--- /dev/null
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \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"
+
+
+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
+ /// 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, 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(lzma_coder *coder, 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)
+{
+ // 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(lzma_coder *coder, const 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, const 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);
+}
+
+
+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;
+
+ 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->filters[0].id = LZMA_VLI_UNKNOWN;
+ 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;
+
+ // 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(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;
+}
projects / zpackage / blobdiff