朝阳网站建设推广,北京网页制作案例,旅游网站建设流程是什么意思,郑州企业网站建设CSAPP Proxy Lab
本实验需要实现一个web代理服务器#xff0c;实现逐步从迭代到并发#xff0c;到最终的具有缓存功能的并发代理服务器。
Web 代理是充当 Web 浏览器和终端服务器之间的中间人的程序。浏览器不是直接联系终端服务器获取网页#xff0c;而是联系代理#x…CSAPP Proxy Lab
本实验需要实现一个web代理服务器实现逐步从迭代到并发到最终的具有缓存功能的并发代理服务器。
Web 代理是充当 Web 浏览器和终端服务器之间的中间人的程序。浏览器不是直接联系终端服务器获取网页而是联系代理代理将请求转发到终端服务器。当终端服务器回复代理时代理将回复发送给浏览器。
本实验共三个部分具体要求如下
在本实验的第一部分您将设置代理以接受传入连接、读取和解析请求、将请求转发到 Web 服务器、读取服务器的响应并将这些响应转发到相应的客户端。第一部分将涉及学习基本的 HTTP 操作以及如何使用套接字编写通过网络连接进行通信的程序。在第二部分中您将升级代理以处理多个并发连接。这将向您介绍如何处理并发这是一个重要的系统概念。在第三部分也是最后一部分您将使用最近访问的 Web 内容的简单主内存缓存将缓存添加到您的代理。
Part I
实现迭代Web代理首先是实现一个处理HTTP/1.0 GET请求的基本迭代代理。开始时我们的代理应侦听端⼝上的传⼊连接端⼝号将在命令行中指定。建⽴连接后您的代理应从客⼾端读取整个请求并解析请求。它应该判断客户端是否发送了⼀个有效的 HTTP 请求如果是这样它就可以建⽴自⼰与适当的 Web 服务器的连接然后请求客⼾端指定的对象。最后您的代理应读取服务器的响应并将其转发给客⼾端。
我们先将tiny.c中的基本框架复制过来移除不需要的函数保留doit,parse_uri,clienterror即可其他还用不到接下来我们需要修改的是doit和parse_uridoit应该做的事如下
读取客户端的请求行判断其是否是GET请求若不是调用clienterror向客户端打印错误信息。parse_uri调用解析uri提取出主机名端口路径信息。代理作为客户端连接目标服务器。调用build_request函数构造新的请求报文new_request。将请求报文build_request发送给目标服务器。接受目标服务器的数据并将其直接发送给源客户端。
代码如下
#include stdio.h#include csapp.h/* Recommended max cache and object sizes */
#define MAX_CACHE_SIZE 1049000
#define MAX_OBJECT_SIZE 102400/* You wont lose style points for including this long line in your code */
static const char *user_agent_hdr User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.3) Gecko/20120305 Firefox/10.0.3\r\n;
static const char *conn_hdr Connection: close\r\n;
static const char *proxy_hdr Proxy-Connection: close\r\n;void doit(int fd);
void parse_uri(char *uri, char *hostname, char *path, int *port);
void build_request(rio_t *real_client, char *new_request, char *hostname, char *port);
void clienterror(int fd, char *cause, char *errnum, char *shortmsg, char *longmsg);int main(int argc, char **argv) {int listenfd, connfd;char hostname[MAXLINE], port[MAXLINE];socklen_t clientlen;struct sockaddr_storage clientaddr;/* Check command line args */if (argc ! 2) {fprintf(stderr, usage: %s port\n, argv[0]);exit(1);}listenfd Open_listenfd(argv[1]);while (1) {clientlen sizeof(clientaddr);connfd Accept(listenfd, (SA *)clientaddr, clientlen);Getnameinfo((SA *)clientaddr, clientlen, hostname, MAXLINE, port, MAXLINE, 0);printf(Accepted connection from (%s, %s)\n, hostname, port);doit(connfd);Close(connfd);}
}void doit(int fd) {int real_server_fd;char buf[MAXLINE], method[MAXLINE], uri[MAXLINE], version[MAXLINE];char hostname[MAXLINE], path[MAXLINE];rio_t rio_client, rio_server;int port;/* Read request line and headers */Rio_readinitb(rio_client, fd); // 初始化rio内部缓冲区if (!Rio_readlineb(rio_client, buf, MAXLINE)) return; // 读到0个字符return// 请求行 GET http://www.cmu.edu/hub/index.html HTTP/1.1sscanf(buf, %s %s %s, method, uri, version);if (strcasecmp(method, GET)) {clienterror(fd, method, 501, Not Implemented, Tiny does not implement this method);return;}// 解析uriparse_uri(uri, hostname, path, port);char port_str[10];sprintf(port_str, %d, port);// 代理作为客户端连接目标服务器real_server_fd Open_clientfd(hostname, port_str);Rio_readinitb(rio_server, real_server_fd); // 初始化riochar new_request[MAXLINE];sprintf(new_request, GET %s HTTP/1.0\r\n, path);build_request(rio_client, new_request, hostname, port_str);// 向目标服务器发送http报文Rio_writen(real_server_fd, new_request, strlen(new_request));int char_nums;// 从目标服务器读到的数据直接发送给客户端while ((char_nums Rio_readlineb(rio_server, buf, MAXLINE))) Rio_writen(fd, buf, char_nums);
}void parse_uri(char *uri, char *hostname, char *path, int *port) {*port 80; // 默认端口char *ptr_hostname strstr(uri, //);// http://hostname:port/pathif (ptr_hostname)ptr_hostname 2; // 绝对urielseptr_hostname uri; // 相对uri相对url不包含http://或https://等协议标识符char *ptr_port strstr(ptr_hostname, :);if (ptr_port) {// 字符串ptr_hostname需要以\0为结尾标记*ptr_port \0;strncpy(hostname, ptr_hostname, MAXLINE);sscanf(ptr_port 1, %d%s, port, path);} else { // uri中没有端口号char *ptr_path strstr(ptr_hostname, /);if (ptr_path) {strncpy(path, ptr_path, MAXLINE);*ptr_path \0;strncpy(hostname, ptr_hostname, MAXLINE);} else {strncpy(hostname, ptr_hostname, MAXLINE);strcpy(path, );}}
}
void build_request(rio_t *real_client, char *new_request, char *hostname, char *port) {char temp_buf[MAXLINE];// 获取client的请求报文while (Rio_readlineb(real_client, temp_buf, MAXLINE) 0) {if (strstr(temp_buf, \r\n)) break; // end// 忽略以下几个字段的信息if (strstr(temp_buf, Host:)) continue;if (strstr(temp_buf, User-Agent:)) continue;if (strstr(temp_buf, Connection:)) continue;if (strstr(temp_buf, Proxy Connection:)) continue;sprintf(new_request, %s%s, new_request, temp_buf);printf(%s\n, new_request);fflush(stdout);}sprintf(new_request, %sHost: %s:%s\r\n, new_request, hostname, port);sprintf(new_request, %s%s%s%s, new_request, user_agent_hdr, conn_hdr, proxy_hdr);sprintf(new_request, %s\r\n, new_request);
}void clienterror(int fd, char *cause, char *errnum, char *shortmsg, char *longmsg) {char buf[MAXLINE];/* Print the HTTP response headers */sprintf(buf, HTTP/1.0 %s %s\r\n, errnum, shortmsg);Rio_writen(fd, buf, strlen(buf));sprintf(buf, Content-type: text/html\r\n\r\n);Rio_writen(fd, buf, strlen(buf));/* Print the HTTP response body */sprintf(buf, htmltitleTiny Error/title);Rio_writen(fd, buf, strlen(buf));sprintf(buf,body bgcolorffffff\r\n);Rio_writen(fd, buf, strlen(buf));sprintf(buf, %s: %s\r\n, errnum, shortmsg);Rio_writen(fd, buf, strlen(buf));sprintf(buf, p%s: %s\r\n, longmsg, cause);Rio_writen(fd, buf, strlen(buf));sprintf(buf, hremThe Tiny Web server/em\r\n);Rio_writen(fd, buf, strlen(buf));
}
若程序出现错误printf大法依然是定位错误的好方法。此外可以通过使用curl来模拟操作。需要注意的是需要先运行proxy和tiny再运行curltiny就相当于一个目标服务器curl则相当于一个客户端。 Part II
接下来我们需要改变上面的程序使其可以处理多个并发请求这里使用多线程来实现并发服务器。具体如下
Accept之后通过创建新的线程来完成doit函数。注意由于并发导致的竞争所以需要注意connfd传入的形式这里选择将每个已连接描述符分配到它自己的动态分配的内存块。
代码如下只需要在Part I 基础上略作修改即可。
#include stdio.h#include csapp.h/* Recommended max cache and object sizes */
#define MAX_CACHE_SIZE 1049000
#define MAX_OBJECT_SIZE 102400/* You wont lose style points for including this long line in your code */
static const char *user_agent_hdr User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.3) Gecko/20120305 Firefox/10.0.3\r\n;
static const char *conn_hdr Connection: close\r\n;
static const char *proxy_hdr Proxy-Connection: close\r\n;void *doit(void *vargp);
void parse_uri(char *uri, char *hostname, char *path, int *port);
void build_request(rio_t *real_client, char *new_request, char *hostname, char *port);
void clienterror(int fd, char *cause, char *errnum, char *shortmsg, char *longmsg);
int main(int argc, char **argv) {int listenfd, *connfd;char hostname[MAXLINE], port[MAXLINE];socklen_t clientlen;struct sockaddr_storage clientaddr;/* Check command line args */if (argc ! 2) {fprintf(stderr, usage: %s port\n, argv[0]);exit(1);}listenfd Open_listenfd(argv[1]);pthread_t tid;while (1) {clientlen sizeof(clientaddr);connfd Malloc(sizeof(int)); // 给已连接的描述符分配其自己的内存块消除竞争*connfd Accept(listenfd, (SA *)clientaddr, clientlen);Getnameinfo((SA *)clientaddr, clientlen, hostname, MAXLINE, port, MAXLINE, 0);printf(Accepted connection from (%s, %s)\n, hostname, port);Pthread_create(tid, NULL, doit, connfd);}
}void *doit(void *vargp) {int fd *((int *)vargp);Free(vargp);Pthread_detach(Pthread_self());int real_server_fd;char buf[MAXLINE], method[MAXLINE], uri[MAXLINE], version[MAXLINE];char hostname[MAXLINE], path[MAXLINE];rio_t rio_client, rio_server;int port;/* Read request line and headers */Rio_readinitb(rio_client, fd); // 初始化rio内部缓冲区if (!Rio_readlineb(rio_client, buf, MAXLINE)) return; // 读到0个字符return// 请求行 GET http://www.cmu.edu/hub/index.html HTTP/1.1sscanf(buf, %s %s %s, method, uri, version);if (strcasecmp(method, GET)) {clienterror(fd, method, 501, Not Implemented, Tiny does not implement this method);return;}// 解析uriparse_uri(uri, hostname, path, port);char port_str[10];sprintf(port_str, %d, port);// 代理作为客户端连接目标服务器real_server_fd Open_clientfd(hostname, port_str);Rio_readinitb(rio_server, real_server_fd); // 初始化riochar new_request[MAXLINE];sprintf(new_request, GET %s HTTP/1.0\r\n, path);build_request(rio_client, new_request, hostname, port_str);// 向目标服务器发送http报文Rio_writen(real_server_fd, new_request, strlen(new_request));int char_nums;// 从目标服务器读到的数据直接发送给客户端while ((char_nums Rio_readlineb(rio_server, buf, MAXLINE))) Rio_writen(fd, buf, char_nums);Close(fd);
}void parse_uri(char *uri, char *hostname, char *path, int *port) {*port 80; // 默认端口char *ptr_hostname strstr(uri, //);// http://hostname:port/pathif (ptr_hostname)ptr_hostname 2; // 绝对urielseptr_hostname uri; // 相对uri相对url不包含http://或https://等协议标识符char *ptr_port strstr(ptr_hostname, :);if (ptr_port) {// 字符串ptr_hostname需要以\0为结尾标记*ptr_port \0;strncpy(hostname, ptr_hostname, MAXLINE);sscanf(ptr_port 1, %d%s, port, path);} else { // uri中没有端口号char *ptr_path strstr(ptr_hostname, /);if (ptr_path) {strncpy(path, ptr_path, MAXLINE);*ptr_path \0;strncpy(hostname, ptr_hostname, MAXLINE);} else {strncpy(hostname, ptr_hostname, MAXLINE);strcpy(path, );}}
}
void build_request(rio_t *real_client, char *new_request, char *hostname, char *port) {char temp_buf[MAXLINE];// 获取client的请求报文while (Rio_readlineb(real_client, temp_buf, MAXLINE) 0) {if (strstr(temp_buf, \r\n)) break; // end// 忽略以下几个字段的信息if (strstr(temp_buf, Host:)) continue;if (strstr(temp_buf, User-Agent:)) continue;if (strstr(temp_buf, Connection:)) continue;if (strstr(temp_buf, Proxy Connection:)) continue;sprintf(new_request, %s%s, new_request, temp_buf);printf(%s\n, new_request);fflush(stdout);}sprintf(new_request, %sHost: %s:%s\r\n, new_request, hostname, port);sprintf(new_request, %s%s%s%s, new_request, user_agent_hdr, conn_hdr, proxy_hdr);sprintf(new_request, %s\r\n, new_request);
}void clienterror(int fd, char *cause, char *errnum, char *shortmsg, char *longmsg) {char buf[MAXLINE];/* Print the HTTP response headers */sprintf(buf, HTTP/1.0 %s %s\r\n, errnum, shortmsg);Rio_writen(fd, buf, strlen(buf));sprintf(buf, Content-type: text/html\r\n\r\n);Rio_writen(fd, buf, strlen(buf));/* Print the HTTP response body */sprintf(buf, htmltitleTiny Error/title);Rio_writen(fd, buf, strlen(buf));sprintf(buf,body bgcolorffffff\r\n);Rio_writen(fd, buf, strlen(buf));sprintf(buf, %s: %s\r\n, errnum, shortmsg);Rio_writen(fd, buf, strlen(buf));sprintf(buf, p%s: %s\r\n, longmsg, cause);Rio_writen(fd, buf, strlen(buf));sprintf(buf, hremThe Tiny Web server/em\r\n);Rio_writen(fd, buf, strlen(buf));
}
Part III
第三部分需要添加缓存web对象的功能。根据实验文档的要求我们需要实现对缓存实现读写者问题且缓存的容量有限当容量不足是要按照类似LRU算法进行驱逐。我们先定义缓存的结构这里使用的是双向链表选择这个数据结构的原因在于LRU算法的需求链尾即使最近最少使用的web对象。关于缓存的定义以及相关操作如下
struct cache {char *url;char *content; // web object这里只是简单的将目标服务器发来的数据进行保存struct cache *prev;struct cache *next;
};struct cache *head NULL;
struct cache *tail NULL;/* 创建缓存节点 */
struct cache *create_cacheNode(char *url, char *content) {struct cache *node (struct cache *)malloc(sizeof(struct cache));int len strlen(url);node-url (char *)malloc(len * sizeof(char));strncpy(node-url, url, len);len strlen(content);node-content (char *)malloc(len * sizeof(char));strncpy(node-content, content, len);node-prev NULL;node-next NULL;return node;
}
/* 将节点添加到缓存头部 */
void add_cacheNode(struct cache *node) {node-next head;node-prev NULL;if (head ! NULL) {head-prev node;}head node;if (tail NULL) {tail node;}total_size strlen(node-content) * sizeof(char);
}
/* 删除缓存尾部节点 */
void delete_tail_cacheNode() {if (tail ! NULL) {total_size - strlen(tail-content) * sizeof(char);Free(tail-content);Free(tail-url);struct cache *tmp tail;tail tail-prev;Free(tmp);if (tail ! NULL) {tail-next NULL;} else {head NULL;}}
}
/* 移动缓存节点到头部 */
void move_cacheNode_to_head(struct cache *node) {if (node head) {return;} else if (node tail) {tail tail-prev;tail-next NULL;} else {node-prev-next node-next;node-next-prev node-prev;}node-prev NULL;node-next head;head-prev node;head node;
}
/* 获取缓存数据 */
char *get_cacheData(char *url) {struct cache *node head;while (node ! NULL) {if (strcmp(node-url, url) 0) {move_cacheNode_to_head(node);return node-content;}node node-next;}return NULL;
}
此外还需要实现读者写者问题为此定义了如下几个相关变量
int readcnt 0; // 目前读者数量
sem_t mutex_read_cnt, mutex_content;
void init() {Sem_init(mutex_content, 0, 1);Sem_init(mutex_read_cnt, 0, 1);
}同时定义了reader和writer函数作为读者和写者。
int reader(int fd, char *url);其内调用get_cacheData检查是否缓存命中若是则将所缓存的数据通过fd发送给客户端否则返回0表示缓存未命中。void writer(char **url*, char **content*);缓存未命中后与之前一样进行代理服务从目标服务器接收数据后发送到客户端如果web object的大小符号要求的话再调用writer将接收的数据进行缓存。
总代码如下
#include stdio.h#include csapp.h/* Recommended max cache and object sizes */
#define MAX_CACHE_SIZE 1049000
#define MAX_OBJECT_SIZE 102400char *content_tmp[MAX_OBJECT_SIZE];
/* You wont lose style points for including this long line in your code */
static const char *user_agent_hdr User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.3) Gecko/20120305 Firefox/10.0.3\r\n;
static const char *conn_hdr Connection: close\r\n;
static const char *proxy_hdr Proxy-Connection: close\r\n;int total_size 0; // 缓存中有效载荷总大小
int readcnt 0; // 目前读者数量
sem_t mutex_read_cnt, mutex_content;struct cache {char *url;char *content; // web 对象这里只是简单的将目标服务器发来的数据进行保存struct cache *prev;struct cache *next;
};struct cache *head NULL;
struct cache *tail NULL;// 缓存操作辅助函数
char *get_cacheData(char *url);
void move_cacheNode_to_head(struct cache *node);
void delete_tail_cacheNode();
void add_cacheNode(struct cache *node);
struct cache *create_cacheNode(char *url, char *content);void writer(char *url, char *content);
int reader(int fd, char *url);
void init();void *doit(void *vargp);
void parse_uri(char *uri, char *hostname, char *path, int *port);
void build_request(rio_t *real_client, char *new_request, char *hostname, char *port);
void clienterror(int fd, char *cause, char *errnum, char *shortmsg, char *longmsg);int main(int argc, char **argv) {init();int listenfd, *connfd;char hostname[MAXLINE], port[MAXLINE];socklen_t clientlen;struct sockaddr_storage clientaddr;/* Check command line args */if (argc ! 2) {fprintf(stderr, usage: %s port\n, argv[0]);exit(1);}listenfd Open_listenfd(argv[1]);pthread_t tid;while (1) {clientlen sizeof(clientaddr);connfd Malloc(sizeof(int)); // 给已连接的描述符分配其自己的内存块消除竞争*connfd Accept(listenfd, (SA *)clientaddr, clientlen);Getnameinfo((SA *)clientaddr, clientlen, hostname, MAXLINE, port, MAXLINE, 0);printf(Accepted connection from (%s, %s)\n, hostname, port);Pthread_create(tid, NULL, doit, connfd);}
}void *doit(void *vargp) {int fd *((int *)vargp);Free(vargp);Pthread_detach(Pthread_self());int real_server_fd;char buf[MAXLINE], method[MAXLINE], uri[MAXLINE], version[MAXLINE];char hostname[MAXLINE], path[MAXLINE], url[MAXLINE];rio_t rio_client, rio_server;int port;/* Read request line and headers */Rio_readinitb(rio_client, fd); // 初始化rio内部缓冲区if (!Rio_readlineb(rio_client, buf, MAXLINE)) return; // 读到0个字符return// 请求行 GET http://www.cmu.edu/hub/index.html HTTP/1.1sscanf(buf, %s %s %s, method, uri, version);if (strcasecmp(method, GET)) {clienterror(fd, method, 501, Not Implemented, Tiny does not implement this method);return;}// 解析uriparse_uri(uri, hostname, path, port);strncpy(url, hostname, MAXLINE);strncat(url, path, MAXLINE);if (reader(fd, url)) {Close(fd);return 1;}// 缓存未命中------char port_str[10];sprintf(port_str, %d, port);// 代理作为客户端连接目标服务器real_server_fd Open_clientfd(hostname, port_str);Rio_readinitb(rio_server, real_server_fd); // 初始化riochar new_request[MAXLINE];sprintf(new_request, GET %s HTTP/1.0\r\n, path);build_request(rio_client, new_request, hostname, port_str);// 向目标服务器发送http报文Rio_writen(real_server_fd, new_request, strlen(new_request));int char_nums;// 从目标服务器读到的数据直接发送给客户端int len 0;content_tmp[0] \0;while ((char_nums Rio_readlineb(rio_server, buf, MAXLINE))) {len char_nums;if (len MAX_OBJECT_SIZE) strncat(content_tmp, buf, char_nums);Rio_writen(fd, buf, char_nums);}if (len MAX_OBJECT_SIZE) {writer(url, content_tmp);}Close(fd); //--------------------------------------------------------
}void parse_uri(char *uri, char *hostname, char *path, int *port) {*port 80; // 默认端口char *ptr_hostname strstr(uri, //);// http://hostname:port/pathif (ptr_hostname)ptr_hostname 2; // 绝对urielseptr_hostname uri; // 相对uri相对url不包含http://或https://等协议标识符char *ptr_port strstr(ptr_hostname, :);if (ptr_port) {// 字符串ptr_hostname需要以\0为结尾标记*ptr_port \0;strncpy(hostname, ptr_hostname, MAXLINE);sscanf(ptr_port 1, %d%s, port, path);} else { // uri中没有端口号char *ptr_path strstr(ptr_hostname, /);if (ptr_path) {strncpy(path, ptr_path, MAXLINE);*ptr_path \0;strncpy(hostname, ptr_hostname, MAXLINE);} else {strncpy(hostname, ptr_hostname, MAXLINE);strcpy(path, );}}
}
void build_request(rio_t *real_client, char *new_request, char *hostname, char *port) {char temp_buf[MAXLINE];// 获取client的请求报文while (Rio_readlineb(real_client, temp_buf, MAXLINE) 0) {if (strstr(temp_buf, \r\n)) break; // end// 忽略以下几个字段的信息if (strstr(temp_buf, Host:)) continue;if (strstr(temp_buf, User-Agent:)) continue;if (strstr(temp_buf, Connection:)) continue;if (strstr(temp_buf, Proxy Connection:)) continue;sprintf(new_request, %s%s, new_request, temp_buf);printf(%s\n, new_request);fflush(stdout);}sprintf(new_request, %sHost: %s:%s\r\n, new_request, hostname, port);sprintf(new_request, %s%s%s%s, new_request, user_agent_hdr, conn_hdr, proxy_hdr);sprintf(new_request, %s\r\n, new_request);
}
void init() {Sem_init(mutex_content, 0, 1);Sem_init(mutex_read_cnt, 0, 1);
}
/* 创建缓存节点 */
struct cache *create_cacheNode(char *url, char *content) {struct cache *node (struct cache *)malloc(sizeof(struct cache));int len strlen(url);node-url (char *)malloc(len * sizeof(char));strncpy(node-url, url, len);len strlen(content);node-content (char *)malloc(len * sizeof(char));strncpy(node-content, content, len);node-prev NULL;node-next NULL;return node;
}
/* 将节点添加到缓存头部 */
void add_cacheNode(struct cache *node) {node-next head;node-prev NULL;if (head ! NULL) {head-prev node;}head node;if (tail NULL) {tail node;}total_size strlen(node-content) * sizeof(char);
}
/* 删除缓存尾部节点 */
void delete_tail_cacheNode() {if (tail ! NULL) {total_size - strlen(tail-content) * sizeof(char);Free(tail-content);Free(tail-url);struct cache *tmp tail;tail tail-prev;Free(tmp);if (tail ! NULL) {tail-next NULL;} else {head NULL;}}
}
/* 移动缓存节点到头部 */
void move_cacheNode_to_head(struct cache *node) {if (node head) {return;} else if (node tail) {tail tail-prev;tail-next NULL;} else {node-prev-next node-next;node-next-prev node-prev;}node-prev NULL;node-next head;head-prev node;head node;
}
/* 获取缓存数据 */
char *get_cacheData(char *url) {struct cache *node head;while (node ! NULL) {if (strcmp(node-url, url) 0) {move_cacheNode_to_head(node);return node-content;}node node-next;}return NULL;
}int reader(int fd, char *url) {int find 0;P(mutex_read_cnt);readcnt;if (readcnt 1) // first inP(mutex_content);V(mutex_read_cnt);char *content get_cacheData(url);if (content) { // 命中Rio_writen(fd, content, strlen(content));find 1;}P(mutex_read_cnt);readcnt--;if (readcnt 0) // last outV(mutex_content);V(mutex_read_cnt);return find;
}
void writer(char *url, char *content) {P(mutex_content);while (total_size strlen(content) * sizeof(char) MAX_CACHE_SIZE) {delete_tail_cacheNode();}struct cache *node create_cacheNode(url, content_tmp);add_cacheNode(node);V(mutex_content);
}
void clienterror(int fd, char *cause, char *errnum, char *shortmsg, char *longmsg) {char buf[MAXLINE];/* Print the HTTP response headers */sprintf(buf, HTTP/1.0 %s %s\r\n, errnum, shortmsg);Rio_writen(fd, buf, strlen(buf));sprintf(buf, Content-type: text/html\r\n\r\n);Rio_writen(fd, buf, strlen(buf));/* Print the HTTP response body */sprintf(buf, htmltitleTiny Error/title);Rio_writen(fd, buf, strlen(buf));sprintf(buf,body bgcolorffffff\r\n);Rio_writen(fd, buf, strlen(buf));sprintf(buf, %s: %s\r\n, errnum, shortmsg);Rio_writen(fd, buf, strlen(buf));sprintf(buf, p%s: %s\r\n, longmsg, cause);Rio_writen(fd, buf, strlen(buf));sprintf(buf, hremThe Tiny Web server/em\r\n);Rio_writen(fd, buf, strlen(buf));
}
总结
测试结果如下顺利拿下满分。 本实验和上一个malloclab实验就不是一个级别的可以说此实验是很简单的也就比datalab略难一下。由于本身也有一些web服务器的学习经验所以做起来还是比较轻松的但此实验无疑新手练习多线程和并发的好实验。
至此CSAPP的最后一个lab也完成了一共8个除开malloclab得了98分外其他7个实验均拿下满分。全部lab见这里。
