wp-async-request.php
8 years ago
wp-background-process.php
7 years ago
wptt-webfont-loader.php
2 years ago
wp-background-process.php
504 lines
| 1 | <?php // @codingStandardsIgnoreLine. |
| 2 | /** |
| 3 | * Abstract WP_Background_Process class. |
| 4 | * |
| 5 | * @package WP-Background-Processing |
| 6 | * @extends WP_Async_Request |
| 7 | */ |
| 8 | |
| 9 | defined( 'ABSPATH' ) || exit; |
| 10 | |
| 11 | /** |
| 12 | * Abstract WP_Background_Process class. |
| 13 | */ |
| 14 | abstract class WP_Background_Process extends WP_Async_Request { |
| 15 | |
| 16 | /** |
| 17 | * Action |
| 18 | * |
| 19 | * (default value: 'background_process') |
| 20 | * |
| 21 | * @var string |
| 22 | * @access protected |
| 23 | */ |
| 24 | protected $action = 'background_process'; |
| 25 | |
| 26 | /** |
| 27 | * Start time of current process. |
| 28 | * |
| 29 | * (default value: 0) |
| 30 | * |
| 31 | * @var int |
| 32 | * @access protected |
| 33 | */ |
| 34 | protected $start_time = 0; |
| 35 | |
| 36 | /** |
| 37 | * Cron_hook_identifier |
| 38 | * |
| 39 | * @var mixed |
| 40 | * @access protected |
| 41 | */ |
| 42 | protected $cron_hook_identifier; |
| 43 | |
| 44 | /** |
| 45 | * Cron_interval_identifier |
| 46 | * |
| 47 | * @var mixed |
| 48 | * @access protected |
| 49 | */ |
| 50 | protected $cron_interval_identifier; |
| 51 | |
| 52 | /** |
| 53 | * Initiate new background process |
| 54 | */ |
| 55 | public function __construct() { |
| 56 | parent::__construct(); |
| 57 | |
| 58 | $this->cron_hook_identifier = $this->identifier . '_cron'; |
| 59 | $this->cron_interval_identifier = $this->identifier . '_cron_interval'; |
| 60 | |
| 61 | add_action( $this->cron_hook_identifier, array( $this, 'handle_cron_healthcheck' ) ); |
| 62 | add_filter( 'cron_schedules', array( $this, 'schedule_cron_healthcheck' ) ); |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Dispatch |
| 67 | * |
| 68 | * @access public |
| 69 | * @return void |
| 70 | */ |
| 71 | public function dispatch() { |
| 72 | // Schedule the cron healthcheck. |
| 73 | $this->schedule_event(); |
| 74 | |
| 75 | // Perform remote post. |
| 76 | return parent::dispatch(); |
| 77 | } |
| 78 | |
| 79 | /** |
| 80 | * Push to queue |
| 81 | * |
| 82 | * @param mixed $data Data. |
| 83 | * |
| 84 | * @return $this |
| 85 | */ |
| 86 | public function push_to_queue( $data ) { |
| 87 | $this->data[] = $data; |
| 88 | |
| 89 | return $this; |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * Save queue |
| 94 | * |
| 95 | * @return $this |
| 96 | */ |
| 97 | public function save() { |
| 98 | $key = $this->generate_key(); |
| 99 | |
| 100 | if ( ! empty( $this->data ) ) { |
| 101 | update_site_option( $key, $this->data ); |
| 102 | } |
| 103 | |
| 104 | return $this; |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * Update queue |
| 109 | * |
| 110 | * @param string $key Key. |
| 111 | * @param array $data Data. |
| 112 | * |
| 113 | * @return $this |
| 114 | */ |
| 115 | public function update( $key, $data ) { |
| 116 | if ( ! empty( $data ) ) { |
| 117 | update_site_option( $key, $data ); |
| 118 | } |
| 119 | |
| 120 | return $this; |
| 121 | } |
| 122 | |
| 123 | /** |
| 124 | * Delete queue |
| 125 | * |
| 126 | * @param string $key Key. |
| 127 | * |
| 128 | * @return $this |
| 129 | */ |
| 130 | public function delete( $key ) { |
| 131 | delete_site_option( $key ); |
| 132 | |
| 133 | return $this; |
| 134 | } |
| 135 | |
| 136 | /** |
| 137 | * Generate key |
| 138 | * |
| 139 | * Generates a unique key based on microtime. Queue items are |
| 140 | * given a unique key so that they can be merged upon save. |
| 141 | * |
| 142 | * @param int $length Length. |
| 143 | * |
| 144 | * @return string |
| 145 | */ |
| 146 | protected function generate_key( $length = 64 ) { |
| 147 | $unique = md5( microtime() . rand() ); |
| 148 | $prepend = $this->identifier . '_batch_'; |
| 149 | |
| 150 | return substr( $prepend . $unique, 0, $length ); |
| 151 | } |
| 152 | |
| 153 | /** |
| 154 | * Maybe process queue |
| 155 | * |
| 156 | * Checks whether data exists within the queue and that |
| 157 | * the process is not already running. |
| 158 | */ |
| 159 | public function maybe_handle() { |
| 160 | // Don't lock up other requests while processing |
| 161 | session_write_close(); |
| 162 | |
| 163 | if ( $this->is_process_running() ) { |
| 164 | // Background process already running. |
| 165 | wp_die(); |
| 166 | } |
| 167 | |
| 168 | if ( $this->is_queue_empty() ) { |
| 169 | // No data to process. |
| 170 | wp_die(); |
| 171 | } |
| 172 | |
| 173 | check_ajax_referer( $this->identifier, 'nonce' ); |
| 174 | |
| 175 | $this->handle(); |
| 176 | |
| 177 | wp_die(); |
| 178 | } |
| 179 | |
| 180 | /** |
| 181 | * Is queue empty |
| 182 | * |
| 183 | * @return bool |
| 184 | */ |
| 185 | protected function is_queue_empty() { |
| 186 | global $wpdb; |
| 187 | |
| 188 | $table = $wpdb->options; |
| 189 | $column = 'option_name'; |
| 190 | |
| 191 | if ( is_multisite() ) { |
| 192 | $table = $wpdb->sitemeta; |
| 193 | $column = 'meta_key'; |
| 194 | } |
| 195 | |
| 196 | $key = $this->identifier . '_batch_%'; |
| 197 | |
| 198 | $count = $wpdb->get_var( $wpdb->prepare( " |
| 199 | SELECT COUNT(*) |
| 200 | FROM {$table} |
| 201 | WHERE {$column} LIKE %s |
| 202 | ", $key ) ); |
| 203 | |
| 204 | return ! ( $count > 0 ); |
| 205 | } |
| 206 | |
| 207 | /** |
| 208 | * Is process running |
| 209 | * |
| 210 | * Check whether the current process is already running |
| 211 | * in a background process. |
| 212 | */ |
| 213 | protected function is_process_running() { |
| 214 | if ( get_site_transient( $this->identifier . '_process_lock' ) ) { |
| 215 | // Process already running. |
| 216 | return true; |
| 217 | } |
| 218 | |
| 219 | return false; |
| 220 | } |
| 221 | |
| 222 | /** |
| 223 | * Lock process |
| 224 | * |
| 225 | * Lock the process so that multiple instances can't run simultaneously. |
| 226 | * Override if applicable, but the duration should be greater than that |
| 227 | * defined in the time_exceeded() method. |
| 228 | */ |
| 229 | protected function lock_process() { |
| 230 | $this->start_time = time(); // Set start time of current process. |
| 231 | |
| 232 | $lock_duration = ( property_exists( $this, 'queue_lock_time' ) ) ? $this->queue_lock_time : 60; // 1 minute |
| 233 | $lock_duration = apply_filters( $this->identifier . '_queue_lock_time', $lock_duration ); |
| 234 | |
| 235 | set_site_transient( $this->identifier . '_process_lock', microtime(), $lock_duration ); |
| 236 | } |
| 237 | |
| 238 | /** |
| 239 | * Unlock process |
| 240 | * |
| 241 | * Unlock the process so that other instances can spawn. |
| 242 | * |
| 243 | * @return $this |
| 244 | */ |
| 245 | protected function unlock_process() { |
| 246 | delete_site_transient( $this->identifier . '_process_lock' ); |
| 247 | |
| 248 | return $this; |
| 249 | } |
| 250 | |
| 251 | /** |
| 252 | * Get batch |
| 253 | * |
| 254 | * @return stdClass Return the first batch from the queue |
| 255 | */ |
| 256 | protected function get_batch() { |
| 257 | global $wpdb; |
| 258 | |
| 259 | $table = $wpdb->options; |
| 260 | $column = 'option_name'; |
| 261 | $key_column = 'option_id'; |
| 262 | $value_column = 'option_value'; |
| 263 | |
| 264 | if ( is_multisite() ) { |
| 265 | $table = $wpdb->sitemeta; |
| 266 | $column = 'meta_key'; |
| 267 | $key_column = 'meta_id'; |
| 268 | $value_column = 'meta_value'; |
| 269 | } |
| 270 | |
| 271 | $key = $this->identifier . '_batch_%'; |
| 272 | |
| 273 | $query = $wpdb->get_row( $wpdb->prepare( " |
| 274 | SELECT * |
| 275 | FROM {$table} |
| 276 | WHERE {$column} LIKE %s |
| 277 | ORDER BY {$key_column} ASC |
| 278 | LIMIT 1 |
| 279 | ", $key ) ); |
| 280 | |
| 281 | $batch = new stdClass(); |
| 282 | $batch->key = $query->$column; |
| 283 | $batch->data = maybe_unserialize( $query->$value_column ); |
| 284 | |
| 285 | return $batch; |
| 286 | } |
| 287 | |
| 288 | /** |
| 289 | * Handle |
| 290 | * |
| 291 | * Pass each queue item to the task handler, while remaining |
| 292 | * within server memory and time limit constraints. |
| 293 | */ |
| 294 | protected function handle() { |
| 295 | $this->lock_process(); |
| 296 | |
| 297 | do { |
| 298 | $batch = $this->get_batch(); |
| 299 | |
| 300 | foreach ( $batch->data as $key => $value ) { |
| 301 | $task = $this->task( $value ); |
| 302 | |
| 303 | if ( false !== $task ) { |
| 304 | $batch->data[ $key ] = $task; |
| 305 | } else { |
| 306 | unset( $batch->data[ $key ] ); |
| 307 | } |
| 308 | |
| 309 | if ( $this->time_exceeded() || $this->memory_exceeded() ) { |
| 310 | // Batch limits reached. |
| 311 | break; |
| 312 | } |
| 313 | } |
| 314 | |
| 315 | // Update or delete current batch. |
| 316 | if ( ! empty( $batch->data ) ) { |
| 317 | $this->update( $batch->key, $batch->data ); |
| 318 | } else { |
| 319 | $this->delete( $batch->key ); |
| 320 | } |
| 321 | } while ( ! $this->time_exceeded() && ! $this->memory_exceeded() && ! $this->is_queue_empty() ); |
| 322 | |
| 323 | $this->unlock_process(); |
| 324 | |
| 325 | // Start next batch or complete process. |
| 326 | if ( ! $this->is_queue_empty() ) { |
| 327 | $this->dispatch(); |
| 328 | } else { |
| 329 | $this->complete(); |
| 330 | } |
| 331 | |
| 332 | wp_die(); |
| 333 | } |
| 334 | |
| 335 | /** |
| 336 | * Memory exceeded |
| 337 | * |
| 338 | * Ensures the batch process never exceeds 90% |
| 339 | * of the maximum WordPress memory. |
| 340 | * |
| 341 | * @return bool |
| 342 | */ |
| 343 | protected function memory_exceeded() { |
| 344 | $memory_limit = $this->get_memory_limit() * 0.9; // 90% of max memory |
| 345 | $current_memory = memory_get_usage( true ); |
| 346 | $return = false; |
| 347 | |
| 348 | if ( $current_memory >= $memory_limit ) { |
| 349 | $return = true; |
| 350 | } |
| 351 | |
| 352 | return apply_filters( $this->identifier . '_memory_exceeded', $return ); |
| 353 | } |
| 354 | |
| 355 | /** |
| 356 | * Get memory limit |
| 357 | * |
| 358 | * @return int |
| 359 | */ |
| 360 | protected function get_memory_limit() { |
| 361 | if ( function_exists( 'ini_get' ) ) { |
| 362 | $memory_limit = ini_get( 'memory_limit' ); |
| 363 | } else { |
| 364 | // Sensible default. |
| 365 | $memory_limit = '128M'; |
| 366 | } |
| 367 | |
| 368 | if ( ! $memory_limit || -1 === $memory_limit ) { |
| 369 | // Unlimited, set to 32GB. |
| 370 | $memory_limit = '32000M'; |
| 371 | } |
| 372 | |
| 373 | return intval( $memory_limit ) * 1024 * 1024; |
| 374 | } |
| 375 | |
| 376 | /** |
| 377 | * Time exceeded. |
| 378 | * |
| 379 | * Ensures the batch never exceeds a sensible time limit. |
| 380 | * A timeout limit of 30s is common on shared hosting. |
| 381 | * |
| 382 | * @return bool |
| 383 | */ |
| 384 | protected function time_exceeded() { |
| 385 | $finish = $this->start_time + apply_filters( $this->identifier . '_default_time_limit', 20 ); // 20 seconds |
| 386 | $return = false; |
| 387 | |
| 388 | if ( time() >= $finish ) { |
| 389 | $return = true; |
| 390 | } |
| 391 | |
| 392 | return apply_filters( $this->identifier . '_time_exceeded', $return ); |
| 393 | } |
| 394 | |
| 395 | /** |
| 396 | * Complete. |
| 397 | * |
| 398 | * Override if applicable, but ensure that the below actions are |
| 399 | * performed, or, call parent::complete(). |
| 400 | */ |
| 401 | protected function complete() { |
| 402 | // Unschedule the cron healthcheck. |
| 403 | $this->clear_scheduled_event(); |
| 404 | } |
| 405 | |
| 406 | /** |
| 407 | * Schedule cron healthcheck |
| 408 | * |
| 409 | * @access public |
| 410 | * @param mixed $schedules Schedules. |
| 411 | * @return mixed |
| 412 | */ |
| 413 | public function schedule_cron_healthcheck( $schedules ) { |
| 414 | $interval = apply_filters( $this->identifier . '_cron_interval', 5 ); |
| 415 | |
| 416 | if ( property_exists( $this, 'cron_interval' ) ) { |
| 417 | $interval = apply_filters( $this->identifier . '_cron_interval', $this->cron_interval ); |
| 418 | } |
| 419 | |
| 420 | // Adds every 5 minutes to the existing schedules. |
| 421 | $schedules[ $this->identifier . '_cron_interval' ] = array( |
| 422 | 'interval' => MINUTE_IN_SECONDS * $interval, |
| 423 | 'display' => sprintf( __( 'Every %d Minutes' ), $interval ), |
| 424 | ); |
| 425 | |
| 426 | return $schedules; |
| 427 | } |
| 428 | |
| 429 | /** |
| 430 | * Handle cron healthcheck |
| 431 | * |
| 432 | * Restart the background process if not already running |
| 433 | * and data exists in the queue. |
| 434 | */ |
| 435 | public function handle_cron_healthcheck() { |
| 436 | if ( $this->is_process_running() ) { |
| 437 | // Background process already running. |
| 438 | exit; |
| 439 | } |
| 440 | |
| 441 | if ( $this->is_queue_empty() ) { |
| 442 | // No data to process. |
| 443 | $this->clear_scheduled_event(); |
| 444 | exit; |
| 445 | } |
| 446 | |
| 447 | $this->handle(); |
| 448 | |
| 449 | exit; |
| 450 | } |
| 451 | |
| 452 | /** |
| 453 | * Schedule event |
| 454 | */ |
| 455 | protected function schedule_event() { |
| 456 | if ( ! wp_next_scheduled( $this->cron_hook_identifier ) ) { |
| 457 | wp_schedule_event( time(), $this->cron_interval_identifier, $this->cron_hook_identifier ); |
| 458 | } |
| 459 | } |
| 460 | |
| 461 | /** |
| 462 | * Clear scheduled event |
| 463 | */ |
| 464 | protected function clear_scheduled_event() { |
| 465 | $timestamp = wp_next_scheduled( $this->cron_hook_identifier ); |
| 466 | |
| 467 | if ( $timestamp ) { |
| 468 | wp_unschedule_event( $timestamp, $this->cron_hook_identifier ); |
| 469 | } |
| 470 | } |
| 471 | |
| 472 | /** |
| 473 | * Cancel Process |
| 474 | * |
| 475 | * Stop processing queue items, clear cronjob and delete batch. |
| 476 | * |
| 477 | */ |
| 478 | public function cancel_process() { |
| 479 | if ( ! $this->is_queue_empty() ) { |
| 480 | $batch = $this->get_batch(); |
| 481 | |
| 482 | $this->delete( $batch->key ); |
| 483 | |
| 484 | wp_clear_scheduled_hook( $this->cron_hook_identifier ); |
| 485 | } |
| 486 | |
| 487 | } |
| 488 | |
| 489 | /** |
| 490 | * Task |
| 491 | * |
| 492 | * Override this method to perform any actions required on each |
| 493 | * queue item. Return the modified item for further processing |
| 494 | * in the next pass through. Or, return false to remove the |
| 495 | * item from the queue. |
| 496 | * |
| 497 | * @param mixed $item Queue item to iterate over. |
| 498 | * |
| 499 | * @return mixed |
| 500 | */ |
| 501 | abstract protected function task( $item ); |
| 502 | |
| 503 | } |
| 504 |