Restored JSON core image generator for performance

PDO SQLite was performing unacceptably poorly.
Let's just load the entire integrity image into RAM…

e107_handlers/e_file_inspector_json.php

@@ -0,0 +1,114 @@
+<?php
+/**
+ * e107 website system
+ *
+ * Copyright (C) 2008-2020 e107 Inc (e107.org)
+ * Released under the terms and conditions of the
+ * GNU General Public License (http://www.gnu.org/licenses/gpl.txt)
+ */
+
+require_once("e_file_inspector.php");
+
+class e_file_inspector_json extends e_file_inspector
+{
+    private $coreImage;
+
+    /**
+     * @param $jsonFilePath string Absolute path to the file inspector database
+     */
+    public function __construct($jsonFilePath = null)
+    {
+        global $core_image;
+        if ($jsonFilePath === null) $jsonFilePath = e_ADMIN . "core_image.php";
+        require($jsonFilePath);
+        $this->coreImage = json_decode($core_image, true);
+        unset($core_image);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function getPathIterator($version = null)
+    {
+        $result = self::array_slash($this->coreImage);
+        if (!empty($version))
+        {
+            $result = array_filter($result, function ($value) use ($version)
+            {
+                return array_key_exists($version, $value);
+            });
+        }
+        return new ArrayIterator(array_keys($result));
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function getChecksums($path)
+    {
+        $path = $this->pathToDefaultPath($path);
+        return self::array_get($this->coreImage, $path, []);
+    }
+
+    /**
+     * Get an item from an array using "slash" notation.
+     *
+     * Based on Illuminate\Support\Arr::get()
+     *
+     * @param array $array
+     * @param string $key
+     * @param mixed $default
+     * @return mixed
+     * @copyright Copyright (c) Taylor Otwell
+     * @license https://github.com/illuminate/support/blob/master/LICENSE.md MIT License
+     */
+    private static function array_get($array, $key, $default = null)
+    {
+        if (is_null($key)) return $array;
+
+        if (isset($array[$key])) return $array[$key];
+
+        foreach (explode('/', $key) as $segment)
+        {
+            if (!is_array($array) || !array_key_exists($segment, $array))
+            {
+                return $default;
+            }
+
+            $array = $array[$segment];
+        }
+
+        return $array;
+    }
+
+    /**
+     * Flatten a multi-dimensional associative array with slashes.
+     * Excludes the second-to-last level of depth from flattening.
+     *
+     * Based on Illuminate\Support\Arr::dot()
+     *
+     * @param array $array
+     * @param string $prepend
+     * @return array
+     * @copyright Copyright (c) Taylor Otwell
+     * @license https://github.com/illuminate/support/blob/master/LICENSE.md MIT License
+     */
+    private static function array_slash($array, $prepend = '')
+    {
+        $results = array();
+
+        foreach ($array as $key => $value)
+        {
+            if (is_array($value) && is_array(reset($value)))
+            {
+                $results = array_merge($results, self::array_slash($value, $prepend . $key . '/'));
+            }
+            else
+            {
+                $results[$prepend . $key] = $value;
+            }
+        }
+
+        return $results;
+    }
+}