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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 03:10:08 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 03:10:08 +0000
commit5262a872f308b3b584c97d621992fb3877e392b8 (patch)
treeb956c322376141abeafe639bd72cfecdf16954b5 /src/liblzma/lz
parentInitial commit. (diff)
downloadxz-utils-5262a872f308b3b584c97d621992fb3877e392b8.tar.xz
xz-utils-5262a872f308b3b584c97d621992fb3877e392b8.zip
Adding upstream version 5.6.1+really5.4.5.upstream/5.6.1+really5.4.5
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/liblzma/lz')
-rw-r--r--src/liblzma/lz/Makefile.inc22
-rw-r--r--src/liblzma/lz/lz_decoder.c304
-rw-r--r--src/liblzma/lz/lz_decoder.h234
-rw-r--r--src/liblzma/lz/lz_encoder.c633
-rw-r--r--src/liblzma/lz/lz_encoder.h341
-rw-r--r--src/liblzma/lz/lz_encoder_hash.h109
-rw-r--r--src/liblzma/lz/lz_encoder_hash_table.h68
-rw-r--r--src/liblzma/lz/lz_encoder_mf.c745
8 files changed, 2456 insertions, 0 deletions
diff --git a/src/liblzma/lz/Makefile.inc b/src/liblzma/lz/Makefile.inc
new file mode 100644
index 0000000..75742a8
--- /dev/null
+++ b/src/liblzma/lz/Makefile.inc
@@ -0,0 +1,22 @@
+##
+## Author: Lasse Collin
+##
+## This file has been put into the public domain.
+## You can do whatever you want with this file.
+##
+
+if COND_ENCODER_LZ
+liblzma_la_SOURCES += \
+ lz/lz_encoder.c \
+ lz/lz_encoder.h \
+ lz/lz_encoder_hash.h \
+ lz/lz_encoder_hash_table.h \
+ lz/lz_encoder_mf.c
+endif
+
+
+if COND_DECODER_LZ
+liblzma_la_SOURCES += \
+ lz/lz_decoder.c \
+ lz/lz_decoder.h
+endif
diff --git a/src/liblzma/lz/lz_decoder.c b/src/liblzma/lz/lz_decoder.c
new file mode 100644
index 0000000..06c95c1
--- /dev/null
+++ b/src/liblzma/lz/lz_decoder.c
@@ -0,0 +1,304 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file lz_decoder.c
+/// \brief LZ out window
+///
+// Authors: Igor Pavlov
+// Lasse Collin
+//
+// This file has been put into the public domain.
+// You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+// liblzma supports multiple LZ77-based filters. The LZ part is shared
+// between these filters. The LZ code takes care of dictionary handling
+// and passing the data between filters in the chain. The filter-specific
+// part decodes from the input buffer to the dictionary.
+
+
+#include "lz_decoder.h"
+
+
+typedef struct {
+ /// Dictionary (history buffer)
+ lzma_dict dict;
+
+ /// The actual LZ-based decoder e.g. LZMA
+ lzma_lz_decoder lz;
+
+ /// Next filter in the chain, if any. Note that LZMA and LZMA2 are
+ /// only allowed as the last filter, but the long-range filter in
+ /// future can be in the middle of the chain.
+ lzma_next_coder next;
+
+ /// True if the next filter in the chain has returned LZMA_STREAM_END.
+ bool next_finished;
+
+ /// True if the LZ decoder (e.g. LZMA) has detected end of payload
+ /// marker. This may become true before next_finished becomes true.
+ bool this_finished;
+
+ /// Temporary buffer needed when the LZ-based filter is not the last
+ /// filter in the chain. The output of the next filter is first
+ /// decoded into buffer[], which is then used as input for the actual
+ /// LZ-based decoder.
+ struct {
+ size_t pos;
+ size_t size;
+ uint8_t buffer[LZMA_BUFFER_SIZE];
+ } temp;
+} lzma_coder;
+
+
+static void
+lz_decoder_reset(lzma_coder *coder)
+{
+ coder->dict.pos = 0;
+ coder->dict.full = 0;
+ coder->dict.buf[coder->dict.size - 1] = '\0';
+ coder->dict.need_reset = false;
+ return;
+}
+
+
+static lzma_ret
+decode_buffer(lzma_coder *coder,
+ 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)
+{
+ while (true) {
+ // Wrap the dictionary if needed.
+ if (coder->dict.pos == coder->dict.size)
+ coder->dict.pos = 0;
+
+ // Store the current dictionary position. It is needed to know
+ // where to start copying to the out[] buffer.
+ const size_t dict_start = coder->dict.pos;
+
+ // Calculate how much we allow coder->lz.code() to decode.
+ // It must not decode past the end of the dictionary
+ // buffer, and we don't want it to decode more than is
+ // actually needed to fill the out[] buffer.
+ coder->dict.limit = coder->dict.pos
+ + my_min(out_size - *out_pos,
+ coder->dict.size - coder->dict.pos);
+
+ // Call the coder->lz.code() to do the actual decoding.
+ const lzma_ret ret = coder->lz.code(
+ coder->lz.coder, &coder->dict,
+ in, in_pos, in_size);
+
+ // Copy the decoded data from the dictionary to the out[]
+ // buffer. Do it conditionally because out can be NULL
+ // (in which case copy_size is always 0). Calling memcpy()
+ // with a null-pointer is undefined even if the third
+ // argument is 0.
+ const size_t copy_size = coder->dict.pos - dict_start;
+ assert(copy_size <= out_size - *out_pos);
+
+ if (copy_size > 0)
+ memcpy(out + *out_pos, coder->dict.buf + dict_start,
+ copy_size);
+
+ *out_pos += copy_size;
+
+ // Reset the dictionary if so requested by coder->lz.code().
+ if (coder->dict.need_reset) {
+ lz_decoder_reset(coder);
+
+ // Since we reset dictionary, we don't check if
+ // dictionary became full.
+ if (ret != LZMA_OK || *out_pos == out_size)
+ return ret;
+ } else {
+ // Return if everything got decoded or an error
+ // occurred, or if there's no more data to decode.
+ //
+ // Note that detecting if there's something to decode
+ // is done by looking if dictionary become full
+ // instead of looking if *in_pos == in_size. This
+ // is because it is possible that all the input was
+ // consumed already but some data is pending to be
+ // written to the dictionary.
+ if (ret != LZMA_OK || *out_pos == out_size
+ || coder->dict.pos < coder->dict.size)
+ return ret;
+ }
+ }
+}
+
+
+static lzma_ret
+lz_decode(void *coder_ptr, 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)
+{
+ lzma_coder *coder = coder_ptr;
+
+ if (coder->next.code == NULL)
+ return decode_buffer(coder, in, in_pos, in_size,
+ out, out_pos, out_size);
+
+ // We aren't the last coder in the chain, we need to decode
+ // our input to a temporary buffer.
+ while (*out_pos < out_size) {
+ // Fill the temporary buffer if it is empty.
+ if (!coder->next_finished
+ && coder->temp.pos == coder->temp.size) {
+ coder->temp.pos = 0;
+ coder->temp.size = 0;
+
+ const lzma_ret ret = coder->next.code(
+ coder->next.coder,
+ allocator, in, in_pos, in_size,
+ coder->temp.buffer, &coder->temp.size,
+ LZMA_BUFFER_SIZE, action);
+
+ if (ret == LZMA_STREAM_END)
+ coder->next_finished = true;
+ else if (ret != LZMA_OK || coder->temp.size == 0)
+ return ret;
+ }
+
+ if (coder->this_finished) {
+ if (coder->temp.size != 0)
+ return LZMA_DATA_ERROR;
+
+ if (coder->next_finished)
+ return LZMA_STREAM_END;
+
+ return LZMA_OK;
+ }
+
+ const lzma_ret ret = decode_buffer(coder, coder->temp.buffer,
+ &coder->temp.pos, coder->temp.size,
+ out, out_pos, out_size);
+
+ if (ret == LZMA_STREAM_END)
+ coder->this_finished = true;
+ else if (ret != LZMA_OK)
+ return ret;
+ else if (coder->next_finished && *out_pos < out_size)
+ return LZMA_DATA_ERROR;
+ }
+
+ return LZMA_OK;
+}
+
+
+static void
+lz_decoder_end(void *coder_ptr, const lzma_allocator *allocator)
+{
+ lzma_coder *coder = coder_ptr;
+
+ lzma_next_end(&coder->next, allocator);
+ lzma_free(coder->dict.buf, 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;
+}
+
+
+extern lzma_ret
+lzma_lz_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
+ const lzma_filter_info *filters,
+ lzma_ret (*lz_init)(lzma_lz_decoder *lz,
+ const lzma_allocator *allocator,
+ lzma_vli id, const void *options,
+ lzma_lz_options *lz_options))
+{
+ // Allocate the base structure if it isn't already allocated.
+ lzma_coder *coder = next->coder;
+ if (coder == NULL) {
+ coder = lzma_alloc(sizeof(lzma_coder), allocator);
+ if (coder == NULL)
+ return LZMA_MEM_ERROR;
+
+ next->coder = coder;
+ next->code = &lz_decode;
+ next->end = &lz_decoder_end;
+
+ coder->dict.buf = NULL;
+ coder->dict.size = 0;
+ coder->lz = LZMA_LZ_DECODER_INIT;
+ coder->next = LZMA_NEXT_CODER_INIT;
+ }
+
+ // Allocate and initialize the LZ-based decoder. It will also give
+ // us the dictionary size.
+ lzma_lz_options lz_options;
+ return_if_error(lz_init(&coder->lz, allocator,
+ filters[0].id, filters[0].options, &lz_options));
+
+ // If the dictionary size is very small, increase it to 4096 bytes.
+ // This is to prevent constant wrapping of the dictionary, which
+ // would slow things down. The downside is that since we don't check
+ // separately for the real dictionary size, we may happily accept
+ // corrupt files.
+ if (lz_options.dict_size < 4096)
+ lz_options.dict_size = 4096;
+
+ // Make dictionary size a multiple of 16. Some LZ-based decoders like
+ // LZMA use the lowest bits lzma_dict.pos to know the alignment of the
+ // data. Aligned buffer is also good when memcpying from the
+ // dictionary to the output buffer, since applications are
+ // recommended to give aligned buffers to liblzma.
+ //
+ // Avoid integer overflow.
+ if (lz_options.dict_size > SIZE_MAX - 15)
+ return LZMA_MEM_ERROR;
+
+ lz_options.dict_size = (lz_options.dict_size + 15) & ~((size_t)(15));
+
+ // Allocate and initialize the dictionary.
+ if (coder->dict.size != lz_options.dict_size) {
+ lzma_free(coder->dict.buf, allocator);
+ coder->dict.buf
+ = lzma_alloc(lz_options.dict_size, allocator);
+ if (coder->dict.buf == NULL)
+ return LZMA_MEM_ERROR;
+
+ coder->dict.size = lz_options.dict_size;
+ }
+
+ lz_decoder_reset(next->coder);
+
+ // Use the preset dictionary if it was given to us.
+ if (lz_options.preset_dict != NULL
+ && lz_options.preset_dict_size > 0) {
+ // If the preset dictionary is bigger than the actual
+ // dictionary, copy only the tail.
+ const size_t copy_size = my_min(lz_options.preset_dict_size,
+ lz_options.dict_size);
+ const size_t offset = lz_options.preset_dict_size - copy_size;
+ memcpy(coder->dict.buf, lz_options.preset_dict + offset,
+ copy_size);
+ coder->dict.pos = copy_size;
+ coder->dict.full = copy_size;
+ }
+
+ // Miscellaneous initializations
+ coder->next_finished = false;
+ coder->this_finished = false;
+ coder->temp.pos = 0;
+ coder->temp.size = 0;
+
+ // Initialize the next filter in the chain, if any.
+ return lzma_next_filter_init(&coder->next, allocator, filters + 1);
+}
+
+
+extern uint64_t
+lzma_lz_decoder_memusage(size_t dictionary_size)
+{
+ return sizeof(lzma_coder) + (uint64_t)(dictionary_size);
+}
diff --git a/src/liblzma/lz/lz_decoder.h b/src/liblzma/lz/lz_decoder.h
new file mode 100644
index 0000000..ad80d4d
--- /dev/null
+++ b/src/liblzma/lz/lz_decoder.h
@@ -0,0 +1,234 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file lz_decoder.h
+/// \brief LZ out window
+///
+// Authors: Igor Pavlov
+// Lasse Collin
+//
+// This file has been put into the public domain.
+// You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef LZMA_LZ_DECODER_H
+#define LZMA_LZ_DECODER_H
+
+#include "common.h"
+
+
+typedef struct {
+ /// Pointer to the dictionary buffer. It can be an allocated buffer
+ /// internal to liblzma, or it can a be a buffer given by the
+ /// application when in single-call mode (not implemented yet).
+ uint8_t *buf;
+
+ /// Write position in dictionary. The next byte will be written to
+ /// buf[pos].
+ size_t pos;
+
+ /// Indicates how full the dictionary is. This is used by
+ /// dict_is_distance_valid() to detect corrupt files that would
+ /// read beyond the beginning of the dictionary.
+ size_t full;
+
+ /// Write limit
+ size_t limit;
+
+ /// Size of the dictionary
+ size_t size;
+
+ /// True when dictionary should be reset before decoding more data.
+ bool need_reset;
+
+} lzma_dict;
+
+
+typedef struct {
+ size_t dict_size;
+ const uint8_t *preset_dict;
+ size_t preset_dict_size;
+} lzma_lz_options;
+
+
+typedef struct {
+ /// Data specific to the LZ-based decoder
+ void *coder;
+
+ /// Function to decode from in[] to *dict
+ lzma_ret (*code)(void *coder,
+ lzma_dict *restrict dict, const uint8_t *restrict in,
+ size_t *restrict in_pos, size_t in_size);
+
+ void (*reset)(void *coder, const void *options);
+
+ /// Set the uncompressed size. If uncompressed_size == LZMA_VLI_UNKNOWN
+ /// then allow_eopm will always be true.
+ void (*set_uncompressed)(void *coder, lzma_vli uncompressed_size,
+ bool allow_eopm);
+
+ /// Free allocated resources
+ void (*end)(void *coder, const lzma_allocator *allocator);
+
+} lzma_lz_decoder;
+
+
+#define LZMA_LZ_DECODER_INIT \
+ (lzma_lz_decoder){ \
+ .coder = NULL, \
+ .code = NULL, \
+ .reset = NULL, \
+ .set_uncompressed = NULL, \
+ .end = NULL, \
+ }
+
+
+extern lzma_ret lzma_lz_decoder_init(lzma_next_coder *next,
+ const lzma_allocator *allocator,
+ const lzma_filter_info *filters,
+ lzma_ret (*lz_init)(lzma_lz_decoder *lz,
+ const lzma_allocator *allocator,
+ lzma_vli id, const void *options,
+ lzma_lz_options *lz_options));
+
+extern uint64_t lzma_lz_decoder_memusage(size_t dictionary_size);
+
+
+//////////////////////
+// Inline functions //
+//////////////////////
+
+/// Get a byte from the history buffer.
+static inline uint8_t
+dict_get(const lzma_dict *const dict, const uint32_t distance)
+{
+ return dict->buf[dict->pos - distance - 1
+ + (distance < dict->pos ? 0 : dict->size)];
+}
+
+
+/// Test if dictionary is empty.
+static inline bool
+dict_is_empty(const lzma_dict *const dict)
+{
+ return dict->full == 0;
+}
+
+
+/// Validate the match distance
+static inline bool
+dict_is_distance_valid(const lzma_dict *const dict, const size_t distance)
+{
+ return dict->full > distance;
+}
+
+
+/// Repeat *len bytes at distance.
+static inline bool
+dict_repeat(lzma_dict *dict, uint32_t distance, uint32_t *len)
+{
+ // Don't write past the end of the dictionary.
+ const size_t dict_avail = dict->limit - dict->pos;
+ uint32_t left = my_min(dict_avail, *len);
+ *len -= left;
+
+ // Repeat a block of data from the history. Because memcpy() is faster
+ // than copying byte by byte in a loop, the copying process gets split
+ // into three cases.
+ if (distance < left) {
+ // Source and target areas overlap, thus we can't use
+ // memcpy() nor even memmove() safely.
+ do {
+ dict->buf[dict->pos] = dict_get(dict, distance);
+ ++dict->pos;
+ } while (--left > 0);
+
+ } else if (distance < dict->pos) {
+ // The easiest and fastest case
+ memcpy(dict->buf + dict->pos,
+ dict->buf + dict->pos - distance - 1,
+ left);
+ dict->pos += left;
+
+ } else {
+ // The bigger the dictionary, the more rare this
+ // case occurs. We need to "wrap" the dict, thus
+ // we might need two memcpy() to copy all the data.
+ assert(dict->full == dict->size);
+ const uint32_t copy_pos
+ = dict->pos - distance - 1 + dict->size;
+ uint32_t copy_size = dict->size - copy_pos;
+
+ if (copy_size < left) {
+ memmove(dict->buf + dict->pos, dict->buf + copy_pos,
+ copy_size);
+ dict->pos += copy_size;
+ copy_size = left - copy_size;
+ memcpy(dict->buf + dict->pos, dict->buf, copy_size);
+ dict->pos += copy_size;
+ } else {
+ memmove(dict->buf + dict->pos, dict->buf + copy_pos,
+ left);
+ dict->pos += left;
+ }
+ }
+
+ // Update how full the dictionary is.
+ if (dict->full < dict->pos)
+ dict->full = dict->pos;
+
+ return unlikely(*len != 0);
+}
+
+
+/// Puts one byte into the dictionary. Returns true if the dictionary was
+/// already full and the byte couldn't be added.
+static inline bool
+dict_put(lzma_dict *dict, uint8_t byte)
+{
+ if (unlikely(dict->pos == dict->limit))
+ return true;
+
+ dict->buf[dict->pos++] = byte;
+
+ if (dict->pos > dict->full)
+ dict->full = dict->pos;
+
+ return false;
+}
+
+
+/// Copies arbitrary amount of data into the dictionary.
+static inline void
+dict_write(lzma_dict *restrict dict, const uint8_t *restrict in,
+ size_t *restrict in_pos, size_t in_size,
+ size_t *restrict left)
+{
+ // NOTE: If we are being given more data than the size of the
+ // dictionary, it could be possible to optimize the LZ decoder
+ // so that not everything needs to go through the dictionary.
+ // This shouldn't be very common thing in practice though, and
+ // the slowdown of one extra memcpy() isn't bad compared to how
+ // much time it would have taken if the data were compressed.
+
+ if (in_size - *in_pos > *left)
+ in_size = *in_pos + *left;
+
+ *left -= lzma_bufcpy(in, in_pos, in_size,
+ dict->buf, &dict->pos, dict->limit);
+
+ if (dict->pos > dict->full)
+ dict->full = dict->pos;
+
+ return;
+}
+
+
+static inline void
+dict_reset(lzma_dict *dict)
+{
+ dict->need_reset = true;
+ return;
+}
+
+#endif
diff --git a/src/liblzma/lz/lz_encoder.c b/src/liblzma/lz/lz_encoder.c
new file mode 100644
index 0000000..5489085
--- /dev/null
+++ b/src/liblzma/lz/lz_encoder.c
@@ -0,0 +1,633 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \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
+
+#include "memcmplen.h"
+
+
+typedef struct {
+ /// 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;
+} lzma_coder;
+
+
+/// \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, const 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;
+
+ // Silence Valgrind. lzma_memcmplen() can read extra bytes
+ // and Valgrind will give warnings if those bytes are uninitialized
+ // because Valgrind cannot see that the values of the uninitialized
+ // bytes are eventually ignored.
+ memzero(coder->mf.buffer + write_pos, LZMA_MEMCMPLEN_EXTRA);
+
+ // 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 uint32_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(void *coder_ptr, 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)
+{
+ lzma_coder *coder = coder_ptr;
+
+ 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, const 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.
+ //
+ // NOTE: Since 5.3.5beta the LZMA encoder ensures that nice_len
+ // is big enough for the selected match finder. This makes it
+ // easier for applications as nice_len = 2 will always be accepted
+ // even though the effective value can be slightly bigger.
+ const uint32_t hash_bytes
+ = mf_get_hash_bytes(lz_options->match_finder);
+ assert(hash_bytes <= mf->nice_len);
+
+ 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;
+*/
+
+ const uint32_t old_hash_count = mf->hash_count;
+ const uint32_t old_sons_count = mf->sons_count;
+ mf->hash_count = hs;
+ mf->sons_count = mf->cyclic_size;
+ if (is_bt)
+ mf->sons_count *= 2;
+
+ // Deallocate the old hash array if it exists and has different size
+ // than what is needed now.
+ if (old_hash_count != mf->hash_count
+ || old_sons_count != mf->sons_count) {
+ lzma_free(mf->hash, allocator);
+ mf->hash = NULL;
+
+ lzma_free(mf->son, allocator);
+ mf->son = NULL;
+ }
+
+ // Maximum number of match finder cycles
+ mf->depth = lz_options->depth;
+ if (mf->depth == 0) {
+ if (is_bt)
+ mf->depth = 16 + mf->nice_len / 2;
+ else
+ mf->depth = 4 + mf->nice_len / 4;
+ }
+
+ return false;
+}
+
+
+static bool
+lz_encoder_init(lzma_mf *mf, const lzma_allocator *allocator,
+ const lzma_lz_options *lz_options)
+{
+ // Allocate the history buffer.
+ if (mf->buffer == NULL) {
+ // lzma_memcmplen() is used for the dictionary buffer
+ // so we need to allocate a few extra bytes to prevent
+ // it from reading past the end of the buffer.
+ mf->buffer = lzma_alloc(mf->size + LZMA_MEMCMPLEN_EXTRA,
+ allocator);
+ if (mf->buffer == NULL)
+ return true;
+
+ // Keep Valgrind happy with lzma_memcmplen() and initialize
+ // the extra bytes whose value may get read but which will
+ // effectively get ignored.
+ memzero(mf->buffer + mf->size, LZMA_MEMCMPLEN_EXTRA);
+ }
+
+ // 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;
+
+#if UINT32_MAX >= SIZE_MAX / 4
+ // Check for integer overflow. (Huge dictionaries are not
+ // possible on 32-bit CPU.)
+ if (mf->hash_count > SIZE_MAX / sizeof(uint32_t)
+ || mf->sons_count > SIZE_MAX / sizeof(uint32_t))
+ return true;
+#endif
+
+ // Allocate and initialize the hash table. Since EMPTY_HASH_VALUE
+ // is zero, we can use lzma_alloc_zero() or memzero() for mf->hash.
+ //
+ // We don't need to initialize mf->son, but not doing that may
+ // make Valgrind complain in normalization (see normalize() in
+ // lz_encoder_mf.c). Skipping the initialization is *very* good
+ // when big dictionary is used but only small amount of data gets
+ // actually compressed: most of the mf->son won't get actually
+ // allocated by the kernel, so we avoid wasting RAM and improve
+ // initialization speed a lot.
+ if (mf->hash == NULL) {
+ mf->hash = lzma_alloc_zero(mf->hash_count * sizeof(uint32_t),
+ allocator);
+ mf->son = lzma_alloc(mf->sons_count * sizeof(uint32_t),
+ allocator);
+
+ if (mf->hash == NULL || mf->son == NULL) {
+ lzma_free(mf->hash, allocator);
+ mf->hash = NULL;
+
+ lzma_free(mf->son, allocator);
+ mf->son = NULL;
+
+ return true;
+ }
+ } else {
+/*
+ for (uint32_t i = 0; i < mf->hash_count; ++i)
+ mf->hash[i] = EMPTY_HASH_VALUE;
+*/
+ memzero(mf->hash, mf->hash_count * sizeof(uint32_t));
+ }
+
+ mf->cyclic_pos = 0;
+
+ // 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,
+ .son = NULL,
+ .hash_count = 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_count) + mf.sons_count) * sizeof(uint32_t)
+ + mf.size + sizeof(lzma_coder);
+}
+
+
+static void
+lz_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
+{
+ lzma_coder *coder = coder_ptr;
+
+ lzma_next_end(&coder->next, allocator);
+
+ lzma_free(coder->mf.son, 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(void *coder_ptr, const lzma_allocator *allocator,
+ const lzma_filter *filters_null lzma_attribute((__unused__)),
+ const lzma_filter *reversed_filters)
+{
+ lzma_coder *coder = coder_ptr;
+
+ 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);
+}
+
+
+static lzma_ret
+lz_encoder_set_out_limit(void *coder_ptr, uint64_t *uncomp_size,
+ uint64_t out_limit)
+{
+ lzma_coder *coder = coder_ptr;
+
+ // This is supported only if there are no other filters chained.
+ if (coder->next.code == NULL && coder->lz.set_out_limit != NULL)
+ return coder->lz.set_out_limit(
+ coder->lz.coder, uncomp_size, out_limit);
+
+ return LZMA_OPTIONS_ERROR;
+}
+
+
+extern lzma_ret
+lzma_lz_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
+ const lzma_filter_info *filters,
+ lzma_ret (*lz_init)(lzma_lz_encoder *lz,
+ const lzma_allocator *allocator,
+ lzma_vli id, const void *options,
+ lzma_lz_options *lz_options))
+{
+#if defined(HAVE_SMALL) && !defined(HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR)
+ // We need that the CRC32 table has been initialized.
+ lzma_crc32_init();
+#endif
+
+ // Allocate and initialize the base data structure.
+ lzma_coder *coder = next->coder;
+ if (coder == NULL) {
+ coder = lzma_alloc(sizeof(lzma_coder), allocator);
+ if (coder == NULL)
+ return LZMA_MEM_ERROR;
+
+ next->coder = coder;
+ next->code = &lz_encode;
+ next->end = &lz_encoder_end;
+ next->update = &lz_encoder_update;
+ next->set_out_limit = &lz_encoder_set_out_limit;
+
+ coder->lz.coder = NULL;
+ coder->lz.code = NULL;
+ coder->lz.end = NULL;
+
+ // mf.size is initialized to silence Valgrind
+ // when used on optimized binaries (GCC may reorder
+ // code in a way that Valgrind gets unhappy).
+ coder->mf.buffer = NULL;
+ coder->mf.size = 0;
+ coder->mf.hash = NULL;
+ coder->mf.son = NULL;
+ coder->mf.hash_count = 0;
+ coder->mf.sons_count = 0;
+
+ coder->next = LZMA_NEXT_CODER_INIT;
+ }
+
+ // Initialize the LZ-based encoder.
+ lzma_lz_options lz_options;
+ return_if_error(lz_init(&coder->lz, allocator,
+ filters[0].id, filters[0].options, &lz_options));
+
+ // Setup the size information into coder->mf and deallocate
+ // old buffers if they have wrong size.
+ if (lz_encoder_prepare(&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(&coder->mf, allocator, &lz_options))
+ return LZMA_MEM_ERROR;
+
+ // Initialize the next filter in the chain, if any.
+ return lzma_next_filter_init(&coder->next, allocator, filters + 1);
+}
+
+
+extern LZMA_API(lzma_bool)
+lzma_mf_is_supported(lzma_match_finder mf)
+{
+ switch (mf) {
+#ifdef HAVE_MF_HC3
+ case LZMA_MF_HC3:
+ return true;
+#endif
+#ifdef HAVE_MF_HC4
+ case LZMA_MF_HC4:
+ return true;
+#endif
+#ifdef HAVE_MF_BT2
+ case LZMA_MF_BT2:
+ return true;
+#endif
+#ifdef HAVE_MF_BT3
+ case LZMA_MF_BT3:
+ return true;
+#endif
+#ifdef HAVE_MF_BT4
+ case LZMA_MF_BT4:
+ return true;
+#endif
+ default:
+ return false;
+ }
+}
diff --git a/src/liblzma/lz/lz_encoder.h b/src/liblzma/lz/lz_encoder.h
new file mode 100644
index 0000000..ffcba02
--- /dev/null
+++ b/src/liblzma/lz/lz_encoder.h
@@ -0,0 +1,341 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file lz_encoder.h
+/// \brief LZ in window and match finder API
+///
+// Authors: Igor Pavlov
+// Lasse Collin
+//
+// This file has been put into the public domain.
+// You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef LZMA_LZ_ENCODER_H
+#define LZMA_LZ_ENCODER_H
+
+#include "common.h"
+
+
+/// A table of these is used by the LZ-based encoder to hold
+/// the length-distance pairs found by the match finder.
+typedef struct {
+ uint32_t len;
+ uint32_t dist;
+} lzma_match;
+
+
+typedef struct lzma_mf_s lzma_mf;
+struct lzma_mf_s {
+ ///////////////
+ // In Window //
+ ///////////////
+
+ /// Pointer to buffer with data to be compressed
+ uint8_t *buffer;
+
+ /// Total size of the allocated buffer (that is, including all
+ /// the extra space)
+ uint32_t size;
+
+ /// Number of bytes that must be kept available in our input history.
+ /// That is, once keep_size_before bytes have been processed,
+ /// buffer[read_pos - keep_size_before] is the oldest byte that
+ /// must be available for reading.
+ uint32_t keep_size_before;
+
+ /// Number of bytes that must be kept in buffer after read_pos.
+ /// That is, read_pos <= write_pos - keep_size_after as long as
+ /// action is LZMA_RUN; when action != LZMA_RUN, read_pos is allowed
+ /// to reach write_pos so that the last bytes get encoded too.
+ uint32_t keep_size_after;
+
+ /// Match finders store locations of matches using 32-bit integers.
+ /// To avoid adjusting several megabytes of integers every time the
+ /// input window is moved with move_window, we only adjust the
+ /// offset of the buffer. Thus, buffer[value_in_hash_table - offset]
+ /// is the byte pointed by value_in_hash_table.
+ uint32_t offset;
+
+ /// buffer[read_pos] is the next byte to run through the match
+ /// finder. This is incremented in the match finder once the byte
+ /// has been processed.
+ uint32_t read_pos;
+
+ /// Number of bytes that have been ran through the match finder, but
+ /// which haven't been encoded by the LZ-based encoder yet.
+ uint32_t read_ahead;
+
+ /// As long as read_pos is less than read_limit, there is enough
+ /// input available in buffer for at least one encoding loop.
+ ///
+ /// Because of the stateful API, read_limit may and will get greater
+ /// than read_pos quite often. This is taken into account when
+ /// calculating the value for keep_size_after.
+ uint32_t read_limit;
+
+ /// buffer[write_pos] is the first byte that doesn't contain valid
+ /// uncompressed data; that is, the next input byte will be copied
+ /// to buffer[write_pos].
+ uint32_t write_pos;
+
+ /// Number of bytes not hashed before read_pos. This is needed to
+ /// restart the match finder after LZMA_SYNC_FLUSH.
+ uint32_t pending;
+
+ //////////////////
+ // Match Finder //
+ //////////////////
+
+ /// Find matches. Returns the number of distance-length pairs written
+ /// to the matches array. This is called only via lzma_mf_find().
+ uint32_t (*find)(lzma_mf *mf, lzma_match *matches);
+
+ /// Skips num bytes. This is like find() but doesn't make the
+ /// distance-length pairs available, thus being a little faster.
+ /// This is called only via mf_skip().
+ void (*skip)(lzma_mf *mf, uint32_t num);
+
+ uint32_t *hash;
+ uint32_t *son;
+ uint32_t cyclic_pos;
+ uint32_t cyclic_size; // Must be dictionary size + 1.
+ uint32_t hash_mask;
+
+ /// Maximum number of loops in the match finder
+ uint32_t depth;
+
+ /// Maximum length of a match that the match finder will try to find.
+ uint32_t nice_len;
+
+ /// Maximum length of a match supported by the LZ-based encoder.
+ /// If the longest match found by the match finder is nice_len,
+ /// mf_find() tries to expand it up to match_len_max bytes.
+ uint32_t match_len_max;
+
+ /// When running out of input, binary tree match finders need to know
+ /// if it is due to flushing or finishing. The action is used also
+ /// by the LZ-based encoders themselves.
+ lzma_action action;
+
+ /// Number of elements in hash[]
+ uint32_t hash_count;
+
+ /// Number of elements in son[]
+ uint32_t sons_count;
+};
+
+
+typedef struct {
+ /// Extra amount of data to keep available before the "actual"
+ /// dictionary.
+ size_t before_size;
+
+ /// Size of the history buffer
+ size_t dict_size;
+
+ /// Extra amount of data to keep available after the "actual"
+ /// dictionary.
+ size_t after_size;
+
+ /// Maximum length of a match that the LZ-based encoder can accept.
+ /// This is used to extend matches of length nice_len to the
+ /// maximum possible length.
+ size_t match_len_max;
+
+ /// Match finder will search matches up to this length.
+ /// This must be less than or equal to match_len_max.
+ size_t nice_len;
+
+ /// Type of the match finder to use
+ lzma_match_finder match_finder;
+
+ /// Maximum search depth
+ uint32_t depth;
+
+ /// TODO: Comment
+ const uint8_t *preset_dict;
+
+ uint32_t preset_dict_size;
+
+} lzma_lz_options;
+
+
+// The total usable buffer space at any moment outside the match finder:
+// before_size + dict_size + after_size + match_len_max
+//
+// In reality, there's some extra space allocated to prevent the number of
+// memmove() calls reasonable. The bigger the dict_size is, the bigger
+// this extra buffer will be since with bigger dictionaries memmove() would
+// also take longer.
+//
+// A single encoder loop in the LZ-based encoder may call the match finder
+// (mf_find() or mf_skip()) at most after_size times. In other words,
+// a single encoder loop may increment lzma_mf.read_pos at most after_size
+// times. Since matches are looked up to
+// lzma_mf.buffer[lzma_mf.read_pos + match_len_max - 1], the total
+// amount of extra buffer needed after dict_size becomes
+// after_size + match_len_max.
+//
+// before_size has two uses. The first one is to keep literals available
+// in cases when the LZ-based encoder has made some read ahead.
+// TODO: Maybe this could be changed by making the LZ-based encoders to
+// store the actual literals as they do with length-distance pairs.
+//
+// Algorithms such as LZMA2 first try to compress a chunk, and then check
+// if the encoded result is smaller than the uncompressed one. If the chunk
+// was incompressible, it is better to store it in uncompressed form in
+// the output stream. To do this, the whole uncompressed chunk has to be
+// still available in the history buffer. before_size achieves that.
+
+
+typedef struct {
+ /// Data specific to the LZ-based encoder
+ void *coder;
+
+ /// Function to encode from *dict to out[]
+ lzma_ret (*code)(void *coder,
+ lzma_mf *restrict mf, uint8_t *restrict out,
+ size_t *restrict out_pos, size_t out_size);
+
+ /// Free allocated resources
+ void (*end)(void *coder, const lzma_allocator *allocator);
+
+ /// Update the options in the middle of the encoding.
+ lzma_ret (*options_update)(void *coder, const lzma_filter *filter);
+
+ /// Set maximum allowed output size
+ lzma_ret (*set_out_limit)(void *coder, uint64_t *uncomp_size,
+ uint64_t out_limit);
+
+} lzma_lz_encoder;
+
+
+// Basic steps:
+// 1. Input gets copied into the dictionary.
+// 2. Data in dictionary gets run through the match finder byte by byte.
+// 3. The literals and matches are encoded using e.g. LZMA.
+//
+// The bytes that have been ran through the match finder, but not encoded yet,
+// are called `read ahead'.
+
+
+/// Get how many bytes the match finder hashes in its initial step.
+/// This is also the minimum nice_len value with the match finder.
+static inline uint32_t
+mf_get_hash_bytes(lzma_match_finder match_finder)
+{
+ return (uint32_t)match_finder & 0x0F;
+}
+
+
+/// Get pointer to the first byte not ran through the match finder
+static inline const uint8_t *
+mf_ptr(const lzma_mf *mf)
+{
+ return mf->buffer + mf->read_pos;
+}
+
+
+/// Get the number of bytes that haven't been ran through the match finder yet.
+static inline uint32_t
+mf_avail(const lzma_mf *mf)
+{
+ return mf->write_pos - mf->read_pos;
+}
+
+
+/// Get the number of bytes that haven't been encoded yet (some of these
+/// bytes may have been ran through the match finder though).
+static inline uint32_t
+mf_unencoded(const lzma_mf *mf)
+{
+ return mf->write_pos - mf->read_pos + mf->read_ahead;
+}
+
+
+/// Calculate the absolute offset from the beginning of the most recent
+/// dictionary reset. Only the lowest four bits are important, so there's no
+/// problem that we don't know the 64-bit size of the data encoded so far.
+///
+/// NOTE: When moving the input window, we need to do it so that the lowest
+/// bits of dict->read_pos are not modified to keep this macro working
+/// as intended.
+static inline uint32_t
+mf_position(const lzma_mf *mf)
+{
+ return mf->read_pos - mf->read_ahead;
+}
+
+
+/// Since everything else begins with mf_, use it also for lzma_mf_find().
+#define mf_find lzma_mf_find
+
+
+/// Skip the given number of bytes. This is used when a good match was found.
+/// For example, if mf_find() finds a match of 200 bytes long, the first byte
+/// of that match was already consumed by mf_find(), and the rest 199 bytes
+/// have to be skipped with mf_skip(mf, 199).
+static inline void
+mf_skip(lzma_mf *mf, uint32_t amount)
+{
+ if (amount != 0) {
+ mf->skip(mf, amount);
+ mf->read_ahead += amount;
+ }
+}
+
+
+/// Copies at most *left number of bytes from the history buffer
+/// to out[]. This is needed by LZMA2 to encode uncompressed chunks.
+static inline void
+mf_read(lzma_mf *mf, uint8_t *out, size_t *out_pos, size_t out_size,
+ size_t *left)
+{
+ const size_t out_avail = out_size - *out_pos;
+ const size_t copy_size = my_min(out_avail, *left);
+
+ assert(mf->read_ahead == 0);
+ assert(mf->read_pos >= *left);
+
+ memcpy(out + *out_pos, mf->buffer + mf->read_pos - *left,
+ copy_size);
+
+ *out_pos += copy_size;
+ *left -= copy_size;
+ return;
+}
+
+
+extern lzma_ret lzma_lz_encoder_init(
+ lzma_next_coder *next, const lzma_allocator *allocator,
+ const lzma_filter_info *filters,
+ lzma_ret (*lz_init)(lzma_lz_encoder *lz,
+ const lzma_allocator *allocator,
+ lzma_vli id, const void *options,
+ lzma_lz_options *lz_options));
+
+
+extern uint64_t lzma_lz_encoder_memusage(const lzma_lz_options *lz_options);
+
+
+// These are only for LZ encoder's internal use.
+extern uint32_t lzma_mf_find(
+ lzma_mf *mf, uint32_t *count, lzma_match *matches);
+
+extern uint32_t lzma_mf_hc3_find(lzma_mf *dict, lzma_match *matches);
+extern void lzma_mf_hc3_skip(lzma_mf *dict, uint32_t amount);
+
+extern uint32_t lzma_mf_hc4_find(lzma_mf *dict, lzma_match *matches);
+extern void lzma_mf_hc4_skip(lzma_mf *dict, uint32_t amount);
+
+extern uint32_t lzma_mf_bt2_find(lzma_mf *dict, lzma_match *matches);
+extern void lzma_mf_bt2_skip(lzma_mf *dict, uint32_t amount);
+
+extern uint32_t lzma_mf_bt3_find(lzma_mf *dict, lzma_match *matches);
+extern void lzma_mf_bt3_skip(lzma_mf *dict, uint32_t amount);
+
+extern uint32_t lzma_mf_bt4_find(lzma_mf *dict, lzma_match *matches);
+extern void lzma_mf_bt4_skip(lzma_mf *dict, uint32_t amount);
+
+#endif
diff --git a/src/liblzma/lz/lz_encoder_hash.h b/src/liblzma/lz/lz_encoder_hash.h
new file mode 100644
index 0000000..4d9971a
--- /dev/null
+++ b/src/liblzma/lz/lz_encoder_hash.h
@@ -0,0 +1,109 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file lz_encoder_hash.h
+/// \brief Hash macros for match finders
+//
+// Author: Igor Pavlov
+//
+// This file has been put into the public domain.
+// You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef LZMA_LZ_ENCODER_HASH_H
+#define LZMA_LZ_ENCODER_HASH_H
+
+#if defined(WORDS_BIGENDIAN) && !defined(HAVE_SMALL)
+ // This is to make liblzma produce the same output on big endian
+ // systems that it does on little endian systems. lz_encoder.c
+ // takes care of including the actual table.
+ lzma_attr_visibility_hidden
+ extern const uint32_t lzma_lz_hash_table[256];
+# define hash_table lzma_lz_hash_table
+#else
+# include "check.h"
+# define hash_table lzma_crc32_table[0]
+#endif
+
+#define HASH_2_SIZE (UINT32_C(1) << 10)
+#define HASH_3_SIZE (UINT32_C(1) << 16)
+#define HASH_4_SIZE (UINT32_C(1) << 20)
+
+#define HASH_2_MASK (HASH_2_SIZE - 1)
+#define HASH_3_MASK (HASH_3_SIZE - 1)
+#define HASH_4_MASK (HASH_4_SIZE - 1)
+
+#define FIX_3_HASH_SIZE (HASH_2_SIZE)
+#define FIX_4_HASH_SIZE (HASH_2_SIZE + HASH_3_SIZE)
+#define FIX_5_HASH_SIZE (HASH_2_SIZE + HASH_3_SIZE + HASH_4_SIZE)
+
+// Endianness doesn't matter in hash_2_calc() (no effect on the output).
+#ifdef TUKLIB_FAST_UNALIGNED_ACCESS
+# define hash_2_calc() \
+ const uint32_t hash_value = read16ne(cur)
+#else
+# define hash_2_calc() \
+ const uint32_t hash_value \
+ = (uint32_t)(cur[0]) | ((uint32_t)(cur[1]) << 8)
+#endif
+
+#define hash_3_calc() \
+ const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \
+ const uint32_t hash_2_value = temp & HASH_2_MASK; \
+ const uint32_t hash_value \
+ = (temp ^ ((uint32_t)(cur[2]) << 8)) & mf->hash_mask
+
+#define hash_4_calc() \
+ const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \
+ const uint32_t hash_2_value = temp & HASH_2_MASK; \
+ const uint32_t hash_3_value \
+ = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \
+ const uint32_t hash_value = (temp ^ ((uint32_t)(cur[2]) << 8) \
+ ^ (hash_table[cur[3]] << 5)) & mf->hash_mask
+
+
+// The following are not currently used.
+
+#define hash_5_calc() \
+ const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \
+ const uint32_t hash_2_value = temp & HASH_2_MASK; \
+ const uint32_t hash_3_value \
+ = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \
+ uint32_t hash_4_value = (temp ^ ((uint32_t)(cur[2]) << 8) ^ \
+ ^ hash_table[cur[3]] << 5); \
+ const uint32_t hash_value \
+ = (hash_4_value ^ (hash_table[cur[4]] << 3)) \
+ & mf->hash_mask; \
+ hash_4_value &= HASH_4_MASK
+
+/*
+#define hash_zip_calc() \
+ const uint32_t hash_value \
+ = (((uint32_t)(cur[0]) | ((uint32_t)(cur[1]) << 8)) \
+ ^ hash_table[cur[2]]) & 0xFFFF
+*/
+
+#define hash_zip_calc() \
+ const uint32_t hash_value \
+ = (((uint32_t)(cur[2]) | ((uint32_t)(cur[0]) << 8)) \
+ ^ hash_table[cur[1]]) & 0xFFFF
+
+#define mt_hash_2_calc() \
+ const uint32_t hash_2_value \
+ = (hash_table[cur[0]] ^ cur[1]) & HASH_2_MASK
+
+#define mt_hash_3_calc() \
+ const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \
+ const uint32_t hash_2_value = temp & HASH_2_MASK; \
+ const uint32_t hash_3_value \
+ = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK
+
+#define mt_hash_4_calc() \
+ const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \
+ const uint32_t hash_2_value = temp & HASH_2_MASK; \
+ const uint32_t hash_3_value \
+ = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \
+ const uint32_t hash_4_value = (temp ^ ((uint32_t)(cur[2]) << 8) ^ \
+ (hash_table[cur[3]] << 5)) & HASH_4_MASK
+
+#endif
diff --git a/src/liblzma/lz/lz_encoder_hash_table.h b/src/liblzma/lz/lz_encoder_hash_table.h
new file mode 100644
index 0000000..8c51717
--- /dev/null
+++ b/src/liblzma/lz/lz_encoder_hash_table.h
@@ -0,0 +1,68 @@
+/* This file has been automatically generated by crc32_tablegen.c. */
+
+const uint32_t lzma_lz_hash_table[256] = {
+ 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA,
+ 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,
+ 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
+ 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,
+ 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE,
+ 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
+ 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC,
+ 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,
+ 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
+ 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
+ 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940,
+ 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
+ 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116,
+ 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
+ 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
+ 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,
+ 0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A,
+ 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
+ 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818,
+ 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
+ 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
+ 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,
+ 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C,
+ 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
+ 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2,
+ 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,
+ 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
+ 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,
+ 0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086,
+ 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
+ 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4,
+ 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,
+ 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
+ 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,
+ 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8,
+ 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
+ 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE,
+ 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,
+ 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
+ 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
+ 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252,
+ 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
+ 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60,
+ 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,
+ 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
+ 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
+ 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04,
+ 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
+ 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A,
+ 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
+ 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
+ 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,
+ 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E,
+ 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
+ 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C,
+ 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,
+ 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
+ 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,
+ 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0,
+ 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
+ 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6,
+ 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
+ 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
+ 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
+};
diff --git a/src/liblzma/lz/lz_encoder_mf.c b/src/liblzma/lz/lz_encoder_mf.c
new file mode 100644
index 0000000..1fdc2d7
--- /dev/null
+++ b/src/liblzma/lz/lz_encoder_mf.c
@@ -0,0 +1,745 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file lz_encoder_mf.c
+/// \brief Match finders
+///
+// 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"
+#include "memcmplen.h"
+
+
+/// \brief Find matches starting from the current byte
+///
+/// \return The length of the longest match found
+extern uint32_t
+lzma_mf_find(lzma_mf *mf, uint32_t *count_ptr, lzma_match *matches)
+{
+ // Call the match finder. It returns the number of length-distance
+ // pairs found.
+ // FIXME: Minimum count is zero, what _exactly_ is the maximum?
+ const uint32_t count = mf->find(mf, matches);
+
+ // Length of the longest match; assume that no matches were found
+ // and thus the maximum length is zero.
+ uint32_t len_best = 0;
+
+ if (count > 0) {
+#ifndef NDEBUG
+ // Validate the matches.
+ for (uint32_t i = 0; i < count; ++i) {
+ assert(matches[i].len <= mf->nice_len);
+ assert(matches[i].dist < mf->read_pos);
+ assert(memcmp(mf_ptr(mf) - 1,
+ mf_ptr(mf) - matches[i].dist - 2,
+ matches[i].len) == 0);
+ }
+#endif
+
+ // The last used element in the array contains
+ // the longest match.
+ len_best = matches[count - 1].len;
+
+ // If a match of maximum search length was found, try to
+ // extend the match to maximum possible length.
+ if (len_best == mf->nice_len) {
+ // The limit for the match length is either the
+ // maximum match length supported by the LZ-based
+ // encoder or the number of bytes left in the
+ // dictionary, whichever is smaller.
+ uint32_t limit = mf_avail(mf) + 1;
+ if (limit > mf->match_len_max)
+ limit = mf->match_len_max;
+
+ // Pointer to the byte we just ran through
+ // the match finder.
+ const uint8_t *p1 = mf_ptr(mf) - 1;
+
+ // Pointer to the beginning of the match. We need -1
+ // here because the match distances are zero based.
+ const uint8_t *p2 = p1 - matches[count - 1].dist - 1;
+
+ len_best = lzma_memcmplen(p1, p2, len_best, limit);
+ }
+ }
+
+ *count_ptr = count;
+
+ // Finally update the read position to indicate that match finder was
+ // run for this dictionary offset.
+ ++mf->read_ahead;
+
+ return len_best;
+}
+
+
+/// Hash value to indicate unused element in the hash. Since we start the
+/// positions from dict_size + 1, zero is always too far to qualify
+/// as usable match position.
+#define EMPTY_HASH_VALUE 0
+
+
+/// Normalization must be done when lzma_mf.offset + lzma_mf.read_pos
+/// reaches MUST_NORMALIZE_POS.
+#define MUST_NORMALIZE_POS UINT32_MAX
+
+
+/// \brief Normalizes hash values
+///
+/// The hash arrays store positions of match candidates. The positions are
+/// relative to an arbitrary offset that is not the same as the absolute
+/// offset in the input stream. The relative position of the current byte
+/// is lzma_mf.offset + lzma_mf.read_pos. The distances of the matches are
+/// the differences of the current read position and the position found from
+/// the hash.
+///
+/// To prevent integer overflows of the offsets stored in the hash arrays,
+/// we need to "normalize" the stored values now and then. During the
+/// normalization, we drop values that indicate distance greater than the
+/// dictionary size, thus making space for new values.
+static void
+normalize(lzma_mf *mf)
+{
+ assert(mf->read_pos + mf->offset == MUST_NORMALIZE_POS);
+
+ // In future we may not want to touch the lowest bits, because there
+ // may be match finders that use larger resolution than one byte.
+ const uint32_t subvalue
+ = (MUST_NORMALIZE_POS - mf->cyclic_size);
+ // & ~((UINT32_C(1) << 10) - 1);
+
+ for (uint32_t i = 0; i < mf->hash_count; ++i) {
+ // If the distance is greater than the dictionary size,
+ // we can simply mark the hash element as empty.
+ if (mf->hash[i] <= subvalue)
+ mf->hash[i] = EMPTY_HASH_VALUE;
+ else
+ mf->hash[i] -= subvalue;
+ }
+
+ for (uint32_t i = 0; i < mf->sons_count; ++i) {
+ // Do the same for mf->son.
+ //
+ // NOTE: There may be uninitialized elements in mf->son.
+ // Valgrind may complain that the "if" below depends on
+ // an uninitialized value. In this case it is safe to ignore
+ // the warning. See also the comments in lz_encoder_init()
+ // in lz_encoder.c.
+ if (mf->son[i] <= subvalue)
+ mf->son[i] = EMPTY_HASH_VALUE;
+ else
+ mf->son[i] -= subvalue;
+ }
+
+ // Update offset to match the new locations.
+ mf->offset -= subvalue;
+
+ return;
+}
+
+
+/// Mark the current byte as processed from point of view of the match finder.
+static void
+move_pos(lzma_mf *mf)
+{
+ if (++mf->cyclic_pos == mf->cyclic_size)
+ mf->cyclic_pos = 0;
+
+ ++mf->read_pos;
+ assert(mf->read_pos <= mf->write_pos);
+
+ if (unlikely(mf->read_pos + mf->offset == UINT32_MAX))
+ normalize(mf);
+}
+
+
+/// When flushing, we cannot run the match finder unless there is nice_len
+/// bytes available in the dictionary. Instead, we skip running the match
+/// finder (indicating that no match was found), and count how many bytes we
+/// have ignored this way.
+///
+/// When new data is given after the flushing was completed, the match finder
+/// is restarted by rewinding mf->read_pos backwards by mf->pending. Then
+/// the missed bytes are added to the hash using the match finder's skip
+/// function (with small amount of input, it may start using mf->pending
+/// again if flushing).
+///
+/// Due to this rewinding, we don't touch cyclic_pos or test for
+/// normalization. It will be done when the match finder's skip function
+/// catches up after a flush.
+static void
+move_pending(lzma_mf *mf)
+{
+ ++mf->read_pos;
+ assert(mf->read_pos <= mf->write_pos);
+ ++mf->pending;
+}
+
+
+/// Calculate len_limit and determine if there is enough input to run
+/// the actual match finder code. Sets up "cur" and "pos". This macro
+/// is used by all find functions and binary tree skip functions. Hash
+/// chain skip function doesn't need len_limit so a simpler code is used
+/// in them.
+#define header(is_bt, len_min, ret_op) \
+ uint32_t len_limit = mf_avail(mf); \
+ if (mf->nice_len <= len_limit) { \
+ len_limit = mf->nice_len; \
+ } else if (len_limit < (len_min) \
+ || (is_bt && mf->action == LZMA_SYNC_FLUSH)) { \
+ assert(mf->action != LZMA_RUN); \
+ move_pending(mf); \
+ ret_op; \
+ } \
+ const uint8_t *cur = mf_ptr(mf); \
+ const uint32_t pos = mf->read_pos + mf->offset
+
+
+/// Header for find functions. "return 0" indicates that zero matches
+/// were found.
+#define header_find(is_bt, len_min) \
+ header(is_bt, len_min, return 0); \
+ uint32_t matches_count = 0
+
+
+/// Header for a loop in a skip function. "continue" tells to skip the rest
+/// of the code in the loop.
+#define header_skip(is_bt, len_min) \
+ header(is_bt, len_min, continue)
+
+
+/// Calls hc_find_func() or bt_find_func() and calculates the total number
+/// of matches found. Updates the dictionary position and returns the number
+/// of matches found.
+#define call_find(func, len_best) \
+do { \
+ matches_count = (uint32_t)(func(len_limit, pos, cur, cur_match, \
+ mf->depth, mf->son, \
+ mf->cyclic_pos, mf->cyclic_size, \
+ matches + matches_count, len_best) \
+ - matches); \
+ move_pos(mf); \
+ return matches_count; \
+} while (0)
+
+
+////////////////
+// Hash Chain //
+////////////////
+
+#if defined(HAVE_MF_HC3) || defined(HAVE_MF_HC4)
+///
+///
+/// \param len_limit Don't look for matches longer than len_limit.
+/// \param pos lzma_mf.read_pos + lzma_mf.offset
+/// \param cur Pointer to current byte (mf_ptr(mf))
+/// \param cur_match Start position of the current match candidate
+/// \param depth Maximum length of the hash chain
+/// \param son lzma_mf.son (contains the hash chain)
+/// \param cyclic_pos lzma_mf.cyclic_pos
+/// \param cyclic_size lzma_mf_cyclic_size
+/// \param matches Array to hold the matches.
+/// \param len_best The length of the longest match found so far.
+static lzma_match *
+hc_find_func(
+ const uint32_t len_limit,
+ const uint32_t pos,
+ const uint8_t *const cur,
+ uint32_t cur_match,
+ uint32_t depth,
+ uint32_t *const son,
+ const uint32_t cyclic_pos,
+ const uint32_t cyclic_size,
+ lzma_match *matches,
+ uint32_t len_best)
+{
+ son[cyclic_pos] = cur_match;
+
+ while (true) {
+ const uint32_t delta = pos - cur_match;
+ if (depth-- == 0 || delta >= cyclic_size)
+ return matches;
+
+ const uint8_t *const pb = cur - delta;
+ cur_match = son[cyclic_pos - delta
+ + (delta > cyclic_pos ? cyclic_size : 0)];
+
+ if (pb[len_best] == cur[len_best] && pb[0] == cur[0]) {
+ uint32_t len = lzma_memcmplen(pb, cur, 1, len_limit);
+
+ if (len_best < len) {
+ len_best = len;
+ matches->len = len;
+ matches->dist = delta - 1;
+ ++matches;
+
+ if (len == len_limit)
+ return matches;
+ }
+ }
+ }
+}
+
+
+#define hc_find(len_best) \
+ call_find(hc_find_func, len_best)
+
+
+#define hc_skip() \
+do { \
+ mf->son[mf->cyclic_pos] = cur_match; \
+ move_pos(mf); \
+} while (0)
+
+#endif
+
+
+#ifdef HAVE_MF_HC3
+extern uint32_t
+lzma_mf_hc3_find(lzma_mf *mf, lzma_match *matches)
+{
+ header_find(false, 3);
+
+ hash_3_calc();
+
+ const uint32_t delta2 = pos - mf->hash[hash_2_value];
+ const uint32_t cur_match = mf->hash[FIX_3_HASH_SIZE + hash_value];
+
+ mf->hash[hash_2_value] = pos;
+ mf->hash[FIX_3_HASH_SIZE + hash_value] = pos;
+
+ uint32_t len_best = 2;
+
+ if (delta2 < mf->cyclic_size && *(cur - delta2) == *cur) {
+ len_best = lzma_memcmplen(cur - delta2, cur,
+ len_best, len_limit);
+
+ matches[0].len = len_best;
+ matches[0].dist = delta2 - 1;
+ matches_count = 1;
+
+ if (len_best == len_limit) {
+ hc_skip();
+ return 1; // matches_count
+ }
+ }
+
+ hc_find(len_best);
+}
+
+
+extern void
+lzma_mf_hc3_skip(lzma_mf *mf, uint32_t amount)
+{
+ do {
+ if (mf_avail(mf) < 3) {
+ move_pending(mf);
+ continue;
+ }
+
+ const uint8_t *cur = mf_ptr(mf);
+ const uint32_t pos = mf->read_pos + mf->offset;
+
+ hash_3_calc();
+
+ const uint32_t cur_match
+ = mf->hash[FIX_3_HASH_SIZE + hash_value];
+
+ mf->hash[hash_2_value] = pos;
+ mf->hash[FIX_3_HASH_SIZE + hash_value] = pos;
+
+ hc_skip();
+
+ } while (--amount != 0);
+}
+#endif
+
+
+#ifdef HAVE_MF_HC4
+extern uint32_t
+lzma_mf_hc4_find(lzma_mf *mf, lzma_match *matches)
+{
+ header_find(false, 4);
+
+ hash_4_calc();
+
+ uint32_t delta2 = pos - mf->hash[hash_2_value];
+ const uint32_t delta3
+ = pos - mf->hash[FIX_3_HASH_SIZE + hash_3_value];
+ const uint32_t cur_match = mf->hash[FIX_4_HASH_SIZE + hash_value];
+
+ mf->hash[hash_2_value ] = pos;
+ mf->hash[FIX_3_HASH_SIZE + hash_3_value] = pos;
+ mf->hash[FIX_4_HASH_SIZE + hash_value] = pos;
+
+ uint32_t len_best = 1;
+
+ if (delta2 < mf->cyclic_size && *(cur - delta2) == *cur) {
+ len_best = 2;
+ matches[0].len = 2;
+ matches[0].dist = delta2 - 1;
+ matches_count = 1;
+ }
+
+ if (delta2 != delta3 && delta3 < mf->cyclic_size
+ && *(cur - delta3) == *cur) {
+ len_best = 3;
+ matches[matches_count++].dist = delta3 - 1;
+ delta2 = delta3;
+ }
+
+ if (matches_count != 0) {
+ len_best = lzma_memcmplen(cur - delta2, cur,
+ len_best, len_limit);
+
+ matches[matches_count - 1].len = len_best;
+
+ if (len_best == len_limit) {
+ hc_skip();
+ return matches_count;
+ }
+ }
+
+ if (len_best < 3)
+ len_best = 3;
+
+ hc_find(len_best);
+}
+
+
+extern void
+lzma_mf_hc4_skip(lzma_mf *mf, uint32_t amount)
+{
+ do {
+ if (mf_avail(mf) < 4) {
+ move_pending(mf);
+ continue;
+ }
+
+ const uint8_t *cur = mf_ptr(mf);
+ const uint32_t pos = mf->read_pos + mf->offset;
+
+ hash_4_calc();
+
+ const uint32_t cur_match
+ = mf->hash[FIX_4_HASH_SIZE + hash_value];
+
+ mf->hash[hash_2_value] = pos;
+ mf->hash[FIX_3_HASH_SIZE + hash_3_value] = pos;
+ mf->hash[FIX_4_HASH_SIZE + hash_value] = pos;
+
+ hc_skip();
+
+ } while (--amount != 0);
+}
+#endif
+
+
+/////////////////
+// Binary Tree //
+/////////////////
+
+#if defined(HAVE_MF_BT2) || defined(HAVE_MF_BT3) || defined(HAVE_MF_BT4)
+static lzma_match *
+bt_find_func(
+ const uint32_t len_limit,
+ const uint32_t pos,
+ const uint8_t *const cur,
+ uint32_t cur_match,
+ uint32_t depth,
+ uint32_t *const son,
+ const uint32_t cyclic_pos,
+ const uint32_t cyclic_size,
+ lzma_match *matches,
+ uint32_t len_best)
+{
+ uint32_t *ptr0 = son + (cyclic_pos << 1) + 1;
+ uint32_t *ptr1 = son + (cyclic_pos << 1);
+
+ uint32_t len0 = 0;
+ uint32_t len1 = 0;
+
+ while (true) {
+ const uint32_t delta = pos - cur_match;
+ if (depth-- == 0 || delta >= cyclic_size) {
+ *ptr0 = EMPTY_HASH_VALUE;
+ *ptr1 = EMPTY_HASH_VALUE;
+ return matches;
+ }
+
+ uint32_t *const pair = son + ((cyclic_pos - delta
+ + (delta > cyclic_pos ? cyclic_size : 0))
+ << 1);
+
+ const uint8_t *const pb = cur - delta;
+ uint32_t len = my_min(len0, len1);
+
+ if (pb[len] == cur[len]) {
+ len = lzma_memcmplen(pb, cur, len + 1, len_limit);
+
+ if (len_best < len) {
+ len_best = len;
+ matches->len = len;
+ matches->dist = delta - 1;
+ ++matches;
+
+ if (len == len_limit) {
+ *ptr1 = pair[0];
+ *ptr0 = pair[1];
+ return matches;
+ }
+ }
+ }
+
+ if (pb[len] < cur[len]) {
+ *ptr1 = cur_match;
+ ptr1 = pair + 1;
+ cur_match = *ptr1;
+ len1 = len;
+ } else {
+ *ptr0 = cur_match;
+ ptr0 = pair;
+ cur_match = *ptr0;
+ len0 = len;
+ }
+ }
+}
+
+
+static void
+bt_skip_func(
+ const uint32_t len_limit,
+ const uint32_t pos,
+ const uint8_t *const cur,
+ uint32_t cur_match,
+ uint32_t depth,
+ uint32_t *const son,
+ const uint32_t cyclic_pos,
+ const uint32_t cyclic_size)
+{
+ uint32_t *ptr0 = son + (cyclic_pos << 1) + 1;
+ uint32_t *ptr1 = son + (cyclic_pos << 1);
+
+ uint32_t len0 = 0;
+ uint32_t len1 = 0;
+
+ while (true) {
+ const uint32_t delta = pos - cur_match;
+ if (depth-- == 0 || delta >= cyclic_size) {
+ *ptr0 = EMPTY_HASH_VALUE;
+ *ptr1 = EMPTY_HASH_VALUE;
+ return;
+ }
+
+ uint32_t *pair = son + ((cyclic_pos - delta
+ + (delta > cyclic_pos ? cyclic_size : 0))
+ << 1);
+ const uint8_t *pb = cur - delta;
+ uint32_t len = my_min(len0, len1);
+
+ if (pb[len] == cur[len]) {
+ len = lzma_memcmplen(pb, cur, len + 1, len_limit);
+
+ if (len == len_limit) {
+ *ptr1 = pair[0];
+ *ptr0 = pair[1];
+ return;
+ }
+ }
+
+ if (pb[len] < cur[len]) {
+ *ptr1 = cur_match;
+ ptr1 = pair + 1;
+ cur_match = *ptr1;
+ len1 = len;
+ } else {
+ *ptr0 = cur_match;
+ ptr0 = pair;
+ cur_match = *ptr0;
+ len0 = len;
+ }
+ }
+}
+
+
+#define bt_find(len_best) \
+ call_find(bt_find_func, len_best)
+
+#define bt_skip() \
+do { \
+ bt_skip_func(len_limit, pos, cur, cur_match, mf->depth, \
+ mf->son, mf->cyclic_pos, \
+ mf->cyclic_size); \
+ move_pos(mf); \
+} while (0)
+
+#endif
+
+
+#ifdef HAVE_MF_BT2
+extern uint32_t
+lzma_mf_bt2_find(lzma_mf *mf, lzma_match *matches)
+{
+ header_find(true, 2);
+
+ hash_2_calc();
+
+ const uint32_t cur_match = mf->hash[hash_value];
+ mf->hash[hash_value] = pos;
+
+ bt_find(1);
+}
+
+
+extern void
+lzma_mf_bt2_skip(lzma_mf *mf, uint32_t amount)
+{
+ do {
+ header_skip(true, 2);
+
+ hash_2_calc();
+
+ const uint32_t cur_match = mf->hash[hash_value];
+ mf->hash[hash_value] = pos;
+
+ bt_skip();
+
+ } while (--amount != 0);
+}
+#endif
+
+
+#ifdef HAVE_MF_BT3
+extern uint32_t
+lzma_mf_bt3_find(lzma_mf *mf, lzma_match *matches)
+{
+ header_find(true, 3);
+
+ hash_3_calc();
+
+ const uint32_t delta2 = pos - mf->hash[hash_2_value];
+ const uint32_t cur_match = mf->hash[FIX_3_HASH_SIZE + hash_value];
+
+ mf->hash[hash_2_value] = pos;
+ mf->hash[FIX_3_HASH_SIZE + hash_value] = pos;
+
+ uint32_t len_best = 2;
+
+ if (delta2 < mf->cyclic_size && *(cur - delta2) == *cur) {
+ len_best = lzma_memcmplen(
+ cur, cur - delta2, len_best, len_limit);
+
+ matches[0].len = len_best;
+ matches[0].dist = delta2 - 1;
+ matches_count = 1;
+
+ if (len_best == len_limit) {
+ bt_skip();
+ return 1; // matches_count
+ }
+ }
+
+ bt_find(len_best);
+}
+
+
+extern void
+lzma_mf_bt3_skip(lzma_mf *mf, uint32_t amount)
+{
+ do {
+ header_skip(true, 3);
+
+ hash_3_calc();
+
+ const uint32_t cur_match
+ = mf->hash[FIX_3_HASH_SIZE + hash_value];
+
+ mf->hash[hash_2_value] = pos;
+ mf->hash[FIX_3_HASH_SIZE + hash_value] = pos;
+
+ bt_skip();
+
+ } while (--amount != 0);
+}
+#endif
+
+
+#ifdef HAVE_MF_BT4
+extern uint32_t
+lzma_mf_bt4_find(lzma_mf *mf, lzma_match *matches)
+{
+ header_find(true, 4);
+
+ hash_4_calc();
+
+ uint32_t delta2 = pos - mf->hash[hash_2_value];
+ const uint32_t delta3
+ = pos - mf->hash[FIX_3_HASH_SIZE + hash_3_value];
+ const uint32_t cur_match = mf->hash[FIX_4_HASH_SIZE + hash_value];
+
+ mf->hash[hash_2_value] = pos;
+ mf->hash[FIX_3_HASH_SIZE + hash_3_value] = pos;
+ mf->hash[FIX_4_HASH_SIZE + hash_value] = pos;
+
+ uint32_t len_best = 1;
+
+ if (delta2 < mf->cyclic_size && *(cur - delta2) == *cur) {
+ len_best = 2;
+ matches[0].len = 2;
+ matches[0].dist = delta2 - 1;
+ matches_count = 1;
+ }
+
+ if (delta2 != delta3 && delta3 < mf->cyclic_size
+ && *(cur - delta3) == *cur) {
+ len_best = 3;
+ matches[matches_count++].dist = delta3 - 1;
+ delta2 = delta3;
+ }
+
+ if (matches_count != 0) {
+ len_best = lzma_memcmplen(
+ cur, cur - delta2, len_best, len_limit);
+
+ matches[matches_count - 1].len = len_best;
+
+ if (len_best == len_limit) {
+ bt_skip();
+ return matches_count;
+ }
+ }
+
+ if (len_best < 3)
+ len_best = 3;
+
+ bt_find(len_best);
+}
+
+
+extern void
+lzma_mf_bt4_skip(lzma_mf *mf, uint32_t amount)
+{
+ do {
+ header_skip(true, 4);
+
+ hash_4_calc();
+
+ const uint32_t cur_match
+ = mf->hash[FIX_4_HASH_SIZE + hash_value];
+
+ mf->hash[hash_2_value] = pos;
+ mf->hash[FIX_3_HASH_SIZE + hash_3_value] = pos;
+ mf->hash[FIX_4_HASH_SIZE + hash_value] = pos;
+
+ bt_skip();
+
+ } while (--amount != 0);
+}
+#endif