data_transmitter.c

#include <stdio.h>
#include <netdb.h>
#include <unistd.h>
#include <string.h>
#include <src/defines.h>
#include <src/prrt/socket.h>
#include <src/prrt/block.h>
#include <src/util/dbg.h>
#include <src/util/common.h>
#include "data_transmitter.h"


int send_packet(PrrtSocket *sock_ptr, PrrtPacket *packet) {
    uint8_t buf[MAX_PAYLOAD_LENGTH];
    memset(buf, 0, sizeof(buf));
    uint32_t length = PrrtPacket_size(packet);

    int encodeResult = PrrtPacket_encode(buf, MAX_PAYLOAD_LENGTH, packet);
    check(encodeResult >= 0, "Buffer too small.");

    // SENDING TO ALL RECEIVERS
    LIST_FOREACH(sock_ptr->receivers, first, next, cur) {
        PrrtReceiver* recv = cur->value;
        struct hostent *hp;

        struct sockaddr_in targetaddr;
        memset((char *) &targetaddr, 0, sizeof(targetaddr));
        targetaddr.sin_family = AF_INET;
        targetaddr.sin_port = htons(recv->port);

        hp = gethostbyname(recv->host_name);
        memcpy((void *) &targetaddr.sin_addr, hp->h_addr_list[0], (size_t) hp->h_length);

        ssize_t sendtoRes = sendto(sock_ptr->dataSocketFd, buf, length, 0, (struct sockaddr *) &targetaddr, sizeof(targetaddr));
        check(sendtoRes >= 0, "Sendto failed.")
    }

    PrrtPacket_destroy(packet);

    return EXIT_SUCCESS;

    error:
        PERROR("Something is wrong%s.", "")
        return EXIT_FAILURE;
}

void * send_data_loop(void *ptr) {
    PrrtSocket *sock_ptr = ptr;

    PrrtBlock *block = NULL;
    PrrtCodingParams *cpar = calloc(1, sizeof(PrrtCodingParams));
    PrrtCodingParams_init(cpar);

    while (1) {
        pthread_mutex_lock(&sock_ptr->outQueueFilledMutex);
        while (List_count(sock_ptr->outQueue) == 0) {
            pthread_mutex_lock(&sock_ptr->closingMutex);
            if(sock_ptr->closing) {
                free(cpar);
                if(block != NULL) {
                    PrrtBlock_destroy(block);
                }
                block = NULL;

                pthread_mutex_unlock(&sock_ptr->closingMutex);
                pthread_mutex_unlock(&sock_ptr->outQueueFilledMutex);
                return NULL;
            }
            pthread_mutex_unlock(&sock_ptr->closingMutex);
            pthread_cond_wait(&sock_ptr->outQueueFilledCv, &sock_ptr->outQueueFilledMutex);
        }

        if(block == NULL) {
            block = calloc(1, sizeof(PrrtBlock));
            check_mem(block);

            PrrtBlock_create(block, cpar, sock_ptr->sequenceNumberRedundancy);
        }

        PrrtPacket *packet = List_shift(sock_ptr->outQueue);

        PrrtBlock_insert_data_packet(block, packet);

        if (PrrtBlock_encode_ready(block)) {
            int j = 0;
            PrrtBlock_encode(block, &sock_ptr->sequenceNumberRedundancy);

            uint32_t redundancyBlocks = List_count(block->redundancyPackets);
            for (j = 0; j < redundancyBlocks; j++) {
                PrrtPacket *red_pkt = PrrtBlock_get_first_red_data(block);
                send_packet(sock_ptr, red_pkt);
            }

            uint32_t dataBlocks = List_count(block->dataPackets);
            for (j = 0; j < dataBlocks; j++) {
                PrrtPacket *data_pkt = PrrtBlock_get_first_data(block);
                send_packet(sock_ptr, data_pkt);
            }

            PrrtBlock_destroy(block);
            block = NULL;
        }

        pthread_mutex_unlock(&sock_ptr->outQueueFilledMutex);
        usleep(1);
    }

    error:
        PERROR("Failed to send packet %s", "");
        return NULL;
}