diff options
Diffstat (limited to 'lzip.h')
| -rw-r--r-- | lzip.h | 104 |
1 files changed, 43 insertions, 61 deletions
@@ -1,5 +1,5 @@ /* Lzip - Data compressor based on the LZMA algorithm - Copyright (C) 2008, 2009, 2010, 2011, 2012 Antonio Diaz Diaz. + Copyright (C) 2008, 2009, 2010, 2011, 2012, 2013 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 @@ -17,41 +17,23 @@ class State { - unsigned char st; + int st; public: enum { states = 12 }; State() : st( 0 ) {} - unsigned char operator()() const { return st; } + int operator()() const { return st; } bool is_char() const { return st < 7; } void set_char() { - static const unsigned char next[states] = - { 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5 }; + static const int next[states] = { 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 4, 5 }; st = next[st]; } - void set_match() - { - static const unsigned char next[states] = - { 7, 7, 7, 7, 7, 7, 7, 10, 10, 10, 10, 10 }; - st = next[st]; - } - - void set_rep() - { - static const unsigned char next[states] = - { 8, 8, 8, 8, 8, 8, 8, 11, 11, 11, 11, 11 }; - st = next[st]; - } - - void set_short_rep() - { - static const unsigned char next[states] = - { 9, 9, 9, 9, 9, 9, 9, 11, 11, 11, 11, 11 }; - st = next[st]; - } + void set_match() { st = ( ( st < 7 ) ? 7 : 10 ); } + void set_rep() { st = ( ( st < 7 ) ? 8 : 11 ); } + void set_short_rep() { st = ( ( st < 7 ) ? 9 : 11 ); } }; @@ -68,7 +50,7 @@ enum { dis_slot_bits = 6, start_dis_model = 4, end_dis_model = 14, - modeled_distances = 1 << (end_dis_model / 2), + modeled_distances = 1 << (end_dis_model / 2), // 128 dis_align_bits = 4, dis_align_size = 1 << dis_align_bits, @@ -86,12 +68,11 @@ enum { max_dis_states = 4 }; -inline int get_dis_state( int len ) - { - len -= min_match_len; - if( len >= max_dis_states ) len = max_dis_states - 1; - return len; - } +inline int get_dis_state( const int len ) + { return std::min( len - min_match_len, max_dis_states - 1 ); } + +inline int get_lit_state( const uint8_t prev_byte ) + { return ( prev_byte >> ( 8 - literal_context_bits ) ); } enum { bit_model_move_bits = 5, @@ -100,17 +81,17 @@ enum { bit_model_move_bits = 5, struct Bit_model { - unsigned int probability; + int probability; Bit_model() : probability( bit_model_total / 2 ) {} }; class Pretty_print { + std::string name_; const char * const stdin_name; - unsigned int longest_name; + unsigned longest_name; const int verbosity_; - std::string name_; mutable bool first_post; public: @@ -118,11 +99,11 @@ public: : stdin_name( "(stdin)" ), longest_name( 0 ), verbosity_( v ), first_post( false ) { - const unsigned int stdin_name_len = std::strlen( stdin_name ); - for( unsigned int i = 0; i < filenames.size(); ++i ) + const unsigned stdin_name_len = std::strlen( stdin_name ); + for( unsigned i = 0; i < filenames.size(); ++i ) { const std::string & s = filenames[i]; - const unsigned int len = ( ( s == "-" ) ? stdin_name_len : s.size() ); + const unsigned len = ( ( s == "-" ) ? stdin_name_len : s.size() ); if( len > longest_name ) longest_name = len; } if( longest_name == 0 ) longest_name = stdin_name_len; @@ -149,9 +130,9 @@ class CRC32 public: CRC32() { - for( unsigned int n = 0; n < 256; ++n ) + for( unsigned n = 0; n < 256; ++n ) { - unsigned int c = n; + unsigned c = n; for( int k = 0; k < 8; ++k ) { if( c & 1 ) c = 0xEDB88320U ^ ( c >> 1 ); else c >>= 1; } data[n] = c; @@ -159,8 +140,10 @@ public: } uint32_t operator[]( const uint8_t byte ) const { return data[byte]; } + void update( uint32_t & crc, const uint8_t byte ) const { crc = data[(crc^byte)&0xFF] ^ ( crc >> 8 ); } + void update( uint32_t & crc, const uint8_t * const buffer, const int size ) const { for( int i = 0; i < size; ++i ) @@ -171,16 +154,15 @@ public: extern const CRC32 crc32; -inline int real_bits( const unsigned int value ) +inline int real_bits( unsigned value ) { - int bits = 0, i = 1; - unsigned int mask = 1; - for( ; mask > 0; ++i, mask <<= 1 ) if( value & mask ) bits = i; + int bits = 0; + while( value > 0 ) { value >>= 1; ++bits; } return bits; } -const uint8_t magic_string[4] = { 'L', 'Z', 'I', 'P' }; +const uint8_t magic_string[4] = { 0x4C, 0x5A, 0x49, 0x50 }; // "LZIP" struct File_header { @@ -196,10 +178,10 @@ struct File_header uint8_t version() const { return data[4]; } bool verify_version() const { return ( data[4] <= 1 ); } - int dictionary_size() const + unsigned dictionary_size() const { - int sz = ( 1 << ( data[5] & 0x1F ) ); - if( sz > min_dictionary_size && sz <= max_dictionary_size ) + unsigned sz = ( 1 << ( data[5] & 0x1F ) ); + if( sz > min_dictionary_size ) sz -= ( sz / 16 ) * ( ( data[5] >> 5 ) & 7 ); return sz; } @@ -233,36 +215,36 @@ struct File_trailer static int size( const int version = 1 ) { return ( ( version >= 1 ) ? 20 : 12 ); } - uint32_t data_crc() const + unsigned data_crc() const { - uint32_t tmp = 0; + unsigned tmp = 0; for( int i = 3; i >= 0; --i ) { tmp <<= 8; tmp += data[i]; } return tmp; } - void data_crc( uint32_t crc ) + void data_crc( unsigned crc ) { for( int i = 0; i <= 3; ++i ) { data[i] = (uint8_t)crc; crc >>= 8; } } - long long data_size() const + unsigned long long data_size() const { - long long tmp = 0; + unsigned long long tmp = 0; for( int i = 11; i >= 4; --i ) { tmp <<= 8; tmp += data[i]; } return tmp; } - void data_size( long long sz ) + void data_size( unsigned long long sz ) { for( int i = 4; i <= 11; ++i ) { data[i] = (uint8_t)sz; sz >>= 8; } } - long long member_size() const + unsigned long long member_size() const { - long long tmp = 0; + unsigned long long tmp = 0; for( int i = 19; i >= 12; --i ) { tmp <<= 8; tmp += data[i]; } return tmp; } - void member_size( long long sz ) + void member_size( unsigned long long sz ) { for( int i = 12; i <= 19; ++i ) { data[i] = (uint8_t)sz; sz >>= 8; } } @@ -276,11 +258,11 @@ struct Error }; +// defined in decoder.cc +int readblock( const int fd, uint8_t * const buf, const int size ); +int writeblock( const int fd, const uint8_t * const buf, const int size ); + // defined in main.cc void show_error( const char * const msg, const int errcode = 0, const bool help = false ); void internal_error( const char * const msg ); - -// defined in decoder.cc -int readblock( const int fd, uint8_t * const buf, const int size ); -int writeblock( const int fd, const uint8_t * const buf, const int size ); |