csse2310-a4/dbclient.c

#include "dbclient.h"

char *construct_header(char *key, char *value) {
    char *header = NULL;

    // If there is no value, make a get request, otherwise make a put request
    // with that value
    if (!value) {
        size_t needed_size = snprintf(NULL, 0, GET_REQUEST, key);
        header = (char *)malloc(needed_size + sizeof(char));
        sprintf(header, GET_REQUEST, key);
    } else {
        size_t body_size = strlen(value) * sizeof(char);
        size_t needed_size =
                snprintf(NULL, 0, PUT_REQUEST, key, body_size, value);
        header = (char *)malloc(needed_size + sizeof(char));
        sprintf(header, PUT_REQUEST, key, body_size, value);
    }

    return header;
}

int handle_connect(char *port, int *fd) {
    struct addrinfo *ai = NULL;
    struct addrinfo hints;
    memset(&hints, 0, sizeof(struct addrinfo));

    // Set hints
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_STREAM;

    // Get address information
    int err;
    if ((err = getaddrinfo("localhost", port, &hints, &ai))) {
        freeaddrinfo(ai);
        fprintf(stderr, "%s\n", gai_strerror(err));
        return EXIT_ERR;
    }

    // Connect to port
    *fd = socket(AF_INET, SOCK_STREAM, 0);
    // clang-format off
    if (connect(*fd, (struct sockaddr *)ai->ai_addr,
            sizeof(struct sockaddr))) {
        // clang-format on
        freeaddrinfo(ai);
        close(*fd);

        fprintf(stderr, "dbclient: unable to connect to port %s\n", port);
        return EXIT_PORT_ERR;
    }
    freeaddrinfo(ai);

    return EXIT_OK;
}

int handle_response(FILE *recv, int valueSet) {
    HttpHeader **responseHeaders = NULL;
    memset(&responseHeaders, 0, sizeof(HttpHeader *));

    int status;
    char *statusExplain = NULL;
    char *body = NULL;
    get_HTTP_response(recv, &status, &statusExplain, &responseHeaders, &body);

    // Print the value only if GET and got status 200
    if (!valueSet && status == 200) {
        printf("%s\n", body);
    }

    free_array_of_headers(responseHeaders);
    free(statusExplain);
    free(body);

    if (status != 200 && valueSet) {
        return EXIT_PUT_ERR;
    } else if (status != 200) {
        return EXIT_GET_ERR;
    }

    return EXIT_OK;
}

int handle_connection(char *port, char *key, char *value) {
    int connectStatus = 0;
    int sendFd;
    if ((connectStatus = handle_connect(port, &sendFd))) {
        close(sendFd);
        return connectStatus;
    }

    // Setup fd's for sending and receiving requests
    int recvFd = dup(sendFd);
    FILE *send = fdopen(sendFd, "w");
    FILE *recv = fdopen(recvFd, "r");

    // Send Request
    char *header = construct_header(key, value);
    fprintf(send, "%s", header);
    fflush(send);
    fclose(send);
    free(header);
    close(sendFd);

    // Get Response
    int valueSet = (value != NULL);
    int exitCode = handle_response(recv, valueSet);
    fclose(recv);
    close(recvFd);

    return exitCode;
}

int is_valid_key(char *key) {
    for (int i = 0; i < strlen(key); i++) {
        if (isspace(key[i])) {
            return 0;
        }
    }

    return 1;
}

int main(int argc, char *argv[]) {
    if (argc < 3) {
        fprintf(stderr, "Usage: dbclient portnum key [value]\n");
        return EXIT_ERR;
    }

    char *portnumArgument = strdup(argv[1]);
    char *keyArgument = strdup(argv[2]);
    char *valueArgument = NULL;

    if (argc > 3) {
        valueArgument = strdup(argv[3]);
    }

    if (!is_valid_key(keyArgument)) {
        fprintf(stderr, "dbclient: key must not contain spaces or newlines\n");
        return EXIT_ERR;
    }

    int exitStatus =
            handle_connection(portnumArgument, keyArgument, valueArgument);

    free(portnumArgument);
    free(keyArgument);
    free(valueArgument);

    return exitStatus;
}