<?php
/**************************************************
* 
* Name: computeyearly 
* Function: this is run from cron once per day and generates the currently daily average and then adds that to 
* the store value and averages the two.  Once it has teh new average it writes that to the file.
* 
* I/O: reads and writes the the outputfile(loadavgfor.monthname), and reads from the other loadavg files.
* 
* By: M. Ward
* Date: May 30/06
* 
**************************************************/

//time for some defines
define('OUTFILEPREFIX','/loadavgfor.');
define('OUTPATH','/home/data/common/monitor/loadstats/');
define('MONTHNUMBER',date('n'));
define('MONTHNAME',date('M'));
define('TODAY', date('d'));

/*************************
* 
* Name: runcatchup
* Function: this function 'catches' up to where we are in the month by processing all of the data available
* upto today, and returns the computed average.
*
* I/O: returns the computed average 
* 
*************************/
function runcatchup($hostname) {
  $monthavg=0;
  for( $day = 1; $day < TODAY; $day++) {
  	$monthavg=$monthavg+getdayavg(OUTPATH . $hostname . "/" . MONTHNAME . OUTFILEPREFIX . $day );
  }
  return round($monthavg/TODAY, 2);
}

/*************************
*
* Name: getdayavg
* function: given the name of a file it reads all of the available data contained within and
* computes the average for that day.  If the file doesn't exist it returns 0
* 
*  I/O: takes the name of the file to be processed, returns the average or 0.
* 
**************************/
function getdayavg($filename) {
  $filedata = @file( $filename );
  #echo "walla: " . $data;
  if ( $filedata !== false ){
  	$count = 0;
  	$average = 0;
    foreach( $filedata as $line ) {
      list( $time,$current,$lastfive,$lastfifteen) = explode(',',rtrim($line));
      $average=$average+$lastfive;
      $count=$count+1;
    }
    return round($average/$count,2);
  } else {
  	return 0;
  }
}


//start the main processing loop
$sysname = php_uname('n');
$currentavg = 0;
//check to see if we have an output file already
if( is_file(OUTPATH . $sysname ."/" . MONTHNAME . OUTFILEPREFIX . MONTHNAME ) == FALSE ){
  $currentavg = runcatchup($sysname);
} else {
  //read the current data
  $filedata = @file( OUTPATH . $sysname ."/" . MONTHNAME . OUTFILEPREFIX .  MONTHNAME);
  $currentavg = rtrim($filedata[0]);
}

//write to the file
$fh = fopen( OUTPATH . $sysname ."/" . MONTHNAME . OUTFILEPREFIX . MONTHNAME, "w+" );

//get todays average
$currentavg = round( ($currentavg + getdayavg(OUTPATH . $sysname ."/" . MONTHNAME . OUTFILEPREFIX . TODAY))/2, 2);

if (fwrite($fh, $currentavg) === false) {
  echo "Cannot write to file \n\r";
}

fclose($fh);

?>