UDPspeeder/lib/rs.cpp

/*
 * rs.c
 *
 *  Created on: Sep 14, 2017
 *      Author: root
 */
#include "rs.h"
#include "stdlib.h"
#include "string.h"

void rs_encode(void *code, char *data[], int size) {
    int k = get_k(code);
    int n = get_n(code);
    for (int i = k; i < n; i++) {
        fec_encode(code, (void **)data, data[i], i, size);
    }

    return;
}

int rs_decode(void *code, char *data[], int size) {
    int k = get_k(code);
    int n = get_n(code);
    int index[n];
    int count = 0;
    for (int i = 0; i < n; i++) {
        if (data[i] != 0) {
            index[count++] = i;
        }
    }
    if (count < k)
        return -1;
    for (int i = 0; i < n; i++) {
        if (i < count)
            data[i] = data[index[i]];
        else
            data[i] = 0;
    }
    return fec_decode(code, (void **)data, index, size);
}

static void *(*table)[256] = 0;
void *get_code(int k, int n) {
    if (table == 0) {
        table = (void *(*)[256])malloc(sizeof(void *) * 256 * 256);
        if (!table) {
            return table;
        }
        memset(table, 0, sizeof(void *) * 256 * 256);
    }
    if (table[k][n] == 0) {
        table[k][n] = fec_new(k, n);
    }
    return table[k][n];
}
void rs_encode2(int k, int n, char *data[], int size) {
    void *code = get_code(k, n);
    rs_encode(code, data, size);
}

int rs_decode2(int k, int n, char *data[], int size) {
    void *code = get_code(k, n);
    return rs_decode(code, data, size);
}