C/C+++服务器之libuv的使用实战

libuv

libuv简介

1: 开源跨平台的异步IO库, 主要功能有网络异步，文件异步等。
2: libuv主页: http://libuv.org/
3: libuv是node.js的底层库;
4: libuv的事件循环模型:
epoll, kqueue, IOCP, event ports;
异步 TCP 与 UDP sockets;
DNS 解析
异步文件读写;
信号处理;
高性能定时器;
进程/线程池;

libuv原理

1:异步: 在用户层同时管理多个句柄请求。
2: loop循环等待所有的事件和句柄,管理好所有的这些请求。
3: 当其中一个请求完成后，loop就会监测得到然后调用用户指定的回掉函数处理;
4: 例如loop监听所有的socket,有数据来了后，loop就会处理，然后转到用户指定的回调函数。
5: libuv编写思想:
1> 创建一个对象, 例如socket;
2> 给loop管理这个对象;
3> 并指定一个回调函数,当有事件发生的时候调用这个回调函数, callback;

6: 1>向loop发送请求;
2>指定结束后的回调函数;
3>当请求结束后，调用调函数;

TCP服务器搭建

首先需要下载libuv库，导入到工程中，设置好include的路径和链接上对应的库
代码如下：

#include <stdio.h>
#include <string.h>
#include <stdlib.h>#include "uv.h"/*
uv_handle_s 数据结构:
UV_HANDLE_FIELDSuv_stream_t  数据结构;
UV_HANDLE_FIELDS
UV_STREAM_FIELDSuv_tcp_t 数据结构;
UV_HANDLE_FIELDS
UV_STREAM_FIELDS
UV_TCP_PRIVATE_FIELDSuv_tcp_t is uv_stream_t is uv_handle_t;
*/static uv_loop_t* loop = NULL;
static uv_tcp_t l_server; // 监听句柄;// 当我们的event loop检车到handle上有数据可以读的时候,
// 就会调用这个函数, 让这个函数给event loop准备好读入数据的内存;
// event loop知道有多少数据,suggested_size,
// handle: 发生读时间的handle;
// suggested_size: 建议我们分配多大的内存来保存这个数据;
// uv_buf_t: 我们准备好的内存，通过uv_buf_t,告诉even loop;
static void 
uv_alloc_buf(uv_handle_t* handle,size_t suggested_size,uv_buf_t* buf) {if (handle->data != NULL) {free(handle->data);handle->data = NULL;}buf->base = malloc(suggested_size + 1);buf->len = suggested_size;handle->data = buf->base;
}static void
on_close(uv_handle_t* handle) {printf("close client\n");if (handle->data) {free(handle->data);handle->data = NULL;}
}static void 
on_shutdown(uv_shutdown_t* req, int status) {uv_close((uv_handle_t*)req->handle, on_close);free(req);
}static void 
after_write(uv_write_t* req, int status) {if (status == 0) {printf("write success\n");}uv_buf_t* w_buf = req->data;if (w_buf) {free(w_buf);}free(req);
}// 参数: 
// uv_stream_t* handle --> uv_tcp_t;
// nread: 读到了多少字节的数据;
// uv_buf_t: 我们的数据都读到到了哪个buf里面, base;
static void after_read(uv_stream_t* stream,ssize_t nread,const uv_buf_t* buf) {// 连接断开了;if (nread < 0) {uv_shutdown_t* reg = malloc(sizeof(uv_shutdown_t));memset(reg, 0, sizeof(uv_shutdown_t));uv_shutdown(reg, stream, on_shutdown);return;}// endbuf->base[nread] = 0;printf("recv %d\n", nread);printf("%s\n", buf->base);// 测试发送给我们的 客户端;uv_write_t* w_req = malloc(sizeof(uv_write_t));uv_buf_t* w_buf = malloc(sizeof(uv_buf_t));w_buf->base = buf->base;w_buf->len = nread;w_req->data = w_buf;uv_write(w_req, stream, w_buf, 1, after_write);
}static void
uv_connection(uv_stream_t* server, int status) {printf("new client comming\n");// 接入客户端;uv_tcp_t* client = malloc(sizeof(uv_tcp_t));memset(client, 0, sizeof(uv_tcp_t));uv_tcp_init(loop, client);uv_accept(server, (uv_stream_t*)client);// end// 告诉event loop,让他帮你管理哪个事件;uv_read_start((uv_stream_t*)client, uv_alloc_buf, after_read);
}int main(int argc, char** argv) {int ret;loop = uv_default_loop();// Tcp 监听服务;uv_tcp_init(loop, &l_server); // 将l_server监听句柄加入到event loop里面;// 你需要event loop来给你做那种管理呢？配置你要的管理类型;struct sockaddr_in addr;uv_ip4_addr("0.0.0.0", 6080, &addr); // ip地址, 端口ret = uv_tcp_bind(&l_server, (const struct sockaddr*) &addr, 0);if (ret != 0) {goto failed;}// 让event loop来做监听管理，当我们的l_server句柄上有人连接的时候;// event loop就会调用用户指定的这个处理函数uv_connection;uv_listen((uv_stream_t*)&l_server, SOMAXCONN, uv_connection);uv_run(loop, UV_RUN_DEFAULT);failed:printf("end\n");system("pause");return 0;
}

UDP服务器搭建

客户端

#include <stdio.h>
#include <string.h>
#include <stdlib.h>#include <WinSock2.h>
#pragma comment(lib, "ws2_32.lib")int main(int argc, char** argv) {WSADATA ws;WSAStartup(MAKEWORD(2, 2), &ws);SOCKET client = socket(AF_INET, SOCK_DGRAM, 0);// 可以bind也可以不绑,如果不要求别人先发给你可以不bind;// end SOCKADDR_IN addr;addr.sin_family = AF_INET;addr.sin_port = htons(6080);addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");int len = sizeof(SOCKADDR_IN);int send_len = sendto(client, "Hello", 5, 0, (const SOCKADDR*)&addr, len);printf("send_len = %d\n", send_len);char buf[128];SOCKADDR_IN sender_addr; // 收到谁发的数据包的地址;int recv_len = recvfrom(client, buf, 128, 0, &sender_addr, &len);if (recv_len > 0) {buf[recv_len] = 0; // 加上结尾符号;printf("%s\n", buf);}WSACleanup();system("pause");return 0;
}

不用libuv版本的服务器

#include <stdio.h>
#include <string.h>
#include <stdlib.h>#include <WinSock2.h>
#pragma comment(lib, "ws2_32.lib")int main(int argc, char** argv) {WSADATA ws;WSAStartup(MAKEWORD(2, 2), &ws);SOCKET client = socket(AF_INET, SOCK_DGRAM, 0);// 可以bind也可以不绑,如果不要求别人先发给你可以不bind;// end SOCKADDR_IN addr;addr.sin_family = AF_INET;addr.sin_port = htons(6080);addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");int len = sizeof(SOCKADDR_IN);int send_len = sendto(client, "Hello", 5, 0, (const SOCKADDR*)&addr, len);printf("send_len = %d\n", send_len);char buf[128];SOCKADDR_IN sender_addr; // 收到谁发的数据包的地址;int recv_len = recvfrom(client, buf, 128, 0, &sender_addr, &len);if (recv_len > 0) {buf[recv_len] = 0; // 加上结尾符号;printf("%s\n", buf);}WSACleanup();system("pause");return 0;
}

libuv的UDP服务器

#include <stdio.h>
#include <string.h>
#include <stdlib.h>#include "uv.h"static uv_loop_t* event_loop = NULL;
static uv_udp_t server; // UDP的句柄;static void 
uv_alloc_buf(uv_handle_t* handle,size_t suggested_size,uv_buf_t* buf) {if (handle->data != NULL) {free(handle->data);handle->data = NULL;}handle->data = malloc(suggested_size + 1); // +1测试的时候，我要收字符串，所以呢要加上1来访结尾符号;buf->base = handle->data;buf->len = suggested_size;
}static void
on_uv_udp_send_end(uv_udp_send_t* req, int status) {if (status == 0) {printf("send sucess\n");}free(req);
}static void 
after_uv_udp_recv(uv_udp_t* handle,ssize_t nread,const uv_buf_t* buf,const struct sockaddr* addr, // 发过来数据包的IP地址 + 端口;unsigned flags) {char ip_addr[128];uv_ip4_name((struct sockaddr_in*)addr, ip_addr, 128);int port = ntohs(((struct sockaddr_in*)addr)->sin_port);printf("ip: %s:%d nread = %d\n", ip_addr, port, nread);char* str_buf = handle->data;str_buf[nread] = 0;printf("recv %s\n", str_buf);uv_buf_t w_buf;w_buf = uv_buf_init("PING", 4);// 写数据;uv_udp_send_t* req = malloc(sizeof(uv_udp_send_t));uv_udp_send(req, handle, &w_buf, 1, addr, on_uv_udp_send_end);// end 
}int main(int argc, char** argv) {event_loop = uv_default_loop();memset(&server, 0 ,sizeof(uv_udp_t));uv_udp_init(event_loop, &server);// bind端口;struct sockaddr_in addr;uv_ip4_addr("0.0.0.0", 6080, &addr);uv_udp_bind(&server, (const struct sockaddr*)&addr, 0);// end // 告诉事件循环,你要他管理recv事件;uv_udp_recv_start(&server, uv_alloc_buf, after_uv_udp_recv);uv_run(event_loop, UV_RUN_DEFAULT);system("pause");return 0;
}

定时器设计

源码

 #include <stdio.h>
#include <string.h>
#include <stdlib.h>#include "uv.h"
#include "time_list.h"#define my_malloc malloc
#define my_free freestruct timer {uv_timer_t uv_timer; // libuv timer handlevoid(*on_timer)(void* udata);void* udata;int repeat_count; // -1一直循环;
};static struct timer* 
alloc_timer(void(*on_timer)(void* udata),void* udata, int repeat_count) {struct timer* t = my_malloc(sizeof(struct timer));memset(t, 0, sizeof(struct timer));t->on_timer = on_timer;t->repeat_count = repeat_count;t->udata = udata;uv_timer_init(uv_default_loop(), &t->uv_timer);return t;
}static void
free_timer(struct timer* t) {my_free(t);
}static void
on_uv_timer(uv_timer_t* handle) {struct timer* t = handle->data;if (t->repeat_count < 0) { // 不断的触发;t->on_timer(t->udata);}else {t->repeat_count --;t->on_timer(t->udata);if (t->repeat_count == 0) { // 函数time结束uv_timer_stop(&t->uv_timer); // 停止这个timerfree_timer(t);}}}struct timer*
schedule(void(*on_timer)(void* udata),void* udata,int after_msec,int repeat_count) {struct timer* t = alloc_timer(on_timer, udata, repeat_count);// 启动一个timer;t->uv_timer.data = t;uv_timer_start(&t->uv_timer, on_uv_timer, after_msec, after_msec);// end return t;
}void
cancel_timer(struct timer* t) {if (t->repeat_count == 0) { // 全部触发完成，;return;}uv_timer_stop(&t->uv_timer);free_timer(t);
}struct timer*
schedule_once(void(*on_timer)(void* udata),void* udata,int after_msec) {return schedule(on_timer, udata, after_msec, 1);
}

#ifndef __MY_TIMER_LIST_H__
#define __MY_TIMER_LIST_H__// on_timer是一个回掉函数,当timer触发的时候调用;
// udata: 是用户传的自定义的数据结构;
// on_timer执行的时候 udata,就是你这个udata;
// after_sec: 多少秒开始执行;
// repeat_count: 执行多少次, repeat_count == -1一直执行;
// 返回timer的句柄;
struct timer;
struct timer*
schedule(void(*on_timer)(void* udata), void* udata, int after_msec,int repeat_count);// 取消掉这个timer;
void 
cancel_timer(struct timer* t);struct timer*
schedule_once(void(*on_timer)(void* udata), void* udata, int after_msec);
#endif

使用

#include <stdio.h>
#include <string.h>
#include <stdlib.h>#include "uv.h"// 获取当前系统从开机到现在运行了多少毫秒;
#ifdef WIN32
#include <windows.h>
static unsigned int
get_cur_ms() {return GetTickCount();
}
#else
#include <sys/time.h>  
#include <time.h> 
#include <limits.h>static unsigned int
get_cur_ms() {struct timeval tv;// struct timezone tz;gettimeofday(&tv, NULL);return ((tv.tv_usec / 1000) + tv.tv_sec * 1000);
}
#endif static uv_loop_t* event_loop = NULL;#include "time_list.h"struct timer* t = NULL;
static void
on_time_func(void* udata) {static int count = 0;char* str = (udata);printf("%s\n", str);count++;if (count == 10) {cancel_timer(t);}
}static void
on_time_func2(void* udata) {char* str = (udata);printf("%s\n", str);
}int main(int argc, char** argv) {event_loop = uv_default_loop();// 每隔5秒掉一次，掉4次;t = schedule(on_time_func, "HelloWorld!!!", 1000, -1);// schedule_once(on_time_func2, "CallFunc!!!", 1000);uv_run(event_loop, UV_RUN_DEFAULT);system("pause");return 0;
}

异步文件读写

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>#include "uv.h"/*
uv_fs_open:loop: 事件循环,uv_fs_t req请求对象;path: 文件路径flags: 标志0mode: 可读，可写... O_RDONLY O_RDWR...
*/
static uv_loop_t* event_loop = NULL;
static uv_fs_t req;
static uv_fs_t w_req;
static uv_file fs_handle;
static char mem_buffer[1024];
/*
uv_file
文件句柄对象: 打开文件以后的文件handle
uv_fs_tresult,每次请求的结果都是这个值来返回;打开文件: result返回打开文件句柄对象uv_file;读文件: result读到的数据长度;写文件: result为写入的数据长度;
*//*
释放掉这个请求req所占的资源
uv_req_cleanup(req);*//*
stdin: 标注的输入文件, scanf, cin>>
stdout: 标准的输出文件 printf;
fprintf(stdout, "xxxxxxx");每个进程在运行的时候:
stdin文件句柄与stdout这个文件句柄始终是打开的;
stdin:标准的输入文件, 
stdout: 标准的输出;
*/static void 
after_read(uv_fs_t* req) {printf("read %d byte\n", req->result);mem_buffer[req->result] = 0; // 字符串结尾;printf("%s\n", mem_buffer);uv_fs_req_cleanup(req);uv_fs_close(event_loop, req, fs_handle, NULL);uv_fs_req_cleanup(req);
}static void 
on_open_fs_cb(uv_fs_t* req) {// 打开文件fs_handle = req->result;uv_fs_req_cleanup(req);printf("open success end\n");uv_buf_t buf = uv_buf_init(mem_buffer, 1024);uv_fs_read(event_loop, req, fs_handle, &buf, 1, 0, after_read);
}int main(int argc, char** argv) {event_loop = uv_default_loop();// step1:打开文件:uv_fs_open(event_loop, &req, "./test.txt", 0, O_RDONLY, on_open_fs_cb);uv_buf_t w_buf = uv_buf_init("Good! BYCW!!!!", 12);uv_fs_write(event_loop, &w_req, (uv_file)1, &w_buf, 1, 0, NULL);uv_fs_req_cleanup(&w_req);uv_run(event_loop, UV_RUN_DEFAULT);system("pause");return 0;
}

websocket协议

1: websocket是基于TCP的一种协议,是H5的一种传输协议;
2: websocket连接协议;
3: websocket 发送数据协议;
4: websocket 接受数据协议;
5: websocket 关闭协议;

建立连接

1:客户端向服务器发送http报文,服务器处理后回客户端连接报文;
2: 客户端发过来的报文:
GET /chat HTTP/1.1
Host: server.example.com
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
Origin: http://example.com
Sec-WebSocket-Protocol: chat, superchat
Sec-WebSocket-Version: 13

3: 服务器回应客户端报文:
:key+migic ， SHA-1 加密， base-64 加密
key=”来自客户端的随机”, migic = “258EAFA5-E914-47DA-95CA-C5AB0DC85B11”;
static char *wb_accept = “HTTP/1.1 101 Switching Protocols\r\n”
“Upgrade:websocket\r\n”
“Connection: Upgrade\r\n”
“Sec-WebSocket-Accept: %s\r\n”
“WebSocket-Protocol:chat\r\n\r\n”;

Sec-WebSocket-Key/Accept的作用

避免服务端收到非法的websocket连接（比如http客户端不小心请求连接websocket服务，此时服务端可以直接拒绝连接）
确保服务端理解websocket连接。因为ws握手阶段采用的是http协议，因此可能ws连接是被一个http服务器处理并返回的，此时客户端可以通过Sec-WebSocket-Key来确保服务端认识ws协议。（并非百分百保险，比如总是存在那么些无聊的http服务器，光处理Sec-WebSocket-Key，但并没有实现ws协议。。。）
用浏览器里发起ajax请求，设置header时，Sec-WebSocket-Key以及其他相关的header是被禁止的。这样可以避免客户端发送ajax请求时，意外请求协议升级（websocket upgrade）
可以防止反向代理（不理解ws协议）返回错误的数据。比如反向代理前后收到两次ws连接的升级请求，反向代理把第一次请求的返回给cache住，然后第二次请求到来时直接把cache住的请求给返回（无意义的返回）。
Sec-WebSocket-Key主要目的并不是确保数据的安全性，因为Sec-WebSocket-Key、Sec-WebSocket-Accept的转换计算公式是公开的，而且非常简单，最主要的作用是预防一些常见的意外情况（非故意的）。

关闭连接

1: 主动关闭socket
2: 客户端关闭socket:
收到 0x88 开头的数据包;
收到tcp socket关闭事件;

发送数据

固定字节(0x81)
包长度字节
原始数据

接收数据

1)固定字节(1000 0001或1000 0010);
2)包长度字节, 去掉最高位, 剩下7为得到一个整数(0, 127);125以内的长度直接表示就可以了；
126表示后面两个字节表示大小,127表示后面的8个字节是数据的长度;(高位存在低地址)
3)mark 掩码为包长之后的 4 个字节
4)兄弟数据：
得到真实数据的方法：将兄弟数据的每一字节 x ，和掩码的第 i%4 字节做 xor 运算，其中 i 是 x 在兄弟数据中的索引

代码

客户端网页

<!DOCTYPE html>
<html>
<head><title>skynet WebSocket example</title>
</head>
<body>   <script>var ws = new WebSocket('ws://127.0.0.1:8001/ws');ws.onopen = function(){alert("open");ws.send('WebSocket'); };ws.onmessage = function(ev){alert(ev.data);};ws.onclose = function(ev){alert("close");};ws.onerror = function(ev){console.log(ev);alert("error");};</script>
</body>
</html>

服务器

该代码在前面的TCP服务器的基础上修改

#include <stdio.h>
#include <string.h>
#include <stdlib.h>#include "../3rd/http_parser/http_parser.h"
#include "../3rd/crypto/sha1.h"
#include "../3rd/crypto/base64_encoder.h"#include "uv.h"struct ws_context {int is_shake_hand; // 是否已经握手char* data; // 读取数据的buf
};static uv_loop_t* loop = NULL;
static uv_tcp_t l_server; // 监听句柄;static void 
uv_alloc_buf(uv_handle_t* handle,size_t suggested_size,uv_buf_t* buf) {struct ws_context* wc = handle->data;if (wc->data != NULL) {free(wc->data);wc->data = NULL;}buf->base = malloc(suggested_size + 1);buf->len = suggested_size;wc->data = buf->base;
}static void
on_close(uv_handle_t* handle) {printf("close client\n");if (handle->data) {struct ws_context* wc = handle->data;free(wc->data);wc->data = NULL;free(wc);handle->data = NULL;}free(handle);
}static void 
on_shutdown(uv_shutdown_t* req, int status) {uv_close((uv_handle_t*)req->handle, on_close);free(req);
}static void 
after_write(uv_write_t* req, int status) {if (status == 0) {printf("write success\n");}uv_buf_t* w_buf = req->data;if (w_buf) {free(w_buf->base);free(w_buf);}free(req);
}static void
send_data(uv_stream_t* stream, unsigned char* send_data, int send_len) {uv_write_t* w_req = malloc(sizeof(uv_write_t));uv_buf_t* w_buf = malloc(sizeof(uv_buf_t));unsigned char* send_buf = malloc(send_len);memcpy(send_buf, send_data, send_len);w_buf->base = send_buf;w_buf->len = send_len;w_req->data = w_buf;uv_write(w_req, stream, w_buf, 1, after_write);
}static char filed_sec_key[512];
static char value_sec_key[512];
static int is_sec_key = 0;
static int has_sec_key = 0;static int 
on_ws_header_field(http_parser* p, const char *at, size_t length) {if (strncmp(at, "Sec-WebSocket-Key", length) == 0) {is_sec_key = 1;}else {is_sec_key = 0;}return 0;
}static int
on_ws_header_value(http_parser* p, const char *at, size_t length) {if (!is_sec_key) {return 0;}strncpy(value_sec_key, at, length);value_sec_key[length] = 0;has_sec_key = 1;return 0;
}// 
static char* wb_migic = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
// base64(sha1(key + wb_migic))
static char *wb_accept = "HTTP/1.1 101 Switching Protocols\r\n"
"Upgrade:websocket\r\n"
"Connection: Upgrade\r\n"
"Sec-WebSocket-Accept: %s\r\n"
"WebSocket-Protocol:chat\r\n\r\n";static void
ws_connect_shake_hand(uv_stream_t* stream, unsigned char* data, int data_len) {http_parser_settings settings;http_parser_settings_init(&settings);settings.on_header_field = on_ws_header_field;settings.on_header_value = on_ws_header_value;http_parser p;http_parser_init(&p, HTTP_REQUEST);is_sec_key = 0;has_sec_key = 0;http_parser_execute(&p, &settings, data, data_len);if (has_sec_key) { // 解析到了websocket里面的Sec-WebSocket-Keyprintf("Sec-WebSocket-Key: %s\n", value_sec_key);// key + migicstatic char key_migic[512];static char sha1_key_migic[SHA1_DIGEST_SIZE];static char send_client[512];int sha1_size;sprintf(key_migic, "%s%s", value_sec_key, wb_migic);crypt_sha1((unsigned char*)key_migic, strlen(key_migic), (unsigned char*)&sha1_key_migic, &sha1_size);int base64_len;char* base_buf = base64_encode(sha1_key_migic, sha1_size, &base64_len);sprintf(send_client, wb_accept, base_buf);base64_encode_free(base_buf);send_data(stream, (unsigned char*)send_client, strlen(send_client));}
}static void 
ws_send_data(uv_stream_t* stream, unsigned char* data, int len) {int head_size = 2;if (len > 125 && len < 65536) { // 两个字节[0, 65535]head_size += 2;}else if (len >= 65536) { // 不做处理head_size += 8;}unsigned char* data_buf = malloc(head_size + len);data_buf[0] = 0x81;if (len <= 125) {data_buf[1] = len;}else if (len > 125 && len < 65536) {data_buf[1] = 126;data_buf[2] = (len & 0x0000ff00) >> 8;data_buf[3] = (len & 0x000000ff);}else { // 127不写了return;}memcpy(data_buf + head_size, data, len);send_data(stream, data_buf, head_size + len);free(data_buf);
}// 收到的是一个数据包;
static void 
ws_on_recv_data(uv_stream_t* stream, unsigned char* data, unsigned int len) {if (data[0] != 0x81 && data[0] != 0x82) {return;}unsigned int data_len = data[1] & 0x0000007f;int head_size = 2;if (data_len == 126) { // 后面两个字节表示的是数据长度;data[2], data[3]data_len = data[3] | (data[2] << 8);head_size += 2;}else if (data_len == 127) { // 后面8个字节表示数据长度; 2, 3, 4, 5 | 6, 7, 8, 9unsigned int low = data[5] | (data[4] << 8) | (data[3] << 16) | (data[2] << 24);unsigned int hight = data[9] | (data[8] << 8) | (data[7] << 16) | (data[6] << 24);data_len = low;head_size += 8;}unsigned char* mask = data + head_size;unsigned char* body = data + head_size + 4;for (unsigned int i = 0; i < data_len; i++) { // 遍历后面所有的数据;body[i] = body[i] ^ mask[i % 4];}// teststatic char test_buf[4096];memcpy(test_buf, body, data_len);test_buf[data_len] = 0;printf("%s\n", test_buf);// 发送协议ws_send_data(stream, "Hello", strlen("Hello"));// end }static void after_read(uv_stream_t* stream,ssize_t nread,const uv_buf_t* buf) {// 连接断开了;if (nread < 0) {uv_shutdown_t* reg = malloc(sizeof(uv_shutdown_t));memset(reg, 0, sizeof(uv_shutdown_t));uv_shutdown(reg, stream, on_shutdown);return;}// endprintf("start websocket!!!\n");struct ws_context* wc = stream->data;// 如果没有握手，就进入websocket握手协议if (wc->is_shake_hand == 0) {ws_connect_shake_hand(stream, buf->base, buf->len);wc->is_shake_hand = 1;return;}// end // 如果客户端主动关闭;0x88, 状态码if ((unsigned char)(buf->base[0]) == 0x88) { // 关闭printf("ws closing!!!!");return;}// end // ws正常的数据, 暂时不处理粘包这些问题;// 假设我们一次性都可以收完websocket发过来的数据包;ws_on_recv_data(stream, buf->base, nread);// end }static void
uv_connection(uv_stream_t* server, int status) {printf("new client comming\n");uv_tcp_t* client = malloc(sizeof(uv_tcp_t));memset(client, 0, sizeof(uv_tcp_t));uv_tcp_init(loop, client);uv_accept(server, (uv_stream_t*)client);struct ws_context* wc = malloc(sizeof(struct ws_context));memset(wc, 0, sizeof(struct ws_context));client->data = wc;uv_read_start((uv_stream_t*)client, uv_alloc_buf, after_read);
}int main(int argc, char** argv) {int ret;loop = uv_default_loop();uv_tcp_init(loop, &l_server); struct sockaddr_in addr;uv_ip4_addr("0.0.0.0", 8001, &addr); // ip地址, 端口ret = uv_tcp_bind(&l_server, (const struct sockaddr*) &addr, 0);if (ret != 0) {goto failed;}uv_listen((uv_stream_t*)&l_server, SOMAXCONN, uv_connection);uv_run(loop, UV_RUN_DEFAULT);failed:printf("end\n");system("pause");return 0;
}

总结

WebSocket是一种基于TCP协议的双向通信协议，与HTTP/HTTPS协议相比，具有更低的延迟和更高的实时性。使用WebSocket协议可以实现实时通信、数据推送、在线游戏等功能。但是，WebSocket协议并没有被广泛采用的原因有以下几个方面：

兼容性问题：WebSocket协议是HTML5标准中新增的协议，对于较老的浏览器可能不支持。虽然现代主流浏览器已经支持WebSocket协议，但是在一些特殊情况下（例如企业内部应用、旧版浏览器等），WebSocket协议的兼容性可能成为问题。

安全问题：由于WebSocket协议实现了双向通信，因此在网络安全方面需要更加关注。例如，在进行WebSocket通信时需要进行恰当的身份验证和加密，以避免数据泄露和劫持等问题。

部署和负载问题：WebSocket协议需要建立长连接，因此在部署WebSocket服务时需要考虑服务器负载和连接管理等问题。如果不恰当地部署WebSocket服务，可能会导致服务器资源浪费、连接管理不当等问题。

用处有限：对于大多数网站来说,HTTP请求已经能满足需求。使用WebSocket可以带来实时性改善,但对许多网站功能影响不大。所以如果没有实时交互等强需求,就不一定需要引入WebSocket。

尽管WebSocket协议存在一些问题，但是在特定的场景下仍然是一种非常有用的协议。例如，在实时通信、数据推送、在线游戏等场景下，WebSocket协议可以发挥出其优势。

HTTP服务器

步骤：
1: 等待socket 连接进来;
2: 接收socket发送过来的数据;–> http协议格式的请求数据包
3: http解析url
4: 根据url来找对应的响应处理;
5: 将要返回的数据打包成http响应格式，发给客户端;
6: 关闭客户端的连接;

以Get请求为例：
1: 客户端提交请求;
2: 服务端解析get的url找到对应的响应;
3: 服务端解析get参数;
5: 处理，返回结果给客户端:
“HTTP/1.1 %d %s\r\n” 状态码，状态描述
“transfer-encoding:%s\r\n”, “identity”
“content-length: %d\r\n\r\n” 内容长度
body数据

6: get携带参数格式?uname=xiaoming&key=18074532323

#include <stdio.h>
#include <string.h>
#include <stdlib.h>#include "uv.h"
#include "../3rd/http_parser/http_parser.h"/*
url 注册管理模块
*/typedef void(*web_get_handle)(uv_stream_t* stream, char* url);
typedef void(*web_post_handle)(uv_stream_t* stream, char* url, char* body);struct url_node {char* url; // url地址web_get_handle get; // url地址对应的处理函数;web_post_handle post; // url地址对应的post函数
};static struct url_node*
alloc_url_node(char* url, web_get_handle get, web_post_handle post) {struct url_node* node = malloc(sizeof(struct url_node));memset(node, 0, sizeof(struct url_node));node->url = strdup(url);node->get = get;node->post = post;return node;
}static struct url_node* url_node[1024];
static int url_count = 0;static void
register_web_handle(char* url, web_get_handle get, web_post_handle post) {url_node[url_count] = alloc_url_node(url, get, post);url_count ++;
}static struct url_node* 
get_url_node(char* url, int len) {for (int i = 0; i < url_count; i++) {if (strncmp(url, url_node[i]->url, len) == 0) {return url_node[i];}}return NULL;
}/*
{
[100] = "Continue",
[101] = "Switching Protocols",
[200] = "OK",
[201] = "Created",
[202] = "Accepted",
[203] = "Non-Authoritative Information",
[204] = "No Content",
[205] = "Reset Content",
[206] = "Partial Content",
[300] = "Multiple Choices",
[301] = "Moved Permanently",
[302] = "Found",
[303] = "See Other",
[304] = "Not Modified",
[305] = "Use Proxy",
[307] = "Temporary Redirect",
[400] = "Bad Request",
[401] = "Unauthorized",
[402] = "Payment Required",
[403] = "Forbidden",
[404] = "Not Found",
[405] = "Method Not Allowed",
[406] = "Not Acceptable",
[407] = "Proxy Authentication Required",
[408] = "Request Time-out",
[409] = "Conflict",
[410] = "Gone",
[411] = "Length Required",
[412] = "Precondition Failed",
[413] = "Request Entity Too Large",
[414] = "Request-URI Too Large",
[415] = "Unsupported Media Type",
[416] = "Requested range not satisfiable",
[417] = "Expectation Failed",
[500] = "Internal Server Error",
[501] = "Not Implemented",
[502] = "Bad Gateway",
[503] = "Service Unavailable",
[504] = "Gateway Time-out",
[505] = "HTTP Version not supported",
}
*//*
uv_handle_s 数据结构:
UV_HANDLE_FIELDSuv_stream_t  数据结构;
UV_HANDLE_FIELDS
UV_STREAM_FIELDSuv_tcp_t 数据结构;
UV_HANDLE_FIELDS
UV_STREAM_FIELDS
UV_TCP_PRIVATE_FIELDSuv_tcp_t is uv_stream_t is uv_handle_t;
*/static uv_loop_t* loop = NULL;
static uv_tcp_t l_server; // 监听句柄;// 当我们的event loop检车到handle上有数据可以读的时候,
// 就会调用这个函数, 让这个函数给event loop准备好读入数据的内存;
// event loop知道有多少数据,suggested_size,
// handle: 发生读时间的handle;
// suggested_size: 建议我们分配多大的内存来保存这个数据;
// uv_buf_t: 我们准备好的内存，通过uv_buf_t,告诉even loop;
static void 
uv_alloc_buf(uv_handle_t* handle,size_t suggested_size,uv_buf_t* buf) {if (handle->data != NULL) {free(handle->data);handle->data = NULL;}buf->base = malloc(suggested_size + 1);buf->len = suggested_size;handle->data = buf->base;
}static void
on_close(uv_handle_t* handle) {printf("close client\n");if (handle->data) {free(handle->data);handle->data = NULL;}
}static void 
on_shutdown(uv_shutdown_t* req, int status) {uv_close((uv_handle_t*)req->handle, on_close);free(req);
}static void 
after_write(uv_write_t* req, int status) {if (status == 0) {printf("write success\n");}uv_buf_t* w_buf = req->data;if (w_buf) {free(w_buf);}free(req);
}static void
send_data(uv_stream_t* stream, unsigned char* send_data, int send_len) {uv_write_t* w_req = malloc(sizeof(uv_write_t));uv_buf_t* w_buf = malloc(sizeof(uv_buf_t));unsigned char* send_buf = malloc(send_len);memcpy(send_buf, send_data, send_len);w_buf->base = send_buf;w_buf->len = send_len;w_req->data = w_buf;uv_write(w_req, stream, w_buf, 1, after_write);
}static char req_url[4096];
int on_url(http_parser* p, const char *at, size_t length) {strncpy(req_url, at, length);req_url[length] = 0;return 0;
}static int 
filter_url(char* url) {char* walk = url;int len = 0;while (*url != '?' && *url != '\0') {len++;url++;}return len;
}static void 
on_http_request(uv_stream_t* stream, char* req, int len) {http_parser_settings settings;http_parser_settings_init(&settings);settings.on_url = on_url;http_parser p;http_parser_init(&p, HTTP_REQUEST);http_parser_execute(&p, &settings, req, len);// http get是可以携带参数的:// http://www.baidu.com:6080/test?name=xiaoming&age=34int url_len = filter_url(req_url);struct url_node* node = get_url_node(req_url, url_len);printf("%s\n", req_url);if (node == NULL) {return;}switch (p.method) { // 请求方法case HTTP_GET:if (node->get != NULL) {node->get(stream, req_url);}break;case HTTP_POST:if (node->post != NULL) {}break;}
}
// 参数: 
// uv_stream_t* handle --> uv_tcp_t;
// nread: 读到了多少字节的数据;
// uv_buf_t: 我们的数据都读到到了哪个buf里面, base;
static void after_read(uv_stream_t* stream,ssize_t nread,const uv_buf_t* buf) {// 连接断开了;if (nread < 0) {uv_shutdown_t* reg = malloc(sizeof(uv_shutdown_t));memset(reg, 0, sizeof(uv_shutdown_t));uv_shutdown(reg, stream, on_shutdown);return;}// endbuf->base[nread] = 0;printf("recv %d\n", nread);printf("%s\n", buf->base);// 处理on_http_request(stream, buf->base, buf->len);// end
}static void
uv_connection(uv_stream_t* server, int status) {printf("new client comming\n");// 接入客户端;uv_tcp_t* client = malloc(sizeof(uv_tcp_t));memset(client, 0, sizeof(uv_tcp_t));uv_tcp_init(loop, client);uv_accept(server, (uv_stream_t*)client);// end// 告诉event loop,让他帮你管理哪个事件;uv_read_start((uv_stream_t*)client, uv_alloc_buf, after_read);
}static void 
test_get(uv_stream_t* stream, char* url) {printf("%s\n", url);char* body = "SUCCESS TEST1";static char respons_buf[4096];char* walk = respons_buf;sprintf(walk, "HTTP/1.1 %d %s\r\n", 200, "OK");walk += strlen(walk);sprintf(walk, "transfer-encoding:%s\r\n", "identity");walk += strlen(walk);sprintf(walk, "content-length: %d\r\n\r\n", strlen(body));walk += strlen(walk);sprintf(walk, "%s", body);send_data(stream, respons_buf, strlen(respons_buf));
}static void 
test2_get(uv_stream_t* stream, char* url) {printf("%s\n", url);char* body = "SUCCESS TEST2";static char respons_buf[4096];char* walk = respons_buf;sprintf(walk, "HTTP/1.1 %d %s\r\n", 200, "OK");walk += strlen(walk);sprintf(walk, "transfer-encoding:%s\r\n", "identity");walk += strlen(walk);sprintf(walk, "content-length: %d\r\n\r\n", strlen(body));walk += strlen(walk);sprintf(walk, "%s", body);send_data(stream, respons_buf, strlen(respons_buf));
}int main(int argc, char** argv) {// 注册一下web请求函数register_web_handle("/test", test_get, NULL);register_web_handle("/test2", test2_get, NULL);// end int ret;loop = uv_default_loop();// Tcp 监听服务;uv_tcp_init(loop, &l_server); // 将l_server监听句柄加入到event loop里面;// 你需要event loop来给你做那种管理呢？配置你要的管理类型;struct sockaddr_in addr;uv_ip4_addr("0.0.0.0", 6080, &addr); // ip地址, 端口ret = uv_tcp_bind(&l_server, (const struct sockaddr*) &addr, 0);if (ret != 0) {goto failed;}// 让event loop来做监听管理，当我们的l_server句柄上有人连接的时候;// event loop就会调用用户指定的这个处理函数uv_connection;uv_listen((uv_stream_t*)&l_server, SOMAXCONN, uv_connection);uv_run(loop, UV_RUN_DEFAULT);failed:printf("end\n");system("pause");return 0;
}

多线程与工作队列

1: 线程相关函数:
uv_thread_create: 创建一个线程;
uv_thread_self: 获取当前线程id号;
uv_thread_join: 等待线程结束;
2: 锁:
uv_mutex_init: 初始化锁;
uv_mutex_destroy: 销毁锁;
uv_mutex_lock: 获取锁，如果被占用，就等待;
uv_mutex_trylock: 尝试获取锁，如果获取不到，直接返回,不等待;
uv_mutex_unlock: 释放锁;
3: 等待/触发事件;
uv_cond_init: 创建条件事件;
uv_cond_destroy: 销毁条件事件;
uv_cond_signal: 触发条件事件;
uv_cond_broadcast: 广播条件事件;
uv_cond_wait/uv_cond_timedwait: 等待事件/等待事件超时;

工作队列：
1: libuv在启动的时候会创建一个线程池;
2: 线程池默认启动的线程数目是4个，最大是128个线程;
3: uv_queue_work工作队列原理:
step1: libuv启动线程池，等待任务的调度;
step2: 用户给工作队列一个执行函数，工作队列执行完后,通知主线程;
step3: 主线程在执行之前设置的回掉函数;
4: 工作队列的使用:
有很多操作，比如读文件，比如读数据库，比如读redis都会等待，所以使用工作队列，
可以工作队列来执行，然后通知主线程，这样就不会卡主线程了。给工作队列一个任务(函数)，并指定好任务完成的回掉函数,线程池就会调度去执行这个任务函数，完成后，通知主线程，主线程调用回掉函数;

#include <stdio.h>
#include <string.h>
#include <stdlib.h>#include "uv.h"// 工作队列的用处:
// 1：复杂的算法放到工作队列 ；
// 2：IO放到我们工作队列,获取数据库结果;
// ....// 是在线程池里面另外一个线程里面调用，不在主线程;
static void 
thread_work(uv_work_t* req) {// printf("user data = %d \n", (int)req->data);printf("thread_work id 0x%d:\n", uv_thread_self());
}// 当工作队列里面的线程执行完上面的任务后，通知主线程;
// 主线程调用这个函数;
static void 
on_work_complete(uv_work_t* req, int status) {printf("on_work_complete thread id 0x%d:\n", uv_thread_self());
}int main(int argc, char** argv) {uv_work_t uv_work;printf("main id 0x%d:\n", uv_thread_self());uv_work.data = (void*)6;uv_queue_work(uv_default_loop(), &uv_work, thread_work, on_work_complete);uv_run(uv_default_loop(), UV_RUN_DEFAULT);system("pause");return 0;
}