huffman.c

#include "heap.h"
#include "tree.h"
#include "code.h"

#define BUFFER_SIZE 1000000

int debug_heap = 0;
int debug_huffman_tree = 0;

/****************************************************************************************
 *
 * Main function: parses parameters
 *                open and load input file
 *                create the heap
 *                builds the huffman tree
 *                generate huffman code
 *
 *****************************************************************************************/

int main(int argc, char **argv)
{
        FILE *in_file;
        char buffer[BUFFER_SIZE];
        int input_size = 0;

        int counting_bin[256];
        int i;

        if (argc != 2)
        {
                fprintf(stderr, "Error: usage: %s [file-name]\n", argv[0]);
                return -1;
        }

        // Open the input file for read
        in_file = fopen(argv[1], "rb");

        if (!in_file)
        {
                fprintf(stderr, "Error: invalud input file: %s\n", argv[1]);
                return -1;
        }

        // Read the input and place the input in the buffer
        input_size = fread(buffer, sizeof(char), BUFFER_SIZE, in_file);

        // Close the input file for read
        fclose(in_file);

        // Check for empty file
        if (input_size <= 0)
                return 0;

        // Counting the frequency of each character
        for (i = 0; i < 256; i++)
                counting_bin[i] = 0;

        for (i = 0; i < input_size; i++)
                counting_bin[(int)buffer[i]]++;

        // Initialize and creating the heap
        heapInit();

        for (i = 0; i < 256; i++)
                if (counting_bin[i])
                        HeapInsert(i, NULL, counting_bin[i]);

        // Insert end of file marker
        HeapInsert(0, NULL, 0);

        // Print the heap
        heapPrint();

        // build the buffman tree
        build_huffman_tree();

        // Print the huffman tree
        print_huffman_tree(huffman_tree, 0);

        // initialize and generate code based on the huffman tree
        init_code();
        gen_code(huffman_tree, 0);

        print_code();

        return 0;
}