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Diffstat (limited to '')
-rw-r--r-- | src/liblzma/common/stream_encoder.c | 282 |
1 files changed, 282 insertions, 0 deletions
diff --git a/src/liblzma/common/stream_encoder.c b/src/liblzma/common/stream_encoder.c new file mode 100644 index 00000000..767b8014 --- /dev/null +++ b/src/liblzma/common/stream_encoder.c @@ -0,0 +1,282 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file stream_encoder.c +/// \brief Encodes .lzma Streams +// +// Copyright (C) 2007-2008 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 "stream_common.h" +#include "stream_encoder.h" +#include "block_encoder.h" +#include "index_encoder.h" + + +struct lzma_coder_s { + enum { + SEQ_STREAM_HEADER, + SEQ_BLOCK_INIT, + SEQ_BLOCK_HEADER, + SEQ_BLOCK_ENCODE, + SEQ_INDEX_ENCODE, + SEQ_STREAM_FOOTER, + } sequence; + + /// Block + lzma_next_coder block_encoder; + + /// Options for the Block encoder + lzma_options_block block_options; + + /// Index encoder. This is separate from Block encoder, because this + /// doesn't take much memory, and when encoding multiple Streams + /// with the same encoding options we avoid reallocating memory. + lzma_next_coder index_encoder; + + /// Index to hold sizes of the Blocks + lzma_index *index; + + /// Read position in buffer[] + size_t buffer_pos; + + /// Total number of bytes in buffer[] + size_t buffer_size; + + /// Buffer to hold Stream Header, Block Header, and Stream Footer. + /// Block Header has biggest maximum size. + uint8_t buffer[LZMA_BLOCK_HEADER_SIZE_MAX]; +}; + + +static lzma_ret +block_encoder_init(lzma_coder *coder, lzma_allocator *allocator) +{ + // Prepare the Block options. + coder->block_options.compressed_size = LZMA_VLI_VALUE_UNKNOWN; + coder->block_options.uncompressed_size = LZMA_VLI_VALUE_UNKNOWN; + + return_if_error(lzma_block_header_size(&coder->block_options)); + + // Initialize the actual Block encoder. + return lzma_block_encoder_init(&coder->block_encoder, allocator, + &coder->block_options); +} + + +static lzma_ret +stream_encode(lzma_coder *coder, 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, size_t out_size, lzma_action action) +{ + // Main loop + while (*out_pos < out_size) + switch (coder->sequence) { + case SEQ_STREAM_HEADER: + case SEQ_BLOCK_HEADER: + case SEQ_STREAM_FOOTER: + bufcpy(coder->buffer, &coder->buffer_pos, coder->buffer_size, + out, out_pos, out_size); + if (coder->buffer_pos < coder->buffer_size) + return LZMA_OK; + + if (coder->sequence == SEQ_STREAM_FOOTER) + return LZMA_STREAM_END; + + coder->buffer_pos = 0; + ++coder->sequence; + break; + + case SEQ_BLOCK_INIT: { + if (*in_pos == in_size) { + // If we are requested to flush or finish the current + // Block, return LZMA_STREAM_END immediatelly since + // there's nothing to do. + if (action != LZMA_FINISH) + return action == LZMA_RUN + ? LZMA_OK : LZMA_STREAM_END; + + // The application had used LZMA_FULL_FLUSH to finish + // the previous Block, but now wants to finish without + // encoding new data, or it is simply creating an + // empty Stream with no Blocks. + // + // Initialize the Index encoder, and continue to + // actually encoding the Index. + return_if_error(lzma_index_encoder_init( + &coder->index_encoder, allocator, + coder->index)); + coder->sequence = SEQ_INDEX_ENCODE; + break; + } + + // Initialize the Block encoder except if this is the first + // Block, because stream_encoder_init() has already + // initialized it. + if (lzma_index_count(coder->index) != 0) + return_if_error(block_encoder_init(coder, allocator)); + + // Encode the Block Header. This shouldn't fail since we have + // already initialized the Block encoder. + if (lzma_block_header_encode(&coder->block_options, + coder->buffer) != LZMA_OK) + return LZMA_PROG_ERROR; + + coder->buffer_size = coder->block_options.header_size; + coder->sequence = SEQ_BLOCK_HEADER; + break; + } + + case SEQ_BLOCK_ENCODE: { + static const lzma_action convert[4] = { + LZMA_RUN, + LZMA_SYNC_FLUSH, + LZMA_FINISH, + LZMA_FINISH, + }; + + const lzma_ret ret = coder->block_encoder.code( + coder->block_encoder.coder, allocator, + in, in_pos, in_size, + out, out_pos, out_size, convert[action]); + if (ret != LZMA_STREAM_END || action == LZMA_SYNC_FLUSH) + return ret; + + // Add a new Index Record. + const lzma_vli total_size = lzma_block_total_size_get( + &coder->block_options); + assert(total_size != 0); + return_if_error(lzma_index_append(coder->index, allocator, + total_size, + coder->block_options.uncompressed_size)); + + coder->sequence = SEQ_BLOCK_INIT; + break; + } + + case SEQ_INDEX_ENCODE: { + // Call the Index encoder. It doesn't take any input, so + // those pointers can be NULL. + const lzma_ret ret = coder->index_encoder.code( + coder->index_encoder.coder, allocator, + NULL, NULL, 0, + out, out_pos, out_size, LZMA_RUN); + if (ret != LZMA_STREAM_END) + return ret; + + // Encode the Stream Footer into coder->buffer. + const lzma_stream_flags stream_flags = { + .backward_size = lzma_index_size(coder->index), + .check = coder->block_options.check, + }; + + if (lzma_stream_footer_encode(&stream_flags, coder->buffer) + != LZMA_OK) + return LZMA_PROG_ERROR; + + coder->buffer_size = LZMA_STREAM_HEADER_SIZE; + coder->sequence = SEQ_STREAM_FOOTER; + break; + } + + default: + assert(0); + return LZMA_PROG_ERROR; + } + + return LZMA_OK; +} + + +static void +stream_encoder_end(lzma_coder *coder, lzma_allocator *allocator) +{ + lzma_next_coder_end(&coder->block_encoder, allocator); + lzma_next_coder_end(&coder->index_encoder, allocator); + lzma_index_end(coder->index, allocator); + lzma_free(coder, allocator); + return; +} + + +static lzma_ret +stream_encoder_init(lzma_next_coder *next, lzma_allocator *allocator, + const lzma_options_filter *filters, lzma_check_type check) +{ + if (filters == NULL) + return LZMA_PROG_ERROR; + + if (next->coder == NULL) { + next->coder = lzma_alloc(sizeof(lzma_coder), allocator); + if (next->coder == NULL) + return LZMA_MEM_ERROR; + + next->code = &stream_encode; + next->end = &stream_encoder_end; + + next->coder->block_encoder = LZMA_NEXT_CODER_INIT; + next->coder->index_encoder = LZMA_NEXT_CODER_INIT; + next->coder->index = NULL; + } + + // Basic initializations + next->coder->sequence = SEQ_STREAM_HEADER; + next->coder->block_options.check = check; + next->coder->block_options.filters = (lzma_options_filter *)(filters); + + // Initialize the Index + next->coder->index = lzma_index_init(next->coder->index, allocator); + if (next->coder->index == NULL) + return LZMA_MEM_ERROR; + + // Encode the Stream Header + lzma_stream_flags stream_flags = { + .check = check, + }; + return_if_error(lzma_stream_header_encode( + &stream_flags, next->coder->buffer)); + + next->coder->buffer_pos = 0; + next->coder->buffer_size = LZMA_STREAM_HEADER_SIZE; + + // Initialize the Block encoder. This way we detect if the given + // filters are supported by the current liblzma build, and the + // application doesn't need to keep the filters structure available + // unless it is going to use LZMA_FULL_FLUSH. + return block_encoder_init(next->coder, allocator); +} + + +extern lzma_ret +lzma_stream_encoder_init(lzma_next_coder *next, lzma_allocator *allocator, + const lzma_options_filter *filters, lzma_check_type check) +{ + lzma_next_coder_init(stream_encoder_init, next, allocator, + filters, check); +} + + +extern LZMA_API lzma_ret +lzma_stream_encoder(lzma_stream *strm, + const lzma_options_filter *filters, lzma_check_type check) +{ + lzma_next_strm_init(strm, stream_encoder_init, filters, check); + + strm->internal->supported_actions[LZMA_RUN] = true; + strm->internal->supported_actions[LZMA_SYNC_FLUSH] = true; + strm->internal->supported_actions[LZMA_FULL_FLUSH] = true; + strm->internal->supported_actions[LZMA_FINISH] = true; + + return LZMA_OK; +} |