File: /home/cafsindia/www/wp-content/plugins/imageseo/src/Async/WPBackgroundProcess.php
<?php
namespace ImageSeoWP\Async;
/**
* Abstract WPBackgroundProcess class.
*
* @abstract
* @extends WP_Async_Request
*/
abstract class WPBackgroundProcess extends WPAsyncRequest
{
/**
* Action.
*
* (default value: 'background_process')
*
* @var string
*/
protected $action = 'background_process';
/**
* Start time of current process.
*
* (default value: 0)
*
* @var int
*/
protected $start_time = 0;
/**
* Cron_hook_identifier.
*
* @var mixed
*/
protected $cron_hook_identifier;
/**
* Cron_interval_identifier.
*
* @var mixed
*/
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, [$this, 'handle_cron_healthcheck']);
add_filter('cron_schedules', [$this, 'schedule_cron_healthcheck']);
}
/**
* Dispatch.
*/
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 $this;
}
public function push_all_data($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.
*/
public 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.
*
* @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'] = [
'interval' => MINUTE_IN_SECONDS * $interval,
'display' => sprintf(__('Every %d Minutes'), $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);
}