libevent http example

http.c

/*************************************************************************
    > File Name: http.c
    > Author: jige003
    > Created Time: Thu 16 May 2019 01:13:57 PM CST
 ************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <event.h>
#include <evhttp.h>
#include <signal.h>
#include <getopt.h>
#include <string.h>
#include <jansson.h>
#include <sys/types.h>

#define DEFAULT_ADDR "127.0.0.1"
#define DEFAULT_PORT 8000
#define Server "jige003"
#define BUFSIZE 1024

void xfree(void*ptr);
void default_handler(struct evhttp_request *req, void *arg);
void json_handler(struct evhttp_request *req, void *arg);
void send_json_resp(struct evhttp_request *req, json_t *req_json, struct event_base* base);

void xfree(void *ptr){
    if (ptr != ((void*)0)) free(ptr);
}

void default_handler(struct evhttp_request *req, void *arg){
    const char *uri;
    uri = evhttp_request_uri(req);
    evhttp_add_header(req->output_headers, "Server", Server);
    evhttp_add_header(req->output_headers, "Content-Type", "text/plain; charset=UTF-8");
    //evhttp_add_header(req->output_headers, "Connection", "close");
    struct evbuffer *buf;
    buf = evbuffer_new();
    evbuffer_add_printf(buf, "404 Not Found\n");
    evbuffer_add_printf(buf, "Yrequest uri is %s\n", uri);
    evhttp_send_reply(req, HTTP_NOTFOUND, "Not Found", buf);
    evbuffer_free(buf);
}

void json_handler(struct evhttp_request *req, void *arg){
    struct evbuffer *req_buf;
    int  req_len;
    char *tmp_req_buf;

    char error_text[BUFSIZE];

    struct event_base *base = (struct event_base *)arg;

    req_buf = evhttp_request_get_input_buffer(req);
    req_len = evbuffer_get_length(req_buf);

    tmp_req_buf = (char *)malloc(req_len * sizeof(char));
    memset(tmp_req_buf, 0, req_len);
    evbuffer_copyout(req_buf, tmp_req_buf, req_len);

    json_t *req_json;
    json_error_t error;

    req_json = json_loadb(tmp_req_buf, req_len, 0, &error);
    xfree(tmp_req_buf);

    if (req_json == NULL){
        sprintf(error_text, "Iuput error: line: %d : %s\n", error.line, error.text);
        fprintf(stderr, "%s\n", error_text);
    }else{
        tmp_req_buf = json_dumps(req_json, JSON_INDENT(0));
        fprintf(stderr, "request json:\n %s\n", tmp_req_buf);
        xfree(tmp_req_buf);
        send_json_resp(req, req_json, base);
        json_decref(req_json);

    }
    //evbuffer_free(req_buf);
    return;
}

void send_json_resp(struct evhttp_request *req, json_t *req_json, struct event_base* base){
    json_t *resp_json;
    json_t *_j_uri;
    char * resp_str_buf;


    //resp_json = json_object();
    resp_json = req_json;
    _j_uri = json_string(evhttp_request_uri(req));

    json_object_set_new(resp_json, "uri", _j_uri);
    resp_str_buf = json_dumps(resp_json, JSON_INDENT(0));
    //json_decref(resp_json);

    //evhttp_add_header(req->output_headers, "Proxy-Connection", "keep-alive");
    evhttp_add_header(req->output_headers, "Content-Type", "application/json");
    struct evbuffer *resp_buf;
    resp_buf = evbuffer_new();
    evbuffer_add_printf(resp_buf, "%s\n", resp_str_buf);
    evhttp_send_reply(req, HTTP_OK, "OK", resp_buf);
    xfree(resp_str_buf);
    evbuffer_free(resp_buf);

}

int main(int c, char **v){
    struct options {
        char *addr;
        short port;
    } o;

    memset(&o, 0, sizeof(o));
    o.port = DEFAULT_PORT;

    int opt;
	while ((opt = getopt(c, v, "s:p:")) != -1) {
        switch(opt){
            case 's': o.addr = strdup(optarg); break;
            case 'p': o.port = atoi(optarg); break;
            default :
                  fprintf(stderr, "Unknown option %c\n", opt);
                  goto end;
        }
    }

    if (o.addr == NULL) {
        o.addr = strdup(DEFAULT_ADDR);
    }

    struct event_base *base = event_base_new();
    struct evhttp *http_server = NULL;
    http_server = evhttp_new(base);
    evhttp_bind_socket(http_server, o.addr, o.port);
    fprintf(stderr, "server started, listen %s:%d\n", o.addr, o.port);

    evhttp_set_gencb(http_server, default_handler ,(void *)base);

    evhttp_set_cb(http_server, "/json" ,json_handler, (void *)base);

    event_base_dispatch(base);
    evhttp_free(http_server);
    event_base_free(base);
    fprintf(stderr, "server exit\n");

end:
    xfree(o.addr);
    return (0);
}

Makefile

all:
	gcc -g -o http http.c -levent -ljansson -lpthread

post.lua

--  wrk -t100 -c400 -d5s --script=post.lua --latency http://localhost:8000/json
wrk.method = "POST"
wrk.headers["Content-Type"] = "application/x-www-form-urlencoded"
wrk.body = '{"a": "b", "c": [1,2], "d": {"f": "e"}}'