Caching mass-delete option

qa-include/Q2A/Storage/CacheFactory.php

@@ -25,17 +25,23 @@
  */
 class Q2A_Storage_CacheFactory
 {
+	private static $cacheDriver = null;
+
 	/**
 	 * Get the appropriate cache handler.
 	 * @return Q2A_Storage_CacheInterface The cache handler.
 	 */
 	public static function getCacheDriver()
 	{
+		if (self::$cacheDriver === null) {
 			$config = array(
 				'enabled' => (int) qa_opt('caching_enabled') === 1,
 				'dir' => defined('QA_CACHE_DIRECTORY') ? QA_CACHE_DIRECTORY : null,
 			);
 
-		return new Q2A_Storage_FileCacheDriver($config);
+			self::$cacheDriver = new Q2A_Storage_FileCacheDriver($config);
+		}
+
+		return self::$cacheDriver;
 	}
 }

qa-include/Q2A/Storage/FileCacheDriver.php

@@ -110,7 +110,7 @@ class Q2A_Storage_FileCacheDriver
 			$file = $this->getFilename($key);
 			$dir = dirname($file);
 			if (is_dir($dir) || mkdir($dir, 0777, true)) {
-				$success = file_put_contents($file, $cache) !== false;
+				$success = @file_put_contents($file, $cache) !== false;
 			}
 		}
 
@@ -118,6 +118,74 @@ class Q2A_Storage_FileCacheDriver
 	}
 
 	/**
+	 * Delete an item from the cache.
+	 * @param  string $key The unique cache identifier.
+	 * @return bool Whether the operation succeeded.
+	 */
+	public function delete($key)
+	{
+		if ($this->enabled) {
+			$file = $this->getFilename($key);
+			$dir = dirname($key);
+
+			return $this->deleteFile($file);
+		}
+
+		return false;
+	}
+
+	/**
+	 * Delete multiple items from the cache.
+	 * @param  int $limit Maximum number of items to process. 0 = unlimited
+	 * @param  int $start Offset from which to start (used for 'batching' deletes).
+	 * @param  bool $expiredOnly Delete cache only if it has expired.
+	 * @return int Number of files deleted.
+	 */
+	public function clear($limit=0, $start=0, $expiredOnly=false)
+	{
+		$seek = $processed = $deleted = 0;
+
+		// fetch directories first to lower memory usage
+		$cacheDirs = glob($this->cacheDir . '/*/*', GLOB_ONLYDIR);
+		foreach ($cacheDirs as $dir) {
+			$cacheFiles = glob($dir . '/*');
+			foreach ($cacheFiles as $file) {
+				if ($seek < $start) {
+					$seek++;
+					continue;
+				}
+
+				$wasDeleted = false;
+				if ($expiredOnly) {
+					if (is_readable($file)) {
+						$fp = fopen($file, 'r');
+						$key = fgets($fp);
+						$expiry = fgets($fp);
+						// fclose($fp);
+						if (is_numeric($expiry) && time() > $expiry) {
+							$wasDeleted = $this->deleteFile($file);
+						}
+					}
+				} else {
+					$wasDeleted = $this->deleteFile($file);
+				}
+
+				if ($wasDeleted) {
+					$deleted++;
+				}
+
+				$processed++;
+				if ($processed >= $limit) {
+					break 2;
+				}
+			}
+		}
+
+		// return how many files were deleted - caller can figure out how many to skip next time
+		return $deleted;
+	}
+
+	/**
 	 * Whether caching is available.
 	 * @return bool
 	 */
@@ -136,6 +204,49 @@ class Q2A_Storage_FileCacheDriver
 	}
 
 	/**
+	 * Get current statistics for the cache.
+	 * @return array Array of stats: 'files' => number of files, 'size' => total file size in bytes.
+	 */
+	public function getStats()
+	{
+		if (!$this->enabled) {
+			return array('files' => 0, 'size' => 0);
+		}
+
+		$totalFiles = 0;
+		$totalBytes = 0;
+		$dirIter = new RecursiveDirectoryIterator($this->cacheDir);
+		foreach (new RecursiveIteratorIterator($dirIter) as $file) {
+			if (strpos($file->getFilename(), '.') === 0) {
+				// TODO: use FilesystemIterator::SKIP_DOTS once we're on minimum PHP 5.3
+				continue;
+			}
+
+			$totalFiles++;
+			$totalBytes += $file->getSize();
+		}
+
+		return array(
+			'files' => $totalFiles,
+			'size' => $totalBytes,
+		);
+	}
+
+	/**
+	 * Delete a specific file
+	 * @param  string $file Filename to delete
+	 * @return bool Whether the file was deleted successfully.
+	 */
+	private function deleteFile($file)
+	{
+		if (is_writable($file)) {
+			return @unlink($file) === true;
+		}
+
+		return false;
+	}
+
+	/**
 	 * Generates filename for cache key, of the form `1/23/123abc`
 	 * @param string $key The unique cache key.
 	 * @return string

qa-include/app/recalc.php

@@ -523,6 +523,29 @@ function qa_recalc_perform_step(&$state)
 				qa_recalc_transition($state, 'doblobstodb_complete');
 			break;
 
+		case 'docacheclear':
+			qa_recalc_transition($state, 'docacheclear_process');
+			break;
+
+		case 'docacheclear_process':
+			$limit = 5;
+			$cacheDriver = Q2A_Storage_CacheFactory::getCacheDriver();
+			$cacheStats = $cacheDriver->getStats();
+
+			if ($next > $length) {
+				qa_recalc_transition($state, 'docacheclear_error');
+				break;
+			}
+			if ($cacheStats['files'] > 0) {
+				$deleted = $cacheDriver->clear($limit, $next);
+				$done += $deleted;
+				$next += $limit - $deleted; // if some files were not deleted, skip them next time
+				$continue = true;
+			} else {
+				qa_recalc_transition($state, 'docacheclear_complete');
+			}
+			break;
+
 		default:
 			$state = '';
 			break;
@@ -609,6 +632,13 @@ function qa_recalc_stage_length($operation)
 			$length = qa_db_count_blobs_on_disk();
 			break;
 
+		case 'docachetrim_process':
+		case 'docacheclear_process':
+			$cacheDriver = Q2A_Storage_CacheFactory::getCacheDriver();
+			$cacheStats = $cacheDriver->getStats();
+			$length = $cacheStats['files'];
+			break;
+
 		default:
 			$length = 0;
 			break;
@@ -749,6 +779,20 @@ function qa_recalc_get_message($state)
 			$message = qa_lang('admin/blobs_move_complete');
 			break;
 
+		case 'docachetrim_process':
+		case 'docacheclear_process':
+			$message = qa_recalc_progress_lang('admin/caching_delete_progress', $done, $length);
+			break;
+
+		case 'docacheclear_error':
+			$message = qa_lang('admin/caching_delete_error');
+			break;
+
+		case 'docachetrim_complete':
+		case 'docacheclear_complete':
+			$message = qa_lang('admin/caching_delete_complete');
+			break;
+
 		default:
 			$message = '';
 			break;

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

@@ -53,9 +53,17 @@ return array(
 	'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_cleanup' => 'Caching clean-up operations',
+	'caching_delete_all' => 'Delete entire cache',
+	'caching_delete_complete' => 'Cache successfully deleted',
+	'caching_delete_error' => 'There was an error deleting some cache files',
+	'caching_delete_expired' => 'Delete expired cache',
+	'caching_delete_progress' => 'Deleted ^1 of ^2 cache files...',
 	'caching_dir_error' => 'The directory ^ defined as QA_CACHE_DIRECTORY is not writable by the web server.',
+	'caching_dir_missing' => 'Cache directory has not been defined.',
 	'caching_dir_public' => 'The directory ^ defined as QA_CACHE_DIRECTORY must be outside the public root.',
+	'caching_disk_size' => 'Total size of cache',
+	'caching_num_files' => 'Number of files',
 	'caching_title' => 'Caching',
 	'cancel_mailing_button' => 'Cancel Mailing',
 	'categories' => 'Categories',

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

@@ -1792,6 +1792,27 @@ switch ($adminsection) {
 	case 'caching':
 		$cacheDriver = Q2A_Storage_CacheFactory::getCacheDriver();
 		$qa_content['error'] = $cacheDriver->getError();
+		$cacheStats = $cacheDriver->getStats();
+
+		$qa_content['form_2'] = array(
+			'tags' => 'method="post" action="' . qa_path_html('admin/recalc') . '"',
+
+			'title' => qa_lang_html('admin/caching_cleanup'),
+
+			'style' => 'wide',
+
+			'buttons' => array(
+				'delete_all' => array(
+					'label' => qa_lang_html('admin/caching_delete_all'),
+					'tags' => 'name="docacheclear" onclick="return qa_recalc_click(this.name, this, ' . qa_js(qa_lang_html('admin/delete_stop')) . ', \'cacheclear_note\');"',
+					'note' => '<span id="cacheclear_note"></span>',
+				),
+			),
+
+			'hidden' => array(
+				'code' => qa_get_form_security_code('admin/recalc'),
+			),
+		);
 		break;
 }