and also prevent the size of + // the Stream exceeding LZMA_VLI_MAX (theoretically possible on + // 64-bit systems). + if (MIN(SIZE_MAX, LZMA_VLI_MAX) - block_bound < HEADERS_BOUND) + return 0; + + return block_bound + HEADERS_BOUND; +} + + +extern LZMA_API lzma_ret +lzma_stream_buffer_encode(lzma_filter *filters, lzma_check check, + lzma_allocator *allocator, const uint8_t *in, size_t in_size, + uint8_t *out, size_t *out_pos_ptr, size_t out_size) +{ + // Sanity checks + if (filters == NULL || (unsigned int)(check) > LZMA_CHECK_ID_MAX + || (in == NULL && in_size != 0) || out == NULL + || out_pos_ptr == NULL || *out_pos_ptr > out_size) + return LZMA_PROG_ERROR; + + // Note for the paranoids: Index encoder prevents the Stream from + // getting too big and still being accepted with LZMA_OK, and Block + // encoder catches if the input is too big. So we don't need to + // separately check if the buffers are too big. + + // Use a local copy. We update *out_pos_ptr only if everything + // succeeds. + size_t out_pos = *out_pos_ptr; + + // Check that there's enough space for both Stream Header and + // Stream Footer. + if (out_size - out_pos <= 2 * LZMA_STREAM_HEADER_SIZE) + return LZMA_BUF_ERROR; + + // Reserve space for Stream Footer so we don't need to check for + // available space again before encoding Stream Footer. + out_size -= LZMA_STREAM_HEADER_SIZE; + + // Encode the Stream Header. + lzma_stream_flags stream_flags = { + .version = 0, + .check = check, + }; + + if (lzma_stream_header_encode(&stream_flags, out + out_pos) + != LZMA_OK) + return LZMA_PROG_ERROR; + + out_pos += LZMA_STREAM_HEADER_SIZE; + + // Block + lzma_block block = { + .version = 0, + .check = check, + .filters = filters, + }; + + return_if_error(lzma_block_buffer_encode(&block, allocator, + in, in_size, out, &out_pos, out_size)); + + // Index + { + // Create an Index with one Record. + lzma_index *i = lzma_index_init(NULL, NULL); + if (i == NULL) + return LZMA_MEM_ERROR; + + lzma_ret ret = lzma_index_append(i, NULL, + lzma_block_unpadded_size(&block), + block.uncompressed_size); + + // If adding the Record was successful, encode the Index + // and get its size which will be stored into Stream Footer. + if (ret == LZMA_OK) { + ret = lzma_index_buffer_encode( + i, out, &out_pos, out_size); + + stream_flags.backward_size = lzma_index_size(i); + } + + lzma_index_end(i, NULL); + + if (ret != LZMA_OK) + return ret; + } + + // Stream Footer. We have already reserved space for this. + if (lzma_stream_footer_encode(&stream_flags, out + out_pos) + != LZMA_OK) + return LZMA_PROG_ERROR; + + out_pos += LZMA_STREAM_HEADER_SIZE; + + // Everything went fine, make the new output position available + // to the application. + *out_pos_ptr = out_pos; + return LZMA_OK; +} |