Complex classes like Jetpack_Sync_Module_Full_Sync often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Jetpack_Sync_Module_Full_Sync, and based on these observations, apply Extract Interface, too.
| 1 | <?php  | 
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| 15 | class Jetpack_Sync_Module_Full_Sync extends Jetpack_Sync_Module { | 
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| 16 | const STATUS_OPTION_PREFIX = 'jetpack_sync_full_';  | 
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| 17 | const FULL_SYNC_TIMEOUT = 3600;  | 
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| 18 | |||
| 19 | 	public function name() { | 
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| 22 | |||
| 23 | 	function init_full_sync_listeners( $callable ) { | 
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| 29 | |||
| 30 | 	function init_before_send() { | 
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| 34 | |||
| 35 | 	function start( $module_configs = null ) { | 
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| 36 | $was_already_running = $this->is_started() && ! $this->is_finished();  | 
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| 37 | |||
| 38 | // remove all evidence of previous full sync items and status  | 
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| 39 | $this->reset_data();  | 
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| 40 | |||
| 41 | 		if ( $was_already_running ) { | 
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| 42 | /**  | 
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| 43 | * Fires when a full sync is cancelled.  | 
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| 44 | *  | 
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| 45 | * @since 4.2.0  | 
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| 46 | */  | 
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| 47 | do_action( 'jetpack_full_sync_cancelled' );  | 
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| 48 | }  | 
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| 49 | |||
| 50 | $this->update_status_option( 'started', time() );  | 
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| 51 | $this->update_status_option( 'params', $module_configs );  | 
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| 52 | |||
| 53 | $enqueue_status = array();  | 
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| 54 | $full_sync_config = array();  | 
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| 55 | |||
| 56 | // default value is full sync  | 
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| 57 | 		if ( ! is_array( $module_configs ) ) { | 
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| 58 | $module_configs = array();  | 
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| 59 | 			foreach ( Jetpack_Sync_Modules::get_modules() as $module ) { | 
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| 60 | $module_configs[ $module->name() ] = true;  | 
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| 61 | }  | 
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| 62 | }  | 
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| 63 | |||
| 64 | // set default configuration, calculate totals, and save configuration if totals > 0  | 
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| 65 | 		foreach ( Jetpack_Sync_Modules::get_modules() as $module ) { | 
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| 66 | $module_name = $module->name();  | 
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| 67 | $module_config = isset( $module_configs[ $module_name ] ) ? $module_configs[ $module_name ] : false;  | 
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| 68 | |||
| 69 | 			if ( ! $module_config ) { | 
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| 70 | continue;  | 
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| 71 | }  | 
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| 72 | |||
| 73 | 			if ( 'users' === $module_name && 'initial' === $module_config ) { | 
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| 74 | $module_config = $module->get_initial_sync_user_config();  | 
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| 75 | }  | 
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| 76 | |||
| 77 | $enqueue_status[ $module_name ] = false;  | 
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| 78 | |||
| 79 | $total_items = $module->estimate_full_sync_actions( $module_config );  | 
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| 80 | |||
| 81 | // if there's information to process, configure this module  | 
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| 82 | 			if ( ! is_null( $total_items ) && $total_items > 0 ) { | 
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| 83 | $full_sync_config[ $module_name ] = $module_config;  | 
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| 84 | $enqueue_status[ $module_name ] = array(  | 
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| 85 | $total_items, // total  | 
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| 86 | 0, // queued  | 
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| 87 | false, // current state  | 
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| 88 | );  | 
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| 89 | }  | 
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| 90 | }  | 
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| 91 | |||
| 92 | $this->set_config( $full_sync_config );  | 
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| 93 | $this->set_enqueue_status( $enqueue_status );  | 
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| 94 | |||
| 95 | /**  | 
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| 96 | * Fires when a full sync begins. This action is serialized  | 
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| 97 | * and sent to the server so that it knows a full sync is coming.  | 
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| 98 | *  | 
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| 99 | * @since 4.2.0  | 
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| 100 | */  | 
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| 101 | do_action( 'jetpack_full_sync_start', $full_sync_config );  | 
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| 102 | |||
| 103 | $this->continue_enqueuing( $full_sync_config, $enqueue_status );  | 
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| 104 | |||
| 105 | return true;  | 
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| 106 | }  | 
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| 107 | |||
| 108 | 	function continue_enqueuing( $configs = null, $enqueue_status = null ) { | 
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| 109 | 		if ( ! $this->is_started() || $this->get_status_option( 'queue_finished' ) ) { | 
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| 110 | return;  | 
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| 111 | }  | 
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| 112 | |||
| 113 | // if full sync queue is full, don't enqueue more items  | 
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| 114 | $max_queue_size_full_sync = Jetpack_Sync_Settings::get_setting( 'max_queue_size_full_sync' );  | 
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| 115 | $full_sync_queue = new Jetpack_Sync_Queue( 'full_sync' );  | 
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| 116 | |||
| 117 | $available_queue_slots = $max_queue_size_full_sync - $full_sync_queue->size();  | 
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| 118 | |||
| 119 | 		if ( $available_queue_slots <= 0 ) { | 
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| 120 | return;  | 
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| 121 | 		} else { | 
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| 122 | $remaining_items_to_enqueue = min( Jetpack_Sync_Settings::get_setting( 'max_enqueue_full_sync' ), $available_queue_slots );  | 
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| 123 | }  | 
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| 124 | |||
| 125 | 		if ( ! $configs ) { | 
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| 126 | $configs = $this->get_config();  | 
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| 127 | }  | 
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| 128 | |||
| 129 | 		if ( ! $enqueue_status ) { | 
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| 130 | $enqueue_status = $this->get_enqueue_status();  | 
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| 131 | }  | 
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| 132 | |||
| 133 | 		foreach ( Jetpack_Sync_Modules::get_modules() as $module ) { | 
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| 134 | $module_name = $module->name();  | 
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| 135 | |||
| 136 | // skip module if not configured for this sync or module is done  | 
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| 137 | if ( ! isset( $configs[ $module_name ] )  | 
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| 138 | || // no module config  | 
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| 139 | ! $configs[ $module_name ]  | 
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| 140 | || // no enqueue status  | 
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| 141 | ! $enqueue_status[ $module_name ]  | 
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| 142 | || // finished enqueuing this module  | 
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| 143 | 					true === $enqueue_status[ $module_name ][ 2 ] ) { | 
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| 144 | continue;  | 
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| 145 | }  | 
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| 146 | |||
| 147 | list( $items_enqueued, $next_enqueue_state ) = $module->enqueue_full_sync_actions( $configs[ $module_name ], $remaining_items_to_enqueue, $enqueue_status[ $module_name ][ 2 ] );  | 
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| 148 | |||
| 149 | $enqueue_status[ $module_name ][ 2 ] = $next_enqueue_state;  | 
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| 150 | |||
| 151 | // if items were processed, subtract them from the limit  | 
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| 152 | 			if ( ! is_null( $items_enqueued ) && $items_enqueued > 0 ) { | 
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| 153 | $enqueue_status[ $module_name ][ 1 ] += $items_enqueued;  | 
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| 154 | $remaining_items_to_enqueue -= $items_enqueued;  | 
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| 155 | }  | 
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| 156 | |||
| 157 | // stop processing if we've reached our limit of items to enqueue  | 
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| 158 | 			if ( 0 >= $remaining_items_to_enqueue ) { | 
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| 159 | $this->set_enqueue_status( $enqueue_status );  | 
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| 160 | return;  | 
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| 161 | }  | 
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| 162 | }  | 
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| 163 | |||
| 164 | $this->set_enqueue_status( $enqueue_status );  | 
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| 165 | |||
| 166 | // setting autoload to true means that it's faster to check whether we should continue enqueuing  | 
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| 167 | $this->update_status_option( 'queue_finished', time(), true );  | 
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| 168 | |||
| 169 | /**  | 
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| 170 | * Fires when a full sync ends. This action is serialized  | 
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| 171 | * and sent to the server with checksums so that we can confirm the  | 
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| 172 | * sync was successful.  | 
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| 173 | *  | 
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| 174 | * @since 4.2.0  | 
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| 175 | */  | 
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| 176 | do_action( 'jetpack_full_sync_end', '' );  | 
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| 177 | }  | 
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| 178 | |||
| 179 | 	function update_sent_progress_action( $actions ) { | 
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| 180 | |||
| 181 | // quick way to map to first items with an array of arrays  | 
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| 182 | $actions_with_counts = array_count_values( array_filter( array_map( array( $this, 'get_action_name' ), $actions ) ) );  | 
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| 183 | |||
| 184 | 		if ( ! $this->is_started() || $this->is_finished() ) { | 
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| 185 | return;  | 
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| 186 | }  | 
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| 187 | |||
| 188 | 		if ( isset( $actions_with_counts['jetpack_full_sync_start'] ) ) { | 
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| 189 | $this->update_status_option( 'send_started', time() );  | 
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| 190 | }  | 
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| 191 | |||
| 192 | 		foreach ( Jetpack_Sync_Modules::get_modules() as $module ) { | 
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| 193 | $module_actions = $module->get_full_sync_actions();  | 
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| 194 | 			$status_option_name = "{$module->name()}_sent"; | 
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| 195 | $items_sent = $this->get_status_option( $status_option_name, 0 );  | 
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| 196 | |||
| 197 | 			foreach ( $module_actions as $module_action ) { | 
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| 198 | 				if ( isset( $actions_with_counts[ $module_action ] ) ) { | 
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| 199 | $items_sent += $actions_with_counts[ $module_action ];  | 
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| 200 | }  | 
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| 201 | }  | 
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| 202 | |||
| 203 | 			if ( $items_sent > 0 ) { | 
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| 204 | $this->update_status_option( $status_option_name, $items_sent );  | 
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| 205 | }  | 
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| 206 | }  | 
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| 207 | |||
| 208 | 		if ( isset( $actions_with_counts['jetpack_full_sync_end'] ) ) { | 
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| 209 | $this->update_status_option( 'finished', time() );  | 
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| 210 | }  | 
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| 211 | }  | 
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| 212 | |||
| 213 | 	public function get_action_name( $queue_item ) { | 
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| 214 | 		if ( is_array( $queue_item ) && isset( $queue_item[0] ) ) { | 
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| 215 | return $queue_item[0];  | 
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| 216 | }  | 
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| 217 | return false;  | 
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| 218 | }  | 
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| 219 | |||
| 220 | 	public function is_started() { | 
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| 221 | return !! $this->get_status_option( 'started' );  | 
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| 222 | }  | 
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| 223 | |||
| 224 | 	public function is_finished() { | 
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| 225 | return !! $this->get_status_option( 'finished' );  | 
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| 226 | }  | 
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| 227 | |||
| 228 | 	public function get_status() { | 
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| 229 | $status = array(  | 
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| 230 | 'started' => $this->get_status_option( 'started' ),  | 
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| 231 | 'queue_finished' => $this->get_status_option( 'queue_finished' ),  | 
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| 232 | 'send_started' => $this->get_status_option( 'send_started' ),  | 
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| 233 | 'finished' => $this->get_status_option( 'finished' ),  | 
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| 234 | 'sent' => array(),  | 
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| 235 | 'queue' => array(),  | 
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| 236 | 'config' => $this->get_status_option( 'params' ),  | 
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| 237 | 'total' => array(),  | 
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| 238 | );  | 
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| 239 | |||
| 240 | $enqueue_status = $this->get_enqueue_status();  | 
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| 241 | $module_config = $this->get_config();  | 
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| 
                                                                                                    
                        
                         | 
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| 242 | |||
| 243 | 		foreach ( Jetpack_Sync_Modules::get_modules() as $module ) { | 
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| 244 | $name = $module->name();  | 
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| 245 | |||
| 246 | 			if ( ! isset( $enqueue_status[ $name ] ) ) { | 
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| 247 | continue;  | 
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| 248 | }  | 
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| 249 | |||
| 250 | list( $total, $queued, $state ) = $enqueue_status[ $name ];  | 
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| 251 | |||
| 252 | 			if ( $total ) { | 
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| 253 | $status[ 'total' ][ $name ] = $total;  | 
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| 254 | }  | 
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| 255 | |||
| 256 | 			if ( $queued ) { | 
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| 257 | $status[ 'queue' ][ $name ] = $queued;  | 
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| 258 | }  | 
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| 259 | |||
| 260 | 			if ( $sent = $this->get_status_option( "{$name}_sent" ) ) { | 
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| 261 | $status[ 'sent' ][ $name ] = $sent;  | 
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| 262 | }  | 
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| 263 | }  | 
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| 264 | |||
| 265 | return $status;  | 
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| 266 | }  | 
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| 267 | |||
| 268 | 	public function clear_status() { | 
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| 269 | $prefix = self::STATUS_OPTION_PREFIX;  | 
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| 270 | 		delete_option( "{$prefix}_started" ); | 
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| 271 | 		delete_option( "{$prefix}_params" ); | 
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| 272 | 		delete_option( "{$prefix}_queue_finished" ); | 
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| 273 | 		delete_option( "{$prefix}_send_started" ); | 
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| 274 | 		delete_option( "{$prefix}_finished" ); | 
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| 275 | |||
| 276 | 		foreach ( Jetpack_Sync_Modules::get_modules() as $module ) { | 
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| 277 | 			delete_option( "{$prefix}_{$module->name()}_sent" ); | 
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| 278 | }  | 
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| 279 | }  | 
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| 280 | |||
| 281 | 	public function reset_data() { | 
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| 287 | |||
| 288 | 	private function get_status_option( $name, $default = null ) { | 
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| 300 | |||
| 301 | 	private function update_status_option( $name, $value, $autoload = false ) { | 
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| 302 | $prefix = self::STATUS_OPTION_PREFIX;  | 
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| 303 | 		update_option( "{$prefix}_{$name}", $value, $autoload ); | 
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| 304 | }  | 
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| 305 | |||
| 306 | 	private function set_enqueue_status( $new_status ) { | 
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| 309 | |||
| 310 | 	private function get_enqueue_status() { | 
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| 313 | |||
| 314 | 	private function set_config( $config ) { | 
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| 317 | |||
| 318 | 	private function get_config() { | 
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| 321 | |||
| 322 | 	private function write_option( $name, $value ) { | 
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| 348 | |||
| 349 | 	private function read_option( $name, $default = null ) { | 
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| 365 | }  | 
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| 366 | 
This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently.
Both the
$myVarassignment in line 1 and the$higherassignment in line 2 are dead. The first because$myVaris never used and the second because$higheris always overwritten for every possible time line.