henrib commented on code in PR #4194: URL: https://github.com/apache/hive/pull/4194#discussion_r1204628282
########## standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/properties/PropertyStore.java: ########## @@ -0,0 +1,222 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.hadoop.hive.metastore.properties; + +import java.util.Collections; +import java.util.Iterator; +import java.util.Map; +import java.util.TreeMap; +import java.util.UUID; +import java.util.function.Function; +import java.util.function.Predicate; + +/** + * The PropertyStore is the persistent container of property maps. + * Maps are addressed in the store by their key - their name prepended by their manager"s namespace. + */ + +public abstract class PropertyStore { + /** + * Fetches a property map. + * @param mapKey the map key + * @param getSchema the method to retrieve a schema if the map needs to be created + * @return the item property map + */ + public abstract PropertyMap fetchProperties(String mapKey, Function<String, PropertySchema> getSchema); + + + /** + * Fetches a map of property maps. + * @param keyPrefix the map key prefix + * @param keyFilter a filter for map keys + * @param getSchema the method to retrieve a schema if the map needs to be created + * @return the map of property map + */ + public abstract Map<String, PropertyMap> selectProperties(final String keyPrefix, Predicate<String> keyFilter, Function<String, PropertySchema> getSchema); + /** + * Fetches a property map digest. + * @param mapKey the map key + * @return the item property map + */ + public abstract UUID fetchDigest(String mapKey); + + /** + * Fetches a map of property maps digest keyed by their name. + * @param keyPrefix the map key prefix + * @param keyFilter a filter for map keys + * @return the map of property map digests + */ + public abstract Map<String, UUID> selectDigest(String keyPrefix, Predicate<String> keyFilter); + + /** + * Persists a property map. + * @param mapKey the map key + * @param map the map instance + */ + protected abstract void saveProperties(String mapKey, PropertyMap map); + + + /** + * Drops a property map. + * @param mapKey the map key + */ + protected abstract boolean dropProperties(String mapKey); + + /** + * Renames a property map. + * @param mapKey the map source key + * @param newKey the new target key + */ + public abstract boolean renameProperties(String mapKey, String newKey); + + /** + * Persists an iterator property map. + * <p>May be useful to override to use one transaction.</p> + * @param save the iterator on pairs for map key, property map + */ + public void saveProperties(Iterator<Map.Entry<String, PropertyMap>> save) { + while(save.hasNext()) { + Map.Entry<String, PropertyMap> pair = save.next(); + PropertyMap map = pair.getValue(); + if (map != null) { + saveProperties(pair.getKey(), map); + } else { + dropProperties(pair.getKey()); + } + } + } + + /** + * Serializes a map as a byte array. + * @param map the (nonnull) map to write + * @return the byte array + */ + public byte[] serialize(PropertyMap map) { + return SerializationProxy.toBytes(map); + } + + /** + * Deserializes a map from a byte array. + * @param bytes the byte array + * @return the (nonnull) oroperty map + */ + public PropertyMap deserialize(byte[] bytes, Function<String, PropertySchema> getSchema) { + return SerializationProxy.fromBytes(bytes, this, getSchema); + } + + /** + * Default ctor. + */ + protected PropertyStore() { + } + + /** + * A non-persistent store, for tests mainly. + */ + public static class Transient extends PropertyStore { Review Comment: Done. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
