patsonluk commented on code in PR #909: URL: https://github.com/apache/solr/pull/909#discussion_r922395415
########## solr/solrj/src/java/org/apache/solr/common/cloud/ZkStateReader.java: ########## @@ -246,6 +246,134 @@ public boolean canBeRemoved() { } } + /** + * A ConcurrentHashMap of active watcher by collection name + * + * <p>Each watcher DocCollectionWatch also contains the latest DocCollection (state) observed + */ + private static class DocCollectionWatches { + private final ConcurrentHashMap<String, StatefulCollectionWatch> + statefulWatchesByCollectionName = new ConcurrentHashMap<>(); + + /** + * Gets the DocCollection (state) of the collection which the corresponding watch last observed + * + * @param collection the collection name to get DocCollection on + * @return The last observed DocCollection(state). if null, that means there's no such + * collection. + */ + private DocCollection getDocCollection(String collection) { + StatefulCollectionWatch watch = statefulWatchesByCollectionName.get(collection); + return watch != null ? watch.currentState : null; + } + + /** + * Gets the active collections (collections that exist) being watched + * + * @return an immutable set of active collection names + */ + private Set<String> activeCollections() { + return statefulWatchesByCollectionName.entrySet().stream() + .filter( + (Entry<String, StatefulCollectionWatch> entry) -> + entry.getValue().currentState != null) + .map(Entry::getKey) + .collect(Collectors.toUnmodifiableSet()); + } + + /** + * Gets the count of active collections (collections that exist) being watched + * + * @return the count of active collections + */ + private long activeCollectionCount() { + return statefulWatchesByCollectionName.entrySet().stream() + .filter( + (Entry<String, StatefulCollectionWatch> entry) -> + entry.getValue().currentState != null) + .count(); + } + + private Set<String> watchedCollections() { + return Collections.unmodifiableSet(statefulWatchesByCollectionName.keySet()); + } + + private Set<Entry<String, StatefulCollectionWatch>> watchedCollectionEntries() { + return Collections.unmodifiableSet(statefulWatchesByCollectionName.entrySet()); + } + + /** + * Updates the latest observed DocCollection (state) of the {@link StatefulCollectionWatch} if + * the collection is being watched + * + * @param collection the collection name + * @param newState the new DocCollection (state) observed + * @return whether the state has changed for the watched collection + */ + private boolean updateDocCollection(String collection, DocCollection newState) { + AtomicBoolean stateHasChanged = new AtomicBoolean(false); + statefulWatchesByCollectionName.computeIfPresent( + collection, + (col, watch) -> { + DocCollection oldState = watch.currentState; + if (oldState == null && newState == null) { + // OK, the collection not yet exist in ZK or already deleted + } else if (oldState == null) { + if (log.isDebugEnabled()) { + log.debug("Add data for [{}] ver [{}]", collection, newState.getZNodeVersion()); + } + watch.currentState = newState; + } else if (newState == null) { + log.debug("Removing cached collection state for [{}]", collection); + watch.currentState = null; + } else { // both new and old states are non-null + int oldCVersion = + oldState.getPerReplicaStates() == null + ? -1 + : oldState.getPerReplicaStates().cversion; + int newCVersion = + newState.getPerReplicaStates() == null + ? -1 + : newState.getPerReplicaStates().cversion; + if (oldState.getZNodeVersion() < newState.getZNodeVersion() + || oldCVersion < newCVersion) { + watch.currentState = newState; + if (log.isDebugEnabled()) { + log.debug( + "Updating data for [{}] from [{}] to [{}]", + collection, + oldState.getZNodeVersion(), + newState.getZNodeVersion()); + } + } + } + stateHasChanged.set(oldState != watch.currentState); + return watch; + }); + + return stateHasChanged.get(); + } + + /** + * Computes the new StatefulCollectionWatch by the supplied remappingFunction. Review Comment: Added! -- 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: issues-unsubscr...@solr.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@solr.apache.org For additional commands, e-mail: issues-h...@solr.apache.org