Archived
148 lines
4.1 KiB
PHP
148 lines
4.1 KiB
PHP
<?php
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class TLC_Transient_Update_Server {
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public function __construct() {
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add_action( 'init', array( $this, 'init' ) );
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}
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public function init() {
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if ( isset( $_POST['_tlc_update'] ) ) {
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$update = get_transient( 'tlc_up__' . $_POST['key'] );
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if ( $update && $update[0] == $_POST['_tlc_update'] ) {
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tlc_transient( $update[1] )
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->expires_in( $update[2] )
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->updates_with( $update[3], (array) $update[4] )
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->set_lock( $update[0] )
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->fetch_and_cache();
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}
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exit();
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}
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}
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}
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new TLC_Transient_Update_Server;
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if ( !class_exists( 'TLC_Transient' ) ) {
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class TLC_Transient {
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public $key;
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private $lock;
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private $callback;
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private $params;
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private $expiration = 0;
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private $force_background_updates = false;
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public function __construct( $key ) {
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$this->key = substr( $key, 0, 37 );
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}
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public function get() {
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$data = get_transient( $this->key );
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if ( false === $data ) {
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// Hard expiration
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if ( $this->force_background_updates ) {
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// In this mode, we never do a just-in-time update
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// We return false, and schedule a fetch on shutdown
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$this->schedule_background_fetch();
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return false;
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} else {
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// Bill O'Reilly mode: "We'll do it live!"
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return $this->fetch_and_cache();
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}
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} else {
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// Soft expiration
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if ( $data[0] !== 0 && $data[0] < time() )
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$this->schedule_background_fetch();
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return $data[1];
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}
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}
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private function schedule_background_fetch() {
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if ( !$this->has_update_lock() ) {
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set_transient( 'tlc_up__' . $this->key, array( $this->new_update_lock(), $this->key, $this->expiration, $this->callback, $this->params ), 300 );
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add_action( 'shutdown', array( $this, 'spawn_server' ) );
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}
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return $this;
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}
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public function spawn_server() {
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$server_url = home_url( '/?tlc_transients_request' );
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wp_remote_post( $server_url, array( 'body' => array( '_tlc_update' => $this->lock, 'key' => $this->key ), 'timeout' => 0.01, 'blocking' => false, 'sslverify' => apply_filters( 'https_local_ssl_verify', true ) ) );
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}
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public function fetch_and_cache() {
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// If you don't supply a callback, we can't update it for you!
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if ( empty( $this->callback ) )
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return false;
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if ( $this->has_update_lock() && !$this->owns_update_lock() )
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return; // Race... let the other process handle it
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try {
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$data = call_user_func_array( $this->callback, $this->params );
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$this->set( $data );
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} catch( Exception $e ) {}
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$this->release_update_lock();
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return $data;
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}
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public function set( $data ) {
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// We set the timeout as part of the transient data.
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// The actual transient has no TTL. This allows for soft expiration.
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$expiration = ( $this->expiration > 0 ) ? time() + $this->expiration : 0;
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set_transient( $this->key, array( $expiration, $data ) );
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return $this;
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}
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public function updates_with( $callback, $params = array() ) {
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$this->callback = $callback;
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if ( is_array( $params ) )
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$this->params = $params;
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return $this;
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}
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private function new_update_lock() {
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$this->lock = md5( uniqid( microtime() . mt_rand(), true ) );
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return $this->lock;
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}
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private function release_update_lock() {
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delete_transient( 'tlc_up__' . $this->key );
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}
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private function get_update_lock() {
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$lock = get_transient( 'tlc_up__' . $this->key );
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if ( $lock )
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return $lock[0];
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else
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return false;
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}
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private function has_update_lock() {
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return (bool) $this->get_update_lock();
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}
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private function owns_update_lock() {
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return $this->lock == $this->get_update_lock();
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}
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public function expires_in( $seconds ) {
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$this->expiration = (int) $seconds;
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return $this;
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}
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public function set_lock( $lock ) {
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$this->lock = $lock;
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return $this;
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}
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public function background_only() {
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$this->force_background_updates = true;
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return $this;
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}
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}
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}
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// API so you don't have to use "new"
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function tlc_transient( $key ) {
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$transient = new TLC_Transient( $key );
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return $transient;
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}
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