Adding upstream version 2.12.1.upstream/2.12.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 263 insertions, 0 deletions

diff --git a/library/Icinga/Chart/Unit/LogarithmicUnit.php b/library/Icinga/Chart/Unit/LogarithmicUnit.php
new file mode 100644
index 0000000..70961e2
--- /dev/null
+++ b/library/Icinga/Chart/Unit/LogarithmicUnit.php
@@ -0,0 +1,263 @@
+<?php
+/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Chart\Unit;
+
+/**
+ * Logarithmic tick distribution over the axis
+ *
+ * This class does not use the actual logarithm, but a slightly altered version called the
+ * Log-Modulo transformation. This is necessary, since a regular logarithmic scale is not able to display negative
+ * values and zero-points. See <a href="http://blogs.sas.com/content/iml/2014/07/14/log-transformation-of-pos-neg>
+ * this article </a> for a more detailed description.
+ */
+class LogarithmicUnit implements AxisUnit
+{
+    /**
+     * @var int
+     */
+    protected $base;
+
+    /**
+     * @var
+     */
+    protected $currentTick;
+
+    /**
+     * @var
+     */
+    protected $minExp;
+
+    /**
+     * @var
+     */
+    protected $maxExp;
+
+    /**
+     * True when the minimum value is static and isn't affected by the data set
+     *
+     * @var bool
+     */
+    protected $staticMin = false;
+
+    /**
+     * True when the maximum value is static and isn't affected by the data set
+     *
+     * @var bool
+     */
+    protected $staticMax = false;
+
+    /**
+     * Create and initialize this AxisUnit
+     *
+     * @param int $nrOfTicks The number of ticks to use
+     */
+    public function __construct($base = 10)
+    {
+        $this->base = $base;
+        $this->minExp = PHP_INT_MAX;
+        $this->maxExp = ~PHP_INT_MAX;
+    }
+
+    /**
+     * Add a dataset and calculate the minimum and maximum value for this AxisUnit
+     *
+     * @param   array $dataset  The dataset to add
+     * @param   int $idx        The idx (0 for x, 1 for y)
+     *
+     * @return  $this            Fluent interface
+     */
+    public function addValues(array $dataset, $idx = 0)
+    {
+        $datapoints = array();
+
+        foreach ($dataset['data'] as $points) {
+            $datapoints[] = $points[$idx];
+        }
+        if (empty($datapoints)) {
+            return $this;
+        }
+        sort($datapoints);
+        if (!$this->staticMax) {
+            $this->maxExp = max($this->maxExp, $this->logCeil($datapoints[count($datapoints) - 1]));
+        }
+        if (!$this->staticMin) {
+            $this->minExp = min($this->minExp, $this->logFloor($datapoints[0]));
+        }
+        $this->currentTick = 0;
+
+        return $this;
+    }
+
+    /**
+     * Transform the absolute value to an axis relative value
+     *
+     * @param   int $value  The absolute coordinate from the data set
+     * @return  float|int   The axis relative coordinate (between 0 and 100)
+     */
+    public function transform($value)
+    {
+        if ($value < $this->pow($this->minExp)) {
+            return 0;
+        } elseif ($value > $this->pow($this->maxExp)) {
+            return 100;
+        } else {
+            return 100 * ($this->log($value) - $this->minExp) / $this->getTicks();
+        }
+    }
+
+    /**
+     * Return the position of the current tick
+     *
+     * @return int
+     */
+    public function current(): int
+    {
+        return $this->currentTick * (100 / $this->getTicks());
+    }
+
+    /**
+     * Calculate the next tick and tick value
+     */
+    public function next(): void
+    {
+        ++ $this->currentTick;
+    }
+
+    /**
+     * Return the label for the current tick
+     *
+     * @return string The label for the current tick
+     */
+    public function key(): string
+    {
+        $currentBase = $this->currentTick + $this->minExp;
+        if (abs($currentBase) > 4) {
+            return $this->base . 'E' . $currentBase;
+        }
+        return (string) intval($this->pow($currentBase));
+    }
+
+    /**
+     * True when we're at a valid tick (iterator interface)
+     *
+     * @return bool
+     */
+    public function valid(): bool
+    {
+        return $this->currentTick >= 0 && $this->currentTick < $this->getTicks();
+    }
+
+    /**
+     * Reset the current tick and label value
+     */
+    public function rewind(): void
+    {
+        $this->currentTick = 0;
+    }
+
+    /**
+     * Perform a log-modulo transformation
+     *
+     * @param $value    The value to transform
+     *
+     * @return double   The transformed value
+     */
+    protected function log($value)
+    {
+        $sign = $value > 0 ? 1 : -1;
+        return $sign * log1p($sign * $value) / log($this->base);
+    }
+
+    /**
+     * Calculate the biggest exponent necessary to display the given data point
+     *
+     * @param $value
+     *
+     * @return float
+     */
+    protected function logCeil($value)
+    {
+        return ceil($this->log($value)) + 1;
+    }
+
+    /**
+     * Calculate the smallest exponent necessary to display the given data point
+     *
+     * @param $value
+     *
+     * @return float
+     */
+    protected function logFloor($value)
+    {
+        return floor($this->log($value));
+    }
+
+    /**
+     * Inverse function to the log-modulo transformation
+     *
+     * @param $value
+     *
+     * @return double
+     */
+    protected function pow($value)
+    {
+        if ($value == 0) {
+            return 0;
+        }
+        $sign = $value > 0 ? 1 : -1;
+        return $sign * (pow($this->base, $sign * $value));
+    }
+
+    /**
+     * Set the axis minimum value to a fixed value
+     *
+     * @param int $min The new minimum value
+     */
+    public function setMin($min)
+    {
+        $this->minExp = $this->logFloor($min);
+        $this->staticMin = true;
+    }
+
+    /**
+     * Set the axis maximum value to a fixed value
+     *
+     * @param int $max The new maximum value
+     */
+    public function setMax($max)
+    {
+        $this->maxExp = $this->logCeil($max);
+        $this->staticMax = true;
+    }
+
+    /**
+     * Return the current minimum value of the axis
+     *
+     * @return int The minimum set for this axis
+     */
+    public function getMin()
+    {
+        return $this->pow($this->minExp);
+    }
+
+    /**
+     * Return the current maximum value of the axis
+     *
+     * @return int The maximum set for this axis
+     */
+    public function getMax()
+    {
+        return $this->pow($this->maxExp);
+    }
+
+    /**
+     * Get the amount of ticks necessary to display this AxisUnit
+     *
+     * @return int
+     */
+    public function getTicks()
+    {
+        return $this->maxExp - $this->minExp;
+    }
+}