需要剖析
- 服务端启动时指定某本地文件夹作为网络共享文件夹
- 共享文件夹中的所有文件及子文件夹均可被客户端拜访
- 应用浏览器作为客户端，在浏览器中可“看到”所有共享文件
- 用户可在浏览器中将指标文件下载到本地
- 服务端可暂定服务，但不影响正在下载指标文件的客户端
技术可行性剖析
服务端网络通讯
- 基于 Http 协定与客户端浏览器通信
- 可应用 tcp socket 实现对 Http 协定的反对
服务端文件操作
- 获取文件夹中的所有文件及子文件夹
- 返回文件列表 或 返回文件内容
零碎概要设计
基础设施
- Socket - Http 协定以 TCP 协定为底座
- Thread - 同时对多个客户端服务（申请响应）
- File - 文件夹信息读取，文件属性读取，文件数据读取
基础设施一 （Socket）
- 思考：是否应用课程中的网络通讯框架作为基础设施？
答：
临时不能课程中通信框架的服务端基于 select 机制，即：
- 服务端工作时会导致程序阻塞 （程序无奈持续向下执行）
- 每次只服务一个客户端（当服务工夫过长，会影响其它服务端通信）
文件服务器工作模型
网络通讯框架改良计划
新增服务端函数
TcpClient *TcpServer_Accept(TcpServer *server);- 阻塞函数，调用后始终期待客户端连贯
- 返回与客户端通信的 TcpClient 构造体
- 返回的 TcpClient 构造体互相独立，并且独立于服务端
TcpClient *TcpServer_Accept(TcpServer *server){ TcpClient *ret = NULL; if (server) { Server *s = (Server*)server; struct sockaddr_in caddr = {0}; socklen_t asize =sizeof(caddr); int fd = accept(s->fd, (struct sockaddr*)&caddr, &asize); if (fd > -1) { ret = TcpClient_From(fd); if (!ret) close(fd); } } return ret;}基础设施二 （Thread）
- 过程：应用程序的一次加载执行（零碎进行资源分配的根本单位）
线程：过程中的程序执行流
- 一个过程中能够存在多个线程 （至多存在一个线程）
- 每个线程执行不同的工作（多个线程可并行执行）
- 同一个过程中的多个线程共享过程的系统资源
## Linux 多线程API
- 头文件：
#include <pthread.h> - 线程创立函数：
int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(start_routine)(void*), void *arg);thread: pthread_t 变量的地址，用于返回线程标识attr: 线程的属性，可设置为 NULL，即：应用默认属性start_routine: 线程入口函数arg: 线程入口函数参数线程标识
- pthread_t pthread_self(void);
- 获取以后线程的 ID 标识
线程期待
int pthread_join(pthread_t thread, void **retval);- 期待指标线程执行完结
多线程编程示例
void *thread_entry(void *arg){ pthread_t id = pthread_self(); int n = (long)(arg); int i = 0; for (i=0; i<n; ++i) { printf("tid = %ld, i = %d\n", id, i); sleep(1); } return arg;}int main(){ pthread_t t1 = 0; pthread_t t2 = 0; int arg1 = 5; int arg2 = 10; printf("create thread...\n"); pthread_create(&t1, NULL, thread_entry, (void*)arg1); pthread_create(&t2, NULL, thread_entry, (void*)arg2); printf("t1 = %ld\n", t1); printf("t2 = %ld\n", t2); pthread_join(t1, NULL); pthread_join(t1, NULL); printf("child thread is finished...\n");}基础设施三 （Dir）
#include <sys/stat.h>#include <dirent.h>DIR *opendir(const char *name);struct dirent *readdir(DIR *dirp);int closedir(DIR *dirp);int stat(const char *file_name, struct stat *buf);
文件夹编程示例
DIR *dirp = opendir(".");if (dirp != NULL) { struct dirent *dp = NULL; while ((dp = readdir(dirp)) != NULL) { struct stat sb = {0}; if (stat(dp->d_name, &sb) != -1) { printf("name: %s, type: %d, len: %ld, mtime: %s", dp->d_name, dp->d_type, sb.st_size, ctime(&sb.st_mtime)); } }}基础设施四 （File）
#include <fcntl.h>int open(const char *pathname, int flags, mode_t mode);sszie_t read(int fd, void *buf, size_t count);ssize_t write(int fd, const void *buf, size_t count);int close(int fd);
文件编程示例
void file_copy(const char *dst, const char *src){ int dfd = open(dst, O_WRONLY|O_CREAT, 0600); int sfd = open(src, O_RDONLY); if ((dfd != -1) && (sfd != -1)) { char buf[512] = {0}; int len = 0; while ((len = read(sfd, buf, sizeof(buf))) > 0) { write(dfd, buf, len); } } close(dfd); close(sfd);}编程试验：后期技术筹备
main.c
#include<stdio.h>#include<stdlib.h>#include<unistd.h>#include<pthread.h>#include <sys/types.h>#include <dirent.h>#include <sys/stat.h>#include <time.h>#include <fcntl.h>#include "tcp_server.h"#include "tcp_client.h" void func1(){ TcpServer *s = TcpServer_New(); TcpServer_Start(s, 9000, 100); if (TcpServer_IsValid(s)) { char buf[64] = {0}; int len = 0; TcpClient *c = TcpServer_Accept(s); if (c) { len = TcpClient_RecvRaw(c, buf, sizeof(buf) - 1); buf[len] = 0; printf("recv = %s\n", buf); TcpClient_SendRaw(c, buf, len); TcpClient_Del(c); } TcpServer_Del(s); }}void *thread_entry(void *arg){ pthread_t id = pthread_self(); int n = (long)(arg); int i = 0; for (i=0; i<n; ++i) { printf("tid = %ld, i = %d\n", id, i); sleep(1); } return arg;}void func2(){ pthread_t t1 = 0; pthread_t t2 = 0; int arg1 = 5; int arg2 = 10; printf("create thread...\n"); pthread_create(&t1, NULL, thread_entry, (void*)arg1); pthread_create(&t2, NULL, thread_entry, (void*)arg2); printf("t1 = %ld\n", t1); printf("t2 = %ld\n", t2); pthread_join(t1, NULL); pthread_join(t1, NULL); printf("child thread is finished...\n");}void func3(){ DIR *dirp = opendir("."); if (dirp != NULL) { struct dirent *dp = NULL; while ((dp = readdir(dirp)) != NULL) { struct stat sb = {0}; if (stat(dp->d_name, &sb) != -1) { printf("name: %s, type: %d, len: %ld, mtime: %s", dp->d_name, dp->d_type, sb.st_size, ctime(&sb.st_mtime)); } } }}void file_copy(const char *dst, const char *src){ int dfd = open(dst, O_WRONLY|O_CREAT, 0600); int sfd = open(src, O_RDONLY); if ((dfd != -1) && (sfd != -1)) { char buf[512] = {0}; int len = 0; while ((len = read(sfd, buf, sizeof(buf))) > 0) { write(dfd, buf, len); } } close(dfd); close(sfd);}int main(void){ printf("=====================\n"); func1(); printf("=====================\n"); func2(); printf("=====================\n"); func3(); printf("=====================\n"); file_copy("new.out", "a.out"); return 0;}输入
=====================recv = http://www.cmsoft.cn=====================create thread...t1 = 140155835639552t2 = 140155827246848tid = 140155835639552, i = 0tid = 140155827246848, i = 0tid = 140155835639552, i = 1tid = 140155827246848, i = 1tid = 140155835639552, i = 2tid = 140155827246848, i = 2tid = 140155835639552, i = 3tid = 140155827246848, i = 3tid = 140155835639552, i = 4tid = 140155827246848, i = 4tid = 140155827246848, i = 5child thread is finished...=====================name: utility.c, type: 8, len: 1875, mtime: Sun Jun 4 18:34:38 2023name: server_task.o, type: 8, len: 6872, mtime: Sun Jun 4 18:34:38 2023name: .., type: 4, len: 4096, mtime: Sun Jun 4 18:34:29 2023name: tcp_server.c, type: 8, len: 4978, mtime: Sun Jun 4 19:29:28 2023name: main.c, type: 8, len: 2353, mtime: Sun Jun 4 20:01:53 2023name: udp_point.h, type: 8, len: 860, mtime: Sun Jun 4 18:34:38 2023name: ., type: 4, len: 4096, mtime: Sun Jun 4 20:02:37 2023name: tcp_client.h, type: 8, len: 932, mtime: Sun Jun 4 18:34:38 2023name: new.out, type: 8, len: 29136, mtime: Sun Jun 4 20:02:18 2023name: message.h, type: 8, len: 482, mtime: Sun Jun 4 18:34:38 2023name: tcp_server.o, type: 8, len: 5864, mtime: Sun Jun 4 19:32:19 2023name: msg_parser.o, type: 8, len: 3960, mtime: Sun Jun 4 19:32:19 2023name: msg_parser.c, type: 8, len: 4218, mtime: Sun Jun 4 18:34:38 2023name: a.out, type: 8, len: 29136, mtime: Sun Jun 4 20:02:37 2023name: tcp_client.c, type: 8, len: 3825, mtime: Sun Jun 4 18:34:38 2023name: msg_parser.h, type: 8, len: 327, mtime: Sun Jun 4 18:34:38 2023name: utility.o, type: 8, len: 2752, mtime: Sun Jun 4 19:32:19 2023name: tcp_server.h, type: 8, len: 770, mtime: Sun Jun 4 19:29:33 2023name: message.o, type: 8, len: 2608, mtime: Sun Jun 4 19:32:19 2023name: msg_def.h, type: 8, len: 134, mtime: Sun Jun 4 18:34:38 2023name: tcp_client.o, type: 8, len: 5472, mtime: Sun Jun 4 19:32:19 2023name: message.c, type: 8, len: 1202, mtime: Sun Jun 4 18:34:38 2023name: utility.h, type: 8, len: 1539, mtime: Sun Jun 4 18:34:38 2023name: udp_point.c, type: 8, len: 4793, mtime: Sun Jun 4 18:34:38 2023name: Makefile, type: 8, len: 274, mtime: Sun Jun 4 18:34:38 2023name: udp_point.o, type: 8, len: 6232, mtime: Sun Jun 4 19:32:19 2023name: main.o, type: 8, len: 5592, mtime: Sun Jun 4 20:01:56 2023=====================