A/B test 有开源的吗

是的，有许多开源的 A/B 测试工具可供使用。

A/B 测试是一种常用的用户体验设计和优化方法，通常用于比较两种不同的设计或策略的效果。

举个例子，如果你是一家电商公司，你可能希望测试两种不同的网站首页设计，看看哪种设计能够吸引更多的客户并促进更多的购买。为了进行这项测试，你可以使用 A/B 测试工具将流量随机分配到两个不同的首页设计中，然后收集数据并比较它们之间的差异。

有许多开源的 A/B 测试工具可供使用，包括 Google Analytics、Optimizely 和 VWO 等。这些工具通常提供简单的拖放界面，让你可以快速设置和运行 A/B 测试。

相关问题

开源工具iperf代码C/C++

以下是iperf3的C代码，可以在GitHub上找到完整的代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include "iperf.h"
#include "iperf_api.h"
#include "iperf_locale.h"
#include "units.h"
#include "net.h"
#include "timer.h"
#include "tcp_window_size.h"
#include "cjson.h"

#ifdef HAVE_SSL
#include <openssl/ssl.h>
#include <openssl/err.h>
#endif

/* Forwards. */
static int iperf_run(struct iperf_test *test);

/**************************************************************************/

int
main(int argc, char **argv)
{
    int i;
    struct iperf_test *test;
    int result;
    struct sigaction sa;
    char client_version[10] = IPERF_VERSION;

    setlocale(LC_ALL, "");
    bindtextdomain("iperf3", LOCALEDIR);
    textdomain("iperf3");

    /* Initialize settings. */
    test = iperf_new_test();

    /* Register a few signal handlers to make clean exit more likely. */
    memset(&sa, 0, sizeof(sa));
    sa.sa_handler = &iperf_got_sigint;
    sigaction(SIGINT, &sa, NULL);
    sa.sa_handler = &iperf_got_sigpipe;
    sigaction(SIGPIPE, &sa, NULL);

    /* Parse command line options, handling some options immediately. */
    i = iperf_parse_arguments(test, argc, argv);
    if (i < 0) {
        fprintf(stderr, "%s", iperf_strerror(i));
        exit(1);
    }
    if (test->version) {
        printf("%s\n", client_version);
        exit(0);
    } else if (test->help) {
        iperf_printf(test, "\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n",
                "Usage: iperf3 [-options] [-s|-c host] [options]\n",
                "Client/Server:",
                "  -V, --version           show version information and quit.",
                "  -h, --help              show this message and quit.",
                "  -i, --interval n        seconds between periodic bandwidth reports.",
                "  -f, --format [kmKM]     format to report: Kbits, Mbits, KBytes, MBytes",
                "  -P, --parallel n        number of parallel client streams to run.");
        iperf_printf(test, "\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n",
                "Client specific:",
                "  -c, --client    <host>  run in client mode, connecting to <host>.",
                "  -u, --udp               use UDP rather than TCP.",
                "  -b, --bitrate #[KMG][/#] target bitrate in bits/sec (0 for unlimited)",
                "                           (default 1 Mbit/sec for UDP, unlimited for TCP)",
                "  -t, --time    n         time in seconds to transmit for (default 10 secs)",
                "  -n, --bytes   n         number of bytes to transmit (instead of -t)",
                "  -k, --blockcount #[KMG] number of blocks (packets) to transmit (instead of -t or -n)",
                "  -l, --length  #[KMG]    length of buffer to read or write",
                "                           (default 128 KB for TCP, dynamic or 8 KB for UDP)",
                "  -R, --reverse           reverse the direction of a test (client sends, server receives).");
        iperf_printf(test, "\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n",
                "Server specific:",
                "  -s, --server            run in server mode.",
                "  -D, --daemon            run the server as a daemon",
                "  -I, --pidfile file      write PID file (default /var/run/iperf3.pid)",
                "  -1, --one-off           handle one client connection then exit.",
                "  -B, --bind      <host>  bind to a specific interface, e.g. eth0");
        iperf_printf(test, "\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n%s\n\n",
                "JSON options:",
                "  -J, --json              output in JSON format",
                "  --logfile f             send output to a log file",
                "",
                "For more information and tuning options, see iperf3's man page.",
                "",
                "Please report bugs to https://github.com/esnet/iperf",
                "");
        exit(0);
    }

    /* Check for version number consistency. */
    if (test->protocol->id == Ptcp && test->version == 3 && test->tcp.omit_version) {
        i = 2;
    } else {
        i = 3;
    }
    if (strncmp(client_version, test->version_string, i) != 0) {
        iperf_printf(test, "warning: version number mismatch (client %s, server %s)\n",
                client_version, test->version_string);
    }

    /* Initialize IP protocol */
    if (test->cookiefile) {
        test->cookie = iperf_load_cookie(test->cookiefile);
        if (test->cookie == NULL) {
            iperf_errexit(test, "unable to load cookie from file '%s'", test->cookiefile);
        }
    }

    if (test->reverse)
        test->settings->reverse = 1;

    if (test->protocol->id == Pudp) {
        if (test->settings->mss || test->settings->socket_bufsize) {
            iperf_printf(test, "warning: MSS and socket buffer size settings are not used in UDP mode.\n");
        }
        if (test->settings->no_delay) {
            iperf_printf(test, "warning: the TCP_NODELAY option is not used in UDP mode.\n");
        }
        if (test->settings->pmtu != -1) {
            iperf_printf(test, "warning: the PMTU option is not used in UDP mode.\n");
        }
    }

#ifdef HAVE_SSL
    /* Initialize SSL library */
    if (test->protocol->id == Ptcp && test->settings->ssl) {
        SSL_load_error_strings();
        SSL_library_init();
        test->sslctx = SSL_CTX_new(TLS_client_method());
        if (test->sslctx == NULL) {
            iperf_errexit(test, "failed to create SSL context\n");
        }
        if (test->settings->ssl_cafile) {
            if (SSL_CTX_load_verify_locations(test->sslctx, test->settings->ssl_cafile, NULL) != 1) {
                SSL_CTX_free(test->sslctx);
                iperf_errexit(test, "failed to load CA certificates from %s\n", test->settings->ssl_cafile);
            }
        }
        if (test->settings->ssl_cert) {
            if (SSL_CTX_use_certificate_chain_file(test->sslctx, test->settings->ssl_cert) != 1) {
                SSL_CTX_free(test->sslctx);
                iperf_errexit(test, "failed to load SSL certificate from %s\n", test->settings->ssl_cert);
            }
        }
        if (test->settings->ssl_key) {
            if (SSL_CTX_use_PrivateKey_file(test->sslctx, test->settings->ssl_key, SSL_FILETYPE_PEM) != 1) {
                SSL_CTX_free(test->sslctx);
                iperf_errexit(test, "failed to load SSL key from %s\n", test->settings->ssl_key);
            }
        }
        SSL_CTX_set_verify(test->sslctx, SSL_VERIFY_PEER, NULL);
    }
#endif

    /* Daemon mode. */
    if (test->daemon) {
        if (daemon(0, 0) != 0) {
            iperf_errexit(test, "error - failed to become a daemon: %s\n", strerror(errno));
        }
        if (test->pidfile) {
            FILE *f;
            f = fopen(test->pidfile, "w");
            if (f == NULL) {
                iperf_errexit(test, "error - unable to write PID file '%s': %s\n", test->pidfile, strerror(errno));
            }
            fprintf(f, "%d\n", getpid());
            fclose(f);
        }
    }

    /* Ignore SIGPIPE to simplify error handling */
    sa.sa_handler = SIG_IGN;
    sigaction(SIGPIPE, &sa, NULL);

    /* If we are doing a single client (-1) and it is a daemon, don't do -D again */
    if (test->daemon && test->num_ostreams == 1)
        test->daemon = 0;

    /* Defer daemon mode until after the above check for single client + daemon */
    if (test->daemon) {
        if (daemon(0, 0) != 0) {
            iperf_errexit(test, "error - failed to become a daemon: %s\n", strerror(errno));
        }
        if (test->pidfile) {
            FILE *f;
            f = fopen(test->pidfile, "w");
            if (f == NULL) {
                iperf_errexit(test, "error - unable to write PID file '%s': %s\n", test->pidfile, strerror(errno));
            }
            fprintf(f, "%d\n", getpid());
            fclose(f);
        }
    }

    /* Ignore SIGPIPE to simplify error handling */
    sa.sa_handler = SIG_IGN;
    sigaction(SIGPIPE, &sa, NULL);

    /* Set up the output stream */
    if (test->json_output) {
        test->outfile = json_get_output_stream(test->json_output_file);
    } else if (test->logfile) {
        test->outfile = fopen(test->logfile, "w");
        if (test->outfile == NULL) {
            iperf_errexit(test, "error - unable to write log to file '%s': %s\n", test->logfile, strerror(errno));
        }
    } else {
        test->outfile = stdout;
    }

    /* Start the client or server */
    if (test->server) {
        if (test->daemon) {
            iperf_printf(test, "Server listening on port %d\n", test->server_port);
        }
        else {
            iperf_printf(test, "-----------------------------------------------------------\n");
            iperf_printf(test, "Server listening on %s port %d\n", test->settings->domain == AF_INET6 ? "[::]" : "0.0.0.0", test->server_port);
            iperf_printf(test, "-----------------------------------------------------------\n");
        }
        result = iperf_run_server(test);
    } else {
        if (test->daemon) {
            iperf_printf(test, "Client connecting to %s, TCP port %d\n", test->server_hostname, test->server_port);
        }
        else {
            if (test->reverse)
                iperf_printf(test, "-----------------------------------------------------------\n");
            iperf_printf(test, "Client connecting to %s, %s port %d\n", test->server_hostname, test->protocol->name, test->server_port);
            if (test->reverse)
                iperf_printf(test, "-----------------------------------------------------------\n");
        }
        result = iperf_run_client(test);
    }

    if (test->cookie)
        iperf_delete_cookie(test->cookie);

#ifdef HAVE_SSL
    if (test->protocol->id == Ptcp && test->settings->ssl) {
        SSL_CTX_free(test->sslctx);
    }
    ERR_free_strings();
#endif

    iperf_free_test(test);

    return result;
}

static int
iperf_run(struct iperf_test *test)
{
    test->start_time = milliseconds();
    test->next_time = test->start_time;
    test->bytes_sent = 0;
    test->blocks_sent = 0;
    test->retransmits = 0;

    if (test->server_hostname) {
        test->server_hostname_len = strlen(test->server_hostname);
    }

    if (test->bind_address) {
        test->bind_address_len = strlen(test->bind_address);
    }

    if (test->json_output) {
        cJSON *json_output = cJSON_CreateObject();
        if (json_output == NULL) {
            iperf_errexit(test, "error - cJSON_CreateObject failed: %s\n", strerror(errno));
        }
        cJSON_AddItemToObject(json_output, "start", cJSON_CreateNumber((double) test->start_time / 1000));
        if (test->verbose) {
            cJSON_AddItemToObject(json_output, "verbose", cJSON_CreateNumber(1));
        }
        cJSON_AddItemToObject(json_output, "system_info", cJSON_CreateObject());
        iperf_json_printf(json_output, "version", "%s", test->version);
        iperf_json_printf(json_output, "system_info", "%s", get_system_info());
        if (test->title) {
            iperf_json_printf(json_output, "title", "%s", test->title);
        }
        if (test->extra_data) {
            cJSON_AddItemToObject(json_output, "extra_data", cJSON_Parse(test->extra_data));
        }
        test->json_start_time = milliseconds();
        test->json_output_string = cJSON_Print(json_output);
        cJSON_Delete(json_output);
        if (test->json_output_string == NULL) {
            iperf_errexit(test, "error - cJSON_Print failed: %s\n", strerror(errno));
        }
    }

    if (test->protocol->id == Ptcp) {
        if (test->settings->socket_bufsize) {
            if (iperf_set_tcp_windowsize(test) != 0) {
                iperf_errexit(test, "error - %s\n", strerror(errno));
            }
        }
    }

    if (test->reverse) {
        if (test->protocol->id == Ptcp) {
            if (iperf_create_streams(test, test->reverse) < 0) {
                iperf_errexit(test, "error - %s\n", strerror(errno));
            }
        }
        if (iperf_connect(test, test->reverse) < 0) {
            iperf_errexit(test, "error - %s\n", strerror(errno));
        }
    } else {
        if (iperf_create_streams(test, test->reverse) < 0) {
            iperf_errexit(test, "error - %s\n", strerror(errno));
        }
        if (iperf_connect(test, test->reverse) < 0) {
            iperf_errexit(test, "error - %s\n", strerror(errno));
        }
    }

    if (test->json_output) {
        cJSON *json_output = cJSON_CreateObject();
        if (json_output == NULL) {
            iperf_errexit(test, "error - cJSON_CreateObject failed: %s\n", strerror(errno));
        }
        cJSON_AddItemToObject(json_output, "start", cJSON_CreateNumber((double) test->start_time / 1000));
        if (test->verbose) {
            cJSON_AddItemToObject(json_output, "verbose", cJSON_CreateNumber(1));
        }
        iperf_json_printf(json_output, "interval", "%d", test->settings->stats_interval);
        if (test->title) {
            iperf_json_printf(json_output, "title", "%s", test->title);
        }
        if (test->extra_data) {
            cJSON_AddItemToObject(json_output, "extra_data", cJSON_Parse(test->extra_data));
        }
        iperf_json_printf(json_output, "start_connected", "%d", test->connected);
        cJSON_AddItemToObject(json_output, "intervals", cJSON_CreateArray());
        test->json_output_string = cJSON_Print(json_output);
        cJSON_Delete(json_output);
        if (test->json_output_string == NULL) {
            iperf_errexit(test, "error - cJSON_Print failed: %s\n", strerror(errno));
        }
    }

    if (test->protocol->id == Pudp) {
        if (iperf_udp_connect(test) < 0) {
            iperf_errexit(test, "error - %s\n", strerror(errno));
        }
    }

    if (test->reverse) {
        if (test->protocol->id == Ptcp) {
            if (iperf_listen(test) < 0) {
                iperf_errexit(test, "error - %s\n", strerror(errno));
            }
        }
        if (test->protocol->id == Pudp || test->protocol->id == Psctp) {
            if (iperf_run_server_udp(test) < 0) {
                iperf_errexit(test, "error - %s\n", strerror(errno));
            }
        } else {
            if (iperf_run_server_tcp(test) < 0) {
                iperf_errexit(test, "error - %s\n", strerror(errno));
            }
        }
    } else {
        if (test->protocol->id == Ptcp) {
            if (iperf_run_client_tcp(test) < 0) {
                iperf_errexit(test, "error - %s\n", strerror(errno));
            }
        } else {
            if (iperf_run_client_udp(test) < 0) {
                iperf_errexit(test, "error - %s\n", strerror(errno));
            }
        }
    }

    if (test->json_output) {
        cJSON *json_output = cJSON_CreateObject();
        if (json_output == NULL) {
            iperf_errexit(test, "error - cJSON_CreateObject failed: %s\n", strerror(errno));
        }
        cJSON_AddItemToObject(json_output, "start", cJSON_CreateNumber((double) test->start_time / 1000));
        if (test->verbose) {
            cJSON_AddItemToObject(json_output, "verbose", cJSON_CreateNumber(1));
        }
        iperf_json_printf(json_output, "interval", "%d", test->settings->stats_interval);
        if (test->title) {
            iperf_json_printf(json_output, "title", "%s", test->title);
        }
        if (test

test:test base64 转码

以下是两种JavaScript中进行Base64编码和解码的方法：

1. 使用JavaScript原生方法：

var encodedString = btoa('test'); // 编码
var decodedString = atob(encodedString); // 解码
console.log(encodedString); // 输出：dGVzdA==
console.log(decodedString); // 输出：test

2. 使用开源的js-base64库：

import { Base64 } from 'js-base64';
var encodedString = Base64.encode('test'); // 编码
var decodedString = Base64.decode(encodedString); // 解码
console.log(encodedString); // 输出：dGVzdA==
console.log(decodedString); // 输出：test