lib: Add util DirectoryIterator

refs #10705

library/Icinga/Util/DirectoryIterator.php

@@ -0,0 +1,191 @@
+<?php
+/* Icinga Web 2 | (c) 2013-2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Util;
+
+use InvalidArgumentException;
+use Iterator;
+
+/**
+ * Iterator for traversing a directory
+ */
+class DirectoryIterator implements Iterator
+{
+    /**
+     * Current directory item
+     *
+     * @var string|false
+     */
+    private $current;
+
+    /**
+     * The file extension to filter for
+     *
+     * @var string
+     */
+    protected $extension;
+
+    /**
+     * Directory handle
+     *
+     * @var resource
+     */
+    private $handle;
+
+    /**
+     * Current key
+     *
+     * @var string
+     */
+    private $key;
+
+    /**
+     * The path of the directory to traverse
+     *
+     * @var string
+     */
+    protected $path;
+
+    /**
+     * Whether to skip empty files
+     *
+     * Defaults to true.
+     *
+     * @var bool
+     */
+    protected $skipEmpty = true;
+
+    /**
+     * Whether to skip hidden files
+     *
+     * Defaults to true.
+     *
+     * @var bool
+     */
+    protected $skipHidden = true;
+
+    /**
+     * Create a new directory iterator from path
+     *
+     * The given path will not be validated whether it is readable. Use {@link isReadable()} before creating a new
+     * directory iterator instance.
+     *
+     * @param   string  $path       The path of the directory to traverse
+     * @param   string  $extension  The file extension to filter for. A leading dot is optional
+     */
+    public function __construct($path, $extension = null)
+    {
+        if (empty($path)) {
+            throw new InvalidArgumentException('The path can\'t be empty');
+        }
+        $this->path = $path;
+        if (! empty($extension)) {
+            $this->extension = '.' . ltrim($extension, '.');
+        }
+    }
+
+    /**
+     * Check whether the given path is a directory and is readable
+     *
+     * @param   string  $path   The path of the directory
+     *
+     * @return  bool
+     */
+    public static function isReadable($path)
+    {
+        return is_dir($path) && is_readable($path);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function current()
+    {
+        return $this->current;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function next()
+    {
+        do {
+            $file = readdir($this->handle);
+            if ($file === false) {
+                $key = false;
+                break;
+            } else {
+                $skip = false;
+                do {
+                    if ($this->skipHidden && $file[0] === '.') {
+                        $skip = true;
+                        break;
+                    }
+
+                    $path = $this->path . '/' . $file;
+
+                    if (is_dir($path)) {
+                        $skip = true;
+                        break;
+                    }
+
+                    if ($this->skipEmpty && ! filesize($path)) {
+                        $skip = true;
+                        break;
+                    }
+
+                    if ($this->extension && ! String::endsWith($file, $this->extension)) {
+                        $skip = true;
+                        break;
+                    }
+
+                    $key = $file;
+                    $file = $path;
+                } while (0);
+            }
+        } while ($skip);
+
+        $this->current = $file;
+        /** @noinspection PhpUndefinedVariableInspection */
+        $this->key = $key;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function key()
+    {
+        return $this->key;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function valid()
+    {
+        return $this->current !== false;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function rewind()
+    {
+        if ($this->handle === null) {
+            $this->handle = opendir($this->path);
+        } else {
+            rewinddir($this->handle);
+        }
+        $this->next();
+    }
+
+    /**
+     * Close directory handle if created
+     */
+    public function __destruct()
+    {
+        if ($this->handle !== null) {
+            closedir($this->handle);
+        }
+    }
+}