1 files changed, 171 insertions, 0 deletions
diff --git a/library/Icingadb/Util/PerfDataFormat.php b/library/Icingadb/Util/PerfDataFormat.php
new file mode 100644
index 0000000..1caffff
--- /dev/null
+++ b/library/Icingadb/Util/PerfDataFormat.php
@@ -0,0 +1,171 @@
+<?php
+
+/* Icinga DB Web | (c) 2021 Icinga GmbH | GPLv2 */
+
+namespace Icinga\Module\Icingadb\Util;
+
+class PerfDataFormat
+{
+    protected static $instance;
+
+    protected static $generalBase = 1000;
+
+    protected static $bitPrefix = ['b', 'kb', 'mb', 'gb', 'tb', 'pb', 'eb', 'zb', 'yb'];
+
+    protected static $bytePrefix = ['B', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
+
+    protected static $wattHourPrefix = ['Wh', 'kWh', 'MWh', 'GWh', 'TWh', 'PWh', 'EWh', 'ZWh', 'YWh'];
+
+    protected static $wattPrefix = [-1 => 'mW', 'W', 'kW', 'MW', 'GW'];
+
+    protected static $amperePrefix = [-3 => 'nA', -2 => 'µA', -1 => 'mA', 'A', 'kA', 'MA', 'GA'];
+
+    protected static $ampSecondPrefix = [-2 => 'µAs', -1 => 'mAs', 'As', 'kAs', 'MAs', 'GAs'];
+
+    protected static $voltPrefix = [-2 => 'µV', -1 => 'mV', 'V', 'kV', 'MV', 'GV'];
+
+    protected static $ohmPrefix = ['Ω'];
+
+    protected static $gramPrefix = [
+        -5 => 'fg',
+        -4 => 'pg',
+        -3 => 'ng',
+        -2 => 'µg',
+        -1 => 'mg',
+        'g',
+        'kg',
+        't',
+        'ktǂ',
+        'Mt',
+        'Gt'
+    ];
+
+    protected static $literPrefix = [
+        -5 => 'fl',
+        -4 => 'pl',
+        -3 => 'nl',
+        -2 => 'µl',
+        -1 => 'ml',
+        'l',
+        'kl',
+        'Ml',
+        'Gl',
+        'Tl',
+        'Pl'
+    ];
+
+    protected static $secondPrefix = [-3 => 'ns', -2 => 'µs', -1 => 'ms', 's'];
+
+    public static function getInstance(): self
+    {
+        if (self::$instance === null) {
+            self::$instance = new PerfDataFormat();
+        }
+
+        return self::$instance;
+    }
+
+    public static function bits($value): string
+    {
+        return self::formatForUnits($value, self::$bitPrefix, self::$generalBase);
+    }
+
+    public static function bytes($value): string
+    {
+        return self::formatForUnits($value, self::$bytePrefix, self::$generalBase);
+    }
+
+    public static function wattHours($value): string
+    {
+        return self::formatForUnits($value, self::$wattHourPrefix, self::$generalBase);
+    }
+
+    public static function watts($value): string
+    {
+        return self::formatForUnits($value, self::$wattPrefix, self::$generalBase);
+    }
+
+    public static function amperes($value): string
+    {
+        return self::formatForUnits($value, self::$amperePrefix, self::$generalBase);
+    }
+
+    public static function ampereSeconds($value): string
+    {
+        return self::formatForUnits($value, self::$ampSecondPrefix, self::$generalBase);
+    }
+
+    public static function volts($value): string
+    {
+        return self::formatForUnits($value, self::$voltPrefix, self::$generalBase);
+    }
+
+    public static function ohms($value): string
+    {
+        return self::formatForUnits($value, self::$ohmPrefix, self::$generalBase);
+    }
+
+    public static function grams($value): string
+    {
+        return self::formatForUnits($value, self::$gramPrefix, self::$generalBase);
+    }
+
+    public static function liters($value): string
+    {
+        return self::formatForUnits($value, self::$literPrefix, self::$generalBase);
+    }
+
+    public static function seconds($value): string
+    {
+        $value = (float) $value;
+        $absValue = abs($value);
+
+        if ($absValue < 60) {
+            return self::formatForUnits($value, self::$secondPrefix, self::$generalBase);
+        } elseif ($absValue < 3600) {
+            return sprintf('%0.2f m', $value / 60);
+        } elseif ($absValue < 86400) {
+            return sprintf('%0.2f h', $value / 3600);
+        }
+
+        return sprintf('%0.2f d', $value / 86400);
+    }
+
+    protected static function formatForUnits(float $value, array &$units, int $base): string
+    {
+        $sign = '';
+        if ($value < 0) {
+            $value = abs($value);
+            $sign = '-';
+        }
+
+        if ($value == 0) {
+            $pow = $result = 0;
+        } else {
+            $pow = floor(log($value, $base));
+
+            // Identify nearest unit if unknown
+            while (! isset($units[$pow])) {
+                if ($pow < 0) {
+                    $pow++;
+                } else {
+                    $pow--;
+                }
+            }
+
+            $result = $value / pow($base, $pow);
+        }
+
+        // 1034.23 looks better than 1.03, but 2.03 is fine:
+        if ($pow > 0 && $result < 2) {
+            $result = $value / pow($base, --$pow);
+        }
+
+        return sprintf(
+            '%s%0.2f %s',
+            $sign,
+            $result,
+            $units[$pow]
+        );
+    }
+}