"Fossies" - the Fresh Open Source Software Archive  

Source code changes of the file "includes/libs/MapCacheLRU.php" between
mediawiki-1.31.1.tar.gz and mediawiki-1.32.0.tar.gz

About: MediaWiki is a wiki engine (the collaborative editing software that runs for e.g. Wikipedia, the free encyclopedia).

MapCacheLRU.php  (mediawiki-1.31.1):MapCacheLRU.php  (mediawiki-1.32.0)
skipping to change at line 28 skipping to change at line 28
* http://www.gnu.org/copyleft/gpl.html * http://www.gnu.org/copyleft/gpl.html
* *
* @file * @file
* @ingroup Cache * @ingroup Cache
*/ */
use Wikimedia\Assert\Assert; use Wikimedia\Assert\Assert;
/** /**
* Handles a simple LRU key/value map with a maximum number of entries * Handles a simple LRU key/value map with a maximum number of entries
* *
* Use ProcessCacheLRU if hierarchical purging is needed or objects can become s * The last-modification timestamp of entries is internally tracked so that call
tale ers can
* specify the maximum acceptable age of entries in calls to the has() method. A
s a convenience,
* the hasField(), getField(), and setField() methods can be used for entries th
at are field/value
* maps themselves; such fields will have their own internally tracked last-modi
fication timestamp.
* *
* @see ProcessCacheLRU * @see ProcessCacheLRU
* @ingroup Cache * @ingroup Cache
* @since 1.23 * @since 1.23
*/ */
class MapCacheLRU { class MapCacheLRU implements IExpiringStore, Serializable {
/** @var array */ /** @var array Map of (key => value) */
protected $cache = []; // (key => value) private $cache = [];
/** @var array Map of (key => (UNIX timestamp, (field => UNIX timestamp))
protected $maxCacheKeys; // integer; max entries ) */
private $timestamps = [];
/** @var float Default entry timestamp if not specified */
private $epoch;
/** @var int Max number of entries */
private $maxCacheKeys;
/** @var float|null */
private $wallClockOverride;
const RANK_TOP = 1.0;
/** @var int Array key that holds the entry's main timestamp (flat key us
e) */
const SIMPLE = 0;
/** @var int Array key that holds the entry's field timestamps (nested ke
y use) */
const FIELDS = 1;
/** /**
* @param int $maxKeys Maximum number of entries allowed (min 1). * @param int $maxKeys Maximum number of entries allowed (min 1)
* @throws Exception When $maxCacheKeys is not an int or not above zero. * @throws Exception When $maxKeys is not an int or not above zero
*/ */
public function __construct( $maxKeys ) { public function __construct( $maxKeys ) {
Assert::parameterType( 'integer', $maxKeys, '$maxKeys' ); Assert::parameterType( 'integer', $maxKeys, '$maxKeys' );
Assert::parameter( $maxKeys > 0, '$maxKeys', 'must be above zero' ); Assert::parameter( $maxKeys > 0, '$maxKeys', 'must be above zero' );
$this->maxCacheKeys = $maxKeys; $this->maxCacheKeys = $maxKeys;
// Use the current time as the default "as of" timestamp of entri
es
$this->epoch = $this->getCurrentTime();
} }
/** /**
* @param array $values Key/value map in order of increasingly recent acc ess * @param array $values Key/value map in order of increasingly recent acc ess
* @param int $maxKeys * @param int $maxKeys
* @return MapCacheLRU * @return MapCacheLRU
* @since 1.30 * @since 1.30
*/ */
public static function newFromArray( array $values, $maxKeys ) { public static function newFromArray( array $values, $maxKeys ) {
$mapCache = new self( $maxKeys ); $mapCache = new self( $maxKeys );
skipping to change at line 89 skipping to change at line 109
* To reduce evictions due to one-off use of many new keys, $rank can be * To reduce evictions due to one-off use of many new keys, $rank can be
* set to have keys start at the top of a bottom fraction of the list. A value * set to have keys start at the top of a bottom fraction of the list. A value
* of 3/8 means values start at the top of the bottom 3/8s of the list an d are * of 3/8 means values start at the top of the bottom 3/8s of the list an d are
* moved to the top of the list when accessed a second time. * moved to the top of the list when accessed a second time.
* *
* @param string $key * @param string $key
* @param mixed $value * @param mixed $value
* @param float $rank Bottom fraction of the list where keys start off [D efault: 1.0] * @param float $rank Bottom fraction of the list where keys start off [D efault: 1.0]
* @return void * @return void
*/ */
public function set( $key, $value, $rank = 1.0 ) { public function set( $key, $value, $rank = self::RANK_TOP ) {
if ( $this->has( $key ) ) { if ( $this->has( $key ) ) {
$this->ping( $key ); $this->ping( $key );
} elseif ( count( $this->cache ) >= $this->maxCacheKeys ) { } elseif ( count( $this->cache ) >= $this->maxCacheKeys ) {
reset( $this->cache ); reset( $this->cache );
$evictKey = key( $this->cache ); $evictKey = key( $this->cache );
unset( $this->cache[$evictKey] ); unset( $this->cache[$evictKey] );
unset( $this->timestamps[$evictKey] );
} }
if ( $rank < 1.0 && $rank > 0 ) { if ( $rank < 1.0 && $rank > 0 ) {
$offset = intval( $rank * count( $this->cache ) ); $offset = intval( $rank * count( $this->cache ) );
$this->cache = array_slice( $this->cache, 0, $offset, tru e ) $this->cache = array_slice( $this->cache, 0, $offset, tru e )
+ [ $key => $value ] + [ $key => $value ]
+ array_slice( $this->cache, $offset, null, true ); + array_slice( $this->cache, $offset, null, true );
} else { } else {
$this->cache[$key] = $value; $this->cache[$key] = $value;
} }
$this->timestamps[$key] = [
self::SIMPLE => $this->getCurrentTime(),
self::FIELDS => []
];
} }
/** /**
* Check if a key exists * Check if a key exists
* *
* @param string $key * @param string $key
* @param float $maxAge Ignore items older than this many seconds [option al] (since 1.32)
* @return bool * @return bool
*/ */
public function has( $key ) { public function has( $key, $maxAge = 0.0 ) {
if ( !is_int( $key ) && !is_string( $key ) ) { if ( !is_int( $key ) && !is_string( $key ) ) {
throw new UnexpectedValueException( throw new UnexpectedValueException(
__METHOD__ . ' called with invalid key. Must be s tring or integer.' ); __METHOD__ . ': invalid key; must be string or in teger.' );
} }
return array_key_exists( $key, $this->cache );
if ( !array_key_exists( $key, $this->cache ) ) {
return false;
}
return ( $maxAge <= 0 || $this->getAge( $key ) <= $maxAge );
} }
/** /**
* Get the value for a key. * Get the value for a key.
* This returns null if the key is not set. * This returns null if the key is not set.
* If the item is already set, it will be pushed to the top of the cache. * If the item is already set, it will be pushed to the top of the cache.
* *
* @param string $key * @param string $key
* @return mixed Returns null if the key was not found * @param float $maxAge Ignore items older than this many seconds [option
al] (since 1.32)
* @return mixed Returns null if the key was not found or is older than $
maxAge
*/ */
public function get( $key ) { public function get( $key, $maxAge = 0.0 ) {
if ( !$this->has( $key ) ) { if ( !$this->has( $key, $maxAge ) ) {
return null; return null;
} }
$this->ping( $key ); $this->ping( $key );
return $this->cache[$key]; return $this->cache[$key];
} }
/** /**
* @param string|int $key
* @param string|int $field
* @param mixed $value
* @param float $initRank
*/
public function setField( $key, $field, $value, $initRank = self::RANK_TO
P ) {
if ( $this->has( $key ) ) {
$this->ping( $key );
} else {
$this->set( $key, [], $initRank );
}
if ( !is_int( $field ) && !is_string( $field ) ) {
throw new UnexpectedValueException(
__METHOD__ . ": invalid field for '$key'; must be
string or integer." );
}
if ( !is_array( $this->cache[$key] ) ) {
$type = gettype( $this->cache[$key] );
throw new UnexpectedValueException( "The value of '$key'
($type) is not an array." );
}
$this->cache[$key][$field] = $value;
$this->timestamps[$key][self::FIELDS][$field] = $this->getCurrent
Time();
}
/**
* @param string|int $key
* @param string|int $field
* @param float $maxAge Ignore items older than this many seconds [option
al] (since 1.32)
* @return bool
*/
public function hasField( $key, $field, $maxAge = 0.0 ) {
$value = $this->get( $key );
if ( !is_int( $field ) && !is_string( $field ) ) {
throw new UnexpectedValueException(
__METHOD__ . ": invalid field for '$key'; must be
string or integer." );
}
if ( !is_array( $value ) || !array_key_exists( $field, $value ) )
{
return false;
}
return ( $maxAge <= 0 || $this->getAge( $key, $field ) <= $maxAge
);
}
/**
* @param string|int $key
* @param string|int $field
* @param float $maxAge Ignore items older than this many seconds [option
al] (since 1.32)
* @return mixed Returns null if the key was not found or is older than $
maxAge
*/
public function getField( $key, $field, $maxAge = 0.0 ) {
if ( !$this->hasField( $key, $field, $maxAge ) ) {
return null;
}
return $this->cache[$key][$field];
}
/**
* @return array * @return array
* @since 1.25 * @since 1.25
*/ */
public function getAllKeys() { public function getAllKeys() {
return array_keys( $this->cache ); return array_keys( $this->cache );
} }
/** /**
* Get an item with the given key, producing and setting it if not found. * Get an item with the given key, producing and setting it if not found.
* *
* If the callback returns false, then nothing is stored. * If the callback returns false, then nothing is stored.
* *
* @since 1.28 * @since 1.28
* @param string $key * @param string $key
* @param callable $callback Callback that will produce the value * @param callable $callback Callback that will produce the value
* @param float $rank Bottom fraction of the list where keys start off [D efault: 1.0] * @param float $rank Bottom fraction of the list where keys start off [D efault: 1.0]
* @param float $maxAge Ignore items older than this many seconds [Defaul t: 0.0] (since 1.32)
* @return mixed The cached value if found or the result of $callback oth erwise * @return mixed The cached value if found or the result of $callback oth erwise
*/ */
public function getWithSetCallback( $key, callable $callback, $rank = 1.0 public function getWithSetCallback(
) { $key, callable $callback, $rank = self::RANK_TOP, $maxAge = 0.0
if ( $this->has( $key ) ) { ) {
if ( $this->has( $key, $maxAge ) ) {
$value = $this->get( $key ); $value = $this->get( $key );
} else { } else {
$value = call_user_func( $callback ); $value = call_user_func( $callback );
if ( $value !== false ) { if ( $value !== false ) {
$this->set( $key, $value, $rank ); $this->set( $key, $value, $rank );
} }
} }
return $value; return $value;
} }
/** /**
* Clear one or several cache entries, or all cache entries * Clear one or several cache entries, or all cache entries
* *
* @param string|array $keys * @param string|array|null $keys
* @return void * @return void
*/ */
public function clear( $keys = null ) { public function clear( $keys = null ) {
if ( $keys === null ) { if ( func_num_args() == 0 ) {
$this->cache = []; $this->cache = [];
$this->timestamps = [];
} else { } else {
foreach ( (array)$keys as $key ) { foreach ( (array)$keys as $key ) {
unset( $this->cache[$key] ); unset( $this->cache[$key] );
unset( $this->timestamps[$key] );
} }
} }
} }
/** /**
* Get the maximum number of keys allowed
*
* @return int
* @since 1.32
*/
public function getMaxSize() {
return $this->maxCacheKeys;
}
/**
* Resize the maximum number of cache entries, removing older entries as
needed
*
* @param int $maxKeys Maximum number of entries allowed (min 1)
* @return void
* @throws Exception When $maxKeys is not an int or not above zero
* @since 1.32
*/
public function setMaxSize( $maxKeys ) {
Assert::parameterType( 'integer', $maxKeys, '$maxKeys' );
Assert::parameter( $maxKeys > 0, '$maxKeys', 'must be above zero'
);
$this->maxCacheKeys = $maxKeys;
while ( count( $this->cache ) > $this->maxCacheKeys ) {
reset( $this->cache );
$evictKey = key( $this->cache );
unset( $this->cache[$evictKey] );
unset( $this->timestamps[$evictKey] );
}
}
/**
* Push an entry to the top of the cache * Push an entry to the top of the cache
* *
* @param string $key * @param string $key
*/ */
protected function ping( $key ) { private function ping( $key ) {
$item = $this->cache[$key]; $item = $this->cache[$key];
unset( $this->cache[$key] ); unset( $this->cache[$key] );
$this->cache[$key] = $item; $this->cache[$key] = $item;
} }
/**
* @param string|int $key
* @param string|int|null $field [optional]
* @return float UNIX timestamp; the age of the given entry or entry fiel
d
*/
private function getAge( $key, $field = null ) {
if ( $field !== null ) {
$mtime = $this->timestamps[$key][self::FIELDS][$field] ??
$this->epoch;
} else {
$mtime = $this->timestamps[$key][self::SIMPLE] ?? $this->
epoch;
}
return ( $this->getCurrentTime() - $mtime );
}
public function serialize() {
return serialize( [
'entries' => $this->cache,
'timestamps' => $this->timestamps
] );
}
public function unserialize( $serialized ) {
$data = unserialize( $serialized );
$this->cache = $data['entries'] ?? [];
$this->timestamps = $data['timestamps'] ?? [];
$this->epoch = $this->getCurrentTime();
}
/**
* @return float UNIX timestamp
* @codeCoverageIgnore
*/
protected function getCurrentTime() {
return $this->wallClockOverride ?: microtime( true );
}
/**
* @param float|null &$time Mock UNIX timestamp for testing
* @codeCoverageIgnore
*/
public function setMockTime( &$time ) {
$this->wallClockOverride =& $time;
}
} }
 End of changes. 23 change blocks. 
22 lines changed or deleted 222 lines changed or added

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