// No negative caching; negative hits on text rows may be due to corrupted replica DBs
$blob = $this->cache->getWithSetCallback(
- // TODO: change key, since this is not necessarily revision text!
- $this->cache->makeKey( 'revisiontext', 'textid', $blobAddress ),
+ $this->getCacheKey( $blobAddress ),
$this->getCacheTTL(),
function ( $unused, &$ttl, &$setOpts ) use ( $blobAddress, $queryFlags ) {
list( $index ) = DBAccessObjectUtils::getDBOptions( $queryFlags );
return $blob;
}
+ /**
+ * Get a cache key for a given Blob address.
+ *
+ * The cache key is constructed in a way that allows cached blobs from the same database
+ * to be re-used between wikis. For example, enwiki and frwiki will use the same cache keys
+ * for blobs from the wikidatawiki database.
+ *
+ * @param string $blobAddress
+ * @return string
+ */
+ private function getCacheKey( $blobAddress ) {
+ return $this->cache->makeGlobalKey(
+ 'BlobStore',
+ 'address',
+ $this->dbLoadBalancer->resolveDomainID( $this->wikiId ),
+ $blobAddress
+ );
+ }
+
/**
* Expand a raw data blob according to the flags given.
*
* @param string|string[] $flags Blob flags, such as 'external' or 'gzip'.
* Note that not including 'utf-8' in $flags will cause the data to be decoded
* according to the legacy encoding specified via setLegacyEncoding.
- * @param string|null $cacheKey May be used for caching if given
+ * @param string|null $cacheKey A blob address for use in the cache key. If not given,
+ * caching is disabled.
*
* @return false|string The expanded blob or false on failure
*/
return false;
}
- if ( $cacheKey && $this->wikiId === false ) {
- // Make use of the wiki-local revision text cache.
+ if ( $cacheKey ) {
// The cached value should be decompressed, so handle that and return here.
- // NOTE: we rely on $this->cache being the right cache for $this->wikiId!
return $this->cache->getWithSetCallback(
- // TODO: change key, since this is not necessarily revision text!
- $this->cache->makeKey( 'revisiontext', 'textid', $cacheKey ),
+ $this->getCacheKey( $cacheKey ),
$this->getCacheTTL(),
function () use ( $url, $flags ) {
// No negative caching per BlobStore::getBlob()