一、构建libevent http服务，支持文件下载
#include <event2/event.h>
#include <event2/listener.h>
#include <event2/http.h>
#include <event2/keyvalq_struct.h>
#include <event2/buffer.h>
#include <string.h>
#ifndef _WIN32
#include <signal.h>
#endif
#include <iostream>
#include <string>
using namespace std;
#define WEBROOT "."
#define DEFAULTINDEX "index.html"
void http_cb(struct evhttp_request *request, void *arg)
{
cout << "http_cb" << endl;
//1 获取请求信息
//uri
const char *uri = evhttp_request_get_uri(request);
cout << "uri:" << uri << endl;
//请求类型 GET POST
string cmdtype;
switch (evhttp_request_get_command(request))
{
case EVHTTP_REQ_GET:
cmdtype = "GET";
break;
case EVHTTP_REQ_POST:
cmdtype = "POST";
break;
}
cout << cmdtype << endl;
// 消息报头
evkeyvalq *headers = evhttp_request_get_input_headers(request);
cout << "====== headers ======" << endl;
for (evkeyval *p = headers->tqh_first; p != NULL; p = p->next.tqe_next)
{
cout << p->key << ":" << p->value << endl;
}
// 请求正文 ( GET为空，POST有表单信息 )
evbuffer *inbuf = evhttp_request_get_input_buffer(request);
char buf[1024] = { 0 };
cout << "======= Input data ======" << endl;
while (evbuffer_get_length(inbuf))
{
int n = evbuffer_remove(inbuf, buf, sizeof(buf) - 1);
if (n > 0)
{
buf[n] = '\0';
cout << buf << endl;
}
}
string filepath = WEBROOT;
filepath += uri;
if (strcmp(uri, "/") == 0)
{
//默认加入首页文件
filepath += DEFAULTINDEX;
}
// 获取消息报头
evkeyvalq *outhead = evhttp_request_get_output_headers(request);
// 设置支持 图片 js css 下载zip文件
int pos = filepath.rfind('.');
string postfix = filepath.substr(pos + 1, filepath.size() - (pos + 1));
if (postfix == "jpg" || postfix == "gif" || postfix == "png")
{
string tmp = "image/" + postfix;
evhttp_add_header(outhead, "Content-Type", tmp.c_str());
}
else if (postfix == "zip")
{
evhttp_add_header(outhead, "Content-Type", "application/zip");
}
else if (postfix == "html")
{
evhttp_add_header(outhead, "Content-Type", "text/html;charset=UTF8");
}
else if (postfix == "css")
{
evhttp_add_header(outhead, "Content-Type", "text/css");
}
//读取文件返回正文
FILE *fp = fopen(filepath.c_str(), "rb");
if (!fp)
{
evhttp_send_reply(request, HTTP_NOTFOUND, "", 0);
return;
}
evbuffer *outbuf = evhttp_request_get_output_buffer(request);
for (;;)
{
int len = fread(buf, 1, sizeof(buf), fp);
if (len <= 0)break;
evbuffer_add(outbuf, buf, len);
}
fclose(fp);
evhttp_send_reply(request, HTTP_OK, "", outbuf);
}
int main()
{
#ifdef _WIN32
//初始化socket库
WSADATA wsa;
WSAStartup(MAKEWORD(2, 2), &wsa);
#else
//忽略管道信号，发送数据给已关闭的socket
if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
return 1;
#endif
//创建libevent的上下文
event_base * base = event_base_new();
if (!base)
return 1;
// http 服务器
//1 创建evhttp上下文
evhttp *evh = evhttp_new(base);
//2 绑定端口和IP
if (evhttp_bind_socket(evh, "0.0.0.0", 8080) != 0)
{
cout << "evhttp_bind_socket failed!" << endl;
}
//3 设定回调函数
evhttp_set_gencb(evh, http_cb, 0);
//4 事件分发处理
if (base)
event_base_dispatch(base);
if (base)
event_base_free(base);
if (evh)
evhttp_free(evh);
#ifdef _WIN32
WSACleanup();
#endif
return 0;
}
一、构建libevent client，解析下载文件
/**
* 回调
*/
void http_client_cb(struct evhttp_request *req, void *ctx)
{
cout << "http_client_cb" << endl;
event_base *base = (event_base *)ctx;
//服务端响应错误
if (req == NULL)
{
int errcode = EVUTIL_SOCKET_ERROR();
cout << "socket error:" << evutil_socket_error_to_string(errcode) << endl;
return;
}
//获取path
const char *path = evhttp_request_get_uri(req);
cout << "request path is " << path << endl;
string filepath = ".";
filepath += path;
cout << "filepath is " << filepath << endl;
//下载文件，如果路径中有目录，需要分析出目录，并创建
FILE *fp = fopen(filepath.c_str(), "wb");
if (!fp)
{
cout << "open file " << filepath << " failed!" << endl;
}
//获取返回的code 200 404
cout << "Response :" << evhttp_request_get_response_code(req); //200
cout << " " << evhttp_request_get_response_code_line(req) << endl;//OK
char buf[1024] = { 0 };
evbuffer *input = evhttp_request_get_input_buffer(req);
for (;;)
{
int len = evbuffer_remove(input, buf, sizeof(buf) - 1);
if (len <= 0)break;
buf[len] = 0;
if (!fp)
continue;
fwrite(buf, 1, len, fp);
}
if (fp)
fclose(fp);
event_base_loopbreak(base);
}
int PostTest()
{
// 创建libevent的上下文
event_base * base = event_base_new();
if (base)
{
cout << "event_base_new success!" << endl;
}
// 生成请求信息 POST
string http_url = "http://127.0.0.1:8080/index.html";
// 分析url地址
// uri
evhttp_uri *uri = evhttp_uri_parse(http_url.c_str());
// http OR https
const char *scheme = evhttp_uri_get_scheme(uri);
if (!scheme)
{
cerr << "scheme is null" << endl;
return -1;
}
cout << "scheme is " << scheme << endl;
int port = evhttp_uri_get_port(uri);
if (port < 0)
{
if (strcmp(scheme, "http") == 0)
port = 80;
}
cout << "port is " << port << endl;
const char *host = evhttp_uri_get_host(uri);
if (!host)
{
cerr << "host is null" << endl;
return -1;
}
cout << "host is " << host << endl;
const char *path = evhttp_uri_get_path(uri);
if (!path || strlen(path) == 0)
{
path = "/";
}
if (path)
cout << "path is " << path << endl;
//?id=1 后面的内容 id=1
const char *query = evhttp_uri_get_query(uri);
if (query)
cout << "query is " << query << endl;
else
cout << "query is NULL" << endl;
// bufferevent 连接http服务器
bufferevent *bev = bufferevent_socket_new(base, -1, BEV_OPT_CLOSE_ON_FREE);
evhttp_connection *evcon = evhttp_connection_base_bufferevent_new(base,
NULL, bev, host, port);
//http client 请求 回调函数设置
evhttp_request *req = evhttp_request_new(http_client_cb, base);
// 设置请求的head 消息报头 信息
evkeyvalq *output_headers = evhttp_request_get_output_headers(req);
evhttp_add_header(output_headers, "Host", host);
//发送post数据
evbuffer *output = evhttp_request_get_output_buffer(req);
evbuffer_add_printf(output, "xcj=%d&b=%d", 1, 2);
//发起请求
evhttp_make_request(evcon, req, EVHTTP_REQ_POST, path);
//事件分发处理
if (base) event_base_dispatch(base);
if (uri) evhttp_uri_free(uri);
if (evcon) evhttp_connection_free(evcon);
if (base) event_base_free(base);
}
int GetTest()
{
//创建libevent的上下文
event_base * base = event_base_new();
// 生成请求信息 GET
string http_url = "http://127.0.0.1/index.html?id=1";
// 分析url地址
// uri
evhttp_uri *uri = evhttp_uri_parse(http_url.c_str());
// http https
const char *scheme = evhttp_uri_get_scheme(uri);
if (!scheme)
{
cerr << "scheme is null" << endl;
return -1;
}
cout << "scheme is " << scheme << endl;
int port = evhttp_uri_get_port(uri);
if (port < 0)
{
if (strcmp(scheme, "http") == 0)
port = 80;
}
cout << "port is " << port << endl;
//host ffmpeg.club
const char *host = evhttp_uri_get_host(uri);
if (!host)
{
cerr << "host is null" << endl;
return -1;
}
cout << "host is " << host << endl;
const char *path = evhttp_uri_get_path(uri);
if (!path || strlen(path) == 0)
{
path = "/";
}
if (path)
cout << "path is " << path << endl;
//?id=1 后面的内容 id=1
const char *query = evhttp_uri_get_query(uri);
if (query)
cout << "query is " << query << endl;
else
cout << "query is NULL" << endl;
// bufferevent 连接http服务器
bufferevent *bev = bufferevent_socket_new(base, -1, BEV_OPT_CLOSE_ON_FREE);
evhttp_connection *evcon = evhttp_connection_base_bufferevent_new(base,
NULL, bev, host, port);
//http client 请求 回调函数设置
evhttp_request *req = evhttp_request_new(http_client_cb, base);
// 设置请求的head 消息报头 信息
evkeyvalq *output_headers = evhttp_request_get_output_headers(req);
evhttp_add_header(output_headers, "Host", host);
//发起请求
evhttp_make_request(evcon, req, EVHTTP_REQ_GET, path);
//事件分发处理
if (base)event_base_dispatch(base);
if (uri)evhttp_uri_free(uri);
if (evcon)evhttp_connection_free(evcon);
if (base)event_base_free(base);
}
