root/foundation-apps/gmemusage-maxx/fastproc.c

/*
        gmemusage

        Copyright 2008-2009, Genirix Systems

*/



#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <stdio.h>
#include <errno.h>

#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/time.h>
//#include <sys/types.h>
//#include <sys/uio.h>

#include "process.h"
#include "extern.h"

/*  Hooks for the optimization code...
    Only for the commercial version
*/

char * fastload(char *);
void fastlist(void);

void fastlist(void)
{
        DIR             *directory;
        struct  dirent          *entry;
        int             i = 0;
    int         fd;

        long    start_time, total_time, end_time;
        long    start_time2, total_time2, end_time2;

        start_time = get_time();

        directory = opendir("/proc");


        while ( (entry = readdir(directory)) )
        {
                char    path[PATH_MAX];

                char*   buf;
                int     z;

                char    tmpString[1024];
                int             tmpInt;
                long    tmpLong;
                char    *cp;

                if (*entry->d_name < '0' || *entry->d_name > '9')
                        continue;

                sprintf(path, "/proc/%s/status", entry->d_name);

                // this will load in a allocate buffer the content of the /proc/PID/status file
                // remember to free it when done with it!

                start_time2 = get_time();

                buf = fastload(path);

                end_time2 = get_time();

                fprintf(stdout,"fastload(%s) %lu usec\n", path, end_time2 - start_time2);


/*
                sscanf(s, "%*s %s", tmpString);
                strncpy(processes[i].name, tmpString, 31);
*/

                i++;

                // dealocate the buffer
                free(buf);
        }
        total_time = get_time () - start_time;

        printf ("\nTime elapsed in fastlist() for %duSec processes=%d\n", total_time, i);

//      processCount = i;
}

/**  fast IO read text file for /proc
 *
 */
char * fastload(char * filename)
{
    int fd ;
    int result;
    char buffer[2048];
    long start_time, end_time;
    int len;
    char *newbuf;

    // check the existance of the file
/*
    start_time = get_time();
    result = access(filename,F_OK);
        end_time = get_time();

        fprintf(stdout,"access() %lu usec, ", end_time - start_time);

    if ( result == -1 )
    {
        fprintf(stderr,"Error while trying to access [%d] %s\n", result ,filename);
        return NULL;
    }
*/

    // open the files
//    start_time = get_time();
    fd = open(filename,O_RDONLY);
//    end_time = get_time();

//    fprintf(stdout,"open() %lu usec, ", end_time - start_time);

    if (fd == -1)
    {
        fprintf(stderr,"Error while trying to open: %s\n", filename);
        return NULL;
    }

    // reset the result var.

//      start_time = get_time();
    result = read(fd, buffer, sizeof(buffer));
    close (fd);
//    end_time = get_time();

//    fprintf(stdout,"read() %lu usec, ", end_time - start_time);


        // some IO error basic handling
        if (result == -1)
        {
                fprintf(stderr,"%s reading file %s\n", strerror(errno),filename);
                return NULL;
        }

        len = strlen(buffer);

        // allocate some memory
        newbuf = (char*) malloc( len+1 );
        newbuf[0] = 0;

        strncpy(newbuf, buffer, (len) );


 //     fprintf(stdout,"read[%d] bytes and returning[%d] bytes\n",sizeof(buffer), strlen(newbuf) );

    return newbuf;
}