diff options
Diffstat (limited to 'inc/lib/batch-processing/class-astra-wp-background-process.php')
| -rw-r--r-- | inc/lib/batch-processing/class-astra-wp-background-process.php | 506 |
1 files changed, 506 insertions, 0 deletions
diff --git a/inc/lib/batch-processing/class-astra-wp-background-process.php b/inc/lib/batch-processing/class-astra-wp-background-process.php new file mode 100644 index 0000000..98c7486 --- /dev/null +++ b/inc/lib/batch-processing/class-astra-wp-background-process.php @@ -0,0 +1,506 @@ +<?php
+/**
+ * WP Background Process
+ *
+ * @package WP-Background-Processing
+ */
+
+if ( ! class_exists( 'Astra_WP_Background_Process' ) ) {
+
+ /**
+ * Abstract Astra_WP_Background_Process class.
+ *
+ * @abstract
+ * @extends Astra_WP_Async_Request
+ */
+ abstract class Astra_WP_Background_Process extends Astra_WP_Async_Request {
+
+ /**
+ * Action
+ *
+ * (default value: 'background_process')
+ *
+ * @var string
+ * @access protected
+ */
+ protected $action = 'background_process';
+
+ /**
+ * Start time of current process.
+ *
+ * (default value: 0)
+ *
+ * @var int
+ * @access protected
+ */
+ protected $start_time = 0;
+
+ /**
+ * Cron_hook_identifier
+ *
+ * @var mixed
+ * @access protected
+ */
+ protected $cron_hook_identifier;
+
+ /**
+ * Cron_interval_identifier
+ *
+ * @var mixed
+ * @access protected
+ */
+ protected $cron_interval_identifier;
+
+ /**
+ * Initiate new background process
+ */
+ public function __construct() {
+ parent::__construct();
+
+ $this->cron_hook_identifier = $this->identifier . '_cron';
+ $this->cron_interval_identifier = $this->identifier . '_cron_interval';
+
+ add_action( $this->cron_hook_identifier, array( $this, 'handle_cron_healthcheck' ) );
+ add_filter( 'cron_schedules', array( $this, 'schedule_cron_healthcheck' ) );
+ }
+
+ /**
+ * Dispatch
+ *
+ * @access public
+ * @return void
+ */
+ public function dispatch() {
+ // Schedule the cron healthcheck.
+ $this->schedule_event();
+
+ // Perform remote post.
+ return parent::dispatch();
+ }
+
+ /**
+ * Push to queue
+ *
+ * @param mixed $data Data.
+ *
+ * @return $this
+ */
+ public function push_to_queue( $data ) {
+ $this->data[] = $data;
+
+ return $this;
+ }
+
+ /**
+ * Save queue
+ *
+ * @return $this
+ */
+ public function save() {
+ $key = $this->generate_key();
+
+ if ( ! empty( $this->data ) ) {
+ update_site_option( $key, $this->data );
+ }
+
+ return $this;
+ }
+
+ /**
+ * Update queue
+ *
+ * @param string $key Key.
+ * @param array $data Data.
+ *
+ * @return $this
+ */
+ public function update( $key, $data ) {
+ if ( ! empty( $data ) ) {
+ update_site_option( $key, $data );
+ }
+
+ return $this;
+ }
+
+ /**
+ * Delete queue
+ *
+ * @param string $key Key.
+ *
+ * @return $this
+ */
+ public function delete( $key ) {
+ delete_site_option( $key );
+
+ return $this;
+ }
+
+ /**
+ * Generate key
+ *
+ * Generates a unique key based on microtime. Queue items are
+ * given a unique key so that they can be merged upon save.
+ *
+ * @param int $length Length.
+ *
+ * @return string
+ */
+ protected function generate_key( $length = 64 ) {
+ $unique = md5( microtime() . rand() );
+ $prepend = $this->identifier . '_batch_';
+
+ return substr( $prepend . $unique, 0, $length );
+ }
+
+ /**
+ * Maybe process queue
+ *
+ * Checks whether data exists within the queue and that
+ * the process is not already running.
+ */
+ public function maybe_handle() {
+ // Don't lock up other requests while processing
+ session_write_close();
+
+ if ( $this->is_process_running() ) {
+ // Background process already running.
+ wp_die();
+ }
+
+ if ( $this->is_queue_empty() ) {
+ // No data to process.
+ wp_die();
+ }
+
+ check_ajax_referer( $this->identifier, 'nonce' );
+
+ $this->handle();
+
+ wp_die();
+ }
+
+ /**
+ * Is queue empty
+ *
+ * @return bool
+ */
+ protected function is_queue_empty() {
+ global $wpdb;
+
+ $table = $wpdb->options;
+ $column = 'option_name';
+
+ if ( is_multisite() ) {
+ $table = $wpdb->sitemeta;
+ $column = 'meta_key';
+ }
+
+ $key = $wpdb->esc_like( $this->identifier . '_batch_' ) . '%';
+
+ $count = $wpdb->get_var( $wpdb->prepare( "
+ SELECT COUNT(*)
+ FROM {$table}
+ WHERE {$column} LIKE %s
+ ", $key ) );
+
+ return ( $count > 0 ) ? false : true;
+ }
+
+ /**
+ * Is process running
+ *
+ * Check whether the current process is already running
+ * in a background process.
+ */
+ protected function is_process_running() {
+ if ( get_site_transient( $this->identifier . '_process_lock' ) ) {
+ // Process already running.
+ return true;
+ }
+
+ return false;
+ }
+
+ /**
+ * Lock process
+ *
+ * Lock the process so that multiple instances can't run simultaneously.
+ * Override if applicable, but the duration should be greater than that
+ * defined in the time_exceeded() method.
+ */
+ protected function lock_process() {
+ $this->start_time = time(); // Set start time of current process.
+
+ $lock_duration = ( property_exists( $this, 'queue_lock_time' ) ) ? $this->queue_lock_time : 60; // 1 minute
+ $lock_duration = apply_filters( $this->identifier . '_queue_lock_time', $lock_duration );
+
+ set_site_transient( $this->identifier . '_process_lock', microtime(), $lock_duration );
+ }
+
+ /**
+ * Unlock process
+ *
+ * Unlock the process so that other instances can spawn.
+ *
+ * @return $this
+ */
+ protected function unlock_process() {
+ delete_site_transient( $this->identifier . '_process_lock' );
+
+ return $this;
+ }
+
+ /**
+ * Get batch
+ *
+ * @return stdClass Return the first batch from the queue
+ */
+ protected function get_batch() {
+ global $wpdb;
+
+ $table = $wpdb->options;
+ $column = 'option_name';
+ $key_column = 'option_id';
+ $value_column = 'option_value';
+
+ if ( is_multisite() ) {
+ $table = $wpdb->sitemeta;
+ $column = 'meta_key';
+ $key_column = 'meta_id';
+ $value_column = 'meta_value';
+ }
+
+ $key = $wpdb->esc_like( $this->identifier . '_batch_' ) . '%';
+
+ $query = $wpdb->get_row( $wpdb->prepare( "
+ SELECT *
+ FROM {$table}
+ WHERE {$column} LIKE %s
+ ORDER BY {$key_column} ASC
+ LIMIT 1
+ ", $key ) );
+
+ $batch = new stdClass();
+ $batch->key = $query->$column;
+ $batch->data = maybe_unserialize( $query->$value_column );
+
+ return $batch;
+ }
+
+ /**
+ * Handle
+ *
+ * Pass each queue item to the task handler, while remaining
+ * within server memory and time limit constraints.
+ */
+ protected function handle() {
+ $this->lock_process();
+
+ do {
+ $batch = $this->get_batch();
+
+ foreach ( $batch->data as $key => $value ) {
+ $task = $this->task( $value );
+
+ if ( false !== $task ) {
+ $batch->data[ $key ] = $task;
+ } else {
+ unset( $batch->data[ $key ] );
+ }
+
+ if ( $this->time_exceeded() || $this->memory_exceeded() ) {
+ // Batch limits reached.
+ break;
+ }
+ }
+
+ // Update or delete current batch.
+ if ( ! empty( $batch->data ) ) {
+ $this->update( $batch->key, $batch->data );
+ } else {
+ $this->delete( $batch->key );
+ }
+ } while ( ! $this->time_exceeded() && ! $this->memory_exceeded() && ! $this->is_queue_empty() );
+
+ $this->unlock_process();
+
+ // Start next batch or complete process.
+ if ( ! $this->is_queue_empty() ) {
+ $this->dispatch();
+ } else {
+ $this->complete();
+ }
+
+ wp_die();
+ }
+
+ /**
+ * Memory exceeded
+ *
+ * Ensures the batch process never exceeds 90%
+ * of the maximum WordPress memory.
+ *
+ * @return bool
+ */
+ protected function memory_exceeded() {
+ $memory_limit = $this->get_memory_limit() * 0.9; // 90% of max memory
+ $current_memory = memory_get_usage( true );
+ $return = false;
+
+ if ( $current_memory >= $memory_limit ) {
+ $return = true;
+ }
+
+ return apply_filters( $this->identifier . '_memory_exceeded', $return );
+ }
+
+ /**
+ * Get memory limit
+ *
+ * @return int
+ */
+ protected function get_memory_limit() {
+ if ( function_exists( 'ini_get' ) ) {
+ $memory_limit = ini_get( 'memory_limit' );
+ } else {
+ // Sensible default.
+ $memory_limit = '128M';
+ }
+
+ if ( ! $memory_limit || -1 === intval( $memory_limit ) ) {
+ // Unlimited, set to 32GB.
+ $memory_limit = '32000M';
+ }
+
+ return intval( $memory_limit ) * 1024 * 1024;
+ }
+
+ /**
+ * Time exceeded.
+ *
+ * Ensures the batch never exceeds a sensible time limit.
+ * A timeout limit of 30s is common on shared hosting.
+ *
+ * @return bool
+ */
+ protected function time_exceeded() {
+ $finish = $this->start_time + apply_filters( $this->identifier . '_default_time_limit', 20 ); // 20 seconds
+ $return = false;
+
+ if ( time() >= $finish ) {
+ $return = true;
+ }
+
+ return apply_filters( $this->identifier . '_time_exceeded', $return );
+ }
+
+ /**
+ * Complete.
+ *
+ * Override if applicable, but ensure that the below actions are
+ * performed, or, call parent::complete().
+ */
+ protected function complete() {
+ // Unschedule the cron healthcheck.
+ $this->clear_scheduled_event();
+ }
+
+ /**
+ * Schedule cron healthcheck
+ *
+ * @access public
+ * @param mixed $schedules Schedules.
+ * @return mixed
+ */
+ public function schedule_cron_healthcheck( $schedules ) {
+ $interval = apply_filters( $this->identifier . '_cron_interval', 5 );
+
+ if ( property_exists( $this, 'cron_interval' ) ) {
+ $interval = apply_filters( $this->identifier . '_cron_interval', $this->cron_interval );
+ }
+
+ // Adds every 5 minutes to the existing schedules.
+ $schedules[ $this->identifier . '_cron_interval' ] = array(
+ 'interval' => MINUTE_IN_SECONDS * $interval,
+ 'display' => sprintf( __( 'Every %d Minutes', 'astra' ), $interval ),
+ );
+
+ return $schedules;
+ }
+
+ /**
+ * Handle cron healthcheck
+ *
+ * Restart the background process if not already running
+ * and data exists in the queue.
+ */
+ public function handle_cron_healthcheck() {
+ if ( $this->is_process_running() ) {
+ // Background process already running.
+ exit;
+ }
+
+ if ( $this->is_queue_empty() ) {
+ // No data to process.
+ $this->clear_scheduled_event();
+ exit;
+ }
+
+ $this->handle();
+
+ exit;
+ }
+
+ /**
+ * Schedule event
+ */
+ protected function schedule_event() {
+ if ( ! wp_next_scheduled( $this->cron_hook_identifier ) ) {
+ wp_schedule_event( time(), $this->cron_interval_identifier, $this->cron_hook_identifier );
+ }
+ }
+
+ /**
+ * Clear scheduled event
+ */
+ protected function clear_scheduled_event() {
+ $timestamp = wp_next_scheduled( $this->cron_hook_identifier );
+
+ if ( $timestamp ) {
+ wp_unschedule_event( $timestamp, $this->cron_hook_identifier );
+ }
+ }
+
+ /**
+ * Cancel Process
+ *
+ * Stop processing queue items, clear cronjob and delete batch.
+ *
+ */
+ public function cancel_process() {
+ if ( ! $this->is_queue_empty() ) {
+ $batch = $this->get_batch();
+
+ $this->delete( $batch->key );
+
+ wp_clear_scheduled_hook( $this->cron_hook_identifier );
+ }
+
+ }
+
+ /**
+ * Task
+ *
+ * Override this method to perform any actions required on each
+ * queue item. Return the modified item for further processing
+ * in the next pass through. Or, return false to remove the
+ * item from the queue.
+ *
+ * @param mixed $item Queue item to iterate over.
+ *
+ * @return mixed
+ */
+ abstract protected function task( $item );
+
+ }
+}
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