Index: xz/src/liblzma/common/stream_encoder.c |
=================================================================== |
--- xz/src/liblzma/common/stream_encoder.c (revision 0) |
+++ xz/src/liblzma/common/stream_encoder.c (revision 0) |
@@ -0,0 +1,331 @@ |
+/////////////////////////////////////////////////////////////////////////////// |
+// |
+/// \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 "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; |
+ |
+ /// True if Block encoder has been initialized by |
+ /// lzma_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]; |
+}; |
+ |
+ |
+static lzma_ret |
+block_encoder_init(lzma_coder *coder, 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(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: |
+ 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 lzma_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[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 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(lzma_coder *coder, lzma_allocator *allocator) |
+{ |
+ lzma_next_end(&coder->block_encoder, allocator); |
+ lzma_next_end(&coder->index_encoder, allocator); |
+ lzma_index_end(coder->index, allocator); |
+ |
+ for (size_t i = 0; coder->filters[i].id != LZMA_VLI_UNKNOWN; ++i) |
+ lzma_free(coder->filters[i].options, allocator); |
+ |
+ lzma_free(coder, allocator); |
+ return; |
+} |
+ |
+ |
+static lzma_ret |
+stream_encoder_update(lzma_coder *coder, lzma_allocator *allocator, |
+ const lzma_filter *filters, |
+ const lzma_filter *reversed_filters) |
+{ |
+ 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 = (lzma_filter *)(filters); |
+ const lzma_ret ret = block_encoder_init(coder, allocator); |
+ coder->block_options.filters = coder->filters; |
+ if (ret != LZMA_OK) |
+ return ret; |
+ |
+ 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. |
+ return_if_error(coder->block_encoder.update( |
+ coder->block_encoder.coder, allocator, |
+ filters, reversed_filters)); |
+ } else { |
+ // Trying to update the filter chain when we are already |
+ // encoding Index or Stream Footer. |
+ return LZMA_PROG_ERROR; |
+ } |
+ |
+ // Free the copy of the old chain and make a copy of the new chain. |
+ for (size_t i = 0; coder->filters[i].id != LZMA_VLI_UNKNOWN; ++i) |
+ lzma_free(coder->filters[i].options, allocator); |
+ |
+ return lzma_filters_copy(filters, coder->filters, allocator); |
+} |
+ |
+ |
+extern lzma_ret |
+lzma_stream_encoder_init(lzma_next_coder *next, lzma_allocator *allocator, |
+ const lzma_filter *filters, lzma_check check) |
+{ |
+ lzma_next_coder_init(&lzma_stream_encoder_init, next, allocator); |
+ |
+ 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->update = &stream_encoder_update; |
+ |
+ 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.version = 0; |
+ next->coder->block_options.check = check; |
+ next->coder->filters[0].id = LZMA_VLI_UNKNOWN; |
+ |
+ // Initialize the Index |
+ lzma_index_end(next->coder->index, allocator); |
+ next->coder->index = lzma_index_init(allocator); |
+ if (next->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, next->coder->buffer)); |
+ |
+ next->coder->buffer_pos = 0; |
+ next->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 written out. |
+ return stream_encoder_update( |
+ next->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(lzma_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_FINISH] = true; |
+ |
+ return LZMA_OK; |
+} |
Property changes on: xz/src/liblzma/common/stream_encoder.c |
___________________________________________________________________ |
Added: svn:eol-style |
+ LF |