源码剖析---------webbench（测压工具）

1、webbench：是一个压力测试工具，最多可以有3万个并发客户端发起请求，适用于小型的网站。主要测试每秒钟请求数和每秒钟数据传输量，同时支持静态、动态、SSL，部署简单，静动态均可测试。

2、安装：特别简单，百度一下就知道。

3、选项：在安装完成后，在命令行输入webbench或webbench -h或webbench -help，

就可以知道他的它的命令选项有哪些。

第一行是他该怎么用，后面的是他的各种选项信息。

4、用法：

例如：对百度进行压力测试，用法为：webbench -c 10 -t 30  http://baidu.com/

-c 后面跟的是请求的客户端个数，-t 请求多长时间 。

5、主要流程图。

6、代码分析：

主要的函数：

  （1）调用getopt_long库函数进行命令行解析。

  （2）build_request函数进行http请求的构造。

  （3）执行bench函数，用Socket函数来判断是否可以连接，创建管道，派生子进程等等。

  （4）子进程执行benchcore函数。

Socket.c

int Socket(const char *host, int clientPort)  {      int sock;      unsigned long inaddr;      struct sockaddr_in ad;      struct hostent *hp;        /* 初始化地址 */      memset(&ad, 0, sizeof(ad));      ad.sin_family = AF_INET;   //ipv4      /* 尝试把主机名转化为数字 */      inaddr = inet_addr(host);  //把ip地址转化为网络字节序    if (inaddr != INADDR_NONE)  //INADDR_NONE是0xffffffff        memcpy(&ad.sin_addr, &inaddr, sizeof(inaddr));      else      {          /* 取得 ip 地址 */          hp = gethostbyname(host);  //百度一下        if (hp == NULL)              return -1;          memcpy(&ad.sin_addr, hp->h_addr, hp->h_length);  //hp->h->addr中以二进制存储的ip地址    }      ad.sin_port = htons(clientPort);        /* 建立 socket */      sock = socket(AF_INET, SOCK_STREAM, 0);      if (sock < 0)          return sock;      /* 建立链接 */      if (connect(sock, (struct sockaddr *)&ad, sizeof(ad)) < 0)          return -1;      return sock;  }  

webbench.c

/*  * (C) Radim Kolar 1997-2004  * This is free software, see GNU Public License version 2 for  * details.  *  * Simple forking WWW Server benchmark:  *  * Usage:  *   webbench --help  *  * Return codes:  *    0 - sucess  *    1 - benchmark failed (server is not on-line)  *    2 - bad param  *    3 - internal error, fork failed  *  */  #include "socket.c"  #include <unistd.h>  #include <sys/param.h>  #include <rpc/types.h>  #include <getopt.h>  #include <strings.h>  #include <time.h>  #include <signal.h>    /* values */  volatile int timerexpired = 0;  //信号是否触发了int speed = 0;    //成功的次数int failed = 0;  //失败的次数int bytes = 0;   //从服务器总共读了多少字节数  /* globals */  int http10 = 1; /* 0 - http/0.9, 1 - http/1.0, 2 - http/1.1 */    /* Allow: GET, HEAD, OPTIONS, TRACE */  #define METHOD_GET 0  #define METHOD_HEAD 1  #define METHOD_OPTIONS 2  #define METHOD_TRACE 3  #define PROGRAM_VERSION "1.5"    /* 默认设置 */  int method = METHOD_GET; /* GET 方式 */  int clients = 1; /* 只模拟一个客户端 */  int force = 0; /* 等待响应 */  int force_reload = 0; /* 失败时不重新请求 */  int proxyport = 80; /* 访问端口 */  char *proxyhost = NULL; /* 代理服务器 */  int benchtime = 30; /* 模拟请求时间 */    /* internal */  int mypipe[2]; /* 管道 */  char host[MAXHOSTNAMELEN]; /* 网络地址 */  #define REQUEST_SIZE 2048  char request[REQUEST_SIZE]; /* 请求 */    static const struct option long_options[]=  {      {"force",no_argument,&force,1},      {"reload",no_argument,&force_reload,1},      {"time",required_argument,NULL,'t'},      {"help",no_argument,NULL,'?'},      {"http09",no_argument,NULL,'9'},      {"http10",no_argument,NULL,'1'},      {"http11",no_argument,NULL,'2'},      {"get",no_argument,&method,METHOD_GET},      {"head",no_argument,&method,METHOD_HEAD},      {"options",no_argument,&method,METHOD_OPTIONS},      {"trace",no_argument,&method,METHOD_TRACE},      {"version",no_argument,NULL,'V'},      {"proxy",required_argument,NULL,'p'},      {"clients",required_argument,NULL,'c'},      {NULL,0,NULL,0}  };    /* prototypes */  static void benchcore(const char* host,const int port, const char *request);  static int bench(void);  static void build_request(const char *url);    static void alarm_handler(int signal)  {      timerexpired = 1;  }    /* help 信息 */  static void usage(void)  {     fprintf(stderr,      "webbench [option]... URL\n"      "  -f|--force               Don't wait for reply from server.\n"      "  -r|--reload              Send reload request - Pragma: no-cache.\n"      "  -t|--time <sec>          Run benchmark for <sec> seconds. Default 30.\n"      "  -p|--proxy <server:port> Use proxy server for request.\n"      "  -c|--clients <n>         Run <n> HTTP clients at once. Default one.\n"      "  -9|--http09              Use HTTP/0.9 style requests.\n"      "  -1|--http10              Use HTTP/1.0 protocol.\n"      "  -2|--http11              Use HTTP/1.1 protocol.\n"      "  --get                    Use GET request method.\n"      "  --head                   Use HEAD request method.\n"      "  --options                Use OPTIONS request method.\n"      "  --trace                  Use TRACE request method.\n"      "  -?|-h|--help             This information.\n"      "  -V|--version             Display program version.\n"      );  };    int main(int argc, char *argv[])  {      int opt = 0;      int options_index = 0;      char *tmp = NULL;        /* 不带参数时直接输出 help 信息 */      if(argc == 1)      {          usage();          return 2;      }        /* getopt_long 为命令行解析的库函数，可通过 man 3 getopt_long 查看 */      while((opt = getopt_long(argc,argv,"912Vfrt:p:c:?h",long_options,&options_index)) != EOF )      {          /* 如果有返回对应的命令行参数 */          switch(opt)          {              case  0 : break;                //flag不为NULL            case 'f': force = 1;break;      //不等待服务器响应            case 'r': force_reload = 1;break;  //失败时重新发送请求            case '9': http10 = 0;break;      //http/0.9            case '1': http10 = 1;break;      //http/1.0            case '2': http10 = 2;break;      //http/1.1            case 'V':     //打印系统的版本（1.5）                      printf(PROGRAM_VERSION"\n");                        exit(0);              case 't':  //压力测试的运行时间                      benchtime = atoi(optarg);   //optarg为选项后面所跟的参数                      break;              case 'p':                        /* proxy server parsing server:port */   //以代理服务器（把一些请求和响应存在本地磁盘）的方式请求 （-p  server:port）                      tmp = strrchr(optarg,':');  //在optarg中找最后一次出现：的位置                      proxyhost = optarg;                        if(tmp == NULL)                        {                            break;                        }                        if(tmp == optarg)                        {                            fprintf(stderr,"Error in option --proxy %s: Missing hostname.\n",optarg);                            return 2;                        }                        if(tmp == optarg + strlen(optarg)-1)  // ：在字符串的尾部，则没有port参数                      {                            fprintf(stderr,"Error in option --proxy %s Port number is missing.\n",optarg);                            return 2;                        }                        *tmp = '\0';                        proxyport = atoi(tmp+1);  //指向端口号地址                      break;              case ':':                          //无效的选项            case 'h':                          //help            case '?': usage();return 2;break;     //无效的选项            case 'c': clients = atoi(optarg);break;  //并发请求的客户端数目        }      }        /* optind 被 getopt_long 设置为命令行参数中未读取的下一个元素下标值 */      if(optind == argc)                 //命令行参数中没有URL argv[optind]指向URL    {          fprintf(stderr,"webbench: Missing URL!\n");          usage();          return 2;      }        // 不能指定客户端数和请求时间为0     if(clients == 0) clients = 1;      if(benchtime == 0) benchtime = 60;        //打印Copyright    fprintf(stderr,"Webbench - Simple Web Benchmark "PROGRAM_VERSION"\n"       "Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.\n"       );        // 构造 HTTP 请求到 request 数组     build_request(argv[optind]);      //使用URL参数构造http请求      /* 以下到函数结束为输出提示信息 */      /* print bench info */      printf("\nBenchmarking: ");      switch(method)      {          case METHOD_GET:          default:              printf("GET");break;          case METHOD_OPTIONS:              printf("OPTIONS");break;          case METHOD_HEAD:              printf("HEAD");break;          case METHOD_TRACE:              printf("TRACE");break;      }        printf(" %s",argv[optind]);      switch(http10)      {          case 0: printf(" (using HTTP/0.9)");break;          case 2: printf(" (using HTTP/1.1)");break;      }        printf("\n");        if(clients == 1) printf("1 client");      else          printf("%d clients",clients);        printf(", running %d sec", benchtime);      if(force) printf(", early socket close");  //不等待服务器响应    if(proxyhost != NULL) printf(", via proxy server %s:%d",proxyhost,proxyport);  //代理服务器    if(force_reload) printf(", forcing reload");  //失败时重新发送请求    printf(".\n");        /* 开始压力测试，返回 bench 函数执行结果 */      return bench();  }     //url--->http://www.baidu.com/      void build_request(const char *url)  //构建http请求篇{      char tmp[10];      int i;        /* 初始化 */      bzero(host,MAXHOSTNAMELEN);      bzero(request,REQUEST_SIZE);        /* 判断应该使用的 HTTP 协议 */      if(force_reload && proxyhost != NULL && http10 < 1) http10 = 1;  //http/0.9 该为http/1.0    if(method == METHOD_HEAD && http10 < 1) http10 = 1;       //http/0.9 该为http/1.0    if(method == METHOD_OPTIONS && http10 < 2) http10 = 2;   //http/1.0或http/0.9改为http/1.1    if(method == METHOD_TRACE && http10 < 2) http10 = 2;     //http/1.0或http/0.9改为http/1.1   /***********构造请求行--》 请求方法 资源路径  版本********/      /*填写 method 方法 */      switch(method)      {          default:          case METHOD_GET: strcpy(request,"GET");break;          case METHOD_HEAD: strcpy(request,"HEAD");break;          case METHOD_OPTIONS: strcpy(request,"OPTIONS");break;          case METHOD_TRACE: strcpy(request,"TRACE");break;      }        strcat(request," ");  //追加      /* URL 合法性判断 */      if(NULL == strstr(url,"://"))  //不合法    {          fprintf(stderr, "\n%s: is not a valid URL.\n",url);          exit(2);      }        if(strlen(url)>1500)  //url太长，不合法    {          fprintf(stderr,"URL is too long.\n");          exit(2);      }        if(proxyhost == NULL)  //不是代理服务器方式        if(0 != strncasecmp("http://",url,7))  //忽略大小写的比较        {              /* 只支持 HTTP 地址 */              fprintf(stderr,"\nOnly HTTP protocol is directly supported, set --proxy for others.\n");              exit(2);          }    /* 找到主机名开始的地方 */  /* protocol/host delimiter */  i = strstr(url,"://")-url+3;     //i=7  // 必须以 / 结束if(strchr(url+i,'/')==NULL)  {  fprintf(stderr,"\nInvalid URL syntax - hostname don't ends with '/'.\n");  exit(2);  }    if(proxyhost == NULL)  //不是代理服务器方式，则没有指定端口号{  /* get port from hostname */  if(index(url+i,':') != NULL && index(url+i,':') < index(url+i,'/'))  //URL中有填写端口号 baidu.com:80{  strncpy(host,url+i,strchr(url+i,':')-url-i);  //host中存放网络地址，host baidu.com/* 端口 */  bzero(tmp,10);  strncpy(tmp,index(url+i,':')+1,strchr(url+i,'/')-index(url+i,':')-1);  //tmp 80proxyport = atoi(tmp);           // 设置端口 if(proxyport==0) proxyport=80;    } else {  strncpy(host,url+i,strcspn(url+i,"/"));   //strcspn->找第一次出现/的位置，下标值    host baidu.com}  strcat(request+strlen(request),url+i+strcspn(url+i,"/"));  //现在请求行里面填有  method 资源路径} else {  strcat(request,url);          }        //给请求行构造版本号    if(http10 == 1)          strcat(request," HTTP/1.0");      else if (http10==2)          strcat(request," HTTP/1.1");      strcat(request,"\r\n");      /*******************以上请求行构造完毕*************************/      /************构造请求消息报头********************/   //格式-->name: value   //name: value   //.......    if(http10 > 0)          strcat(request,"User-Agent: WebBench "PROGRAM_VERSION"\r\n");   //告诉服务器你的信息      if(proxyhost == NULL && http10 > 0)  //不是代理服务器方式    {          strcat(request,"Host: ");  //发送请求时，报头域时必须的。        strcat(request,host);          strcat(request,"\r\n");      }        if(force_reload && proxyhost != NULL)  //失败时重新发送和是代理服务器方式    {          strcat(request,"Pragma: no-cache\r\n");   //请求消息不能缓存    }        if(http10 > 1)          strcat(request,"Connection: close\r\n");  //如果版本号为1.1时，就通知服务器响应完成后，就关闭连接。/****************以上是构造请求消息报头******************//*********构造空行*************/    if(http10>0) strcat(request,"\r\n");  }    /* vraci system rc error kod */  static int bench(void)  {      int i,j,k;      pid_t pid = 0;      FILE *f;        /* 作为测试地址是否合法 */      /* check avaibility of target server */      i = Socket(proxyhost == NULL?host:proxyhost, proxyport);  //i为创建的套接字    if(i < 0){          fprintf(stderr,"\nConnect to server failed. Aborting benchmark.\n");          return 1;      }      close(i);    //测试阶段      /* 建立管道 */      /* create pipe */      if(pipe(mypipe))    //匿名管道    {          perror("pipe failed.");          return 3;      }        /* not needed, since we have alarm() in childrens */      /* wait 4 next system clock tick */      /*      * cas=time(NULL);      * while(time(NULL)==cas)      * sched_yield();      * */        /* 派生子进程 */      /* fork childs */      for(i = 0;i < clients;i++)      {          pid = fork();          if(pid <= (pid_t)0)  //特别重要        {              /* child process or error*/              sleep(1); /* make childs faster */              break; /* 子进程立刻跳出循环，要不就子进程继续 fork 了 */          }      }        //创建失败    if( pid < (pid_t)0)      {          fprintf(stderr,"problems forking worker no. %d\n",i);          perror("fork failed.");          return 3;      }        //子进程    if(pid == (pid_t)0)      {          /* 子进程发出实际请求 */          /* I am a child */          if(proxyhost == NULL)              benchcore(host,proxyport,request);         //跳到下面的函数        else              benchcore(proxyhost,proxyport,request);            /* 打开管道写 */          /* write results to pipe */          f = fdopen(mypipe[1],"w");   //将一个现有的文件描述符与标准I/O相结合，也就是把文件描述符转为文件指针        if(f == NULL)          {              perror("open pipe for writing failed.");              return 3;          }            /* fprintf(stderr,"Child - %d %d\n",speed,failed); */          fprintf(f,"%d %d %d\n",speed,failed,bytes);          fclose(f);            return 0;        } else {          /* 父进程打开管道读 */          f = fdopen(mypipe[0],"r");          if(f == NULL)          {              perror("open pipe for reading failed.");              return 3;          }               setvbuf(f,NULL,_IONBF,0);   //设置文件流的缓冲区，类型：IONRF：无缓冲区，        speed = 0; /* 传输速度 */          failed = 0; /* 失败请求数 */          bytes = 0; /* 传输字节数 */            while(1)          {              pid = fscanf(f,"%d %d %d",&i,&j,&k);              if(pid<2)              {                  fprintf(stderr,"Some of our childrens died.\n");                  break;              }  //汇总            speed += i;              failed += j;              bytes += k;              /* fprintf(stderr,"*Knock* %d %d read=%d\n",speed,failed,pid); */              /* 子进程是否读取完 */              if(--clients == 0) break;          }          fclose(f);            /* 结果计算 */          printf("\nSpeed=%d pages/min, %d bytes/sec.\nRequests: %d susceed, %d failed.\n",                  (int)((speed+failed)/(benchtime/60.0f)),                  (int)(bytes/(float)benchtime),                  speed,                  failed);      }      return i;  }    //子进程来发送请求void benchcore(const char *host,const int port,const char *req)         //ip   端口号   http请求{      int rlen;      char buf[1500];      int s,i;      struct sigaction sa;        /*安装信号 */      /* setup alarm signal handler */      sa.sa_handler = alarm_handler;  //对信号进行处理的函数    sa.sa_flags = 0;      if(sigaction(SIGALRM,&sa,NULL))  //设置信号处理        exit(3);        /* 设置闹钟函数 */      alarm(benchtime);        rlen = strlen(req);    nexttry:      while(1){          /* 收到信号则 timerexpired = 1 */          if(timerexpired)          {              if(failed > 0)  //因为信号而导致的失败            {                  /* fprintf(stderr,"Correcting failed by signal\n"); */                  failed--;              }              return;          }          /* 建立 socket, 进行 HTTP 请求 */          s = Socket(host,port);          if(s < 0)          {              failed++;              continue;          }          if(rlen!=write(s,req,rlen))          {              failed++;              close(s);              continue;          }          /* HTTP 0.9 的处理 */          if(http10==0)              /* 如果关闭不成功 */              if(shutdown(s,1))   //禁止在一个套接字上进行写，成功0，失败-1            {                  failed++;                  close(s);                  continue;              }            /* -f 选项时不读取服务器回复 */          if(force == 0)  //等待服务器的响应        {              /* read all available data from socket */              while(1)              {                  if(timerexpired) break;   //信号触发了                i = read(s,buf,1500);                  /* fprintf(stderr,"%d\n",i); */                  if(i<0)                  {                      failed++;                      close(s);                      goto nexttry;                  }                  else                      if(i == 0) break;                      else bytes+=i;              }          }          if(close(s))          {              failed++;              continue;          }          speed++;      }  }