objectcache: add setMockTime() method to BagOStuff/WANObjectCache

[lhc/web/wiklou.git] / includes / libs / objectcache / WANObjectCache.php

diff --git a/includes/libs/objectcache/WANObjectCache.php b/includes/libs/objectcache/WANObjectCache.php
index d939819..658b225 100644 (file)
--- a/includes/libs/objectcache/WANObjectCache.php
+++ b/includes/libs/objectcache/WANObjectCache.php
@@ -118,6 +118,9 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
        /** @var int Key fetched */
        private $warmupKeyMisses = 0;
 
+       /** @var float|null */
+       private $wallClockOverride;
+
        /** Max time expected to pass between delete() and DB commit finishing */
        const MAX_COMMIT_DELAY = 3;
        /** Max replication+snapshot lag before applying TTL_LAGGED or disallowing set() */
@@ -134,8 +137,6 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
        const LOCK_TTL = 10;
        /** Default remaining TTL at which to consider pre-emptive regeneration */
        const LOW_TTL = 30;
-       /** Default time-since-expiry on a miss that makes a key "hot" */
-       const LOCK_TSE = 1;
 
        /** Never consider performing "popularity" refreshes until a key reaches this age */
        const AGE_NEW = 60;
@@ -284,7 +285,8 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
         * (e.g. the default REPEATABLE-READ in innoDB). Even for mutable data, that
         * isolation can largely be maintained by doing the following:
         *   - a) Calling delete() on entity change *and* creation, before DB commit
-        *   - b) Keeping transaction duration shorter than delete() hold-off TTL
+        *   - b) Keeping transaction duration shorter than the delete() hold-off TTL
+        *   - c) Disabling interim key caching via useInterimHoldOffCaching() before get() calls
         *
         * However, pre-snapshot values might still be seen if an update was made
         * in a remote datacenter but the purge from delete() didn't relay yet.
@@ -518,18 +520,18 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
                        // Case B: any long-running transaction; ignore this set()
                        } elseif ( $age > self::MAX_READ_LAG ) {
                                $this->logger->info( 'Rejected set() for {cachekey} due to snapshot lag.',
-                                       [ 'cachekey' => $key ] );
+                                       [ 'cachekey' => $key, 'lag' => $lag, 'age' => $age ] );
 
                                return true; // no-op the write for being unsafe
                        // Case C: high replication lag; lower TTL instead of ignoring all set()s
                        } elseif ( $lag === false || $lag > self::MAX_READ_LAG ) {
                                $ttl = $ttl ? min( $ttl, self::TTL_LAGGED ) : self::TTL_LAGGED;
                                $this->logger->warning( 'Lowered set() TTL for {cachekey} due to replication lag.',
-                                       [ 'cachekey' => $key ] );
+                                       [ 'cachekey' => $key, 'lag' => $lag, 'age' => $age ] );
                        // Case D: medium length request with medium replication lag; ignore this set()
                        } else {
                                $this->logger->info( 'Rejected set() for {cachekey} due to high read lag.',
-                                       [ 'cachekey' => $key ] );
+                                       [ 'cachekey' => $key, 'lag' => $lag, 'age' => $age ] );
 
                                return true; // no-op the write for being unsafe
                        }
@@ -1537,7 +1539,7 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
        }
 
        /**
-        * Locally set a key to expire soon if it is stale based on $purgeTimestamp
+        * Set a key to soon expire in the local cluster if it pre-dates $purgeTimestamp
         *
         * This sets stale keys' time-to-live at HOLDOFF_TTL seconds, which both avoids
         * broadcasting in mcrouter setups and also avoids races with new tombstones.
@@ -1569,7 +1571,7 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
        }
 
        /**
-        * Locally set a "check" key to expire soon if it is stale based on $purgeTimestamp
+        * Set a "check" key to soon expire in the local cluster if it pre-dates $purgeTimestamp
         *
         * @param string $key Cache key
         * @param int $purgeTimestamp UNIX timestamp of purge
@@ -1582,7 +1584,7 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
                if ( $purge && $purge[self::FLD_TIME] < $purgeTimestamp ) {
                        $isStale = true;
                        $this->logger->warning( "Reaping stale check key '$key'." );
-                       $ok = $this->cache->changeTTL( self::TIME_KEY_PREFIX . $key, 1 );
+                       $ok = $this->cache->changeTTL( self::TIME_KEY_PREFIX . $key, self::TTL_SECOND );
                        if ( !$ok ) {
                                $this->logger->error( "Could not complete reap of check key '$key'." );
                        }
@@ -1825,7 +1827,7 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
                                'cmd' => 'set',
                                'key' => $key,
                                'val' => 'PURGED:$UNIXTIME$:' . (int)$holdoff,
-                               'ttl' => max( $ttl, 1 ),
+                               'ttl' => max( $ttl, self::TTL_SECOND ),
                                'sbt' => true, // substitute $UNIXTIME$ with actual microtime
                        ] );
 
@@ -2065,14 +2067,6 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
                return isset( $parts[1] ) ? $parts[1] : $parts[0]; // sanity
        }
 
-       /**
-        * @return float UNIX timestamp
-        * @codeCoverageIgnore
-        */
-       protected function getCurrentTime() {
-               return microtime( true );
-       }
-
        /**
         * @param string $value Wrapped value like "PURGED:<timestamp>:<holdoff>"
         * @return array|bool Array containing a UNIX timestamp (float) and holdoff period (integer),
@@ -2174,4 +2168,21 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
 
                return $warmupCache;
        }
+
+       /**
+        * @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;
+               $this->cache->setMockTime( $time );
+       }
 }