怎么在网站上做音乐,a站进入,网站自己做自己的品牌好做,北京化妆品网站建设1、 示例程序
程序从stdin读取http/https URL#xff0c;抓取网页并把内容打印到stdout#xff0c;并将请求和响应的http header打印在stderr。 为了简单起见#xff0c;程序用Ctrl-C退出#xff0c;但会保证所有资源先被完全释放。
#include signal.h
#include …1、 示例程序
程序从stdin读取http/https URL抓取网页并把内容打印到stdout并将请求和响应的http header打印在stderr。 为了简单起见程序用Ctrl-C退出但会保证所有资源先被完全释放。
#include signal.h
#include stdlib.h
#include stdio.h
#include string.h
#include string
#include workflow/HttpMessage.h
#include workflow/HttpUtil.h
#include workflow/WFTaskFactory.h#ifndef _WIN32
#include unistd.h
#endif#define REDIRECT_MAX 5
#define RETRY_MAX 2void wget_callback(WFHttpTask *task)
{protocol::HttpRequest *req task-get_req();protocol::HttpResponse *resp task-get_resp();int state task-get_state();int error task-get_error();switch (state){case WFT_STATE_SYS_ERROR:fprintf(stderr, system error: %s\n, strerror(error));break;case WFT_STATE_DNS_ERROR:fprintf(stderr, DNS error: %s\n, gai_strerror(error));break;case WFT_STATE_SSL_ERROR:fprintf(stderr, SSL error: %d\n, error);break;case WFT_STATE_TASK_ERROR:fprintf(stderr, Task error: %d\n, error);break;case WFT_STATE_SUCCESS:break;}if (state ! WFT_STATE_SUCCESS){fprintf(stderr, Failed. Press Ctrl-C to exit.\n);return;}std::string name;std::string value;/* Print request. */fprintf(stderr, %s %s %s\r\n, req-get_method(),req-get_http_version(),req-get_request_uri());protocol::HttpHeaderCursor req_cursor(req);while (req_cursor.next(name, value))fprintf(stderr, %s: %s\r\n, name.c_str(), value.c_str());fprintf(stderr, \r\n);/* Print response header. */fprintf(stderr, %s %s %s\r\n, resp-get_http_version(),resp-get_status_code(),resp-get_reason_phrase());protocol::HttpHeaderCursor resp_cursor(resp);while (resp_cursor.next(name, value))fprintf(stderr, %s: %s\r\n, name.c_str(), value.c_str());fprintf(stderr, \r\n);/* Print response body. */const void *body;size_t body_len;resp-get_parsed_body(body, body_len);fwrite(body, 1, body_len, stdout);fflush(stdout);fprintf(stderr, \nSuccess. Press Ctrl-C to exit.\n);
}void sig_handler(int signo) { }int main(int argc, char *argv[])
{WFHttpTask *task;if (argc ! 2){fprintf(stderr, USAGE: %s http URL\n, argv[0]);exit(1);}signal(SIGINT, sig_handler);std::string url argv[1];if (strncasecmp(argv[1], http://, 7) ! 0 strncasecmp(argv[1], https://, 8) ! 0){url http:// url;}task WFTaskFactory::create_http_task(url, REDIRECT_MAX, RETRY_MAX,wget_callback);protocol::HttpRequest *req task-get_req();req-add_header_pair(Accept, */*);req-add_header_pair(User-Agent, Wget/1.14 (linux-gnu));req-add_header_pair(Connection, close);task-start();
#ifndef _WIN32pause();
#elsegetchar();
#endifreturn 0;
}2、类继承关系 3、源码分析
create_http_task
#HttpTaskImpl.cc
WFHttpTask *WFTaskFactory::create_http_task(const std::string url,int redirect_max,int retry_max,http_callback_t callback)
{auto *task new ComplexHttpTask(redirect_max,retry_max,std::move(callback));ParsedURI uri;URIParser::parse(url, uri);task-init(std::move(uri));task-set_keep_alive(HTTP_KEEPALIVE_DEFAULT);return task;
}ComplexHttpTask
#HttpTaskImpl.cc
class ComplexHttpTask : public WFComplexClientTaskHttpRequest, HttpResponse
{
public:ComplexHttpTask(int redirect_max,int retry_max,http_callback_t callback):WFComplexClientTask(retry_max, std::move(callback)),redirect_max_(redirect_max),redirect_count_(0){HttpRequest *client_req this-get_req();client_req-set_method(HttpMethodGet);client_req-set_http_version(HTTP/1.1);}protected:virtual CommMessageOut *message_out();virtual CommMessageIn *message_in();virtual int keep_alive_timeout();virtual bool init_success();virtual void init_failed();virtual bool finish_once();protected:bool need_redirect(ParsedURI uri);bool redirect_url(HttpResponse *client_resp, ParsedURI uri);void set_empty_request();void check_response();private:int redirect_max_;int redirect_count_;
};WFComplexClientTask
#WFTaskFactory.inl
templateclass REQ, class RESP, typename CTX bool
class WFComplexClientTask : public WFClientTaskREQ, RESP
{
protected:using task_callback_t std::functionvoid (WFNetworkTaskREQ, RESP *);public:WFComplexClientTask(int retry_max, task_callback_t cb):WFClientTaskREQ, RESP(NULL, WFGlobal::get_scheduler(), std::move(cb)){type_ TT_TCP;fixed_addr_ false;retry_max_ retry_max;retry_times_ 0;redirect_ false;ns_policy_ NULL;router_task_ NULL;}protected:// new api for childrenvirtual bool init_success() { return true; }virtual void init_failed() {}virtual bool check_request() { return true; }virtual WFRouterTask *route();virtual bool finish_once() { return true; }public:void init(const ParsedURI uri){uri_ uri;init_with_uri();}void init(ParsedURI uri){uri_ std::move(uri);init_with_uri();}void init(TransportType type,const struct sockaddr *addr,socklen_t addrlen,const std::string info);void set_transport_type(TransportType type){type_ type;}TransportType get_transport_type() const { return type_; }virtual const ParsedURI *get_current_uri() const { return uri_; }void set_redirect(const ParsedURI uri){redirect_ true;init(uri);}void set_redirect(TransportType type, const struct sockaddr *addr,socklen_t addrlen, const std::string info){redirect_ true;init(type, addr, addrlen, info);}bool is_fixed_addr() const { return this-fixed_addr_; }protected:void set_fixed_addr(int fixed) { this-fixed_addr_ fixed; }void set_info(const std::string info){info_.assign(info);}void set_info(const char *info){info_.assign(info);}protected:virtual void dispatch();virtual SubTask *done();void clear_resp(){size_t size this-resp.get_size_limit();this-resp.~RESP();new(this-resp) RESP();this-resp.set_size_limit(size);}void disable_retry(){retry_times_ retry_max_;}protected:TransportType type_;ParsedURI uri_;std::string info_;bool fixed_addr_;bool redirect_;CTX ctx_;int retry_max_;int retry_times_;WFNSPolicy *ns_policy_;WFRouterTask *router_task_;RouteManager::RouteResult route_result_;WFNSTracing tracing_;public:CTX *get_mutable_ctx() { return ctx_; }private:void clear_prev_state();void init_with_uri();bool set_port();void router_callback(void *t);void switch_callback(void *t);
};WFClientTask
#WFTask.inl
templateclass REQ, class RESP
class WFClientTask : public WFNetworkTaskREQ, RESP
{
protected:virtual CommMessageOut *message_out(){/* By using prepare function, users can modify request after* the connection is established. */if (this-prepare)this-prepare(this);return this-req;}virtual CommMessageIn *message_in() { return this-resp; }protected:virtual WFConnection *get_connection() const{CommConnection *conn;if (this-target){conn this-CommSession::get_connection();if (conn)return (WFConnection *)conn;}errno ENOTCONN;return NULL;}protected:virtual SubTask *done(){SeriesWork *series series_of(this);if (this-state WFT_STATE_SYS_ERROR this-error 0){this-state WFT_STATE_SSL_ERROR;this-error -this-error;}if (this-callback)this-callback(this);delete this;return series-pop();}public:void set_prepare(std::functionvoid (WFNetworkTaskREQ, RESP *) prep){this-prepare std::move(prep);}protected:std::functionvoid (WFNetworkTaskREQ, RESP *) prepare;public:WFClientTask(CommSchedObject *object, CommScheduler *scheduler,std::functionvoid (WFNetworkTaskREQ, RESP *) cb) :WFNetworkTaskREQ, RESP(object, scheduler, std::move(cb)){}protected:virtual ~WFClientTask() { }
};WFNetworkTask
#WFTask.h
templateclass REQ, class RESP
class WFNetworkTask : public CommRequest
{
public:/* start(), dismiss() are for client tasks only. */void start(){assert(!series_of(this));Workflow::start_series_work(this, nullptr);}void dismiss(){assert(!series_of(this));delete this;}public:REQ *get_req() { return this-req; }RESP *get_resp() { return this-resp; }public:void *user_data;public:int get_state() const { return this-state; }int get_error() const { return this-error; }/* Call when error is ETIMEDOUT, return values:* TOR_NOT_TIMEOUT, TOR_WAIT_TIMEOUT, TOR_CONNECT_TIMEOUT,* TOR_TRANSMIT_TIMEOUT (send or receive).* SSL connect timeout also returns TOR_CONNECT_TIMEOUT. */int get_timeout_reason() const { return this-timeout_reason; }/* Call only in callback or servers process. */long long get_task_seq() const{if (!this-target){errno ENOTCONN;return -1;}return this-get_seq();}int get_peer_addr(struct sockaddr *addr, socklen_t *addrlen) const;virtual WFConnection *get_connection() const 0;public:/* All in milliseconds. timeout -1 for unlimited. */void set_send_timeout(int timeout) { this-send_timeo timeout; }void set_receive_timeout(int timeout) { this-receive_timeo timeout; }void set_keep_alive(int timeout) { this-keep_alive_timeo timeout; }public:/* Do not reply this request. */void noreply(){if (this-state WFT_STATE_TOREPLY)this-state WFT_STATE_NOREPLY;}/* Push reply data synchronously. */virtual int push(const void *buf, size_t size){return this-scheduler-push(buf, size, this);}/* To check if the connection was closed before replying.Always returns true in callback. */bool closed() const{if (this-state WFT_STATE_TOREPLY)return !this-get_target()-has_idle_conn();elsereturn this-state ! WFT_STATE_UNDEFINED;}public:void set_callback(std::functionvoid (WFNetworkTaskREQ, RESP *) cb){this-callback std::move(cb);}protected:virtual int send_timeout() { return this-send_timeo; }virtual int receive_timeout() { return this-receive_timeo; }virtual int keep_alive_timeout() { return this-keep_alive_timeo; }protected:int send_timeo;int receive_timeo;int keep_alive_timeo;REQ req;RESP resp;std::functionvoid (WFNetworkTaskREQ, RESP *) callback;protected:WFNetworkTask(CommSchedObject *object, CommScheduler *scheduler,std::functionvoid (WFNetworkTaskREQ, RESP *) cb) :CommRequest(object, scheduler),callback(std::move(cb)){this-send_timeo -1;this-receive_timeo -1;this-keep_alive_timeo 0;this-target NULL;this-timeout_reason TOR_NOT_TIMEOUT;this-user_data NULL;this-state WFT_STATE_UNDEFINED;this-error 0;}virtual ~WFNetworkTask() { }
};CommRequest
# CommRequest.h
class CommRequest : public SubTask, public CommSession
{
public:CommRequest(CommSchedObject *object, CommScheduler *scheduler){this-scheduler scheduler;this-object object;this-wait_timeout 0;}CommSchedObject *get_request_object() const { return this-object; }void set_request_object(CommSchedObject *object) { this-object object; }int get_wait_timeout() const { return this-wait_timeout; }void set_wait_timeout(int timeout) { this-wait_timeout timeout; }public:virtual void dispatch(){if (this-scheduler-request(this, this-object, this-wait_timeout,this-target) 0){this-handle(CS_STATE_ERROR, errno);}}protected:int state;int error;protected:CommTarget *target;
#define TOR_NOT_TIMEOUT 0
#define TOR_WAIT_TIMEOUT 1
#define TOR_CONNECT_TIMEOUT 2
#define TOR_TRANSMIT_TIMEOUT 3int timeout_reason;protected:int wait_timeout;CommSchedObject *object;CommScheduler *scheduler;protected:virtual void handle(int state, int error);
};(1)应用程序调用start()时调用到 WFNetworkTask类的
void start(){assert(!series_of(this));Workflow::start_series_work(this, nullptr);}2
inline void
Workflow::start_series_work(SubTask *first, series_callback_t callback)
{new SeriesWork(first, std::move(callback));first-dispatch();
}(3)调用 WFComplexClientTaskREQ, RESP, CTX::dispatch() 这里为什么不是调用 CommRequest 的 dispatch
templateclass REQ, class RESP, typename CTX
void WFComplexClientTaskREQ, RESP, CTX::dispatch()
{switch (this-state){case WFT_STATE_UNDEFINED: // 第一次是这个状态if (this-check_request()) // 这里直接return true {if (this-route_result_.request_object) // 第一次走着初始化是空的直接到下面产生router_task_{case WFT_STATE_SUCCESS: // 第二次就直接success了this-set_request_object(route_result_.request_object);this-WFClientTaskREQ, RESP::dispatch(); //这里会调用到 CommRequest 的 dispatchreturn;}// 第一次直接过来了产生route做dns解析// 产生一个router_task_插入到前面去做dns解析router_task_ this-route();series_of(this)-push_front(this);series_of(this)-push_front(router_task_);}default:break;}this-subtask_done();
}4CommRequest::dispatch 组成 dns解析完后
this-WFClientTaskREQ, RESP::dispatch();调用CommRequest的dispatch
void CommRequest::dispatch()
{// 发送请求this-scheduler-request(this, this-object, this-wait_timeout,this-target);...
}5scheduler是在 WFComplexClientTask的初始化列表中创建此时传入的是NULL
WFComplexClientTask(int retry_max, task_callback_t cb):WFClientTaskREQ, RESP(NULL, WFGlobal::get_scheduler(), std::move(cb))而什么时候才初始化呢? 在WFComplexClientTask的dispatch中set_request_object
templateclass REQ, class RESP, typename CTX
void WFComplexClientTaskREQ, RESP, CTX::dispatch()
{switch (this-state){case WFT_STATE_UNDEFINED:if (this-check_request()){if (this-route_result_.request_object){case WFT_STATE_SUCCESS:this-set_request_object(route_result_.request_object);this-WFClientTaskREQ, RESP::dispatch();return;}...
}这里如何产生的route_result_.request_object是通过dns去做的这里先略过在dns那一节详细阐述。
可以看出我们给个urldns解析出来之后我们有了request的目标了
6scheduler 的reques执行的是
/* wait_timeout in microseconds, -1 for no timeout. */int request(CommSession *session, CommSchedObject *object,int wait_timeout, CommTarget **target){int ret -1;*target object-acquire(wait_timeout); //获取通信targetif (*target){ret this-comm.request(session, *target); // 调用request去发request请求if (ret 0)(*target)-release();}return ret;}这里CommTarget 才是通讯目标基本上就是ipport, 还有两个超时参数。连接池什么的都在target里
4、参考链接
https://github.com/chanchann/workflow_annotation/blob/main/src_analysis/18_http_01.md
