Webbench源代码分析
Web Bench是一个网站压力测试的工具。其最后更新时间是2004年,已经十年多了。其源代码总共才500多行,全部使用C语言编写,最多可以模拟上万个并发连接。
其原理也比较简单,就是使用fork创建子进程,通过子进程来测试http连接,把测试结果写到管道,再有父进程读取管道信息来计算测试结果。流程图下:
其源代码有2个文件组成
socket.c是创建socket连接的。主要的代码在webbench.c中。
webbench.c中有几个主要的函数。
static void usage(void)是在使用出错时提示怎么使用本程序。
void build_request(const char *url)是用来创建http连接请求的。
static int bench(void)中创建管道和子进程,调用测试http函数。
void benchcore(const char *host,const int port,const char *req)对http请求进行测试。
socket.c源代码及注释:
/* $Id: socket.c 1.1 1995/01/01 07:11:14 cthuang Exp $ * * This module has been modified by Radim Kolar for OS/2 emx */ /*********************************************************************** module: socket.c program: popclient SCCS ID: @(#)socket.c 1.5 4/1/94 programmer: Virginia Tech Computing Center compiler: DEC RISC C compiler (Ultrix 4.1) environment: DEC Ultrix 4.3 description: UNIX sockets code. ***********************************************************************/ #include <sys/types.h> #include <sys/socket.h> #include <fcntl.h> #include <netinet/in.h> #include <arpa/inet.h> #include <netdb.h> #include <sys/time.h> #include <string.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <stdarg.h> /*********** 功能:通过地址和端口建立网络连接 @host:网络地址 @clientPort:端口 Return:建立的socket连接。 如果返回-1,表示建立连接失败 ************/ int Socket(const char *host, int clientPort) { int sock; unsigned long inaddr; struct sockaddr_in ad; struct hostent *hp; memset(&ad, 0, sizeof(ad)); ad.sin_family = AF_INET; inaddr = inet_addr(host);//将点分的十进制的IP转为无符号长整形 if (inaddr != INADDR_NONE) memcpy(&ad.sin_addr, &inaddr, sizeof(inaddr)); else//如果host是域名 { hp = gethostbyname(host);//用域名获取IP if (hp == NULL) return -1; memcpy(&ad.sin_addr, hp->h_addr, hp->h_length); } ad.sin_port = htons(clientPort); sock = socket(AF_INET, SOCK_STREAM, 0); if (sock < 0) return sock; //连接 if (connect(sock, (struct sockaddr *)&ad, sizeof(ad)) < 0) return -1; return sock; }
/* * (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; int speed=0; int failed=0; int bytes=0; /* globals */ //http协议的版本号 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" int method=METHOD_GET;//全局变量,指定http方法 int clients=1;//并发数 int force=0;//是否等待服务器应答。默认为不等待 int force_reload=0; int proxyport=80;//代理服务器端口号。默认为80 char *proxyhost=NULL;//代理服务器的地址 int benchtime=30;//运行多久。默认为30s。可以通过-t指定 /* internal */ int mypipe[2]; char host[MAXHOSTNAMELEN]; #define REQUEST_SIZE 2048 char request[REQUEST_SIZE]; //struct option结构体,配合getopt_long函数使用 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; } /************** 程序使用方法 ***************/ 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; if(argc==1)//使用方法不合适 { usage(); return 2; } //检查输入参数,并设置对应选项 while((opt=getopt_long(argc,argv,"912Vfrt:p:c:?h",long_options,&options_index))!=EOF ) { switch(opt) { case 0 : break; case 'f': force=1;break; case 'r': force_reload=1;break; case '9': http10=0;break; case '1': http10=1;break; case '2': http10=2;break; case 'V': printf(PROGRAM_VERSION"\n");exit(0);//输入版本号 case 't': benchtime=atoi(optarg);break; //optarg表示命令后的参数,例如-c 100,optarg为100。 //atoi表示把字符串转换成长整型。 case 'p': /* proxy server parsing server:port */ tmp=strrchr(optarg,':'); proxyhost=optarg;//设定地址 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) { fprintf(stderr,"Error in option --proxy %s Port number is missing.\n",optarg); return 2; } *tmp='\0'; proxyport=atoi(tmp+1);break;//重设端口号 case ':': case 'h': case '?': usage();return 2;break; case 'c': clients=atoi(optarg);break;//并发数 } } //optind为对应参数的下标位置 if(optind==argc) { fprintf(stderr,"webbench: Missing URL!\n"); usage(); return 2; } if(clients==0) clients=1; if(benchtime==0) benchtime=60; /* Copyright */ fprintf(stderr,"Webbench - Simple Web Benchmark "PROGRAM_VERSION"\n" "Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.\n" ); //使用中,最后为URL,所以optind应该是URL的位置 build_request(argv[optind]); /* 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"); if(proxyhost!=NULL) printf(", via proxy server %s:%d",proxyhost,proxyport); if(force_reload) printf(", forcing reload"); printf(".\n"); return bench(); } /**************** 创建URL请求连接 @url:url地址 创建好的请求放在全局变量request中 ****************/ void build_request(const char *url) { char tmp[10]; int i; //请求地址和请求连接清零 bzero(host,MAXHOSTNAMELEN); bzero(request,REQUEST_SIZE); if(force_reload && proxyhost!=NULL && http10<1) http10=1; if(method==METHOD_HEAD && http10<1) http10=1; if(method==METHOD_OPTIONS && http10<2) http10=2; if(method==METHOD_TRACE && http10<2) http10=2; 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," "); if(NULL==strstr(url,"://"))//找“://”在URL中的位置 { fprintf(stderr, "\n%s: is not a valid URL.\n",url); exit(2); } if(strlen(url)>1500)//url是否太长 { fprintf(stderr,"URL is too long.\n"); exit(2); } if(proxyhost==NULL)//代理服务器是否为空 if (0!=strncasecmp("http://",url,7)) //比较前7个字符串 { fprintf(stderr,"\nOnly HTTP protocol is directly supported, set --proxy for others.\n"); exit(2); } /* protocol/host delimiter */ i=strstr(url,"://")-url+3;//i指向http://后第一个位置 /* printf("%d\n",i); */ if(strchr(url+i,'/')==NULL) { fprintf(stderr,"\nInvalid URL syntax - hostname don't ends with '/'.\n"); exit(2); } if(proxyhost==NULL) { /* get port from hostname */ if(index(url+i,':')!=NULL && index(url+i,':')<index(url+i,'/'))//判断url中是否指定了端口号 { strncpy(host,url+i,strchr(url+i,':')-url-i);//取出主机地址 bzero(tmp,10); strncpy(tmp,index(url+i,':')+1,strchr(url+i,'/')-index(url+i,':')-1); /* printf("tmp=%s\n",tmp); */ proxyport=atoi(tmp);//端口号转换为int if(proxyport==0) proxyport=80; } else { strncpy(host,url+i,strcspn(url+i,"/")); } // printf("Host=%s\n",host); strcat(request+strlen(request),url+i+strcspn(url+i,"/")); } else { // printf("ProxyHost=%s\nProxyPort=%d\n",proxyhost,proxyport); strcat(request,url); } if(http10==1)//版本号 strcat(request," HTTP/1.0"); else if (http10==2) strcat(request," HTTP/1.1"); strcat(request,"\r\n"); if(http10>0) strcat(request,"User-Agent: WebBench "PROGRAM_VERSION"\r\n"); if(proxyhost==NULL && http10>0) { strcat(request,"Host: "); strcat(request,host); strcat(request,"\r\n"); } if(force_reload && proxyhost!=NULL) { strcat(request,"Pragma: no-cache\r\n"); } if(http10>1) strcat(request,"Connection: close\r\n"); /* add empty line at end */ if(http10>0) strcat(request,"\r\n"); // printf("Req=%s\n",request); } /* vraci system rc error kod */ /********************** 创建管道和子进程,对http请求进行测试 **********************/ static int bench(void) { int i,j,k; pid_t pid=0; FILE *f; /* check avaibility of target server */ i=Socket(proxyhost==NULL?host:proxyhost,proxyport); if(i<0) { fprintf(stderr,"\nConnect to server failed. Aborting benchmark.\n"); return 1; } close(i); /* create pipe */ if(pipe(mypipe)) { 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(); */ /* fork childs */ for(i=0;i<clients;i++) { pid=fork(); if(pid <= (pid_t) 0) { /* child process or error*/ sleep(1); /* make childs faster */ break; } } if( pid< (pid_t) 0) { fprintf(stderr,"problems forking worker no. %d\n",i); perror("fork failed."); return 3; } if(pid== (pid_t) 0) { /* I am a child */ if(proxyhost==NULL)//是否使用proxyhost benchcore(host,proxyport,request); else benchcore(proxyhost,proxyport,request); /* write results to pipe */ f=fdopen(mypipe[1],"w"); 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);//把每个子进程运行的结果放到管道。 fclose(f); return 0; } else { f=fdopen(mypipe[0],"r"); if(f==NULL) { perror("open pipe for reading failed."); return 3; } setvbuf(f,NULL,_IONBF,0); speed=0; failed=0; bytes=0; while(1)//父进程读取管道数据,并做加法 { pid=fscanf(f,"%d %d %d",&i,&j,&k); if(pid<2) { fprintf(stderr,"Some of our childrens died.\n"); break; } speed+=i; failed+=j; bytes+=k; /* fprintf(stderr,"*Knock* %d %d read=%d\n",speed,failed,pid); */ if(--clients==0) break; } fclose(f); //输出测试结果 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; } /****************************** 这里才是测试http的地方 @host:地址 @port:端口 @req:http格式方法 ********************************/ void benchcore(const char *host,const int port,const char *req) { int rlen; char buf[1500]; int s,i; struct sigaction sa; /* setup alarm signal handler */ sa.sa_handler=alarm_handler;//定时器方法 sa.sa_flags=0; if(sigaction(SIGALRM,&sa,NULL)) exit(3); alarm(benchtime); rlen=strlen(req); nexttry:while(1) { if(timerexpired)//定时器到时后,会设定timerexpired=1,函数就会返回 { if(failed>0) { /* fprintf(stderr,"Correcting failed by signal\n"); */ failed--; } return; } s=Socket(host,port); //创建连接 if(s<0) { failed++;continue;} //连接失败,failed加1 if(rlen!=write(s,req,rlen)) {failed++;close(s);continue;}//发送失败 if(http10==0) if(shutdown(s,1)) { failed++;close(s);continue;} if(force==0) //force等于0表示要读取http请求数据 { /* read all available data from socket */ while(1) { if(timerexpired) break; 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;//读取字节数增加 } } if(close(s)) {failed++;continue;} speed++;//http测试成功一次,speed加1 } }
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