Adding upstream version 1.24.1.upstream/1.24.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 184 insertions, 0 deletions

diff --git a/fast_encoder.cc b/fast_encoder.cc
new file mode 100644
index 0000000..c6ec497
--- /dev/null
+++ b/fast_encoder.cc
@@ -0,0 +1,184 @@
+/* Lzip - LZMA lossless data compressor
+   Copyright (C) 2008-2024 Antonio Diaz Diaz.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 2 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#define _FILE_OFFSET_BITS 64
+
+#include <algorithm>
+#include <cerrno>
+#include <cstdlib>
+#include <cstring>
+#include <string>
+#include <vector>
+#include <stdint.h>
+
+#include "lzip.h"
+#include "encoder_base.h"
+#include "fast_encoder.h"
+
+
+int FLZ_encoder::longest_match_len( int * const distance )
+  {
+  enum { len_limit = 16 };
+  const int available = std::min( available_bytes(), (int)max_match_len );
+  if( available < len_limit ) return 0;
+
+  const uint8_t * const data = ptr_to_current_pos();
+  key4 = ( ( key4 << 4 ) ^ data[3] ) & key4_mask;
+  const int pos1 = pos + 1;
+  int newpos1 = prev_positions[key4];
+  prev_positions[key4] = pos1;
+  int32_t * ptr0 = pos_array + cyclic_pos;
+  int maxlen = 0;
+
+  for( int count = 4; ; )
+    {
+    int delta;
+    if( newpos1 <= 0 || --count < 0 ||
+        ( delta = pos1 - newpos1 ) > dictionary_size ) { *ptr0 = 0; break; }
+    int32_t * const newptr = pos_array +
+      ( cyclic_pos - delta +
+          ( ( cyclic_pos >= delta ) ? 0 : dictionary_size + 1 ) );
+
+    if( data[maxlen-delta] == data[maxlen] )
+      {
+      int len = 0;
+      while( len < available && data[len-delta] == data[len] ) ++len;
+      if( maxlen < len )
+        { maxlen = len; *distance = delta - 1;
+          if( maxlen >= len_limit ) { *ptr0 = *newptr; break; } }
+      }
+
+    *ptr0 = newpos1;
+    ptr0 = newptr;
+    newpos1 = *ptr0;
+    }
+  return maxlen;
+  }
+
+
+bool FLZ_encoder::encode_member( const unsigned long long member_size )
+  {
+  const unsigned long long member_size_limit =
+    member_size - Lzip_trailer::size - max_marker_size;
+  int rep = 0;
+  int reps[num_rep_distances];
+  State state;
+  for( int i = 0; i < num_rep_distances; ++i ) reps[i] = 0;
+
+  if( data_position() != 0 || renc.member_position() != Lzip_header::size )
+    return false;				// can be called only once
+
+  if( !data_finished() )			// encode first byte
+    {
+    const uint8_t prev_byte = 0;
+    const uint8_t cur_byte = peek( 0 );
+    renc.encode_bit( bm_match[state()][0], 0 );
+    encode_literal( prev_byte, cur_byte );
+    crc32.update_byte( crc_, cur_byte );
+    reset_key4();
+    update_and_move( 1 );
+    }
+
+  while( !data_finished() && renc.member_position() < member_size_limit )
+    {
+    int match_distance;
+    const int main_len = longest_match_len( &match_distance );
+    const int pos_state = data_position() & pos_state_mask;
+    int len = 0;
+
+    for( int i = 0; i < num_rep_distances; ++i )
+      {
+      const int tlen = true_match_len( 0, reps[i] + 1 );
+      if( tlen > len ) { len = tlen; rep = i; }
+      }
+    if( len > min_match_len && len + 3 > main_len )
+      {
+      crc32.update_buf( crc_, ptr_to_current_pos(), len );
+      renc.encode_bit( bm_match[state()][pos_state], 1 );
+      renc.encode_bit( bm_rep[state()], 1 );
+      renc.encode_bit( bm_rep0[state()], rep != 0 );
+      if( rep == 0 )
+        renc.encode_bit( bm_len[state()][pos_state], 1 );
+      else
+        {
+        renc.encode_bit( bm_rep1[state()], rep > 1 );
+        if( rep > 1 )
+          renc.encode_bit( bm_rep2[state()], rep > 2 );
+        const int distance = reps[rep];
+        for( int i = rep; i > 0; --i ) reps[i] = reps[i-1];
+        reps[0] = distance;
+        }
+      state.set_rep();
+      renc.encode_len( rep_len_model, len, pos_state );
+      move_pos();
+      update_and_move( len - 1 );
+      continue;
+      }
+
+    if( main_len > min_match_len )
+      {
+      crc32.update_buf( crc_, ptr_to_current_pos(), main_len );
+      renc.encode_bit( bm_match[state()][pos_state], 1 );
+      renc.encode_bit( bm_rep[state()], 0 );
+      state.set_match();
+      for( int i = num_rep_distances - 1; i > 0; --i ) reps[i] = reps[i-1];
+      reps[0] = match_distance;
+      encode_pair( match_distance, main_len, pos_state );
+      move_pos();
+      update_and_move( main_len - 1 );
+      continue;
+      }
+
+    const uint8_t prev_byte = peek( 1 );
+    const uint8_t cur_byte = peek( 0 );
+    const uint8_t match_byte = peek( reps[0] + 1 );
+    move_pos();
+    crc32.update_byte( crc_, cur_byte );
+
+    if( match_byte == cur_byte )
+      {
+      const int short_rep_price = price1( bm_match[state()][pos_state] ) +
+                                  price1( bm_rep[state()] ) +
+                                  price0( bm_rep0[state()] ) +
+                                  price0( bm_len[state()][pos_state] );
+      int price = price0( bm_match[state()][pos_state] );
+      if( state.is_char() )
+        price += price_literal( prev_byte, cur_byte );
+      else
+        price += price_matched( prev_byte, cur_byte, match_byte );
+      if( short_rep_price < price )
+        {
+        renc.encode_bit( bm_match[state()][pos_state], 1 );
+        renc.encode_bit( bm_rep[state()], 1 );
+        renc.encode_bit( bm_rep0[state()], 0 );
+        renc.encode_bit( bm_len[state()][pos_state], 0 );
+        state.set_short_rep();
+        continue;
+        }
+      }
+
+    // literal byte
+    renc.encode_bit( bm_match[state()][pos_state], 0 );
+    if( state.is_char_set_char() )
+      encode_literal( prev_byte, cur_byte );
+    else
+      encode_matched( prev_byte, cur_byte, match_byte );
+    }
+
+  full_flush( state );
+  return true;
+  }