bharos commented on code in PR #12171:
URL: https://github.com/apache/gravitino/pull/12171#discussion_r3686817587
##########
core/src/main/java/org/apache/gravitino/cache/SupportsRelationEntityCache.java:
##########
@@ -102,4 +102,40 @@ <E extends Entity & HasIdentifier> void put(
Entity.EntityType type,
SupportsRelationOperations.Type relType,
List<E> entities);
+
+ /**
+ * Returns an opaque generation token for the cache slot that holds the
given relation. Callers
+ * that populate the cache from a backend using a cache-aside pattern should
snapshot this token
+ * before reading the backend (right after observing a cache miss) and pass
it to {@link
+ * #putIfNotInvalidatedSince}, so a concurrent invalidation that happens
during the backend read
+ * is detected and the possibly-stale result is not written.
+ *
+ * @param ident the name identifier
+ * @param type the entity type
+ * @param relType the relation type
+ * @return the current generation token for the relation's cache slot
+ */
+ long relationGeneration(
+ NameIdentifier ident, Entity.EntityType type,
SupportsRelationOperations.Type relType);
+
+ /**
+ * Puts a list of related entities into the cache only if the relation has
not been invalidated
+ * since the given generation token was snapshotted. If the relation was
invalidated in the
+ * meantime, the put is skipped so a stale backend result cannot overwrite a
concurrent
+ * invalidation; the entry is left absent and rebuilt on the next read.
+ *
+ * @param ident The name identifier of the entity to cache the related
entities for
+ * @param type The type of the entity to cache the related entities for
+ * @param relType The relation type to cache the related entities for
+ * @param entities The list of related entities to cache
+ * @param sinceGeneration The generation token snapshotted via {@link
#relationGeneration} before
+ * the backend read
+ * @param <E> The class of the related entities
+ */
+ <E extends Entity & HasIdentifier> void putIfNotInvalidatedSince(
Review Comment:
Sure, I will check
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
