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-rw-r--r--src/liblzma/common/stream_encoder.c282
1 files changed, 282 insertions, 0 deletions
diff --git a/src/liblzma/common/stream_encoder.c b/src/liblzma/common/stream_encoder.c
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+///////////////////////////////////////////////////////////////////////////////
+//
+/// \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;
+}