Merging upstream version 0.7.

Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>

1 files changed, 20 insertions, 26 deletions

diff --git a/lzd.cc b/lzd.cc
index f1a500e..30dde48 100644
--- a/lzd.cc
+++ b/lzd.cc
@@ -1,5 +1,5 @@
-/*  Lzd - Educational decompressor for lzip files
-    Copyright (C) 2013, 2014 Antonio Diaz Diaz.
+/*  Lzd - Educational decompressor for the lzip format
+    Copyright (C) 2013-2015 Antonio Diaz Diaz.
 
     This program is free software: you have unlimited permission
     to copy, distribute and modify it.
@@ -241,7 +241,7 @@ class LZ_decoder
 
   void flush_data();
 
-  uint8_t get_byte( const unsigned distance ) const
+  uint8_t peek( const unsigned distance ) const
     {
     unsigned i = pos - distance - 1;
     if( pos <= distance ) i += dictionary_size;
@@ -255,7 +255,7 @@ class LZ_decoder
     }
 
 public:
-  LZ_decoder( const unsigned dict_size )
+  explicit LZ_decoder( const unsigned dict_size )
     :
     partial_data_pos( 0 ),
     dictionary_size( dict_size ),
@@ -282,7 +282,7 @@ void LZ_decoder::flush_data()
     crc32.update_buf( crc_, buffer + stream_pos, size );
     errno = 0;
     if( std::fwrite( buffer + stream_pos, 1, size, stdout ) != size )
-      { std::fprintf( stderr, "Write error: %s.\n", std::strerror( errno ) );
+      { std::fprintf( stderr, "Write error: %s\n", std::strerror( errno ) );
         std::exit( 1 ); }
     if( pos >= dictionary_size ) { partial_data_pos += pos; pos = 0; }
     stream_pos = pos;
@@ -315,16 +315,16 @@ bool LZ_decoder::decode_member()		// Returns false if error
     const int pos_state = data_position() & pos_state_mask;
     if( rdec.decode_bit( bm_match[state()][pos_state] ) == 0 )	// 1st bit
       {
-      const uint8_t prev_byte = get_byte( 0 );
+      const uint8_t prev_byte = peek( 0 );
       const int literal_state = prev_byte >> ( 8 - literal_context_bits );
       Bit_model * const bm = bm_literal[literal_state];
       if( state.is_char() )
         put_byte( rdec.decode_tree( bm, 8 ) );
       else
-        put_byte( rdec.decode_matched( bm, get_byte( rep0 ) ) );
+        put_byte( rdec.decode_matched( bm, peek( rep0 ) ) );
       state.set_char();
       }
-    else
+    else					// match or repeated match
       {
       int len;
       if( rdec.decode_bit( bm_rep[state()] ) != 0 )		// 2nd bit
@@ -348,12 +348,12 @@ bool LZ_decoder::decode_member()		// Returns false if error
         else
           {
           if( rdec.decode_bit( bm_len[state()][pos_state] ) == 0 ) // 4th bit
-            { state.set_short_rep(); put_byte( get_byte( rep0 ) ); continue; }
+            { state.set_short_rep(); put_byte( peek( rep0 ) ); continue; }
           }
         state.set_rep();
         len = min_match_len + rdec.decode_len( rep_len_model, pos_state );
         }
-      else
+      else					// match
         {
         rep3 = rep2; rep2 = rep1; rep1 = rep0;
         len = min_match_len + rdec.decode_len( match_len_model, pos_state );
@@ -372,7 +372,7 @@ bool LZ_decoder::decode_member()		// Returns false if error
             {
             rep0 += rdec.decode( direct_bits - dis_align_bits ) << dis_align_bits;
             rep0 += rdec.decode_tree_reversed( bm_align, dis_align_bits );
-            if( rep0 == 0xFFFFFFFFU )		// Marker found
+            if( rep0 == 0xFFFFFFFFU )		// marker found
               {
               flush_data();
               return ( len == min_match_len );	// End Of Stream marker
@@ -383,7 +383,7 @@ bool LZ_decoder::decode_member()		// Returns false if error
         if( rep0 >= dictionary_size || rep0 >= data_position() )
           { flush_data(); return false; }
         }
-      for( int i = 0; i < len; ++i ) put_byte( get_byte( rep0 ) );
+      for( int i = 0; i < len; ++i ) put_byte( peek( rep0 ) );
       }
     }
   flush_data();
@@ -395,14 +395,14 @@ int main( const int argc, const char * const argv[] )
   {
   if( argc > 1 )
     {
-    std::printf( "Lzd %s - Educational decompressor for lzip files.\n",
+    std::printf( "Lzd %s - Educational decompressor for the lzip format.\n",
                  PROGVERSION );
     std::printf( "Study the source to learn how a lzip decompressor works.\n"
                  "See the lzip manual for an explanation of the code.\n"
                  "It is not safe to use lzd for any real work.\n"
                  "\nUsage: %s < file.lz > file\n", argv[0] );
     std::printf( "Lzd decompresses from standard input to standard output.\n"
-                 "\nCopyright (C) 2014 Antonio Diaz Diaz.\n"
+                 "\nCopyright (C) 2015 Antonio Diaz Diaz.\n"
                  "This is free software: you are free to change and redistribute it.\n"
                  "There is NO WARRANTY, to the extent permitted by law.\n"
                  "Report bugs to lzip-bug@nongnu.org\n"
@@ -419,28 +419,22 @@ int main( const int argc, const char * const argv[] )
     {
     File_header header;
     for( int i = 0; i < 6; ++i ) header[i] = std::getc( stdin );
-    if( std::feof( stdin ) || std::memcmp( header, "LZIP", 4 ) != 0 )
+    if( std::feof( stdin ) || std::memcmp( header, "LZIP\x01", 5 ) != 0 )
       {
       if( first_member )
-        { std::fprintf( stderr, "Bad magic number (file not in lzip format)\n" );
+        { std::fputs( "Bad magic number (file not in lzip format).\n", stderr );
           return 2; }
       break;
       }
-    if( header[4] != 1 )
-      {
-      std::fprintf( stderr, "Version %d member format not supported.\n",
-                    header[4] );
-      return 2;
-      }
     unsigned dict_size = 1 << ( header[5] & 0x1F );
     dict_size -= ( dict_size / 16 ) * ( ( header[5] >> 5 ) & 7 );
     if( dict_size < min_dictionary_size || dict_size > max_dictionary_size )
-      { std::fprintf( stderr, "Invalid dictionary size in member header\n" );
+      { std::fputs( "Invalid dictionary size in member header.\n", stderr );
         return 2; }
 
     LZ_decoder decoder( dict_size );
     if( !decoder.decode_member() )
-      { std::fprintf( stderr, "Data error\n" ); return 2; }
+      { std::fputs( "Data error\n", stderr ); return 2; }
 
     File_trailer trailer;
     for( int i = 0; i < 20; ++i ) trailer[i] = std::getc( stdin );
@@ -449,11 +443,11 @@ int main( const int argc, const char * const argv[] )
     unsigned long long data_size = 0;
     for( int i = 11; i >= 4; --i ) { data_size <<= 8; data_size += trailer[i]; }
     if( crc != decoder.crc() || data_size != decoder.data_position() )
-      { std::fprintf( stderr, "CRC error\n" ); return 2; }
+      { std::fputs( "CRC error\n", stderr ); return 2; }
     }
 
   if( std::fclose( stdout ) != 0 )
-    { std::fprintf( stderr, "Can't close stdout: %s.\n", std::strerror( errno ) );
+    { std::fprintf( stderr, "Can't close stdout: %s\n", std::strerror( errno ) );
       return 1; }
   return 0;
   }