add piwik installation

www/analytics/core/AssetManager/UIAssetMinifier.php

@@ -0,0 +1,66 @@
+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ *
+ * @method static \Piwik\AssetManager\UIAssetMinifier getInstance()
+ */
+namespace Piwik\AssetManager;
+
+use Exception;
+use Piwik\Singleton;
+use JShrink\Minifier;
+
+class UIAssetMinifier extends Singleton
+{
+    const MINIFIED_JS_RATIO = 100;
+
+    protected function __construct()
+    {
+        self::validateDependency();
+        parent::__construct();
+    }
+
+
+    /**
+     * Indicates if the provided JavaScript content has already been minified or not.
+     * The heuristic is based on a custom ratio : (size of file) / (number of lines).
+     * The threshold (100) has been found empirically on existing files :
+     * - the ratio never exceeds 50 for non-minified content and
+     * - it never goes under 150 for minified content.
+     *
+     * @param string $content Contents of the JavaScript file
+     * @return boolean
+     */
+    public function isMinifiedJs($content)
+    {
+        $lineCount = substr_count($content, "\n");
+        if ($lineCount == 0) {
+            return true;
+        }
+
+        $contentSize = strlen($content);
+
+        $ratio = $contentSize / $lineCount;
+
+        return $ratio > self::MINIFIED_JS_RATIO;
+    }
+
+    /**
+     * @param string $content
+     * @return string
+     */
+    public function minifyJs($content)
+    {
+        return Minifier::minify($content);
+    }
+
+    private static function validateDependency()
+    {
+        if (!class_exists("JShrink\\Minifier"))
+            throw new Exception("JShrink could not be found, maybe you are using Piwik from git and need to have update Composer. <br>php composer.phar update");
+    }
+
+}