diff --git a/alib2algo/src/stringology/compression/ArithmeticCompression.h b/alib2algo/src/stringology/compression/ArithmeticCompression.h
index 41e277631f1a984bff68da32241fba7bed4bf7c5..04c98a80623482b673d16d558d1a4d6abb1093ca 100644
--- a/alib2algo/src/stringology/compression/ArithmeticCompression.h
+++ b/alib2algo/src/stringology/compression/ArithmeticCompression.h
@@ -8,7 +8,8 @@
#include "ArithmeticModel.h"
#include <alib/vector>
-#include <alib/string>
+
+#include <string/LinearString.h>
namespace stringology {
@@ -23,39 +24,37 @@ class AdaptiveIntegerArithmeticCompression {
}
}
public:
-
- static ext::vector < bool > compress ( ext::string & source ) {
- ext::set < char > alphabet;
- for ( int i = 0; i < 256; ++ i )
- alphabet.insert ( i );
- ArithmeticModel < char > model ( alphabet );
+ template < class SymbolType >
+ static ext::vector < bool > compress ( const string::LinearString < SymbolType > & source ) {
+ ArithmeticModel < SymbolType > model ( source.getAlphabet ( ) );
ext::vector < bool > result;
unsigned pending_bits = 0;
+ unsigned valid_bits = sizeof ( unsigned long long ) * 8 / 2;
- unsigned max_code = ~0u;
- unsigned one_half = ( max_code >> 1 ) + 1;
- unsigned one_fourth = ( max_code >> 2 ) + 1;
- unsigned three_fourths = one_half + one_fourth;
+ unsigned long long max_code = ~0ull >> valid_bits;
+ unsigned long long one_half = ( max_code >> 1 ) + 1;
+ unsigned long long one_fourth = ( max_code >> 2 ) + 1;
+ unsigned long long three_fourths = one_half + one_fourth;
- unsigned low = 0;
- unsigned high = max_code;
+ unsigned long long low = 0;
+ unsigned long long high = max_code;
- for ( size_t index = 0; index < source.size ( ) + 1; ++ index ) {
+ for ( size_t index = 0; index < source.getContent ( ).size ( ) + 1; ++ index ) {
unsigned prob_low, prob_high;
unsigned prob_count = model.getCount ( );
- if ( index >= source.size ( ) )
- std::tie ( prob_low, prob_high ) = model.getProbabilityEof ( );
+ if ( index >= source.getContent ( ).size ( ) )
+ model.getProbabilityEof ( prob_low, prob_high );
else {
- std::tie ( prob_low, prob_high ) = model.getProbability ( source [ index ] );
- model.update ( source [ index ] );
+ model.getProbability ( source.getContent ( ) [ index ], prob_low, prob_high );
+ model.update ( source.getContent ( ) [ index ] );
}
- unsigned long long range = ( unsigned long long ) ( high - low ) + 1;
- high = low + ( unsigned ) ( range * prob_high / prob_count - 1 );
- low = low + ( unsigned ) ( range * prob_low / prob_count );
+ unsigned long long range = high - low + 1;
+ high = low + range * prob_high / prob_count - 1;
+ low = low + range * prob_low / prob_count;
for ( ; ; ) {
if ( high < one_half || low >= one_half )
put_bit_plus_pending(result, low >= one_half, pending_bits);
@@ -68,6 +67,9 @@ public:
high <<= 1;
high++;
low <<= 1;
+
+ low &= max_code;
+ high &= max_code;
}
}
pending_bits++;
diff --git a/alib2algo/src/stringology/compression/ArithmeticDecompression.h b/alib2algo/src/stringology/compression/ArithmeticDecompression.h
index 9a63d3cf30a9d424b66624c2b8152ddeabd632b4..27d90ae62aa7bd773d93808814c1974ac532b93c 100644
--- a/alib2algo/src/stringology/compression/ArithmeticDecompression.h
+++ b/alib2algo/src/stringology/compression/ArithmeticDecompression.h
@@ -7,19 +7,18 @@
#include "ArithmeticModel.h"
+#include <string/LinearString.h>
+
namespace stringology {
namespace compression {
class AdaptiveIntegerArithmeticDecompression {
public:
- static ext::string decompress ( ext::vector < bool > &source ) {
- ext::set < char > alphabet;
- for ( int i = 0; i < 256; ++ i )
- alphabet.insert ( i );
- ArithmeticModel < char > model ( alphabet );
-
- ext::string result;
+ template < class SymbolType >
+ static string::LinearString < SymbolType > decompress ( const ext::vector < bool > & source, const ext::set < SymbolType > & alphabet ) {
+ ArithmeticModel < SymbolType > model ( alphabet );
+ ext::vector < SymbolType > result;
unsigned valid_bits = sizeof ( unsigned long long ) * 8 / 2;
@@ -59,17 +58,17 @@ public:
if ( model.isEof ( scaled_value ) )
break;
- char c;
unsigned prob_low, prob_high;
unsigned prob_count = model.getCount ( );
- std::tie ( prob_low, prob_high, c ) = model.getChar ( scaled_value );
+ SymbolType c = model.getChar ( scaled_value, prob_low, prob_high );
model.update ( c );
- result += c;
- high = low + ( range * prob_high ) / prob_count - 1;
- low = low + ( range * prob_low ) / prob_count;
+ result.push_back ( c );
+ high = low + range * prob_high / prob_count - 1;
+ low = low + range * prob_low / prob_count;
}
- return result;
+
+ return string::LinearString < SymbolType > ( alphabet, result );
}
};
diff --git a/alib2algo/src/stringology/compression/ArithmeticModel.h b/alib2algo/src/stringology/compression/ArithmeticModel.h
index 9586b74f8a120096bb51e84f816df701661b3615..298263fc451a825e4085967ce88c03bc3b412ff1 100644
--- a/alib2algo/src/stringology/compression/ArithmeticModel.h
+++ b/alib2algo/src/stringology/compression/ArithmeticModel.h
@@ -3,7 +3,6 @@
#include <stdexcept>
#include <alib/map>
-#include <alib/variant>
#include <alib/set>
template < class SymbolType >
@@ -19,35 +18,36 @@ public:
m_global_high = frequency + 1;
}
- void update ( const ext::variant < void, SymbolType > & symbol ) {
+ void update ( const SymbolType & symbol ) {
for ( auto i = m_high_cumulative_frequency.find ( symbol ); i != m_high_cumulative_frequency.end ( ) ; ++ i )
i->second += 1;
m_global_high += 1;
}
- std::tuple < unsigned, unsigned > getProbability ( const SymbolType & c ) const {
+ void getProbability ( const SymbolType & c, unsigned & low_prob, unsigned & high_prob ) const {
auto i = m_high_cumulative_frequency.find ( c );
- unsigned low_prob = 0;
+ high_prob = i->second;
+ low_prob = 0;
if ( i != m_high_cumulative_frequency.begin ( ) )
low_prob = std::prev ( i )->second;
-
- return std::make_tuple ( low_prob, i->second );
}
- std::tuple < unsigned, unsigned > getProbabilityEof ( ) const {
- return std::make_tuple ( m_global_high - 1, m_global_high );
+ void getProbabilityEof ( unsigned & low_prob, unsigned & high_prob ) const {
+ low_prob = m_global_high - 1;
+ high_prob = m_global_high;
}
- std::tuple < unsigned, unsigned, SymbolType > getChar ( unsigned scaled_value ) const {
+ SymbolType getChar ( unsigned scaled_value, unsigned & low_prob, unsigned & high_prob ) const {
for ( auto i = m_high_cumulative_frequency.begin ( ); i != m_high_cumulative_frequency.end ( ); ++ i )
if ( scaled_value < i->second ) {
- unsigned low_prob = 0;
+ high_prob = i->second;
+ low_prob = 0;
if ( i != m_high_cumulative_frequency.begin ( ) )
low_prob = std::prev ( i )->second;
- return std::make_tuple ( low_prob, i->second, i->first );
+ return i->first;
}
throw std::logic_error("error");
}
diff --git a/alib2algo/test-src/stringology/compression/ArithmeticCompressionTest.cpp b/alib2algo/test-src/stringology/compression/ArithmeticCompressionTest.cpp
index 869eb81332519238b62905adb8e8f80746891897..f90e719a4068fabfb92a9f72439b56dacd560570 100644
--- a/alib2algo/test-src/stringology/compression/ArithmeticCompressionTest.cpp
+++ b/alib2algo/test-src/stringology/compression/ArithmeticCompressionTest.cpp
@@ -13,12 +13,15 @@ void ArithmeticCompressionTest::tearDown() {
}
void ArithmeticCompressionTest::basics() {
- ext::string input ( "abbabbabaae2378 8723 babababb ab bapobababbbabaaabbafjfjdjlvldsuiueqwpomvdhgataewpvdihviasubababbba 5475 baaabba" );
+ ext::string rawInput ( "abbabbabaae123456789r0 8723 babababb ab bapobababbbabaaabbafjfjdjlvldsuiueqwpomvdhgataewpvdihviasubababbba 5475 baaabba" );
+ string::LinearString < char > input ( rawInput );
+
ext::vector < bool > compressed = stringology::compression::AdaptiveIntegerArithmeticCompression::compress ( input );
std::cout << "compressed = " << compressed << std::endl;
- ext::string output = stringology::compression::AdaptiveIntegerArithmeticDecompression::decompress ( compressed );
+ string::LinearString < char > output = stringology::compression::AdaptiveIntegerArithmeticDecompression::decompress ( compressed, input.getAlphabet ( ) );
- std::cout << "original= " << input << " decompressed = " << output << std::endl;
+ std::cout << "original= " << input << std::endl << "decompressed = " << output << std::endl;
+ std::cout << "compressed size = " << compressed.size ( ) << std::endl << "original_size = " << input.getContent ( ).size ( ) * 8 << std::endl;
CPPUNIT_ASSERT ( input == output );
}