html/ampy.inc.php

   1 <?php
   2 /*
   3  * Ampy helpers
   4  */
   5
   6 require_once('config.php');
   7
   8 function ampy_flush_rrd_daemon() {
   9         exec("/usr/bin/rrdtool flushcached --daemon ".escapeshellarg(RRDSOCK)." ".escapeshellarg(RRDFILE));
  10 }
  11
  12 /*
  13  * Initialized the counter file with an absolute value.
  14  * Note that the file mtime is important.
  15  */
  16 function ampy_set_counter($newcounter) {
  17         file_put_contents(COUNTERFILE.'.new', $newcounter);
  18         rename(COUNTERFILE.'.new', COUNTERFILE);
  19 }
  20
  21 /*
  22  * Returns an array
  23  * 0 => kWh counter value (file content)
  24  * 1 => last update (file mtime)
  25  */
  26 function ampy_get_old_counter_info() {
  27         $fd = fopen(COUNTERFILE, 'r');
  28         $mtime = fstat($fd)['mtime'];
  29         $counter = (double)fread($fd, 128);
  30         fclose($fd);
  31         #echo($mtime.'<br>');
  32         #echo('counter='.$counter.'<br>');
  33         return [$counter, $mtime];
  34 }
  35
  36 /*
  37  * Returns how many kWh have been spent since a date.
  38  * @param mtime seconds since epoch
  39  * @return float kW.h
  40  */
  41 function ampy_get_kwh_since($mtime) {
  42
  43         $params = [
  44                 '--daemon', RRDSOCK,
  45                 '-s', $mtime,
  46                 'DEF:watts='.RRDFILE.':watts:AVERAGE',
  47                 'VDEF:avg=watts,AVERAGE',
  48                 #'VDEF:last=watts,LAST',
  49                 'PRINT:avg:%lf',
  50                 #'PRINT:last:%lf',
  51         ];
  52         $info=rrd_graph( '-', $params);
  53         #print_r($info);
  54         $watts_since_counter = (double)$info['calcpr'][0];
  55         #echo('watts_since_counter='.$watts_since_counter.'<br>');
  56         #echo('hours_since_counter='.((time() - $mtime) / 3600.).'<br>');
  57         $wh_since_counter = $watts_since_counter * (time() - $mtime) / 3600.;
  58         #echo('wh_since_counter='.$wh_since_counter.'<br>');
  59         return $wh_since_counter / 1000.;
  60
  61 }
  62
  63 function ampy_get_counter() {
  64         $counter_mtime = ampy_get_old_counter_info();
  65         $counter = $counter_mtime[0];
  66         $mtime = $counter_mtime[1];
  67
  68         $counter += ampy_get_kwh_since($mtime);
  69         #echo('newcounter='.($counter/1000).' kWh<br>');
  70
  71         return $counter;
  72 }
  73 ?>