loadredis.cpp

loadredis.cpp

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <ctime>
#include <random>
#include <hiredis/hiredis.h>

int main() {
    const std::time_t now = std::time(NULL);
    const std::time_t yest = now - 86400;

    std::string line;
    std::ifstream fh ("/etc/dictionaries-common/words");
    std::vector<std::string> words;

    // read the dict into a vector
    ulong c = 0;
    if (fh.is_open()) {
        while (fh.good()) {
            getline(fh,line);
            if (line.length() > 0) {
                words.push_back(line);
                c++;
            }
        }
        fh.close();
    }
    c--; // we will treat this as zero offset

    // the pseudo-random number generator
    std::mt19937 prng;
    // seed it with the current utc time, a suitable uint32_t
    prng.seed(now);
    // over the range of 0..count of words in the dict file, c
    std::uniform_int_distribution<uint32_t> pr_word_index(0,c);

    // connect to redis
    redisContext *conn;
    redisReply *reply;
    const struct timeval timeout = { 1, 500000 }; // 1.5 seconds
    conn = redisConnectWithTimeout((char*)"127.0.0.1", 6379, timeout);
    if (conn->err) {
        std::cerr << "connection error " << conn->errstr << std::endl;
        exit(1);
    }
    reply = (redisReply *) redisCommand(conn,"FLUSHALL");
    freeReplyObject(reply);
    
    // for each second, get a random word, then insert it into redis
    for (auto i=yest;i<=now;i++) {
        // random word index
        const uint32_t r = pr_word_index(prng);
        const std::string rw = words.at(r);
        const std::string is = std::to_string(i);
        reply = (redisReply *) redisCommand(conn,"SET %s %s",is.c_str(),rw.c_str());
        if (reply->type != REDIS_REPLY_STATUS) {
            std::cerr << "set err " << reply->str << std::endl;
            exit(1);
        }
        freeReplyObject(reply);
    }

    return 0;
}