package org.infinispan.metadata;
import org.infinispan.container.entries.CacheEntry;
/**
* Utility method for Metadata classes.
*
* @author Galder Zamarreño
* @since 5.3
*/
public class Metadatas {
private Metadatas() {
}
/**
* Applies version in source metadata to target metadata, if no version
* in target metadata. This method can be useful in scenarios where source
* version information must be kept around, i.e. write skew, or when
* reading metadata from cache store.
*
* @param source Metadata object which is source, whose version might be
* is of interest for the target metadata
* @param target Metadata object on which version might be applied
* @return either, the target Metadata instance as it was when it was
* called, or a brand new target Metadata instance with version from source
* metadata applied.
*/
public static Metadata applyVersion(Metadata source, Metadata target) {
if (target.version() == null && source.version() != null)
return target.builder().version(source.version()).build();
return target;
}
/**
* Set the {@code providedMetadata} on the cache entry.
*
* If the entry already has a version, copy the version in the new metadata.
*/
public static void updateMetadata(CacheEntry entry, Metadata providedMetadata) {
if (entry != null && providedMetadata != null) {
Metadata mergedMetadata;
if (entry.getMetadata() == null) {
mergedMetadata = providedMetadata;
} else {
mergedMetadata = applyVersion(entry.getMetadata(), providedMetadata);
}
entry.setMetadata(mergedMetadata);
}
}
}