1 files changed, 406 insertions, 0 deletions
diff --git a/src/liblzma/lzma/lzma2_encoder.c b/src/liblzma/lzma/lzma2_encoder.c
new file mode 100644
index 00000000..b2cd176b
--- /dev/null
+++ b/src/liblzma/lzma/lzma2_encoder.c
@@ -0,0 +1,406 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       lzma2_encoder.c
+/// \brief      LZMA2 encoder
+//
+//  Copyright (C) 1999-2008 Igor Pavlov
+//  Copyright (C) 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 "lz_encoder.h"
+#include "lzma_encoder.h"
+#include "fastpos.h"
+#include "lzma2_encoder.h"
+
+
+/// Maximum number of bytes of actual data per chunk (no headers)
+#define LZMA2_CHUNK_MAX (UINT32_C(1) << 16)
+
+/// Maximum uncompressed size of LZMA chunk (no headers)
+#define LZMA2_UNCOMPRESSED_MAX (UINT32_C(1) << 21)
+
+/// Maximum size of LZMA2 headers
+#define LZMA2_HEADER_MAX 6
+
+/// Size of a header for uncompressed chunk
+#define LZMA2_HEADER_UNCOMPRESSED 3
+
+
+struct lzma_coder_s {
+	enum {
+		SEQ_INIT,
+		SEQ_LZMA_ENCODE,
+		SEQ_LZMA_COPY,
+		SEQ_UNCOMPRESSED_HEADER,
+		SEQ_UNCOMPRESSED_COPY,
+	} sequence;
+
+	/// LZMA encoder
+	lzma_coder *lzma;
+
+	/// If this is not NULL, we will check new options from this
+	/// structure when starting a new chunk.
+	const lzma_options_lzma *opt_new;
+
+	/// 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];
+};
+
+
+static void
+lzma2_header_lzma(lzma_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_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(lzma_coder *restrict coder, lzma_mf *restrict mf,
+		uint8_t *restrict out, size_t *restrict out_pos,
+		size_t out_size)
+{
+	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;
+		}
+
+		// Look if there are new options. At least for now,
+		// only lc/lp/pb can be changed.
+		if (coder->opt_new != NULL
+				&& (coder->opt_cur.literal_context_bits
+					!= coder->opt_new->literal_context_bits
+				|| coder->opt_cur.literal_pos_bits
+					!= coder->opt_new->literal_pos_bits
+				|| coder->opt_cur.pos_bits
+					!= coder->opt_new->pos_bits)) {
+			// Options have been changed, copy them to opt_cur.
+			coder->opt_cur.literal_context_bits
+					= coder->opt_new->literal_context_bits;
+			coder->opt_cur.literal_pos_bits
+					= coder->opt_new->literal_pos_bits;
+			coder->opt_cur.pos_bits
+					= coder->opt_new->pos_bits;
+
+			// We need to write the new options and reset
+			// the encoder state.
+			coder->need_properties = true;
+			coder->need_state_reset = true;
+		}
+
+		if (coder->need_state_reset)
+			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 immediatelly 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(lzma_coder *coder, lzma_allocator *allocator)
+{
+	lzma_free(coder->lzma, allocator);
+	lzma_free(coder, allocator);
+	return;
+}
+
+
+static lzma_ret
+lzma2_encoder_init(lzma_lz_encoder *lz, lzma_allocator *allocator,
+		const void *options, lzma_lz_options *lz_options)
+{
+	if (options == NULL)
+		return LZMA_PROG_ERROR;
+
+	if (lz->coder == NULL) {
+		lz->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+		if (lz->coder == NULL)
+			return LZMA_MEM_ERROR;
+
+		lz->code = &lzma2_encode;
+		lz->end = &lzma2_encoder_end;
+
+		lz->coder->lzma = NULL;
+	}
+
+	lz->coder->sequence = SEQ_INIT;
+	lz->coder->need_properties = true;
+	lz->coder->need_state_reset = false;
+	lz->coder->need_dictionary_reset = true;
+
+	lz->coder->opt_cur = *(const lzma_options_lzma *)(options);
+	lz->coder->opt_new = lz->coder->opt_cur.persistent
+				? options : NULL;
+
+	// Initialize LZMA encoder
+	return_if_error(lzma_lzma_encoder_create(&lz->coder->lzma, allocator,
+			&lz->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->dictionary_size
+			< LZMA2_CHUNK_MAX)
+		lz_options->before_size = LZMA2_CHUNK_MAX
+				- lz_options->dictionary_size;
+
+	return LZMA_OK;
+}
+
+
+extern lzma_ret
+lzma_lzma2_encoder_init(lzma_next_coder *next, 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_memusage = lzma_lzma_encoder_memusage(options);
+	if (lzma_memusage == UINT64_MAX)
+		return UINT64_MAX;
+
+	return sizeof(lzma_coder) + lzma_memusage;
+}
+
+
+extern lzma_ret
+lzma_lzma2_props_encode(const void *options, uint8_t *out)
+{
+	const lzma_options_lzma *const opt = options;
+	uint32_t d = MAX(opt->dictionary_size, LZMA_DICTIONARY_SIZE_MIN);
+
+	// Round up to 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_pos_slot(d + 1) - 24;
+
+	return LZMA_OK;
+}