Github user lei-xia commented on a diff in the pull request: https://github.com/apache/helix/pull/145#discussion_r175833400 --- Diff: helix-core/src/main/java/org/apache/helix/api/rebalancer/constraint/AbstractRebalanceSoftConstraint.java --- @@ -0,0 +1,56 @@ +package org.apache.helix.api.rebalancer.constraint; + +/* + * 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. + */ + +import org.apache.helix.controller.common.ResourcesStateMap; + +import java.util.Map; + +public abstract class AbstractRebalanceSoftConstraint { + private static int DEFAULT_IMPORTANCE = 1; + protected int _importance = DEFAULT_IMPORTANCE; + + /** + * Evaluate how the given assignment fits the constraint. + * @param resource Target resource + * @param proposedAssignment Map of <PartitionName, lists of possible ParticipantName> + * @return Evaluation about the assignment. Larger number means better fit under this constraint. + */ + public abstract Map<String, int[]> evaluate(String resource, + Map<String, String[]> proposedAssignment); + + /** + * @return The soft constraint's importance that will be used to compare with other soft constraint results. + * Aggregated evaluation score = SUM(constraint_evaluation * importance). + */ + public int getConstraintImportance() { --- End diff -- Is importance same as priority?
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