1 files changed, 414 insertions, 0 deletions
diff --git a/src/liblzma/lzma/lzma2_encoder.c b/src/liblzma/lzma/lzma2_encoder.c
new file mode 100644
index 0000000..4b6b231
--- /dev/null
+++ b/src/liblzma/lzma/lzma2_encoder.c
@@ -0,0 +1,414 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       lzma2_encoder.c
+/// \brief      LZMA2 encoder
+///
+//  Authors:    Igor Pavlov
+//              Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "lz_encoder.h"
+#include "lzma_encoder.h"
+#include "fastpos.h"
+#include "lzma2_encoder.h"
+
+
+typedef struct {
+	enum {
+		SEQ_INIT,
+		SEQ_LZMA_ENCODE,
+		SEQ_LZMA_COPY,
+		SEQ_UNCOMPRESSED_HEADER,
+		SEQ_UNCOMPRESSED_COPY,
+	} sequence;
+
+	/// LZMA encoder
+	void *lzma;
+
+	/// LZMA options currently in use.
+	lzma_options_lzma opt_cur;
+
+	bool need_properties;
+	bool need_state_reset;
+	bool need_dictionary_reset;
+
+	/// Uncompressed size of a chunk
+	size_t uncompressed_size;
+
+	/// Compressed size of a chunk (excluding headers); this is also used
+	/// to indicate the end of buf[] in SEQ_LZMA_COPY.
+	size_t compressed_size;
+
+	/// Read position in buf[]
+	size_t buf_pos;
+
+	/// Buffer to hold the chunk header and LZMA compressed data
+	uint8_t buf[LZMA2_HEADER_MAX + LZMA2_CHUNK_MAX];
+} lzma_lzma2_coder;
+
+
+static void
+lzma2_header_lzma(lzma_lzma2_coder *coder)
+{
+	assert(coder->uncompressed_size > 0);
+	assert(coder->uncompressed_size <= LZMA2_UNCOMPRESSED_MAX);
+	assert(coder->compressed_size > 0);
+	assert(coder->compressed_size <= LZMA2_CHUNK_MAX);
+
+	size_t pos;
+
+	if (coder->need_properties) {
+		pos = 0;
+
+		if (coder->need_dictionary_reset)
+			coder->buf[pos] = 0x80 + (3 << 5);
+		else
+			coder->buf[pos] = 0x80 + (2 << 5);
+	} else {
+		pos = 1;
+
+		if (coder->need_state_reset)
+			coder->buf[pos] = 0x80 + (1 << 5);
+		else
+			coder->buf[pos] = 0x80;
+	}
+
+	// Set the start position for copying.
+	coder->buf_pos = pos;
+
+	// Uncompressed size
+	size_t size = coder->uncompressed_size - 1;
+	coder->buf[pos++] += size >> 16;
+	coder->buf[pos++] = (size >> 8) & 0xFF;
+	coder->buf[pos++] = size & 0xFF;
+
+	// Compressed size
+	size = coder->compressed_size - 1;
+	coder->buf[pos++] = size >> 8;
+	coder->buf[pos++] = size & 0xFF;
+
+	// Properties, if needed
+	if (coder->need_properties)
+		lzma_lzma_lclppb_encode(&coder->opt_cur, coder->buf + pos);
+
+	coder->need_properties = false;
+	coder->need_state_reset = false;
+	coder->need_dictionary_reset = false;
+
+	// The copying code uses coder->compressed_size to indicate the end
+	// of coder->buf[], so we need add the maximum size of the header here.
+	coder->compressed_size += LZMA2_HEADER_MAX;
+
+	return;
+}
+
+
+static void
+lzma2_header_uncompressed(lzma_lzma2_coder *coder)
+{
+	assert(coder->uncompressed_size > 0);
+	assert(coder->uncompressed_size <= LZMA2_CHUNK_MAX);
+
+	// If this is the first chunk, we need to include dictionary
+	// reset indicator.
+	if (coder->need_dictionary_reset)
+		coder->buf[0] = 1;
+	else
+		coder->buf[0] = 2;
+
+	coder->need_dictionary_reset = false;
+
+	// "Compressed" size
+	coder->buf[1] = (coder->uncompressed_size - 1) >> 8;
+	coder->buf[2] = (coder->uncompressed_size - 1) & 0xFF;
+
+	// Set the start position for copying.
+	coder->buf_pos = 0;
+	return;
+}
+
+
+static lzma_ret
+lzma2_encode(void *coder_ptr, lzma_mf *restrict mf,
+		uint8_t *restrict out, size_t *restrict out_pos,
+		size_t out_size)
+{
+	lzma_lzma2_coder *restrict coder = coder_ptr;
+
+	while (*out_pos < out_size)
+	switch (coder->sequence) {
+	case SEQ_INIT:
+		// If there's no input left and we are flushing or finishing,
+		// don't start a new chunk.
+		if (mf_unencoded(mf) == 0) {
+			// Write end of payload marker if finishing.
+			if (mf->action == LZMA_FINISH)
+				out[(*out_pos)++] = 0;
+
+			return mf->action == LZMA_RUN
+					? LZMA_OK : LZMA_STREAM_END;
+		}
+
+		if (coder->need_state_reset)
+			return_if_error(lzma_lzma_encoder_reset(
+					coder->lzma, &coder->opt_cur));
+
+		coder->uncompressed_size = 0;
+		coder->compressed_size = 0;
+		coder->sequence = SEQ_LZMA_ENCODE;
+
+	// Fall through
+
+	case SEQ_LZMA_ENCODE: {
+		// Calculate how much more uncompressed data this chunk
+		// could accept.
+		const uint32_t left = LZMA2_UNCOMPRESSED_MAX
+				- coder->uncompressed_size;
+		uint32_t limit;
+
+		if (left < mf->match_len_max) {
+			// Must flush immediately since the next LZMA symbol
+			// could make the uncompressed size of the chunk too
+			// big.
+			limit = 0;
+		} else {
+			// Calculate maximum read_limit that is OK from point
+			// of view of LZMA2 chunk size.
+			limit = mf->read_pos - mf->read_ahead
+					+ left - mf->match_len_max;
+		}
+
+		// Save the start position so that we can update
+		// coder->uncompressed_size.
+		const uint32_t read_start = mf->read_pos - mf->read_ahead;
+
+		// Call the LZMA encoder until the chunk is finished.
+		const lzma_ret ret = lzma_lzma_encode(coder->lzma, mf,
+				coder->buf + LZMA2_HEADER_MAX,
+				&coder->compressed_size,
+				LZMA2_CHUNK_MAX, limit);
+
+		coder->uncompressed_size += mf->read_pos - mf->read_ahead
+				- read_start;
+
+		assert(coder->compressed_size <= LZMA2_CHUNK_MAX);
+		assert(coder->uncompressed_size <= LZMA2_UNCOMPRESSED_MAX);
+
+		if (ret != LZMA_STREAM_END)
+			return LZMA_OK;
+
+		// See if the chunk compressed. If it didn't, we encode it
+		// as uncompressed chunk. This saves a few bytes of space
+		// and makes decoding faster.
+		if (coder->compressed_size >= coder->uncompressed_size) {
+			coder->uncompressed_size += mf->read_ahead;
+			assert(coder->uncompressed_size
+					<= LZMA2_UNCOMPRESSED_MAX);
+			mf->read_ahead = 0;
+			lzma2_header_uncompressed(coder);
+			coder->need_state_reset = true;
+			coder->sequence = SEQ_UNCOMPRESSED_HEADER;
+			break;
+		}
+
+		// The chunk did compress at least by one byte, so we store
+		// the chunk as LZMA.
+		lzma2_header_lzma(coder);
+
+		coder->sequence = SEQ_LZMA_COPY;
+	}
+
+	// Fall through
+
+	case SEQ_LZMA_COPY:
+		// Copy the compressed chunk along its headers to the
+		// output buffer.
+		lzma_bufcpy(coder->buf, &coder->buf_pos,
+				coder->compressed_size,
+				out, out_pos, out_size);
+		if (coder->buf_pos != coder->compressed_size)
+			return LZMA_OK;
+
+		coder->sequence = SEQ_INIT;
+		break;
+
+	case SEQ_UNCOMPRESSED_HEADER:
+		// Copy the three-byte header to indicate uncompressed chunk.
+		lzma_bufcpy(coder->buf, &coder->buf_pos,
+				LZMA2_HEADER_UNCOMPRESSED,
+				out, out_pos, out_size);
+		if (coder->buf_pos != LZMA2_HEADER_UNCOMPRESSED)
+			return LZMA_OK;
+
+		coder->sequence = SEQ_UNCOMPRESSED_COPY;
+
+	// Fall through
+
+	case SEQ_UNCOMPRESSED_COPY:
+		// Copy the uncompressed data as is from the dictionary
+		// to the output buffer.
+		mf_read(mf, out, out_pos, out_size, &coder->uncompressed_size);
+		if (coder->uncompressed_size != 0)
+			return LZMA_OK;
+
+		coder->sequence = SEQ_INIT;
+		break;
+	}
+
+	return LZMA_OK;
+}
+
+
+static void
+lzma2_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
+{
+	lzma_lzma2_coder *coder = coder_ptr;
+	lzma_free(coder->lzma, allocator);
+	lzma_free(coder, allocator);
+	return;
+}
+
+
+static lzma_ret
+lzma2_encoder_options_update(void *coder_ptr, const lzma_filter *filter)
+{
+	lzma_lzma2_coder *coder = coder_ptr;
+
+	// New options can be set only when there is no incomplete chunk.
+	// This is the case at the beginning of the raw stream and right
+	// after LZMA_SYNC_FLUSH.
+	if (filter->options == NULL || coder->sequence != SEQ_INIT)
+		return LZMA_PROG_ERROR;
+
+	// Look if there are new options. At least for now,
+	// only lc/lp/pb can be changed.
+	const lzma_options_lzma *opt = filter->options;
+	if (coder->opt_cur.lc != opt->lc || coder->opt_cur.lp != opt->lp
+			|| coder->opt_cur.pb != opt->pb) {
+		// Validate the options.
+		if (opt->lc > LZMA_LCLP_MAX || opt->lp > LZMA_LCLP_MAX
+				|| opt->lc + opt->lp > LZMA_LCLP_MAX
+				|| opt->pb > LZMA_PB_MAX)
+			return LZMA_OPTIONS_ERROR;
+
+		// The new options will be used when the encoder starts
+		// a new LZMA2 chunk.
+		coder->opt_cur.lc = opt->lc;
+		coder->opt_cur.lp = opt->lp;
+		coder->opt_cur.pb = opt->pb;
+		coder->need_properties = true;
+		coder->need_state_reset = true;
+	}
+
+	return LZMA_OK;
+}
+
+
+static lzma_ret
+lzma2_encoder_init(lzma_lz_encoder *lz, const lzma_allocator *allocator,
+		lzma_vli id lzma_attribute((__unused__)), const void *options,
+		lzma_lz_options *lz_options)
+{
+	if (options == NULL)
+		return LZMA_PROG_ERROR;
+
+	lzma_lzma2_coder *coder = lz->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_lzma2_coder), allocator);
+		if (coder == NULL)
+			return LZMA_MEM_ERROR;
+
+		lz->coder = coder;
+		lz->code = &lzma2_encode;
+		lz->end = &lzma2_encoder_end;
+		lz->options_update = &lzma2_encoder_options_update;
+
+		coder->lzma = NULL;
+	}
+
+	coder->opt_cur = *(const lzma_options_lzma *)(options);
+
+	coder->sequence = SEQ_INIT;
+	coder->need_properties = true;
+	coder->need_state_reset = false;
+	coder->need_dictionary_reset
+			= coder->opt_cur.preset_dict == NULL
+			|| coder->opt_cur.preset_dict_size == 0;
+
+	// Initialize LZMA encoder
+	return_if_error(lzma_lzma_encoder_create(&coder->lzma, allocator,
+			LZMA_FILTER_LZMA2, &coder->opt_cur, lz_options));
+
+	// Make sure that we will always have enough history available in
+	// case we need to use uncompressed chunks. They are used when the
+	// compressed size of a chunk is not smaller than the uncompressed
+	// size, so we need to have at least LZMA2_COMPRESSED_MAX bytes
+	// history available.
+	if (lz_options->before_size + lz_options->dict_size < LZMA2_CHUNK_MAX)
+		lz_options->before_size
+				= LZMA2_CHUNK_MAX - lz_options->dict_size;
+
+	return LZMA_OK;
+}
+
+
+extern lzma_ret
+lzma_lzma2_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
+		const lzma_filter_info *filters)
+{
+	return lzma_lz_encoder_init(
+			next, allocator, filters, &lzma2_encoder_init);
+}
+
+
+extern uint64_t
+lzma_lzma2_encoder_memusage(const void *options)
+{
+	const uint64_t lzma_mem = lzma_lzma_encoder_memusage(options);
+	if (lzma_mem == UINT64_MAX)
+		return UINT64_MAX;
+
+	return sizeof(lzma_lzma2_coder) + lzma_mem;
+}
+
+
+extern lzma_ret
+lzma_lzma2_props_encode(const void *options, uint8_t *out)
+{
+	if (options == NULL)
+		return LZMA_PROG_ERROR;
+
+	const lzma_options_lzma *const opt = options;
+	uint32_t d = my_max(opt->dict_size, LZMA_DICT_SIZE_MIN);
+
+	// Round up to the next 2^n - 1 or 2^n + 2^(n - 1) - 1 depending
+	// on which one is the next:
+	--d;
+	d |= d >> 2;
+	d |= d >> 3;
+	d |= d >> 4;
+	d |= d >> 8;
+	d |= d >> 16;
+
+	// Get the highest two bits using the proper encoding:
+	if (d == UINT32_MAX)
+		out[0] = 40;
+	else
+		out[0] = get_dist_slot(d + 1) - 24;
+
+	return LZMA_OK;
+}
+
+
+extern uint64_t
+lzma_lzma2_block_size(const void *options)
+{
+	const lzma_options_lzma *const opt = options;
+
+	// Use at least 1 MiB to keep compression ratio better.
+	return my_max((uint64_t)(opt->dict_size) * 3, UINT64_C(1) << 20);
+}