Refactor extension functions to add_extensions scripts

src/scripts/extensions/extension_map.php

@@ -0,0 +1,109 @@
+<?php
+
+/**
+ * Class for a map of extensions and their dependent extensions.
+ *
+ * Class ExtensionMap
+ */
+class ExtensionMap {
+    /** @var string Directory in which shared extensions are stored. */
+    private $extension_dir;
+
+    /** @var string File extension for PHP extension file. */
+    private $file_extension;
+
+    /** @var string Prefix in PHP extension file. */
+    private $file_prefix;
+
+    /** @var string String to store the map */
+    private $map;
+
+    /**
+     * ExtensionMap constructor.
+     */
+    function __construct() {
+        $this->extension_dir = ini_get('extension_dir');
+        $this->file_extension = (PHP_OS == 'WINNT' ? '.dll' : '.so');
+        $this->file_prefix = (PHP_OS == 'WINNT' ? 'php_' : '');
+        $this->map = '';
+    }
+
+    /**
+     * Function to check if a shared extension file exists.
+     *
+     * @param string $extension
+     * @return bool
+     */
+    public function checkSharedExtension($extension) {
+        $extension_file = $this->extension_dir. DIRECTORY_SEPARATOR . $this->file_prefix . $extension . $this->file_extension;
+        return file_exists($extension_file);
+    }
+
+    /**
+     * Function to get all shared extensions.
+     *
+     * @return string[]
+     */
+    public function getSharedExtensions() {
+        $files = scandir($this->extension_dir);
+        $extensions = array_diff($files, array('.','..'));
+        $filter_pattern = "/$this->file_extension|$this->file_prefix/";
+        return array_map(function ($extension) use($filter_pattern) {
+            return preg_replace($filter_pattern, '', $extension);
+        }, $extensions);
+    }
+
+    /**
+     * Function to patch dependencies if there are any bugs in Reflection data.
+     *
+     * @param string $extension
+     * @param array $dependencies
+     * @return array
+     */
+    public function patchDependencies($extension, $dependencies) {
+        // memcached 2.2.0 has no dependencies in reflection data.
+        if($extension == 'memcached') {
+            $dependencies = array_unique(array_merge($dependencies, array('igbinary', 'json', 'msgpack')));
+        }
+        return $dependencies;
+    }
+
+    /**
+     * Function to add extension to the map.
+     *
+     * @param string $extension
+     * @throws ReflectionException
+     */
+    public function addExtensionToMap($extension) {
+        // PHP 5.3 does not allow using $this.
+        $self = $this;
+
+        $ref = new ReflectionExtension($extension);
+        $dependencies = array_keys(array_map('strtolower', $ref->getDependencies()));
+        $dependencies = $this->patchDependencies($extension, $dependencies);
+        $dependencies = array_filter($dependencies, function ($dependency) use ($self) {
+            return $self->checkSharedExtension($dependency);
+        });
+        $self->map .= $extension . ': ' . implode(' ', $dependencies) . PHP_EOL;
+    }
+
+    /**
+     * Function to print the map of shared extensions and their dependent extensions.
+     *
+     * @return string
+     */
+    public function __toString() {
+        $extensions = array_map('strtolower', $this->getSharedExtensions());
+        foreach ($extensions as $extension) {
+            try {
+                $this->addExtensionToMap($extension);
+            } catch (ReflectionException $e) {
+
+            }
+        }
+        return $this->map;
+    }
+}
+
+$extension_map = new ExtensionMap();
+echo $extension_map;