webBench源码加注释版本

main->build_request->bench->benchcore

/*
 * (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 */
//控制测试的时长：经过benchtime时间，通过发送SIGALARM信号调用函数alarm_handler，将timerexpired置为1，停止测试
volatile int timerexpired=0;
//测试的结果
int speed=0;
int failed=0;
int bytes=0;
/* 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"
int method=METHOD_GET;
int clients=1;
//???
int force=0;
int force_reload=0;
int proxyport=80;
char *proxyhost=NULL;
int benchtime=30;
/* internal */
int mypipe[2];
char host[MAXHOSTNAMELEN];
#define REQUEST_SIZE 2048
char request[REQUEST_SIZE];
/*
struct option{
    //不带短横线的参数名
    const char *name;
    //选项是否需要参数: no_argument(0)/required_argument(1)/optional_argument(2)
    int has_arg;
    //如果flag为NULL，getopt_long返回结构体中val的值；如果flag不为NULL，getopt_long返回0，flag所指对象的值为val的值，如果没有发现长选项，则flag所指的值不变
    int *flag;
    //发现长选项后的返回值，一般为短选项字符常量，或者是flag不为NULL时，载入flag的值
    int val;
}
*/
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;
}    

static void usage(void)
{
   fprintf(stderr,
    "webbench [option]... URL
"
    "  -f|--force               Don't wait for reply from server.
"
    "  -r|--reload              Send reload request - Pragma: no-cache.
"
    "  -t|--time <sec>          Run benchmark for <sec> seconds. Default 30.
"
    "  -p|--proxy <server:port> Use proxy server for request.
"
    "  -c|--clients <n>         Run <n> HTTP clients at once. Default one.
"
    "  -9|--http09              Use HTTP/0.9 style requests.
"
    "  -1|--http10              Use HTTP/1.0 protocol.
"
    "  -2|--http11              Use HTTP/1.1 protocol.
"
    "  --get                    Use GET request method.
"
    "  --head                   Use HEAD request method.
"
    "  --options                Use OPTIONS request method.
"
    "  --trace                  Use TRACE request method.
"
    "  -?|-h|--help             This information.
"
    "  -V|--version             Display program version.
"
    );
};
int main(int argc, char *argv[])
{
 int opt=0;
 int options_index=0;
 char *tmp=NULL;

 if(argc==1)
 {
      usage();
          return 2;
 } 
/**
    函数名：getlong_opt
    参数：int argc
          char * const argv[]
          const char* optstring:所有定义的短选项字符,如果短选项字符后加‘：’表示必须跟参数
          const struct option* longopts:长选项结构体
          int* longindex:当前找到的参数在longopts中的下标值
    返回值：如果为短选项，返回短选项的选项名
            如果为长选项，返回长选项结构体定义的返回值
            如果分析选项时遇到没有定义的选项，则返回？
            如果已经分析完所有选项，返回-1
    备注：两个全局变量（optarg/opyint)
          optarg:当前处理选项的参数值
          optint:下一个被处理的参数在argv中的下标值，当处理完所有选项，optint指向第一个非选项参数        
**/
    
 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"
");exit(0);
   case 't': benchtime=atoi(optarg);break;         
   case 'p': 
         /* proxy server parsing server:port */
         tmp=strrchr(optarg,':');//strrchr:查找字符在字符串中从左边开始，最后一次出现的位置，返回该字符及其后面的字符串
         proxyhost=optarg;
         if(tmp==NULL)
         {
             break;
         }
         if(tmp==optarg)
         {
             fprintf(stderr,"Error in option --proxy %s: Missing hostname.
",optarg);
             return 2;
         }
         if(tmp==optarg+strlen(optarg)-1)
         {
             fprintf(stderr,"Error in option --proxy %s Port number is missing.
",optarg);
             return 2;
         }
         *tmp='';
         proxyport=atoi(tmp+1);break;
   case ':':
   case 'h':
   case '?': usage();return 2;break;
   case 'c': clients=atoi(optarg);break;
  }
 }
 
 if(optind==argc) {
                      fprintf(stderr,"webbench: Missing URL!
");
              usage();
              return 2;
                    }

 if(clients==0) clients=1;
 if(benchtime==0) benchtime=60;//默认运行时间60
 /* Copyright */
 fprintf(stderr,"Webbench - Simple Web Benchmark "PROGRAM_VERSION"
"
     "Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.
"
     );
 build_request(argv[optind]);//构造请求消息体
 /* print bench info */
 printf("
Benchmarking: ");
 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("
");
 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(".
");
 return bench();
}

/*构造请求消息体*/
/***消息示例
****
GET http://www.tencent.com:8080/ http/1.0
User-Agent: WebBench PROGRAM_VERSION
Host: www.tencent.com
Pragma: no-cache
Connection: close
****
*/
void build_request(const char *url)
{
  char tmp[10];
  int i;

  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,"://"))
  {
      fprintf(stderr, "
%s: is not a valid URL.
",url);
      exit(2);
  }
  if(strlen(url)>1500)
  {
         fprintf(stderr,"URL is too long.
");
     exit(2);
  }
  if(proxyhost==NULL)
       if (0!=strncasecmp("http://",url,7)) 
       { fprintf(stderr,"
Only HTTP protocol is directly supported, set --proxy for others.
");
             exit(2);
           }
  /* protocol/host delimiter */
  i=strstr(url,"://")-url+3;
  /* printf("%d
",i); */

  if(strchr(url+i,'/')==NULL) {
                                fprintf(stderr,"
Invalid URL syntax - hostname don't ends with '/'.
");
                                exit(2);
                              }
  if(proxyhost==NULL)
  {
   /* get port from hostname */
   if(index(url+i,':')!=NULL &&
      index(url+i,':')<index(url+i,'/'))
   {
       strncpy(host,url+i,strchr(url+i,':')-url-i);
       bzero(tmp,10);
       strncpy(tmp,index(url+i,':')+1,strchr(url+i,'/')-index(url+i,':')-1);
       /* printf("tmp=%s
",tmp); */
       proxyport=atoi(tmp);
       if(proxyport==0) proxyport=80;
   } else
   {
     strncpy(host,url+i,strcspn(url+i,"/"));
   }
   // printf("Host=%s
",host);
   strcat(request+strlen(request),url+i+strcspn(url+i,"/"));
  } else
  {
   // printf("ProxyHost=%s
ProxyPort=%d
",proxyhost,proxyport);
   strcat(request,url);
  }
  if(http10==1)
      strcat(request," HTTP/1.0");
  else if (http10==2)
      strcat(request," HTTP/1.1");
  strcat(request,"
");
  if(http10>0)
      strcat(request,"User-Agent: WebBench "PROGRAM_VERSION"
");
  if(proxyhost==NULL && http10>0)
  {
      strcat(request,"Host: ");
      strcat(request,host);
      strcat(request,"
");
  }
  if(force_reload && proxyhost!=NULL)
  {
      strcat(request,"Pragma: no-cache
");
  }
  if(http10>1)
      strcat(request,"Connection: close
");
  /* add empty line at end */
  if(http10>0) strcat(request,"
"); 
  // printf("Req=%s
",request);
}

/* vraci system rc error kod */
/*
父进程创建clients个子进程，父子进程通过pipe通信
*/
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,"
Connect to server failed. Aborting benchmark.
");
           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
",i);
      perror("fork failed.");
      return 3;
  }

  if(pid== (pid_t) 0)
  {
    /* I am a child */
    if(proxyhost==NULL)
      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
",speed,failed); */
     fprintf(f,"%d %d %d
",speed,failed,bytes);
     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)
      {
          pid=fscanf(f,"%d %d %d",&i,&j,&k);
          if(pid<2)
                  {
                       fprintf(stderr,"Some of our childrens died.
");
                       break;
                  }
          speed+=i;
          failed+=j;
          bytes+=k;
          /* fprintf(stderr,"*Knock* %d %d read=%d
",speed,failed,pid); */
          if(--clients==0) break;
      }
      fclose(f);

  printf("
Speed=%d pages/min, %d bytes/sec.
Requests: %d susceed, %d failed.
",
          (int)((speed+failed)/(benchtime/60.0f)),
          (int)(bytes/(float)benchtime),
          speed,
          failed);
  }
  return i;
}
/*
    子进程通过socket向被测服务器发送请求，该过程会改变speed、failed、bytes的值
*/
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;
 sa.sa_flags=0;
 if(sigaction(SIGALRM,&sa,NULL))
    exit(3);
 alarm(benchtime);

 rlen=strlen(req);
 nexttry:while(1)
 {
    if(timerexpired)
    {
       if(failed>0)
       {
          /* fprintf(stderr,"Correcting failed by signal
"); */
          failed--;
       }
       return;
    }
    s=Socket(host,port);                          
    if(s<0) { failed++;continue;} 
    if(rlen!=write(s,req,rlen)) {failed++;close(s);continue;}
    if(http10==0) 
        if(shutdown(s,1)) { failed++;close(s);continue;}
    if(force==0) 
    {
            /* read all available data from socket */
        while(1)
        {
              if(timerexpired) break; 
          i=read(s,buf,1500);
              /* fprintf(stderr,"%d
",i); */
          if(i<0) 
              { 
                 failed++;
                 close(s);
                 goto nexttry;
              }
           else
               if(i==0) break;
               else
                   bytes+=i;
        }
    }
    if(close(s)) {failed++;continue;}
    speed++;
 }
}