Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party

xz/src/liblzma/lz/lz_encoder.c

Index: xz/src/liblzma/lz/lz_encoder.c
===================================================================
--- xz/src/liblzma/lz/lz_encoder.c	(revision 0)
+++ xz/src/liblzma/lz/lz_encoder.c	(revision 0)
@@ -0,0 +1,582 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       lz_encoder.c
+/// \brief      LZ in window
+///
+//  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 "lz_encoder_hash.h"
+
+// See lz_encoder_hash.h. This is a bit hackish but avoids making
+// endianness a conditional in makefiles.
+#if defined(WORDS_BIGENDIAN) && !defined(HAVE_SMALL)
+#	include "lz_encoder_hash_table.h"
+#endif
+
+
+struct lzma_coder_s {
+	/// LZ-based encoder e.g. LZMA
+	lzma_lz_encoder lz;
+
+	/// History buffer and match finder
+	lzma_mf mf;
+
+	/// Next coder in the chain
+	lzma_next_coder next;
+};
+
+
+/// \brief      Moves the data in the input window to free space for new data
+///
+/// mf->buffer is a sliding input window, which keeps mf->keep_size_before
+/// bytes of input history available all the time. Now and then we need to
+/// "slide" the buffer to make space for the new data to the end of the
+/// buffer. At the same time, data older than keep_size_before is dropped.
+///
+static void
+move_window(lzma_mf *mf)
+{
+	// Align the move to a multiple of 16 bytes. Some LZ-based encoders
+	// like LZMA use the lowest bits of mf->read_pos to know the
+	// alignment of the uncompressed data. We also get better speed
+	// for memmove() with aligned buffers.
+	assert(mf->read_pos > mf->keep_size_before);
+	const uint32_t move_offset
+		= (mf->read_pos - mf->keep_size_before) & ~UINT32_C(15);
+
+	assert(mf->write_pos > move_offset);
+	const size_t move_size = mf->write_pos - move_offset;
+
+	assert(move_offset + move_size <= mf->size);
+
+	memmove(mf->buffer, mf->buffer + move_offset, move_size);
+
+	mf->offset += move_offset;
+	mf->read_pos -= move_offset;
+	mf->read_limit -= move_offset;
+	mf->write_pos -= move_offset;
+
+	return;
+}
+
+
+/// \brief      Tries to fill the input window (mf->buffer)
+///
+/// If we are the last encoder in the chain, our input data is in in[].
+/// Otherwise we call the next filter in the chain to process in[] and
+/// write its output to mf->buffer.
+///
+/// This function must not be called once it has returned LZMA_STREAM_END.
+///
+static lzma_ret
+fill_window(lzma_coder *coder, lzma_allocator *allocator, const uint8_t *in,
+		size_t *in_pos, size_t in_size, lzma_action action)
+{
+	assert(coder->mf.read_pos <= coder->mf.write_pos);
+
+	// Move the sliding window if needed.
+	if (coder->mf.read_pos >= coder->mf.size - coder->mf.keep_size_after)
+		move_window(&coder->mf);
+
+	// Maybe this is ugly, but lzma_mf uses uint32_t for most things
+	// (which I find cleanest), but we need size_t here when filling
+	// the history window.
+	size_t write_pos = coder->mf.write_pos;
+	lzma_ret ret;
+	if (coder->next.code == NULL) {
+		// Not using a filter, simply memcpy() as much as possible.
+		lzma_bufcpy(in, in_pos, in_size, coder->mf.buffer,
+				&write_pos, coder->mf.size);
+
+		ret = action != LZMA_RUN && *in_pos == in_size
+				? LZMA_STREAM_END : LZMA_OK;
+
+	} else {
+		ret = coder->next.code(coder->next.coder, allocator,
+				in, in_pos, in_size,
+				coder->mf.buffer, &write_pos,
+				coder->mf.size, action);
+	}
+
+	coder->mf.write_pos = write_pos;
+
+	// If end of stream has been reached or flushing completed, we allow
+	// the encoder to process all the input (that is, read_pos is allowed
+	// to reach write_pos). Otherwise we keep keep_size_after bytes
+	// available as prebuffer.
+	if (ret == LZMA_STREAM_END) {
+		assert(*in_pos == in_size);
+		ret = LZMA_OK;
+		coder->mf.action = action;
+		coder->mf.read_limit = coder->mf.write_pos;
+
+	} else if (coder->mf.write_pos > coder->mf.keep_size_after) {
+		// This needs to be done conditionally, because if we got
+		// only little new input, there may be too little input
+		// to do any encoding yet.
+		coder->mf.read_limit = coder->mf.write_pos
+				- coder->mf.keep_size_after;
+	}
+
+	// Restart the match finder after finished LZMA_SYNC_FLUSH.
+	if (coder->mf.pending > 0
+			&& coder->mf.read_pos < coder->mf.read_limit) {
+		// Match finder may update coder->pending and expects it to
+		// start from zero, so use a temporary variable.
+		const size_t pending = coder->mf.pending;
+		coder->mf.pending = 0;
+
+		// Rewind read_pos so that the match finder can hash
+		// the pending bytes.
+		assert(coder->mf.read_pos >= pending);
+		coder->mf.read_pos -= pending;
+
+		// Call the skip function directly instead of using
+		// mf_skip(), since we don't want to touch mf->read_ahead.
+		coder->mf.skip(&coder->mf, pending);
+	}
+
+	return ret;
+}
+
+
+static lzma_ret
+lz_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)
+{
+	while (*out_pos < out_size
+			&& (*in_pos < in_size || action != LZMA_RUN)) {
+		// Read more data to coder->mf.buffer if needed.
+		if (coder->mf.action == LZMA_RUN && coder->mf.read_pos
+				>= coder->mf.read_limit)
+			return_if_error(fill_window(coder, allocator,
+					in, in_pos, in_size, action));
+
+		// Encode
+		const lzma_ret ret = coder->lz.code(coder->lz.coder,
+				&coder->mf, out, out_pos, out_size);
+		if (ret != LZMA_OK) {
+			// Setting this to LZMA_RUN for cases when we are
+			// flushing. It doesn't matter when finishing or if
+			// an error occurred.
+			coder->mf.action = LZMA_RUN;
+			return ret;
+		}
+	}
+
+	return LZMA_OK;
+}
+
+
+static bool
+lz_encoder_prepare(lzma_mf *mf, lzma_allocator *allocator,
+		const lzma_lz_options *lz_options)
+{
+	// For now, the dictionary size is limited to 1.5 GiB. This may grow
+	// in the future if needed, but it needs a little more work than just
+	// changing this check.
+	if (lz_options->dict_size < LZMA_DICT_SIZE_MIN
+			|| lz_options->dict_size
+				> (UINT32_C(1) << 30) + (UINT32_C(1) << 29)
+			|| lz_options->nice_len > lz_options->match_len_max)
+		return true;
+
+	mf->keep_size_before = lz_options->before_size + lz_options->dict_size;
+
+	mf->keep_size_after = lz_options->after_size
+			+ lz_options->match_len_max;
+
+	// To avoid constant memmove()s, allocate some extra space. Since
+	// memmove()s become more expensive when the size of the buffer
+	// increases, we reserve more space when a large dictionary is
+	// used to make the memmove() calls rarer.
+	//
+	// This works with dictionaries up to about 3 GiB. If bigger
+	// dictionary is wanted, some extra work is needed:
+	//   - Several variables in lzma_mf have to be changed from uint32_t
+	//     to size_t.
+	//   - Memory usage calculation needs something too, e.g. use uint64_t
+	//     for mf->size.
+	uint32_t reserve = lz_options->dict_size / 2;
+	if (reserve > (UINT32_C(1) << 30))
+		reserve /= 2;
+
+	reserve += (lz_options->before_size + lz_options->match_len_max
+			+ lz_options->after_size) / 2 + (UINT32_C(1) << 19);
+
+	const uint32_t old_size = mf->size;
+	mf->size = mf->keep_size_before + reserve + mf->keep_size_after;
+
+	// Deallocate the old history buffer if it exists but has different
+	// size than what is needed now.
+	if (mf->buffer != NULL && old_size != mf->size) {
+		lzma_free(mf->buffer, allocator);
+		mf->buffer = NULL;
+	}
+
+	// Match finder options
+	mf->match_len_max = lz_options->match_len_max;
+	mf->nice_len = lz_options->nice_len;
+
+	// cyclic_size has to stay smaller than 2 Gi. Note that this doesn't
+	// mean limiting dictionary size to less than 2 GiB. With a match
+	// finder that uses multibyte resolution (hashes start at e.g. every
+	// fourth byte), cyclic_size would stay below 2 Gi even when
+	// dictionary size is greater than 2 GiB.
+	//
+	// It would be possible to allow cyclic_size >= 2 Gi, but then we
+	// would need to be careful to use 64-bit types in various places
+	// (size_t could do since we would need bigger than 32-bit address
+	// space anyway). It would also require either zeroing a multigigabyte
+	// buffer at initialization (waste of time and RAM) or allow
+	// normalization in lz_encoder_mf.c to access uninitialized
+	// memory to keep the code simpler. The current way is simple and
+	// still allows pretty big dictionaries, so I don't expect these
+	// limits to change.
+	mf->cyclic_size = lz_options->dict_size + 1;
+
+	// Validate the match finder ID and setup the function pointers.
+	switch (lz_options->match_finder) {
+#ifdef HAVE_MF_HC3
+	case LZMA_MF_HC3:
+		mf->find = &lzma_mf_hc3_find;
+		mf->skip = &lzma_mf_hc3_skip;
+		break;
+#endif
+#ifdef HAVE_MF_HC4
+	case LZMA_MF_HC4:
+		mf->find = &lzma_mf_hc4_find;
+		mf->skip = &lzma_mf_hc4_skip;
+		break;
+#endif
+#ifdef HAVE_MF_BT2
+	case LZMA_MF_BT2:
+		mf->find = &lzma_mf_bt2_find;
+		mf->skip = &lzma_mf_bt2_skip;
+		break;
+#endif
+#ifdef HAVE_MF_BT3
+	case LZMA_MF_BT3:
+		mf->find = &lzma_mf_bt3_find;
+		mf->skip = &lzma_mf_bt3_skip;
+		break;
+#endif
+#ifdef HAVE_MF_BT4
+	case LZMA_MF_BT4:
+		mf->find = &lzma_mf_bt4_find;
+		mf->skip = &lzma_mf_bt4_skip;
+		break;
+#endif
+
+	default:
+		return true;
+	}
+
+	// Calculate the sizes of mf->hash and mf->son and check that
+	// nice_len is big enough for the selected match finder.
+	const uint32_t hash_bytes = lz_options->match_finder & 0x0F;
+	if (hash_bytes > mf->nice_len)
+		return true;
+
+	const bool is_bt = (lz_options->match_finder & 0x10) != 0;
+	uint32_t hs;
+
+	if (hash_bytes == 2) {
+		hs = 0xFFFF;
+	} else {
+		// Round dictionary size up to the next 2^n - 1 so it can
+		// be used as a hash mask.
+		hs = lz_options->dict_size - 1;
+		hs |= hs >> 1;
+		hs |= hs >> 2;
+		hs |= hs >> 4;
+		hs |= hs >> 8;
+		hs >>= 1;
+		hs |= 0xFFFF;
+
+		if (hs > (UINT32_C(1) << 24)) {
+			if (hash_bytes == 3)
+				hs = (UINT32_C(1) << 24) - 1;
+			else
+				hs >>= 1;
+		}
+	}
+
+	mf->hash_mask = hs;
+
+	++hs;
+	if (hash_bytes > 2)
+		hs += HASH_2_SIZE;
+	if (hash_bytes > 3)
+		hs += HASH_3_SIZE;
+/*
+	No match finder uses this at the moment.
+	if (mf->hash_bytes > 4)
+		hs += HASH_4_SIZE;
+*/
+
+	// If the above code calculating hs is modified, make sure that
+	// this assertion stays valid (UINT32_MAX / 5 is not strictly the
+	// exact limit). If it doesn't, you need to calculate that
+	// hash_size_sum + sons_count cannot overflow.
+	assert(hs < UINT32_MAX / 5);
+
+	const uint32_t old_count = mf->hash_size_sum + mf->sons_count;
+	mf->hash_size_sum = hs;
+	mf->sons_count = mf->cyclic_size;
+	if (is_bt)
+		mf->sons_count *= 2;
+
+	const uint32_t new_count = mf->hash_size_sum + mf->sons_count;
+
+	// Deallocate the old hash array if it exists and has different size
+	// than what is needed now.
+	if (old_count != new_count) {
+		lzma_free(mf->hash, allocator);
+		mf->hash = NULL;
+	}
+
+	// Maximum number of match finder cycles
+	mf->depth = lz_options->depth;
+	if (mf->depth == 0) {
+		mf->depth = 16 + (mf->nice_len / 2);
+		if (!is_bt)
+			mf->depth /= 2;
+	}
+
+	return false;
+}
+
+
+static bool
+lz_encoder_init(lzma_mf *mf, lzma_allocator *allocator,
+		const lzma_lz_options *lz_options)
+{
+	// Allocate the history buffer.
+	if (mf->buffer == NULL) {
+		mf->buffer = lzma_alloc(mf->size, allocator);
+		if (mf->buffer == NULL)
+			return true;
+	}
+
+	// Use cyclic_size as initial mf->offset. This allows
+	// avoiding a few branches in the match finders. The downside is
+	// that match finder needs to be normalized more often, which may
+	// hurt performance with huge dictionaries.
+	mf->offset = mf->cyclic_size;
+	mf->read_pos = 0;
+	mf->read_ahead = 0;
+	mf->read_limit = 0;
+	mf->write_pos = 0;
+	mf->pending = 0;
+
+	// Allocate match finder's hash array.
+	const size_t alloc_count = mf->hash_size_sum + mf->sons_count;
+
+#if UINT32_MAX >= SIZE_MAX / 4
+	// Check for integer overflow. (Huge dictionaries are not
+	// possible on 32-bit CPU.)
+	if (alloc_count > SIZE_MAX / sizeof(uint32_t))
+		return true;
+#endif
+
+	if (mf->hash == NULL) {
+		mf->hash = lzma_alloc(alloc_count * sizeof(uint32_t),
+				allocator);
+		if (mf->hash == NULL)
+			return true;
+	}
+
+	mf->son = mf->hash + mf->hash_size_sum;
+	mf->cyclic_pos = 0;
+
+	// Initialize the hash table. Since EMPTY_HASH_VALUE is zero, we
+	// can use memset().
+/*
+	for (uint32_t i = 0; i < hash_size_sum; ++i)
+		mf->hash[i] = EMPTY_HASH_VALUE;
+*/
+	memzero(mf->hash, (size_t)(mf->hash_size_sum) * sizeof(uint32_t));
+
+	// We don't need to initialize mf->son, but not doing that will
+	// make Valgrind complain in normalization (see normalize() in
+	// lz_encoder_mf.c).
+	//
+	// Skipping this initialization is *very* good when big dictionary is
+	// used but only small amount of data gets actually compressed: most
+	// of the mf->hash won't get actually allocated by the kernel, so
+	// we avoid wasting RAM and improve initialization speed a lot.
+	//memzero(mf->son, (size_t)(mf->sons_count) * sizeof(uint32_t));
+
+	// Handle preset dictionary.
+	if (lz_options->preset_dict != NULL
+			&& lz_options->preset_dict_size > 0) {
+		// If the preset dictionary is bigger than the actual
+		// dictionary, use only the tail.
+		mf->write_pos = my_min(lz_options->preset_dict_size, mf->size);
+		memcpy(mf->buffer, lz_options->preset_dict
+				+ lz_options->preset_dict_size - mf->write_pos,
+				mf->write_pos);
+		mf->action = LZMA_SYNC_FLUSH;
+		mf->skip(mf, mf->write_pos);
+	}
+
+	mf->action = LZMA_RUN;
+
+	return false;
+}
+
+
+extern uint64_t
+lzma_lz_encoder_memusage(const lzma_lz_options *lz_options)
+{
+	// Old buffers must not exist when calling lz_encoder_prepare().
+	lzma_mf mf = {
+		.buffer = NULL,
+		.hash = NULL,
+		.hash_size_sum = 0,
+		.sons_count = 0,
+	};
+
+	// Setup the size information into mf.
+	if (lz_encoder_prepare(&mf, NULL, lz_options))
+		return UINT64_MAX;
+
+	// Calculate the memory usage.
+	return (uint64_t)(mf.hash_size_sum + mf.sons_count)
+				* sizeof(uint32_t)
+			+ (uint64_t)(mf.size) + sizeof(lzma_coder);
+}
+
+
+static void
+lz_encoder_end(lzma_coder *coder, lzma_allocator *allocator)
+{
+	lzma_next_end(&coder->next, allocator);
+
+	lzma_free(coder->mf.hash, allocator);
+	lzma_free(coder->mf.buffer, allocator);
+
+	if (coder->lz.end != NULL)
+		coder->lz.end(coder->lz.coder, allocator);
+	else
+		lzma_free(coder->lz.coder, allocator);
+
+	lzma_free(coder, allocator);
+	return;
+}
+
+
+static lzma_ret
+lz_encoder_update(lzma_coder *coder, lzma_allocator *allocator,
+		const lzma_filter *filters_null lzma_attribute((unused)),
+		const lzma_filter *reversed_filters)
+{
+	if (coder->lz.options_update == NULL)
+		return LZMA_PROG_ERROR;
+
+	return_if_error(coder->lz.options_update(
+			coder->lz.coder, reversed_filters));
+
+	return lzma_next_filter_update(
+			&coder->next, allocator, reversed_filters + 1);
+}
+
+
+extern lzma_ret
+lzma_lz_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+		const lzma_filter_info *filters,
+		lzma_ret (*lz_init)(lzma_lz_encoder *lz,
+			lzma_allocator *allocator, const void *options,
+			lzma_lz_options *lz_options))
+{
+#ifdef HAVE_SMALL
+	// We need that the CRC32 table has been initialized.
+	lzma_crc32_init();
+#endif
+
+	// Allocate and initialize the base data structure.
+	if (next->coder == NULL) {
+		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+		if (next->coder == NULL)
+			return LZMA_MEM_ERROR;
+
+		next->code = &lz_encode;
+		next->end = &lz_encoder_end;
+		next->update = &lz_encoder_update;
+
+		next->coder->lz.coder = NULL;
+		next->coder->lz.code = NULL;
+		next->coder->lz.end = NULL;
+
+		next->coder->mf.buffer = NULL;
+		next->coder->mf.hash = NULL;
+		next->coder->mf.hash_size_sum = 0;
+		next->coder->mf.sons_count = 0;
+
+		next->coder->next = LZMA_NEXT_CODER_INIT;
+	}
+
+	// Initialize the LZ-based encoder.
+	lzma_lz_options lz_options;
+	return_if_error(lz_init(&next->coder->lz, allocator,
+			filters[0].options, &lz_options));
+
+	// Setup the size information into next->coder->mf and deallocate
+	// old buffers if they have wrong size.
+	if (lz_encoder_prepare(&next->coder->mf, allocator, &lz_options))
+		return LZMA_OPTIONS_ERROR;
+
+	// Allocate new buffers if needed, and do the rest of
+	// the initialization.
+	if (lz_encoder_init(&next->coder->mf, allocator, &lz_options))
+		return LZMA_MEM_ERROR;
+
+	// Initialize the next filter in the chain, if any.
+	return lzma_next_filter_init(&next->coder->next, allocator,
+			filters + 1);
+}
+
+
+extern LZMA_API(lzma_bool)
+lzma_mf_is_supported(lzma_match_finder mf)
+{
+	bool ret = false;
+
+#ifdef HAVE_MF_HC3
+	if (mf == LZMA_MF_HC3)
+		ret = true;
+#endif
+
+#ifdef HAVE_MF_HC4
+	if (mf == LZMA_MF_HC4)
+		ret = true;
+#endif
+
+#ifdef HAVE_MF_BT2
+	if (mf == LZMA_MF_BT2)
+		ret = true;
+#endif
+
+#ifdef HAVE_MF_BT3
+	if (mf == LZMA_MF_BT3)
+		ret = true;
+#endif
+
+#ifdef HAVE_MF_BT4
+	if (mf == LZMA_MF_BT4)
+		ret = true;
+#endif
+
+	return ret;
+}
Property changes on: xz/src/liblzma/lz/lz_encoder.c
___________________________________________________________________
Added: svn:eol-style
   + LF