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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 03:10:08 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 03:10:08 +0000 |
commit | 5262a872f308b3b584c97d621992fb3877e392b8 (patch) | |
tree | b956c322376141abeafe639bd72cfecdf16954b5 /src/liblzma/common/stream_encoder.c | |
parent | Initial commit. (diff) | |
download | xz-utils-5262a872f308b3b584c97d621992fb3877e392b8.tar.xz xz-utils-5262a872f308b3b584c97d621992fb3877e392b8.zip |
Adding upstream version 5.6.1+really5.4.5.upstream/5.6.1+really5.4.5
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/liblzma/common/stream_encoder.c')
-rw-r--r-- | src/liblzma/common/stream_encoder.c | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/src/liblzma/common/stream_encoder.c b/src/liblzma/common/stream_encoder.c new file mode 100644 index 0000000..ee92046 --- /dev/null +++ b/src/liblzma/common/stream_encoder.c @@ -0,0 +1,355 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file stream_encoder.c +/// \brief Encodes .xz Streams +// +// Author: Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "block_encoder.h" +#include "index_encoder.h" + + +typedef struct { + enum { + SEQ_STREAM_HEADER, + SEQ_BLOCK_INIT, + SEQ_BLOCK_HEADER, + SEQ_BLOCK_ENCODE, + SEQ_INDEX_ENCODE, + SEQ_STREAM_FOOTER, + } sequence; + + /// True if Block encoder has been initialized by + /// stream_encoder_init() or stream_encoder_update() + /// and thus doesn't need to be initialized in stream_encode(). + bool block_encoder_is_initialized; + + /// Block + lzma_next_coder block_encoder; + + /// Options for the Block encoder + lzma_block block_options; + + /// The filter chain currently in use + lzma_filter filters[LZMA_FILTERS_MAX + 1]; + + /// 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]; +} lzma_stream_coder; + + +static lzma_ret +block_encoder_init(lzma_stream_coder *coder, const lzma_allocator *allocator) +{ + // Prepare the Block options. Even though Block encoder doesn't need + // compressed_size, uncompressed_size, and header_size to be + // initialized, it is a good idea to do it here, because this way + // we catch if someone gave us Filter ID that cannot be used in + // Blocks/Streams. + coder->block_options.compressed_size = LZMA_VLI_UNKNOWN; + coder->block_options.uncompressed_size = LZMA_VLI_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(void *coder_ptr, 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, size_t out_size, lzma_action action) +{ + lzma_stream_coder *coder = coder_ptr; + + // Main loop + while (*out_pos < out_size) + switch (coder->sequence) { + case SEQ_STREAM_HEADER: + case SEQ_BLOCK_HEADER: + case SEQ_STREAM_FOOTER: + lzma_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 immediately 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 unless it was already + // initialized by stream_encoder_init() or + // stream_encoder_update(). + if (!coder->block_encoder_is_initialized) + return_if_error(block_encoder_init(coder, allocator)); + + // Make it false so that we don't skip the initialization + // with the next Block. + coder->block_encoder_is_initialized = false; + + // 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[LZMA_ACTION_MAX + 1] = { + LZMA_RUN, + LZMA_SYNC_FLUSH, + LZMA_FINISH, + 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 unpadded_size = lzma_block_unpadded_size( + &coder->block_options); + assert(unpadded_size != 0); + return_if_error(lzma_index_append(coder->index, allocator, + unpadded_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 = { + .version = 0, + .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(void *coder_ptr, const lzma_allocator *allocator) +{ + lzma_stream_coder *coder = coder_ptr; + + lzma_next_end(&coder->block_encoder, allocator); + lzma_next_end(&coder->index_encoder, allocator); + lzma_index_end(coder->index, allocator); + + lzma_filters_free(coder->filters, allocator); + + lzma_free(coder, allocator); + return; +} + + +static lzma_ret +stream_encoder_update(void *coder_ptr, const lzma_allocator *allocator, + const lzma_filter *filters, + const lzma_filter *reversed_filters) +{ + lzma_stream_coder *coder = coder_ptr; + lzma_ret ret; + + // Make a copy to a temporary buffer first. This way it is easier + // to keep the encoder state unchanged if an error occurs with + // lzma_filters_copy(). + lzma_filter temp[LZMA_FILTERS_MAX + 1]; + return_if_error(lzma_filters_copy(filters, temp, allocator)); + + if (coder->sequence <= SEQ_BLOCK_INIT) { + // There is no incomplete Block waiting to be finished, + // thus we can change the whole filter chain. Start by + // trying to initialize the Block encoder with the new + // chain. This way we detect if the chain is valid. + coder->block_encoder_is_initialized = false; + coder->block_options.filters = temp; + ret = block_encoder_init(coder, allocator); + coder->block_options.filters = coder->filters; + if (ret != LZMA_OK) + goto error; + + coder->block_encoder_is_initialized = true; + + } else if (coder->sequence <= SEQ_BLOCK_ENCODE) { + // We are in the middle of a Block. Try to update only + // the filter-specific options. + ret = coder->block_encoder.update( + coder->block_encoder.coder, allocator, + filters, reversed_filters); + if (ret != LZMA_OK) + goto error; + } else { + // Trying to update the filter chain when we are already + // encoding Index or Stream Footer. + ret = LZMA_PROG_ERROR; + goto error; + } + + // Free the options of the old chain. + lzma_filters_free(coder->filters, allocator); + + // Copy the new filter chain in place. + memcpy(coder->filters, temp, sizeof(temp)); + + return LZMA_OK; + +error: + lzma_filters_free(temp, allocator); + return ret; +} + + +static lzma_ret +stream_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator, + const lzma_filter *filters, lzma_check check) +{ + lzma_next_coder_init(&stream_encoder_init, next, allocator); + + if (filters == NULL) + return LZMA_PROG_ERROR; + + lzma_stream_coder *coder = next->coder; + + if (coder == NULL) { + coder = lzma_alloc(sizeof(lzma_stream_coder), allocator); + if (coder == NULL) + return LZMA_MEM_ERROR; + + next->coder = coder; + next->code = &stream_encode; + next->end = &stream_encoder_end; + next->update = &stream_encoder_update; + + coder->filters[0].id = LZMA_VLI_UNKNOWN; + coder->block_encoder = LZMA_NEXT_CODER_INIT; + coder->index_encoder = LZMA_NEXT_CODER_INIT; + coder->index = NULL; + } + + // Basic initializations + coder->sequence = SEQ_STREAM_HEADER; + coder->block_options.version = 0; + coder->block_options.check = check; + + // Initialize the Index + lzma_index_end(coder->index, allocator); + coder->index = lzma_index_init(allocator); + if (coder->index == NULL) + return LZMA_MEM_ERROR; + + // Encode the Stream Header + lzma_stream_flags stream_flags = { + .version = 0, + .check = check, + }; + return_if_error(lzma_stream_header_encode( + &stream_flags, coder->buffer)); + + coder->buffer_pos = 0; + coder->buffer_size = LZMA_STREAM_HEADER_SIZE; + + // Initialize the Block encoder. This way we detect unsupported + // filter chains when initializing the Stream encoder instead of + // giving an error after Stream Header has already been written out. + return stream_encoder_update(coder, allocator, filters, NULL); +} + + +extern LZMA_API(lzma_ret) +lzma_stream_encoder(lzma_stream *strm, + const lzma_filter *filters, lzma_check check) +{ + lzma_next_strm_init(stream_encoder_init, strm, 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_FULL_BARRIER] = true; + strm->internal->supported_actions[LZMA_FINISH] = true; + + return LZMA_OK; +} |