Add caching admin options, basic setup checks

qa-config-example.php

@@ -86,6 +86,15 @@
 */
 
 /*
+	If you wish to use caching, you must define QA_CACHE_DIRECTORY to store the cache files. The
+	directory must be writable by the web server. It also must be OUTSIDE the public root. For
+	example if your site resides in '/var/www/yoursite/public_html', then the cache directory could
+	be '/var/www/yoursite/qa-cache', but it cannot be '/var/www/yoursite/public_html/qa-cache'.
+
+	define('QA_CACHE_DIRECTORY', '/path/to/writable_cache_directory/');
+*/
+
+/*
 	If you wish, you can define QA_COOKIE_DOMAIN so that any cookies created by Q2A are assigned
 	to a specific domain name, instead of the full domain name of the request by default. This is
 	useful if you're running multiple Q2A sites on subdomains with a shared user base.

qa-include/Q2A/Storage/CacheManager.php

+<?php
+/*
+	Question2Answer by Gideon Greenspan and contributors
+	http://www.question2answer.org/
+
+	File: qa-include/Q2A/Storage/CacheManager.php
+	Description: Handler for caching system.
+
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation; either version 2
+	of the License, or (at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	More about this license: http://www.question2answer.org/license.php
+*/
+
+/**
+ * Caches data (typically from database queries) to the filesystem.
+ */
+class Q2A_Storage_CacheManager
+{
+	private $enabled = false;
+	private $error = '';
+	private $dir;
+
+	/**
+	 * Creates a new CacheManager instance and checks it's set up properly.
+	 */
+	public function __construct()
+	{
+		$optEnabled = qa_opt('caching_enabled') == 1;
+
+		if (defined('QA_CACHE_DIRECTORY')) {
+			// expand symlinks so we compare true paths
+			$this->dir = realpath(QA_CACHE_DIRECTORY);
+			$baseDir = realpath(QA_BASE_DIR);
+
+			if (!is_writable($this->dir)) {
+				$this->error = qa_lang_html_sub('admin/caching_dir_error', QA_CACHE_DIRECTORY);
+			} elseif (strpos($this->dir, $baseDir) === 0) {
+				$this->error = qa_lang_html_sub('admin/caching_dir_public', QA_CACHE_DIRECTORY);
+			}
+
+			$this->enabled = empty($this->error) && $optEnabled;
+		} elseif ($optEnabled) {
+			$this->error = qa_lang_html('admin/caching_dir_missing');
+		}
+	}
+
+	/**
+	 * Whether caching is available.
+	 * @return bool
+	 */
+	public function isEnabled()
+	{
+		return $this->enabled;
+	}
+
+	/**
+	 * Get the last error.
+	 * @return string
+	 */
+	public function getError()
+	{
+		return $this->error;
+	}
+}

qa-include/app/admin.php

@@ -341,6 +341,11 @@
 				'url' => qa_path_html('admin/spam'),
 			);
 
+			$navigation['admin/caching']=array(
+				'label' => qa_lang_html('admin/caching_title'),
+				'url' => qa_path_html('admin/caching'),
+			);
+
 			$navigation['admin/stats']=array(
 				'label' => qa_lang_html('admin/stats_title'),
 				'url' => qa_path_html('admin/stats'),

qa-include/app/options.php

@@ -213,6 +213,9 @@
 			'avatar_q_page_q_size' => 50,
 			'avatar_store_size' => 400,
 			'avatar_users_size' => 30,
+			'caching_enabled' => 0,
+			'caching_q_time' => 5,
+			'caching_qlist_time' => 5,
 			'captcha_on_anon_post' => 1,
 			'captcha_on_feedback' => 1,
 			'captcha_on_register' => 1,

qa-include/lang/qa-lang-admin.php

@@ -53,6 +53,10 @@
 		'block_ips_note' => 'Use a hyphen for ranges or * to match any number. Examples: 192.168.0.4 , 192.168.0.0-192.168.0.31 , 192.168.0.*',
 		'block_user_popup' => 'Block user',
 		'block_words_note' => 'Use a * to match any letters. Examples: doh (will only match exact word doh) , doh* (will match doh or dohno) , do*h (will match doh, dooh, dough).',
+		'caching_dir_missing' => 'Cache directory has not been defined.',
+		'caching_dir_error' => 'The directory ^ defined as QA_CACHE_DIRECTORY is not writable by the web server.',
+		'caching_dir_public' => 'The directory ^ defined as QA_CACHE_DIRECTORY must be outside the public root.',
+		'caching_title' => 'Caching',
 		'cancel_mailing_button' => 'Cancel Mailing',
 		'categories' => 'Categories',
 		'categories_introduction' => 'To get started with categories, click the \'Add Category\' button.',

qa-include/lang/qa-lang-options.php

@@ -45,6 +45,9 @@
 		'avatar_users_size' => 'Avatar size on top users page:',
 		'block_bad_words' => 'Censored words - separate by spaces or commas:',
 		'block_ips_write' => 'Blocked IP addresses - separate by spaces or commas:',
+		'caching_enabled' => 'Enable caching:',
+		'caching_q_time' => 'Cache question pages for:',
+		'caching_qlist_time' => 'Cache question lists for:',
 		'captcha_module' => 'Use captcha module:',
 		'captcha_on_anon_post' => 'Use captcha for anonymous posts:',
 		'captcha_on_feedback' => 'Use captcha on feedback form:',

qa-include/pages/admin/admin-default.php

@@ -32,6 +32,8 @@
 	require_once QA_INCLUDE_DIR.'app/admin.php';
 
 
+//	Pages handled by this controller: general, emails, users, layout, viewing, lists, posting, permissions, feeds, spam, caching, mailing
+
 	$adminsection = strtolower(qa_request_part(1));
 
 
@@ -71,6 +73,8 @@
 		'avatar_q_page_q_size' => 'number',
 		'avatar_store_size' => 'number',
 		'avatar_users_size' => 'number',
+		'caching_q_time' => 'number',
+		'caching_qlist_time' => 'number',
 		'columns_tags' => 'number',
 		'columns_users' => 'number',
 		'feed_number_items' => 'number',
@@ -143,6 +147,7 @@
 		'avatar_allow_gravatar' => 'checkbox',
 		'avatar_allow_upload' => 'checkbox',
 		'avatar_default_show' => 'checkbox',
+		'caching_enabled' => 'checkbox',
 		'captcha_on_anon_post' => 'checkbox',
 		'captcha_on_feedback' => 'checkbox',
 		'captcha_on_register' => 'checkbox',
@@ -636,6 +641,19 @@
 			$checkboxtodisplay['moderate_update_time'] = $checkboxtodisplay['moderate_edited_again'];
 			break;
 
+		case 'caching':
+			$subtitle = 'admin/caching_title';
+			$formstyle = 'wide';
+
+			$showoptions = array('caching_enabled', 'caching_q_time', 'caching_qlist_time');
+
+			$checkboxtodisplay = array(
+				'caching_q_time' => 'option_caching_enabled',
+				'caching_qlist_time' => 'option_caching_enabled',
+			);
+
+			break;
+
 		case 'mailing':
 			require_once QA_INCLUDE_DIR.'app/mailing.php';
 
@@ -1530,6 +1548,11 @@
 				case 'mailing_per_minute':
 					$optionfield['suffix'] = qa_lang_html('admin/emails_per_minute');
 					break;
+
+				case 'caching_q_time':
+				case 'caching_qlist_time':
+					$optionfield['note'] = qa_lang_html_sub('main/x_minutes', '');
+				break;
 			}
 
 			if (isset($feedrequest) && $value)
@@ -1756,6 +1779,15 @@
 				$qa_content['form']['fields']['mailing_body']['note'] = qa_lang_html('admin/mailing_unsubscribe');
 			}
 			break;
+
+		case 'caching':
+			$cacheManager = new Q2A_Storage_CacheManager;
+			if (!$cacheManager->isEnabled()) {
+				$cacheError = $cacheManager->getError();
+				if ($cacheError)
+					$qa_content['error'] = $cacheError;
+			}
+			break;
 	}