--- /dev/null
+<?php
+/**
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Cache
+ * @author Aaron Schulz
+ */
+
+/**
+ * Multi-datacenter aware caching interface
+ *
+ * All operations go to the local cache, except the delete()
+ * and touchCheckKey(), which broadcast to all clusters.
+ * This class is intended for caching data from primary stores.
+ * If the get() method does not return a value, then the caller
+ * should query the new value and backfill the cache using set().
+ * When the source data changes, the delete() method should be called.
+ * Since delete() is expensive, it should be avoided. One can do so if:
+ * - a) The object cached is immutable; or
+ * - b) Validity is checked against the source after get(); or
+ * - c) Using a modest TTL is reasonably correct and performant
+ * Consider using getWithSetCallback() instead of the get()/set() cycle.
+ *
+ * Instances of this class must be configured to point to a valid
+ * PubSub endpoint, and there must be listeners on the cache servers
+ * that subscribe to the endpoint and update the caches.
+ *
+ * Broadcasted operations like delete() and touchCheckKey() are done
+ * synchronously in the local cluster, but are relayed asynchronously.
+ * This means that callers in other datacenters will see older values
+ * for a however many milliseconds the datacenters are apart. As with
+ * any cache, this should not be relied on for cases where reads are
+ * used to determine writes to source (e.g. non-cache) data stores.
+ *
+ * All values are wrapped in metadata arrays. Keys use a "WANCache:" prefix
+ * to avoid collisions with keys that are not wrapped as metadata arrays. The
+ * prefixes are as follows:
+ * - a) "WANCache:v" : used for regular value keys
+ * - b) "WANCache:s" : used for temporarily storing values of tombstoned keys
+ * - c) "WANCache:t" : used for storing timestamp "check" keys
+ *
+ * @ingroup Cache
+ * @since 1.26
+ */
+class WANObjectCache {
+ /** @var BagOStuff The local cluster cache */
+ protected $cache;
+ /** @var string Cache pool name */
+ protected $pool;
+ /** @var EventRelayer */
+ protected $relayer;
+
+ /** @var int */
+ protected $lastRelayError = self::ERR_NONE;
+
+ /** Seconds to tombstone keys on delete() */
+ const HOLDOFF_TTL = 10;
+ /** Seconds to keep dependency purge keys around */
+ const CHECK_KEY_TTL = 31536000; // 1 year
+ /** Seconds to keep lock keys around */
+ const LOCK_TTL = 5;
+
+ /** Cache format version number */
+ const VERSION = 1;
+
+ /** Fields of value holder arrays */
+ const FLD_VERSION = 0;
+ const FLD_VALUE = 1;
+ const FLD_TTL = 2;
+ const FLD_TIME = 3;
+
+ /** Possible values for getLastError() */
+ const ERR_NONE = 0; // no error
+ const ERR_NO_RESPONSE = 1; // no response
+ const ERR_UNREACHABLE = 2; // can't connect
+ const ERR_UNEXPECTED = 3; // response gave some error
+ const ERR_RELAY = 4; // relay broadcast failed
+
+ const VALUE_KEY_PREFIX = 'WANCache:v:';
+ const STASH_KEY_PREFIX = 'WANCache:s:';
+ const TIME_KEY_PREFIX = 'WANCache:t:';
+
+ const PURGE_VAL_PREFIX = 'PURGED:';
+
+ /**
+ * @param array $params
+ * - cache : BagOStuff object
+ * - pool : pool name
+ * - relayer : EventRelayer object
+ */
+ public function __construct( array $params ) {
+ $this->cache = $params['cache'];
+ $this->pool = $params['pool'];
+ $this->relayer = $params['relayer'];
+ }
+
+ /**
+ * Fetch the value of a key from cache
+ *
+ * If passed in, $curTTL is set to the remaining TTL (current time left):
+ * - a) INF; if the key exists and has no TTL
+ * - b) float (>=0); if the key exists and has a TTL
+ * - c) float (<0); if the key is tombstoned or expired by $checkKeys
+ * - d) null; if the key does not exist and is not tombstoned
+ *
+ * If a key is tombstoned, $curTTL will reflect the time since delete().
+ *
+ * The timestamp of $key will be checked against the last-purge timestamp
+ * of each of $checkKeys. Those $checkKeys not in cache will have the last-purge
+ * initialized to the current timestamp. If any of $checkKeys have a timestamp
+ * greater than that of $key, then $curTTL will reflect how long ago $key
+ * became invalid. Callers can use $curTTL to know when the value is stale.
+ * The $checkKeys parameter allow mass invalidations by updating a single key:
+ * - a) Each "check" key represents "last purged" of some source data
+ * - b) Callers pass in relevant "check" keys as $checkKeys in get()
+ * - c) When the source data that "check" keys represent changes,
+ * the touchCheckKey() method is called on them
+ *
+ * For keys that are hot/expensive, consider using getWithSetCallback() instead.
+ *
+ * @param string $key Cache key
+ * @param mixed $curTTL Approximate TTL left on the key if present [returned]
+ * @param array $checkKeys List of "check" keys
+ * @return mixed Value of cache key or false on failure
+ */
+ final public function get( $key, &$curTTL = null, array $checkKeys = array() ) {
+ $curTTLs = array();
+ $values = $this->getMulti( array( $key ), $curTTLs, $checkKeys );
+ $curTTL = isset( $curTTLs[$key] ) ? $curTTLs[$key] : null;
+
+ return isset( $values[$key] ) ? $values[$key] : false;
+ }
+
+ /**
+ * Fetch the value of several keys from cache
+ *
+ * @see WANObjectCache::get()
+ *
+ * @param array $keys List of cache keys
+ * @param array $curTTLs Map of (key => approximate TTL left) for existing keys [returned]
+ * @param array $checkKeys List of "check" keys
+ * @return array Map of (key => value) for keys that exist
+ */
+ final public function getMulti(
+ array $keys, &$curTTLs = array(), array $checkKeys = array()
+ ) {
+ $result = array();
+ $curTTLs = array();
+
+ $vPrefixLen = strlen( self::VALUE_KEY_PREFIX );
+ $valueKeys = self::prefixCacheKeys( $keys, self::VALUE_KEY_PREFIX );
+ $checkKeys = self::prefixCacheKeys( $checkKeys, self::TIME_KEY_PREFIX );
+
+ // Fetch all of the raw values
+ $wrappedValues = $this->cache->getMulti( array_merge( $valueKeys, $checkKeys ) );
+ $now = microtime( true );
+
+ // Get/initialize the timestamp of all the "check" keys
+ $checkKeyTimes = array();
+ foreach ( $checkKeys as $checkKey ) {
+ $timestamp = isset( $wrappedValues[$checkKey] )
+ ? self::parsePurgeValue( $wrappedValues[$checkKey] )
+ : false;
+ if ( !is_float( $timestamp ) ) {
+ // Key is not set or invalid; regenerate
+ $this->cache->add( $checkKey,
+ self::PURGE_VAL_PREFIX . $now, self::CHECK_KEY_TTL );
+ $timestamp = $now;
+ }
+
+ $checkKeyTimes[] = $timestamp;
+ }
+
+ // Get the main cache value for each key and validate them
+ foreach ( $valueKeys as $vKey ) {
+ if ( !isset( $wrappedValues[$vKey] ) ) {
+ continue; // not found
+ }
+
+ $key = substr( $vKey, $vPrefixLen ); // unprefix
+
+ list( $value, $curTTL ) = $this->unwrap( $wrappedValues[$vKey], $now );
+ if ( $value !== false ) {
+ $result[$key] = $value;
+ foreach ( $checkKeyTimes as $checkKeyTime ) {
+ // Force dependant keys to be invalid for a while after purging
+ // to reduce race conditions involving stale data getting cached
+ $safeTimestamp = $checkKeyTime + self::HOLDOFF_TTL;
+ if ( $safeTimestamp >= $wrappedValues[$vKey][self::FLD_TIME] ) {
+ $curTTL = min( $curTTL, $checkKeyTime - $now );
+ }
+ }
+ }
+
+ $curTTLs[$key] = $curTTL;
+ }
+
+ return $result;
+ }
+
+ /**
+ * Set the value of a key from cache
+ *
+ * Simply calling this method when source data changes is not valid because
+ * the changes do not replicate to the other WAN sites. In that case, delete()
+ * should be used instead. This method is intended for use on cache misses.
+ *
+ * @param string $key Cache key
+ * @param mixed $value
+ * @param integer $ttl Seconds to live [0=forever]
+ * @return bool Success
+ */
+ final public function set( $key, $value, $ttl = 0 ) {
+ $key = self::VALUE_KEY_PREFIX . $key;
+ $wrapped = $this->wrap( $value, $ttl );
+
+ $func = function ( $cache, $key, $cWrapped ) use ( $wrapped ) {
+ return ( is_string( $cWrapped ) )
+ ? false // key is tombstoned; do nothing
+ : $wrapped;
+ };
+
+ return $this->cache->merge( $key, $func, $ttl, 1 );
+ }
+
+ /**
+ * Purge a key from all clusters
+ *
+ * This instantiates a hold-off period where the key cannot be
+ * written to avoid race conditions where dependent keys get updated
+ * with a stale value (e.g. from a DB slave).
+ *
+ * This should only be called when the underlying data (being cached)
+ * changes in a significant way. If called twice on the same key, then
+ * the last TTL takes precedence.
+ *
+ * @param string $key Cache key
+ * @param integer $ttl How long to block writes to the key [seconds]
+ * @return bool True if the item was purged or not found, false on failure
+ */
+ final public function delete( $key, $ttl = self::HOLDOFF_TTL ) {
+ $key = self::VALUE_KEY_PREFIX . $key;
+ // Update the local cluster immediately
+ $ok = $this->cache->set( $key, self::PURGE_VAL_PREFIX . microtime( true ), $ttl );
+ // Publish the purge to all clusters
+ return $this->relayPurge( $key, $ttl ) && $ok;
+ }
+
+ /**
+ * Fetch the value of a timestamp "check" key
+ *
+ * @param string $key
+ * @return float|bool TS_UNIX timestamp of the key; false if not present
+ */
+ final public function getCheckKeyTime( $key ) {
+ return self::parsePurgeValue( $this->cache->get( self::TIME_KEY_PREFIX . $key ) );
+ }
+
+ /**
+ * Purge a "check" key from all clusters, invalidating keys that use it
+ *
+ * This should only be called when the underlying data (being cached)
+ * changes in a significant way, and it is impractical to call delete()
+ * on all keys that should be changed. When get() is called on those
+ * keys, the relevant "check" keys must be supplied for this to work.
+ *
+ * The "check" key essentially represents a last-modified field.
+ * It is set in the future a few seconds when this is called, to
+ * avoid race conditions where dependent keys get updated with a
+ * stale value (e.g. from a DB slave).
+ *
+ * @see WANObjectCache::get()
+ *
+ * @param string $key Cache key
+ * @return bool True if the item was purged or not found, false on failure
+ */
+ final public function touchCheckKey( $key ) {
+ $key = self::TIME_KEY_PREFIX . $key;
+ // Update the local cluster immediately
+ $ok = $this->cache->set( $key,
+ self::PURGE_VAL_PREFIX . microtime( true ), self::CHECK_KEY_TTL );
+ // Publish the purge to all clusters
+ return $this->relayPurge( $key, self::CHECK_KEY_TTL ) && $ok;
+ }
+
+ /**
+ * Method to fetch/regenerate cache keys
+ *
+ * On cache miss, the key will be set to the callback result.
+ * The callback function returns the new value given the current
+ * value (false if not present). If false is returned, then nothing
+ * will be saved to cache.
+ *
+ * Most callers should ignore the current value, but it can be used
+ * to maintain "most recent X" values that come from time or sequence
+ * based source data, provided that the "as of" id/time is tracked.
+ *
+ * Usage of $checkKeys is the same as with get().
+ *
+ * The simplest way to avoid stampedes for hot keys is to use
+ * the 'lockTSE' option in $opts. If cache purges are needed, also:
+ * a) Pass $key into $checkKeys
+ * b) Use touchCheckKey( $key ) instead of delete( $key )
+ * Following this pattern lets the old cache be used until a
+ * single thread updates it as needed. Also consider tweaking
+ * the 'lowTTL' parameter.
+ *
+ * Example usage:
+ * <code>
+ * $key = wfMemcKey( 'cat-recent-actions', $catId );
+ * // Function that derives the new key value given the old value
+ * $callback = function( $cValue ) { ... };
+ * // Get the key value from cache or from source on cache miss;
+ * // try to only let one cluster thread manage doing cache updates
+ * $opts = array( 'lockTSE' => 5, 'lowTTL' => 10 );
+ * $value = $cache->getWithSetCallback( $key, $callback, 60, array(), $opts );
+ * </code>
+ *
+ * Example usage:
+ * <code>
+ * $key = wfMemcKey( 'cat-state', $catId );
+ * // The "check" keys that represent things the value depends on;
+ * // Calling touchCheckKey() on them invalidates "cat-state"
+ * $checkKeys = array(
+ * wfMemcKey( 'water-bowls', $houseId ),
+ * wfMemcKey( 'food-bowls', $houseId ),
+ * wfMemcKey( 'people-present', $houseId )
+ * );
+ * // Function that derives the new key value
+ * $callback = function() { ... };
+ * // Get the key value from cache or from source on cache miss;
+ * // try to only let one cluster thread manage doing cache updates
+ * $opts = array( 'lockTSE' => 5, 'lowTTL' => 10 );
+ * $value = $cache->getWithSetCallback( $key, $callback, 60, $checkKeys, $opts );
+ * </code>
+ *
+ * @see WANObjectCache::get()
+ *
+ * @param string $key Cache key
+ * @param callable $callback Value generation function
+ * @param integer $ttl Seconds to live when the key is updated [0=forever]
+ * @param array $checkKeys List of "check" keys
+ * @param array $opts Options map:
+ * - lowTTL : consider pre-emptive updates when the current TTL (sec)
+ * of the key is less than this. It becomes more likely
+ * over time, becoming a certainty once the key is expired.
+ * - lockTSE : if the key is tombstoned or expired less (by $checkKeys)
+ * than this many seconds ago, then try to have a single
+ * thread handle cache regeneration at any given time.
+ * Other threads will try to use stale values if possible.
+ * - tempTTL : when 'lockTSE' is set, this determines the TTL of the temp
+ * key used to cache values while a key is tombstoned.
+ * This avoids excessive regeneration of hot keys on delete() but
+ * may result in stale values.
+ * @return mixed Value to use for the key
+ */
+ final public function getWithSetCallback(
+ $key, $callback, $ttl, array $checkKeys = array(), array $opts = array()
+ ) {
+ $lowTTL = isset( $opts['lowTTL'] ) ? $opts['lowTTL'] : min( 10, $ttl );
+ $lockTSE = isset( $opts['lockTSE'] ) ? $opts['lockTSE'] : -1;
+ $tempTTL = isset( $opts['tempTTL'] ) ? $opts['tempTTL'] : 5;
+
+ // Get the current key value
+ $curTTL = null;
+ $cValue = $this->get( $key, $curTTL, $checkKeys ); // current value
+ $value = $cValue; // return value
+
+ // Determine if a regeneration is desired
+ if ( $value !== false && $curTTL > 0 && !$this->worthRefresh( $curTTL, $lowTTL ) ) {
+ return $value;
+ }
+
+ if ( !is_callable( $callback ) ) {
+ throw new InvalidArgumentException( "Invalid cache miss callback provided." );
+ }
+
+ // Assume a key is hot if requested soon after invalidation
+ $isHot = ( $curTTL !== null && $curTTL <= 0 && abs( $curTTL ) <= $lockTSE );
+ $isTombstone = ( $curTTL !== null && $value === false );
+
+ $locked = false;
+ if ( $isHot || $isTombstone ) {
+ // Acquire a cluster-local non-blocking lock
+ if ( $this->cache->lock( $key, 0, self::LOCK_TTL ) ) {
+ // Lock acquired; this thread should update the key
+ $locked = true;
+ } elseif ( $value !== false ) {
+ // If it cannot be acquired; then the stale value can be used
+ return $value;
+ } else {
+ // Either another thread has the lock or the lock failed.
+ // Use the stash value, which is likely from the prior thread.
+ $value = $this->cache->get( self::STASH_KEY_PREFIX . $key );
+ // Regenerate on timeout or if the other thread failed
+ if ( $value !== false ) {
+ return $value;
+ }
+ }
+ }
+
+ // Generate the new value from the callback...
+ $value = call_user_func( $callback, $cValue );
+ // When delete() is called, writes are write-holed by the tombstone,
+ // so use a special stash key to pass the new value around threads.
+ if ( $value !== false && ( $isHot || $isTombstone ) ) {
+ $this->cache->set( self::STASH_KEY_PREFIX . $key, $value, $tempTTL );
+ }
+
+ if ( $locked ) {
+ $this->cache->unlock( $key );
+ }
+
+ if ( $value !== false ) {
+ // Update the cache; this will fail if the key is tombstoned
+ $this->set( $key, $value, $ttl );
+ }
+
+ return $value;
+ }
+
+ /**
+ * Get the "last error" registered; clearLastError() should be called manually
+ * @return int ERR_* constant for the "last error" registry
+ */
+ final public function getLastError() {
+ if ( $this->lastRelayError ) {
+ // If the cache and the relayer failed, focus on the later.
+ // An update not making it to the relayer means it won't show up
+ // in other DCs (nor will consistent re-hashing see up-to-date values).
+ // On the other hand, if just the cache update failed, then it should
+ // eventually be applied by the relayer.
+ return $this->lastRelayError;
+ }
+
+ $code = $this->cache->getLastError();
+ switch ( $code ) {
+ case BagOStuff::ERR_NONE:
+ return self::ERR_NONE;
+ case BagOStuff::ERR_NO_RESPONSE:
+ return self::ERR_NO_RESPONSE;
+ case BagOStuff::ERR_UNREACHABLE:
+ return self::ERR_UNREACHABLE;
+ default:
+ return self::ERR_UNEXPECTED;
+ }
+ }
+
+ /**
+ * Clear the "last error" registry
+ */
+ final public function clearLastError() {
+ $this->cache->clearLastError();
+ $this->lastRelayError = self::ERR_NONE;
+ }
+
+ /**
+ * Do the actual async bus purge of a key
+ *
+ * This must set the key to "PURGED:<UNIX timestamp>"
+ *
+ * @param string $key Cache key
+ * @param integer $ttl How long to keep the tombstone [seconds]
+ * @return bool Success
+ */
+ protected function relayPurge( $key, $ttl ) {
+ $event = $this->cache->modifySimpleRelayEvent( array(
+ 'cmd' => 'set',
+ 'key' => $key,
+ 'val' => 'PURGED:$UNIXTIME$',
+ 'ttl' => max( $ttl, 1 ),
+ 'sbt' => true, // substitute $UNIXTIME$ with actual microtime
+ ) );
+
+ $ok = $this->relayer->notify( "{$this->pool}:purge", $event );
+ if ( !$ok ) {
+ $this->lastRelayError = self::ERR_RELAY;
+ }
+
+ return $ok;
+ }
+
+ /**
+ * Check if a key should be regenerated (using random probability)
+ *
+ * This returns false if $curTTL >= $lowTTL. Otherwise, the chance
+ * of returning true increases steadily from 0% to 100% as the $curTTL
+ * moves from $lowTTL to 0 seconds. This handles widely varying
+ * levels of cache access traffic.
+ *
+ * @param float|INF $curTTL Approximate TTL left on the key if present
+ * @param float $lowTTL Consider a refresh when $curTTL is less than this
+ * @return bool
+ */
+ protected function worthRefresh( $curTTL, $lowTTL ) {
+ if ( $curTTL >= $lowTTL ) {
+ return false;
+ } elseif ( $curTTL <= 0 ) {
+ return true;
+ }
+
+ $chance = ( 1 - $curTTL / $lowTTL );
+
+ return mt_rand( 1, 1e9 ) <= 1e9 * $chance;
+ }
+
+ /**
+ * Do not use this method outside WANObjectCache
+ *
+ * @param mixed $value
+ * @param integer $ttl [0=forever]
+ * @return string
+ */
+ protected function wrap( $value, $ttl ) {
+ return array(
+ self::FLD_VERSION => self::VERSION,
+ self::FLD_VALUE => $value,
+ self::FLD_TTL => $ttl,
+ self::FLD_TIME => microtime( true )
+ );
+ }
+
+ /**
+ * Do not use this method outside WANObjectCache
+ *
+ * @param array|string|bool $wrapped
+ * @param float $now Unix Current timestamp (preferrable pre-query)
+ * @return array (mixed; false if absent/invalid, current time left)
+ */
+ protected function unwrap( $wrapped, $now ) {
+ // Check if the value is a tombstone
+ $purgeTimestamp = self::parsePurgeValue( $wrapped );
+ if ( is_float( $purgeTimestamp ) ) {
+ // Purged values should always have a negative current $ttl
+ $curTTL = min( -0.000001, $purgeTimestamp - $now );
+ return array( false, $curTTL );
+ }
+
+ if ( !is_array( $wrapped ) // not found
+ || !isset( $wrapped[self::FLD_VERSION] ) // wrong format
+ || $wrapped[self::FLD_VERSION] !== self::VERSION // wrong version
+ ) {
+ return array( false, null );
+ }
+
+ if ( $wrapped[self::FLD_TTL] > 0 ) {
+ // Get the approximate time left on the key
+ $age = $now - $wrapped[self::FLD_TIME];
+ $curTTL = max( $wrapped[self::FLD_TTL] - $age, 0.0 );
+ } else {
+ // Key had no TTL, so the time left is unbounded
+ $curTTL = INF;
+ }
+
+ return array( $wrapped[self::FLD_VALUE], $curTTL );
+ }
+
+ /**
+ * @param array $keys
+ * @param string $prefix
+ * @return string
+ */
+ protected static function prefixCacheKeys( array $keys, $prefix ) {
+ $res = array();
+ foreach ( $keys as $key ) {
+ $res[] = $prefix . $key;
+ }
+
+ return $res;
+ }
+
+ /**
+ * @param string $value String like "PURGED:<timestamp>"
+ * @return float|bool UNIX timestamp or false on failure
+ */
+ protected static function parsePurgeValue( $value ) {
+ $m = array();
+ if ( is_string( $value ) &&
+ preg_match( '/^' . self::PURGE_VAL_PREFIX . '([^:]+)$/', $value, $m )
+ ) {
+ return (float)$m[1];
+ } else {
+ return false;
+ }
+ }
+}
--- /dev/null
+<?php
+
+class WANObjectCacheTest extends MediaWikiTestCase {
+ /** @var WANObjectCache */
+ private $cache;
+
+ protected function setUp() {
+ parent::setUp();
+
+ if ( $this->getCliArg( 'use-wanobjectcache' ) ) {
+ $name = $this->getCliArg( 'use-wanobjectcache' );
+
+ $this->cache = ObjectCache::getWANInstance( $name );
+ } else {
+ $this->cache = new WANObjectCache( array(
+ 'cache' => new HashBagOStuff(),
+ 'pool' => 'testcache-hash',
+ 'relayer' => new EventRelayerNull( array() )
+ ) );
+ }
+ }
+
+ /**
+ * @dataProvider provider_testSetAndGet
+ * @covers WANObjectCache::set()
+ * @covers WANObjectCache::get()
+ * @param mixed $value
+ * @param integer $ttl
+ */
+ public function testSetAndGet( $value, $ttl ) {
+ $key = wfRandomString();
+ $this->cache->set( $key, $value, $ttl );
+
+ $curTTL = null;
+ $this->assertEquals( $value, $this->cache->get( $key, $curTTL ) );
+ if ( is_infinite( $ttl ) || $ttl == 0 ) {
+ $this->assertTrue( is_infinite( $curTTL ), "Current TTL is infinite" );
+ } else {
+ $this->assertGreaterThan( 0, $curTTL, "Current TTL > 0" );
+ $this->assertLessThanOrEqual( $ttl, $curTTL, "Current TTL < nominal TTL" );
+ }
+ }
+
+ public static function provider_testSetAndGet() {
+ return array(
+ array( 14141, 3 ),
+ array( 3535.666, 3 ),
+ array( array(), 3 ),
+ array( null, 3 ),
+ array( '0', 3 ),
+ array( (object)array( 'meow' ), 3 ),
+ array( INF, 3 ),
+ array( '', 3 ),
+ array( 'pizzacat', INF ),
+ );
+ }
+
+ public function testGetNotExists() {
+ $key = wfRandomString();
+ $curTTL = null;
+ $value = $this->cache->get( $key, $curTTL );
+
+ $this->assertFalse( $value, "Non-existing key has false value" );
+ $this->assertNull( $curTTL, "Non-existing key has null current TTL" );
+ }
+
+ public function testSetOver() {
+ $key = wfRandomString();
+ for ( $i=0; $i<3; ++$i ) {
+ $value = wfRandomString();
+ $this->cache->set($key, $value, 3);
+
+ $this->assertEquals( $this->cache->get( $key ), $value );
+ }
+ }
+
+ /**
+ * @covers WANObjectCache::getWithSetCallback()
+ */
+ public function testGetWithSetCallback() {
+ $cache = $this->cache;
+
+ $key = wfRandomString();
+ $value = wfRandomString();
+ $cKey1 = wfRandomString();
+ $cKey2 = wfRandomString();
+
+ $wasSet = 0;
+ $func = function() use ( &$wasSet, $value ) { ++$wasSet; return $value; };
+
+ $wasSet = 0;
+ $v = $cache->getWithSetCallback( $key, $func, 30, array(), array( 'lockTSE' => 5 ) );
+ $this->assertEquals( $v, $value );
+ $this->assertEquals( 1, $wasSet, "Value regenerated" );
+
+ $wasSet = 0;
+ $v = $cache->getWithSetCallback( $key, $func, 30, array(), array( 'lockTSE' => 5 ) );
+ $this->assertEquals( $v, $value );
+ $this->assertEquals( 0, $wasSet, "Value not regenerated" );
+
+ $priorTime = microtime( true );
+ usleep( 1 );
+ $wasSet = 0;
+ $v = $cache->getWithSetCallback( $key, $func, 30, array( $cKey1, $cKey2 ) );
+ $this->assertEquals( $v, $value );
+ $this->assertEquals( 1, $wasSet, "Value regenerated due to check keys" );
+ $t1 = $cache->getCheckKeyTime( $cKey1 );
+ $this->assertGreaterThanOrEqual( $priorTime, $t1, 'Check keys generated on miss' );
+ $t2 = $cache->getCheckKeyTime( $cKey2 );
+ $this->assertGreaterThanOrEqual( $priorTime, $t2, 'Check keys generated on miss' );
+
+ $priorTime = microtime( true );
+ $wasSet = 0;
+ $v = $cache->getWithSetCallback( $key, $func, 30, array( $cKey1, $cKey2 ) );
+ $this->assertEquals( $v, $value );
+ $this->assertEquals( 1, $wasSet, "Value regenerated due to still-recent check keys" );
+ $t1 = $cache->getCheckKeyTime( $cKey1 );
+ $this->assertLessThanOrEqual( $priorTime, $t1, 'Check keys did not change again' );
+ $t2 = $cache->getCheckKeyTime( $cKey2 );
+ $this->assertLessThanOrEqual( $priorTime, $t2, 'Check keys did not change again' );
+
+ $curTTL = null;
+ $v = $cache->get( $key, $curTTL, array( $cKey1, $cKey2 ) );
+ $this->assertEquals( $v, $value );
+ $this->assertLessThanOrEqual( 0, $curTTL, "Value has current TTL < 0 due to check keys" );
+ }
+
+ /**
+ * @covers WANObjectCache::getMulti()
+ */
+ public function testGetMulti() {
+ $cache = $this->cache;
+
+ $value1 = array( 'this' => 'is', 'a' => 'test' );
+ $value2 = array( 'this' => 'is', 'another' => 'test' );
+
+ $key1 = wfRandomString();
+ $key2 = wfRandomString();
+ $key3 = wfRandomString();
+
+ $cache->set( $key1, $value1, 5 );
+ $cache->set( $key2, $value2, 10 );
+
+ $curTTLs = array();
+ $this->assertEquals(
+ array( $key1 => $value1, $key2 => $value2 ),
+ $cache->getMulti( array( $key1, $key2, $key3 ), $curTTLs )
+ );
+
+ $this->assertEquals( 2, count( $curTTLs ), "Two current TTLs in array" );
+ $this->assertGreaterThan( 0, $curTTLs[$key1], "Key 1 has current TTL > 0" );
+ $this->assertGreaterThan( 0, $curTTLs[$key2], "Key 2 has current TTL > 0" );
+
+ $cKey1 = wfRandomString();
+ $cKey2 = wfRandomString();
+ $curTTLs = array();
+ $this->assertEquals(
+ array( $key1 => $value1, $key2 => $value2 ),
+ $cache->getMulti( array( $key1, $key2, $key3 ), $curTTLs ),
+ 'Result array populated'
+ );
+
+ $priorTime = microtime( true );
+ usleep( 1 );
+ $curTTLs = array();
+ $this->assertEquals(
+ array( $key1 => $value1, $key2 => $value2 ),
+ $cache->getMulti( array( $key1, $key2, $key3 ), $curTTLs, array( $cKey1, $cKey2 ) ),
+ "Result array populated even with new check keys"
+ );
+ $t1 = $cache->getCheckKeyTime( $cKey1 );
+ $this->assertGreaterThanOrEqual( $priorTime, $t1, 'Check key 1 generated on miss' );
+ $t2 = $cache->getCheckKeyTime( $cKey2 );
+ $this->assertGreaterThanOrEqual( $priorTime, $t2, 'Check key 2 generated on miss' );
+ $this->assertEquals( 2, count( $curTTLs ), "Current TTLs array set" );
+ $this->assertLessThanOrEqual( 0, $curTTLs[$key1], 'Key 1 has current TTL <= 0' );
+ $this->assertLessThanOrEqual( 0, $curTTLs[$key2], 'Key 2 has current TTL <= 0' );
+
+ usleep( 1 );
+ $curTTLs = array();
+ $this->assertEquals(
+ array( $key1 => $value1, $key2 => $value2 ),
+ $cache->getMulti( array( $key1, $key2, $key3 ), $curTTLs, array( $cKey1, $cKey2 ) ),
+ "Result array still populated even with new check keys"
+ );
+ $this->assertEquals( 2, count( $curTTLs ), "Current TTLs still array set" );
+ $this->assertLessThan( 0, $curTTLs[$key1], 'Key 1 has negative current TTL' );
+ $this->assertLessThan( 0, $curTTLs[$key2], 'Key 2 has negative current TTL' );
+ }
+
+ /**
+ * @covers WANObjectCache::delete()
+ */
+ public function testDelete() {
+ $key = wfRandomString();
+ $value = wfRandomString();
+ $this->cache->set( $key, $value );
+
+ $curTTL = null;
+ $v = $this->cache->get( $key, $curTTL );
+ $this->assertEquals( $value, $v, "Key was created with value" );
+ $this->assertGreaterThan( 0, $curTTL, "Existing key has current TTL > 0" );
+
+ $this->cache->delete( $key );
+
+ $curTTL = null;
+ $v = $this->cache->get( $key, $curTTL );
+ $this->assertFalse( $v, "Deleted key has false value" );
+ $this->assertLessThan( 0, $curTTL, "Deleted key has current TTL < 0" );
+
+ $this->cache->set( $key, $value . 'more' );
+ $this->assertFalse( $v, "Deleted key is tombstoned and has false value" );
+ $this->assertLessThan( 0, $curTTL, "Deleted key is tombstoned and has current TTL < 0" );
+ }
+
+ /**
+ * @covers WANObjectCache::touchCheckKey()
+ * @covers WANObjectCache::getCheckKeyTime()
+ */
+ public function testTouchKeys() {
+ $key = wfRandomString();
+
+ $t0 = $this->cache->getCheckKeyTime( $key );
+ $this->assertFalse( $t0, 'Check key time is false' );
+
+ $priorTime = microtime( true );
+ usleep( 1 );
+ $this->cache->touchCheckKey( $key );
+ $t1 = $this->cache->getCheckKeyTime( $key );
+ $this->assertGreaterThanOrEqual( $priorTime, $t1, 'Check key created' );
+
+ $t2 = $this->cache->getCheckKeyTime( $key );
+ $this->assertEquals( $t1, $t2, 'Check key time did not change' );
+
+ usleep( 1 );
+ $this->cache->touchCheckKey( $key );
+ $t3 = $this->cache->getCheckKeyTime( $key );
+ $this->assertGreaterThan( $t2, $t3, 'Check key time increased' );
+
+ $t4 = $this->cache->getCheckKeyTime( $key );
+ $this->assertEquals( $t3, $t4, 'Check key time did not change' );
+ }
+}
\ No newline at end of file
dépôts / lhc / web / wiklou.git / commitdiff