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         trigger_error("Counter was reset to $newcounter", E_USER_WARNING);
  20 }
  21
  22 /*
  23  * Returns an array
  24  * 0 => kWh counter value (file content)
  25  * 1 => last update (file mtime)
  26  */
  27 function ampy_get_old_counter_info() {
  28         $fd = fopen(COUNTERFILE, 'r');
  29         $mtime = fstat($fd)['mtime'];
  30         $counter = (double)fread($fd, 128);
  31         fclose($fd);
  32         #echo($mtime.'<br>');
  33         #echo('counter='.$counter.'<br>');
  34         return [$counter, $mtime];
  35 }
  36
  37 /*
  38  * Returns how many kWh have been spent since a date.
  39  * The information is based on what has been recorded in the RRD database.
  40  * @param mtime seconds since epoch
  41  * @return float kW.h
  42  */
  43 function ampy_get_kwh_since($mtime) {
  44
  45         $params = [
  46                 '--daemon', RRDSOCK,
  47                 '-s', $mtime,
  48                 'DEF:watts='.RRDFILE.':watts:AVERAGE',
  49                 'VDEF:avg=watts,AVERAGE',
  50                 #'VDEF:last=watts,LAST',
  51                 'PRINT:avg:%lf',
  52                 #'PRINT:last:%lf',
  53         ];
  54         $info=rrd_graph( '-', $params);
  55         #print_r($info);
  56         $watts_since_counter = (double)$info['calcpr'][0];
  57         #echo('watts_since_counter='.$watts_since_counter.'<br>');
  58         #echo('hours_since_counter='.((time() - $mtime) / 3600.).'<br>');
  59         $wh_since_counter = $watts_since_counter * (time() - $mtime) / 3600.;
  60         #echo('wh_since_counter='.$wh_since_counter.'<br>');
  61         return $wh_since_counter / 1000.;
  62
  63 }
  64
  65 /*
  66  * Get counter current value
  67  * The value is based on:
  68  *  last value stored in counter file + ampy_get_kwh_since
  69  * @return float kWh on the counter.
  70  */
  71 function ampy_get_counter() {
  72         $counter_mtime = ampy_get_old_counter_info();
  73         $counter = $counter_mtime[0];
  74         $mtime = $counter_mtime[1];
  75
  76         $counter += ampy_get_kwh_since($mtime);
  77         #echo('newcounter='.($counter/1000).' kWh<br>');
  78
  79         return $counter;
  80 }
  81
  82 /*
  83  * Return all the information.
  84  * Make sure you call ampy_flush_rrd_daemon() first if you need real time
  85  * value.
  86  * @return array['lastupdate'=>timestamps,
  87  *               'watts'=>last_watt_value,
  88  *               'counter'=>total_kWh,
  89  */
  90 function ampy_get_info() {
  91         $info=rrd_lastupdate(RRDFILE);
  92         if ($info === FALSE)
  93                 $result=[
  94                         //'last_update' => 'unknown',
  95                         //'watts' => 'unknown',
  96                         'error' => rrd_error(),
  97                 ];
  98         else
  99                 $result=[
 100                         'last_update' => $info['last_update'],
 101                         'watts' => (double)$info['data'][0],
 102                 ];
 103
 104         $result['counter'] = ampy_get_counter();
 105         return $result;
 106 }
 107 ?>