<html>
<!-- Courtsey ruler
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<head>
<style>
p {
font: 14px ariel, sans serif;
}
#errorMsg {
font:bold 18px arial,sans-serif;
color:red;
text-align:center;
}
.chartContainer {
padding: 2px;
}
img.chart {
width:100%;
}
</style>
</head>
<body>
<?php
/*
Script: arednsig.php
Description: This scripts generates on the server charts showing
signal data spanning the period supplied by the user. The script
does the following:
- converts user supplied dates to epoch time
- gets the times of the first and last data point in the round
robin database (RRD)
- from above validates user supplied begin and end dates
- creates charts of the specified period
Copyright 2020 Jeff Owrey
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see http://www.gnu.org/license.
Revision History
* v20 released 18 Jan 2020 by J L Owrey; first release
*/
# Define global constants
# round robin database file
define("_RRD_FILE", str_replace("public_html/arednsig/arednsig.php",
"database/arednsigData.rrd",
$_SERVER["SCRIPT_FILENAME"]));
# charts html directory
define("_CHART_DIRECTORY", str_replace("arednsig.php",
"dynamic/",
$_SERVER["SCRIPT_FILENAME"]));
# standard chart width in pixels
define("_CHART_WIDTH", 600);
# standard chart height in pixels
define("_CHART_HEIGHT", 150);
# debug mode
define("_DEBUG", false);
# Set error handling modes.
error_reporting(E_ALL);
# Get user supplied chart begin and end dates.
$beginDate = $_POST["beginDate"];
$endDate = $_POST["endDate"];
# Convert the user supplied dates to epoch time stamps.
$beginDateEp = strtotime($beginDate);
$endDateEp = strtotime($endDate);
# Get the time stamp of the earliest data point in the RRD file.
$cmd = sprintf("rrdtool first %s --rraindex 1", _RRD_FILE);
$firstDP = shell_exec($cmd);
# Get the time stamp of the latest data point in the RRD file.
$cmd = sprintf("rrdtool last %s", _RRD_FILE);
$lastDP = shell_exec($cmd);
# Determine validity of user supplied dates. User supplied begin
# date must be less than user supplied end date. Furthermore both
# dates must be within the range of dates stored in the RRD.
if ($beginDateEp > $endDateEp) {
echo "<p id=\"errorMsg\">" .
"End date must be after begin date.</p>";
} elseif ($beginDateEp < $firstDP || $endDateEp > $lastDP) {
echo "<p id=\"errorMsg\">" .
"Date range must be between " .
date('m / d / Y', $firstDP) . " and " .
date('m / d / Y', $lastDP) . ".</p>";
} else {
# Generate charts from validated user supplied dates.
if (_DEBUG) {
echo "<p>Date range: " . $beginDateEp . " thru " .
$endDateEp . "</p>";
}
createChart('custom_signal', 'S', 'dBm',
'RSSI', $beginDateEp, $endDateEp,
0, 0, 2, false);
createChart('custom_snr', 'SNR', 'dBm',
'S/N', $beginDateEp, $endDateEp,
0, 0, 2, false);
# Send html commands to client browser.
echo "<div class=\"chartContainer\">" .
"<img class=\"chart\" src=\"dynamic/custom_signal.png\">" .
"</div>";
echo "<div class=\"chartContainer\">" .
"<img class=\"chart\" src=\"dynamic/custom_snr.png\">" .
"</div>";
}
function createChart($chartFile, $dataItem, $label, $title, $begin,
$end, $lower, $upper, $addTrend, $autoScale) {
/*
Uses rrdtool to create a chart of specified aredn node data item.
Parameters:
fileName - name of the created chart file
dataItem - data item to be charted
label - string containing a label for the item to be charted
title - string containing a title for the chart
begin - beginning time of the chart data
end - ending time of the data to be charted
lower - lower bound for chart ordinate #NOT USED
upper - upper bound for chart ordinate #NOT USED
addTrend - 0, show only chart data
1, show only a trend line
2, show a trend line and the chart data
autoScale - if True, then use vertical axis auto scaling
(lower and upper parameters are ignored), otherwise use
lower and upper parameters to set vertical axis scale
Returns: True if successful, False otherwise
*/
# Define path on server to chart files.
$chartPath = _CHART_DIRECTORY . $chartFile . ".png";
# Format the rrdtool chart command.
# Set chart file name, start time, end time, height, and width.
$cmdfmt = "rrdtool graph %s -a PNG -s %s -e %s -w %s -h %s ";
$cmd = sprintf($cmdfmt, $chartPath, $begin, $end, _CHART_WIDTH,
_CHART_HEIGHT);
$cmdfmt = "-l %s -u %s -r ";
# Set upper and lower ordinate bounds.
if ($lower < $upper) {
$cmd .= sprintf($cmdfmt, $lower, $upper);
} elseif ($autoScale) {
$cmd .= "-A ";
}
$cmd .= "-Y ";
# Set the chart ordinate label and chart title.
$cmdfmt = "-v %s -t %s ";
$cmd .= sprintf($cmdfmt, $label, $title);
# Define moving average window width.
$trendWindow = floor(($end - $begin) / 12);
# Show the data, or a moving average trend line over
# the data, or both.
$cmdfmt = "DEF:dSeries=%s:%s:LAST ";
$cmd .= sprintf($cmdfmt, _RRD_FILE, $dataItem);
if ($addTrend == 0) {
$cmd .= "LINE1:dSeries#0400ff ";
} elseif ($addTrend == 1) {
$cmdfmt = "CDEF:smoothed=dSeries,%s,TREND LINE2:smoothed#006600 ";
$cmd .= sprintf($cmdfmt, $trendWindow);
} elseif ($addTrend == 2) {
$cmd .= "LINE1:dSeries#0400ff ";
$cmdfmt = "CDEF:smoothed=dSeries,%s,TREND LINE2:smoothed#006600 ";
$cmd .= sprintf($cmdfmt, $trendWindow);
}
# Execute the formatted rrdtool command in the shell. The rrdtool
# command will complete execution before the html image tags get
# sent to the browser. This assures that the charts are available
# when the client browser executes the html code that loads the
# charts into the document displayed by the client browser.
if (_DEBUG) {
echo "<p>chart command:<br>" . $cmd . "</p>";
}
$result = shell_exec($cmd . " 2>&1");
if (_DEBUG) {
echo "<p>result:<br>" . $result . "</p>";
}
}
?>
</body>
</html>