Huffman Template Library

**Sebastiani** · 09-22-2009

Well, the Huffman contest just sort of floundered, so I've decided to go ahead and release the implementation I've been working on.

So basically, it's just templated version of the algorithm that works on iterators, the only real requirement being that the input data appears as a stream of bytes (the output is treated the same).

I'd love to hear your opinions/criticisms.

Test program:

Code:

       
    
    
#include <iostream>
#include <fstream>
#include <vector>
#include <iterator>
#include <cassert>
#include <ctime>
#include <iomanip>
#include "huffman.hpp"

using namespace 
    std;

typedef xtd::compression::huffman< size_t >
    encoder_t;
encoder_t
    encoder;
    
enum encoding_mode_t
{
    compress, 
    decompress
};    
    
void process( vector< char >& pre_processed, vector< char >& post_processed, encoding_mode_t mode )
{    
    clock_t
        start, 
        stop;
    post_processed.clear( );
    start = clock( );
    if( mode == compress )
        encoder.compress( pre_processed.begin( ), pre_processed.end( ), back_inserter( post_processed ) );
    else
        encoder.decompress( pre_processed.begin( ), pre_processed.end( ), back_inserter( post_processed ) );
    stop = clock( );
    double
        result = double( stop - start ) / CLK_TCK;
    cout << pre_processed.size( ) << " bytes processed in " << result << " seconds" << endl;    
} 
    
int main( int argc, char** argv )
{
    vector< char >
        uncompressed, 
        compressed, 
        decompressed;
    cout << "Huffman Test" << endl;
    if( argc == 1 )
    {
        cout << "Usage: " << *argv << " <FILES>" << endl;
        return 1;
    }
    while( *( ++argv ) )
    {
        char const*
            filename = *argv;
        ifstream
            in( filename, ios::binary );
        if( !in )
        {
            cerr << "Error: cannot process file '" << filename << "'" << endl;
            continue;
        }        
        cout << "File: '" << filename << "'" << endl;
        cout << "...reading file..." << endl;
        uncompressed.clear( );
        char
            ch;
        while( in.read( &ch, 1 ) )
            uncompressed.push_back( ch );
        if( in.bad( ) )
        {
            cerr << "Error: could not read file '" << filename << "'" << endl;
            continue;
        }
        cout << "Uncompressed size: " << uncompressed.size( ) << endl;
        cout << "...compressing..." << endl;
        process( uncompressed, compressed, compress );
        double
            ratio = ( double( compressed.size( ) ) / uncompressed.size( ) ) * 100;
        cout << "Compressed size: " << compressed.size( ) 
            << " (" << setprecision( 2 ) << ratio << "%)" << endl;
        cout << "...decompressing..." << endl;
        process( compressed, decompressed, decompress );
        cout << "...verifying..." << endl;
        bool
            passed = ( uncompressed == decompressed );
        cout << "Result: " << ( passed ? "pass" : "fail" ) << endl;
    }
    return 0;
}