Jetpack_Sync_Queue::lag() - Code Metrics - Inspection of "Add dashboard for triggering/testing" - Automattic/jetpack - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — add/sync-rest-2 ( 4e2aeb...44e329 )

unknown

created 2016-04-20 22:23 UTC

Jetpack_Sync_Queue::lag() A

↳ Parent: Jetpack_Sync_Queue

Complexity

Conditions	2
Paths	2

Size

Total Lines	19
Code Lines	10

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	1

Metric	Value
c	1
b	0
f	1
dl	0
loc	19
rs	9.4285
cc	2
eloc	10
nc	2
nop	0

<?php

/**
 * A buffer of items from the queue that can be checked out
 */
class Jetpack_Sync_Queue_Buffer {
	public $id;
	public $items_with_ids;

	public function __construct( $items_with_ids ) {
		$this->id             = uniqid();
		$this->items_with_ids = $items_with_ids;
	}

	public function get_items() {
		return Jetpack_Sync_Utils::get_item_values( $this->items_with_ids );
	}

	public function get_item_ids() {
		return Jetpack_Sync_Utils::get_item_ids( $this->items_with_ids );
	}
}

/**
 * A persistent queue that can be flushed in increments of N items,
 * and which blocks reads until checked-out buffers are checked in or
 * closed. This uses raw SQL for two reasons: speed, and not triggering
 * tons of added_option callbacks.
 */
class Jetpack_Sync_Queue {

	public $id;
	private $checkout_size;
	private $row_iterator;

	function __construct( $id, $checkout_size = 10 ) {
		$this->id            = str_replace( '-', '_', $id ); // necessary to ensure we don't have ID collisions in the SQL
		$this->checkout_size = $checkout_size;
		$this->row_iterator  = 0;
	}

	function add( $item ) {
		global $wpdb;
		$added = false;
		// this basically tries to add the option until enough time has elapsed that
		// it has a unique (microtime-based) option key
		while ( ! $added ) {
			$rows_added = $wpdb->query( $wpdb->prepare(
				"INSERT INTO $wpdb->options (option_name, option_value) VALUES (%s, %s)",
				$this->get_next_data_row_option_name(),
				serialize( $item )
			) );
			$added      = ( $rows_added !== 0 );
		}
	}

	// Attempts to insert all the items in a single SQL query. May be subject to query size limits!
	function add_all( $items ) {
		global $wpdb;
		$base_option_name = $this->get_next_data_row_option_name();

		$query = "INSERT INTO $wpdb->options (option_name, option_value) VALUES ";

		$rows = array();

		for ( $i = 0; $i < count( $items ); $i += 1 ) {
for ($i=0; $i<count($array); $i++) { // calls count() on each iteration
}

// Better
for ($i=0, $c=count($array); $i<$c; $i++) { // calls count() just once
}
			$option_name  = esc_sql( $base_option_name . '-' . $i );
			$option_value = esc_sql( serialize( $items[ $i ] ) );
			$rows[]       = "('$option_name', '$option_value')";
		}

		$rows_added = $wpdb->query( $query . join( ',', $rows ) );

		if ( $rows_added !== count( $items ) ) {
			return new WP_Error( 'row_count_mismatch', "The number of rows inserted didn't match the size of the input array" );
		}
	}

	// Peek at the front-most item on the queue without checking it out
	function peek( $count = 1 ) {
		$items = $this->fetch_items( $count );
		if ( $items ) {
			return Jetpack_Sync_Utils::get_item_values( $items );
		}

		return array();
	}

	// lag is the difference in time between the age of the oldest item and the current time
	function lag() {
		global $wpdb;

		$last_item_name = $wpdb->get_var( $wpdb->prepare( 
			"SELECT option_name FROM $wpdb->options WHERE option_name LIKE %s ORDER BY option_name DESC LIMIT 1",
			"jpsq_{$this->id}-%"
		) );

		if ( ! $last_item_name ) {
			return null;
		}

		// break apart the item name to get the timestamp
		// return 'jpsq_' . $this->id . '-' . $timestamp . '-' . getmypid() . '-' . $this->row_iterator;
		$matches = null;
		preg_match( '/^jpsq_'.$this->id.'-(\d+).(\d+)/', $last_item_name, $matches );

		return time() - $matches[1];
	}

	function reset() {
		global $wpdb;
		$this->delete_checkout_id();
		$wpdb->query( $wpdb->prepare(
			"DELETE FROM $wpdb->options WHERE option_name LIKE %s", "jpsq_{$this->id}-%"
		) );
	}

	function size() {
		global $wpdb;

		return $wpdb->get_var( $wpdb->prepare(
			"SELECT count(*) FROM $wpdb->options WHERE option_name LIKE %s", "jpsq_{$this->id}-%"
		) );
	}

	// we use this peculiar implementation because it's much faster than count(*)
	function has_any_items() {
		global $wpdb;
		$value = $wpdb->get_var( $wpdb->prepare(
			"SELECT exists( SELECT option_name FROM $wpdb->options WHERE option_name LIKE %s )", "jpsq_{$this->id}-%"
		) );

		return ( $value === "1" );
	}

	function checkout() {
		if ( $this->get_checkout_id() ) {
			return new WP_Error( 'unclosed_buffer', 'There is an unclosed buffer' );
		}

		$items = $this->fetch_items( $this->checkout_size );

		if ( count( $items ) === 0 ) {
			return false;
		}

		$buffer = new Jetpack_Sync_Queue_Buffer( array_slice( $items, 0, $this->checkout_size ) );

		$result = $this->set_checkout_id( $buffer->id );

		if ( ! $result || is_wp_error( $result ) ) {
			error_log( "badness setting checkout ID (this should not happen)" );

			return $result;
		}

		return $buffer;
	}

	function checkin( $buffer ) {
		$is_valid = $this->validate_checkout( $buffer );

		if ( is_wp_error( $is_valid ) ) {
			return $is_valid;
		}

		$this->delete_checkout_id();

		return true;
	}

	function close( $buffer ) {
		$is_valid = $this->validate_checkout( $buffer );

		if ( is_wp_error( $is_valid ) ) {
			return $is_valid;
		}

		$this->delete_checkout_id();

		global $wpdb;

		// all this fanciness is basically so we can prepare a statement with an IN(id1, id2, id3) clause
		$ids_to_remove = $buffer->get_item_ids();
		if ( count( $ids_to_remove ) > 0 ) {
			$sql   = "DELETE FROM $wpdb->options WHERE option_name IN (" . implode( ', ', array_fill( 0, count( $ids_to_remove ), '%s' ) ) . ')';
			$query = call_user_func_array( array( $wpdb, 'prepare' ), array_merge( array( $sql ), $ids_to_remove ) );
			$wpdb->query( $query );
		}

		return true;
	}

	function flush_all() {
		$items = Jetpack_Sync_Utils::get_item_values( $this->fetch_items() );
		$this->reset();

		return $items;
	}

	function get_all() {
		return $this->fetch_items();
	}

	function set_checkout_size( $new_size ) {
		$this->checkout_size = $new_size;
	}

	private function get_checkout_id() {
		return get_option( $this->get_checkout_option_name(), false );
	}

	private function set_checkout_id( $checkout_id ) {
		$added = add_option( $this->get_checkout_option_name(), $checkout_id, null, true ); // this one we should autoload
		if ( ! $added ) {
			return new WP_Error( 'buffer_mismatch', 'Another buffer is already checked out: ' . $this->get_checkout_id() );
		} else {
			return true;
		}
	}

	private function delete_checkout_id() {
		delete_option( $this->get_checkout_option_name() );
	}

	private function get_checkout_option_name() {
		return "jpsq_{$this->id}-checkout";
	}

	private function get_next_data_row_option_name() {
		// this option is specifically chosen to, as much as possible, preserve time order
		// and minimise the possibility of collisions between multiple processes working 
		// at the same time
		// TODO: confirm we only need to support PHP 5.05+ (otherwise we'll need to emulate microtime as float, and avoid PHP_INT_MAX)

		// @see: http://php.net/manual/en/function.microtime.php
		$timestamp = sprintf( '%.6f', microtime( true ) );

		// row iterator is used to avoid collisions where we're writing data waaay fast in a single process
		if ( $this->row_iterator === PHP_INT_MAX ) {
			$this->row_iterator = 0;
		} else {
			$this->row_iterator += 1;
		}

		return 'jpsq_' . $this->id . '-' . $timestamp . '-' . getmypid() . '-' . $this->row_iterator;
	}

	private function fetch_items( $limit = null ) {
		global $wpdb;

		if ( $limit ) {
			$query_sql = $wpdb->prepare( "SELECT option_name AS id, option_value AS value FROM $wpdb->options WHERE option_name LIKE %s ORDER BY option_name ASC LIMIT %d", "jpsq_{$this->id}-%", $limit );
		} else {
			$query_sql = $wpdb->prepare( "SELECT option_name AS id, option_value AS value FROM $wpdb->options WHERE option_name LIKE %s ORDER BY option_name ASC", "jpsq_{$this->id}-%" );
		}

		$items = $wpdb->get_results( $query_sql );
		foreach ( $items as $item ) {
			$item->value = maybe_unserialize( $item->value );
		}

		return $items;
	}

	private function validate_checkout( $buffer ) {
		if ( ! $buffer instanceof Jetpack_Sync_Queue_Buffer ) {
			return new WP_Error( 'not_a_buffer', 'You must checkin an instance of Jetpack_Sync_Queue_Buffer' );
		}

		$checkout_id = $this->get_checkout_id();

		if ( ! $checkout_id ) {
			return new WP_Error( 'buffer_not_checked_out', 'There are no checked out buffers' );
		}

		if ( $checkout_id != $buffer->id ) {
			return new WP_Error( 'buffer_mismatch', 'The buffer you checked in was not checked out' );
		}

		return true;
	}
}

class Jetpack_Sync_Utils {


	static function get_item_values( $items ) {
		return array_map( array( __CLASS__, 'get_item_value' ), $items );
	}

	static function get_item_ids( $items ) {
		return array_map( array( __CLASS__, 'get_item_id' ), $items );
	}

	static private function get_item_value( $item ) {

		return $item->value;
	}

	static private function get_item_id( $item ) {

		return $item->id;
	}
}


1			<?php
2
3			/**
4			* A buffer of items from the queue that can be checked out
5			*/
6			class Jetpack_Sync_Queue_Buffer {
7			public $id;
8			public $items_with_ids;
9
10			public function __construct( $items_with_ids ) {
11			$this->id = uniqid();
12			$this->items_with_ids = $items_with_ids;
13			}
14
15			public function get_items() {
16			return Jetpack_Sync_Utils::get_item_values( $this->items_with_ids );
17			}
18
19			public function get_item_ids() {
20			return Jetpack_Sync_Utils::get_item_ids( $this->items_with_ids );
21			}
22			}
23
24			/**
25			* A persistent queue that can be flushed in increments of N items,
26			* and which blocks reads until checked-out buffers are checked in or
27			* closed. This uses raw SQL for two reasons: speed, and not triggering
28			* tons of added_option callbacks.
29			*/
30			class Jetpack_Sync_Queue {
			0 ignored issues – show Coding Style Compatibility introduced 2016-04-14 21:57 UTC by Report Bug Copy Issue Report PSR1 recommends that each class should be in its own file to aid autoloaders. Having each class in a dedicated file usually plays nice with PSR autoloaders and is therefore a well established practice. If you use other autoloaders, you might not want to follow this rule. Loading history...
31			public $id;
32			private $checkout_size;
33			private $row_iterator;
34
35			function __construct( $id, $checkout_size = 10 ) {
36			$this->id = str_replace( '-', '_', $id ); // necessary to ensure we don't have ID collisions in the SQL
37			$this->checkout_size = $checkout_size;
38			$this->row_iterator = 0;
39			}
40
41			function add( $item ) {
42			global $wpdb;
43			$added = false;
44			// this basically tries to add the option until enough time has elapsed that
45			// it has a unique (microtime-based) option key
46			while ( ! $added ) {
47			$rows_added = $wpdb->query( $wpdb->prepare(
48			"INSERT INTO $wpdb->options (option_name, option_value) VALUES (%s, %s)",
49			$this->get_next_data_row_option_name(),
50			serialize( $item )
51			) );
52			$added = ( $rows_added !== 0 );
53			}
54			}
55
56			// Attempts to insert all the items in a single SQL query. May be subject to query size limits!
57			function add_all( $items ) {
58			global $wpdb;
59			$base_option_name = $this->get_next_data_row_option_name();
60
61			$query = "INSERT INTO $wpdb->options (option_name, option_value) VALUES ";
62
63			$rows = array();
64
65			for ( $i = 0; $i < count( $items ); $i += 1 ) {
			0 ignored issues – show Performance Best Practice introduced 2016-04-17 19:11 UTC by Report Bug Copy Issue Report It seems like you are calling the size function `count()` as part of the test condition. You might want to compute the size beforehand, and not on each iteration. If the size of the collection does not change during the iteration, it is generally a good practice to compute it beforehand, and not on each iteration: for ($i=0; $i<count($array); $i++) { // calls count() on each iteration } // Better for ($i=0, $c=count($array); $i<$c; $i++) { // calls count() just once } Loading history...
66			$option_name = esc_sql( $base_option_name . '-' . $i );
67			$option_value = esc_sql( serialize( $items[ $i ] ) );
68			$rows[] = "('$option_name', '$option_value')";
69			}
70
71			$rows_added = $wpdb->query( $query . join( ',', $rows ) );
72
73			if ( $rows_added !== count( $items ) ) {
74			return new WP_Error( 'row_count_mismatch', "The number of rows inserted didn't match the size of the input array" );
75			}
76			}
77
78			// Peek at the front-most item on the queue without checking it out
79			function peek( $count = 1 ) {
80			$items = $this->fetch_items( $count );
81			if ( $items ) {
82			return Jetpack_Sync_Utils::get_item_values( $items );
83			}
84
85			return array();
86			}
87
88			// lag is the difference in time between the age of the oldest item and the current time
89			function lag() {
90			global $wpdb;
91
92			$last_item_name = $wpdb->get_var( $wpdb->prepare(
93			"SELECT option_name FROM $wpdb->options WHERE option_name LIKE %s ORDER BY option_name DESC LIMIT 1",
94			"jpsq_{$this->id}-%"
95			) );
96
97			if ( ! $last_item_name ) {
98			return null;
99			}
100
101			// break apart the item name to get the timestamp
102			// return 'jpsq_' . $this->id . '-' . $timestamp . '-' . getmypid() . '-' . $this->row_iterator;
103			$matches = null;
104			preg_match( '/^jpsq_'.$this->id.'-(\d+).(\d+)/', $last_item_name, $matches );
105
106			return time() - $matches[1];
107			}
108
109			function reset() {
110			global $wpdb;
111			$this->delete_checkout_id();
112			$wpdb->query( $wpdb->prepare(
113			"DELETE FROM $wpdb->options WHERE option_name LIKE %s", "jpsq_{$this->id}-%"
114			) );
115			}
116
117			function size() {
118			global $wpdb;
119
120			return $wpdb->get_var( $wpdb->prepare(
121			"SELECT count(*) FROM $wpdb->options WHERE option_name LIKE %s", "jpsq_{$this->id}-%"
122			) );
123			}
124
125			// we use this peculiar implementation because it's much faster than count(*)
126			function has_any_items() {
127			global $wpdb;
128			$value = $wpdb->get_var( $wpdb->prepare(
129			"SELECT exists( SELECT option_name FROM $wpdb->options WHERE option_name LIKE %s )", "jpsq_{$this->id}-%"
130			) );
131
132			return ( $value === "1" );
133			}
134
135			function checkout() {
136			if ( $this->get_checkout_id() ) {
137			return new WP_Error( 'unclosed_buffer', 'There is an unclosed buffer' );
138			}
139
140			$items = $this->fetch_items( $this->checkout_size );
141
142			if ( count( $items ) === 0 ) {
143			return false;
144			}
145
146			$buffer = new Jetpack_Sync_Queue_Buffer( array_slice( $items, 0, $this->checkout_size ) );
147
148			$result = $this->set_checkout_id( $buffer->id );
149
150			if ( ! $result \|\| is_wp_error( $result ) ) {
151			error_log( "badness setting checkout ID (this should not happen)" );
152
153			return $result;
154			}
155
156			return $buffer;
157			}
158
159			function checkin( $buffer ) {
160			$is_valid = $this->validate_checkout( $buffer );
161
162			if ( is_wp_error( $is_valid ) ) {
163			return $is_valid;
164			}
165
166			$this->delete_checkout_id();
167
168			return true;
169			}
170
171			function close( $buffer ) {
172			$is_valid = $this->validate_checkout( $buffer );
173
174			if ( is_wp_error( $is_valid ) ) {
175			return $is_valid;
176			}
177
178			$this->delete_checkout_id();
179
180			global $wpdb;
181
182			// all this fanciness is basically so we can prepare a statement with an IN(id1, id2, id3) clause
183			$ids_to_remove = $buffer->get_item_ids();
184			if ( count( $ids_to_remove ) > 0 ) {
185			$sql = "DELETE FROM $wpdb->options WHERE option_name IN (" . implode( ', ', array_fill( 0, count( $ids_to_remove ), '%s' ) ) . ')';
186			$query = call_user_func_array( array( $wpdb, 'prepare' ), array_merge( array( $sql ), $ids_to_remove ) );
187			$wpdb->query( $query );
188			}
189
190			return true;
191			}
192
193			function flush_all() {
194			$items = Jetpack_Sync_Utils::get_item_values( $this->fetch_items() );
195			$this->reset();
196
197			return $items;
198			}
199
200			function get_all() {
201			return $this->fetch_items();
202			}
203
204			function set_checkout_size( $new_size ) {
205			$this->checkout_size = $new_size;
206			}
207
208			private function get_checkout_id() {
209			return get_option( $this->get_checkout_option_name(), false );
210			}
211
212			private function set_checkout_id( $checkout_id ) {
213			$added = add_option( $this->get_checkout_option_name(), $checkout_id, null, true ); // this one we should autoload
214			if ( ! $added ) {
215			return new WP_Error( 'buffer_mismatch', 'Another buffer is already checked out: ' . $this->get_checkout_id() );
216			} else {
217			return true;
218			}
219			}
220
221			private function delete_checkout_id() {
222			delete_option( $this->get_checkout_option_name() );
223			}
224
225			private function get_checkout_option_name() {
226			return "jpsq_{$this->id}-checkout";
227			}
228
229			private function get_next_data_row_option_name() {
230			// this option is specifically chosen to, as much as possible, preserve time order
231			// and minimise the possibility of collisions between multiple processes working
232			// at the same time
233			// TODO: confirm we only need to support PHP 5.05+ (otherwise we'll need to emulate microtime as float, and avoid PHP_INT_MAX)
			0 ignored issues – show Coding Style Best Practice introduced 2016-04-19 19:44 UTC by Report Bug Copy Issue Report Comments for TODO tasks are often forgotten in the code; it might be better to use a dedicated issue tracker. Loading history...
234			// @see: http://php.net/manual/en/function.microtime.php
235			$timestamp = sprintf( '%.6f', microtime( true ) );
236
237			// row iterator is used to avoid collisions where we're writing data waaay fast in a single process
238			if ( $this->row_iterator === PHP_INT_MAX ) {
239			$this->row_iterator = 0;
240			} else {
241			$this->row_iterator += 1;
242			}
243
244			return 'jpsq_' . $this->id . '-' . $timestamp . '-' . getmypid() . '-' . $this->row_iterator;
245			}
246
247			private function fetch_items( $limit = null ) {
248			global $wpdb;
249
250			if ( $limit ) {
251			$query_sql = $wpdb->prepare( "SELECT option_name AS id, option_value AS value FROM $wpdb->options WHERE option_name LIKE %s ORDER BY option_name ASC LIMIT %d", "jpsq_{$this->id}-%", $limit );
252			} else {
253			$query_sql = $wpdb->prepare( "SELECT option_name AS id, option_value AS value FROM $wpdb->options WHERE option_name LIKE %s ORDER BY option_name ASC", "jpsq_{$this->id}-%" );
254			}
255
256			$items = $wpdb->get_results( $query_sql );
257			foreach ( $items as $item ) {
258			$item->value = maybe_unserialize( $item->value );
259			}
260
261			return $items;
262			}
263
264			private function validate_checkout( $buffer ) {
265			if ( ! $buffer instanceof Jetpack_Sync_Queue_Buffer ) {
266			return new WP_Error( 'not_a_buffer', 'You must checkin an instance of Jetpack_Sync_Queue_Buffer' );
267			}
268
269			$checkout_id = $this->get_checkout_id();
270
271			if ( ! $checkout_id ) {
272			return new WP_Error( 'buffer_not_checked_out', 'There are no checked out buffers' );
273			}
274
275			if ( $checkout_id != $buffer->id ) {
276			return new WP_Error( 'buffer_mismatch', 'The buffer you checked in was not checked out' );
277			}
278
279			return true;
280			}
281			}
282
283			class Jetpack_Sync_Utils {
			0 ignored issues – show Coding Style Compatibility introduced 2016-04-19 21:52 UTC by Report Bug Copy Issue Report PSR1 recommends that each class should be in its own file to aid autoloaders. Having each class in a dedicated file usually plays nice with PSR autoloaders and is therefore a well established practice. If you use other autoloaders, you might not want to follow this rule. Loading history...
284
285			static function get_item_values( $items ) {
286			return array_map( array( __CLASS__, 'get_item_value' ), $items );
287			}
288
289			static function get_item_ids( $items ) {
290			return array_map( array( __CLASS__, 'get_item_id' ), $items );
291			}
292
293			static private function get_item_value( $item ) {
			0 ignored issues – show Coding Style introduced 2016-04-19 21:52 UTC by Report Bug Copy Issue Report As per PSR2, the `static` declaration should come after the visibility declaration. Loading history...
294			return $item->value;
295			}
296
297			static private function get_item_id( $item ) {
			0 ignored issues – show Coding Style introduced 2016-04-19 21:52 UTC by Report Bug Copy Issue Report As per PSR2, the `static` declaration should come after the visibility declaration. Loading history...
298			return $item->id;
299			}
300			}
301

Automattic / jetpack

Push — add/sync-rest-2 ( 4e2aeb...44e329 )

Jetpack_Sync_Queue::lag() A

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Duplication

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