strongduanmu commented on a change in pull request #13943: URL: https://github.com/apache/shardingsphere/pull/13943#discussion_r763780704
########## File path: shardingsphere-features/shardingsphere-readwrite-splitting/shardingsphere-readwrite-splitting-core/src/main/java/org/apache/shardingsphere/readwritesplitting/algorithm/WeightReplicaLoadBalanceAlgorithm.java ########## @@ -0,0 +1,121 @@ +/* + * 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.shardingsphere.readwritesplitting.algorithm; + +import org.apache.shardingsphere.readwritesplitting.spi.ReplicaLoadBalanceAlgorithm; + +import java.util.Arrays; +import java.util.List; +import java.util.Properties; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.ThreadLocalRandom; + +/** + * Weight replica load-balance algorithm. + */ +public final class WeightReplicaLoadBalanceAlgorithm implements ReplicaLoadBalanceAlgorithm { + + private static final ConcurrentHashMap<String, Double[]> WEIGHT_MAP = new ConcurrentHashMap<>(); + + /** + * Cumulative accuracy loss threshold + */ + private static final double ACCURACY_THRESHOLD = 0.0001; + + private Properties props = new Properties(); + + @Override + public Properties getProps() { + return this.props; + } + + @Override + public void setProps(final Properties props) { + this.props = props; + } + + @Override + public String getType() { + return "WEIGHT"; + } + + @Override + public String getDataSource(final String name, final String writeDataSourceName, final List<String> readDataSourceNames) { + Double[] weight = WEIGHT_MAP.containsKey(name) ? WEIGHT_MAP.get(name) : initWeight(readDataSourceNames); + WEIGHT_MAP.putIfAbsent(name, weight); + return getDataSourceName(readDataSourceNames, weight); + } + + private String getDataSourceName(final List<String> readDataSourceNames, final Double[] weight) { + double randomWeight = ThreadLocalRandom.current().nextDouble(0, 1); + int index = Arrays.binarySearch(weight, randomWeight); + if (index < 0) { + index = -index - 1; + return index < weight.length && randomWeight < weight[index] ? readDataSourceNames.get(index) : readDataSourceNames.get(readDataSourceNames.size() - 1); + } else { + return readDataSourceNames.get(index); + } + } + + private Double[] initWeight(final List<String> readDataSourceNames) { + Double[] weights = getWeights(readDataSourceNames); + if (weights.length != 0 && Math.abs(weights[weights.length - 1] - 1.0D) >= ACCURACY_THRESHOLD) { + throw new IllegalStateException("The cumulative weight is calculated incorrectly, and the sum of the probabilities is not equal to 1."); + } + return weights; + } + + private Double[] getWeights(final List<String> readDataSourceNames) { Review comment: @cherubimLV This method is too long, and some logic is not easy to understand. Is it possible to improve readability by extracting methods and naming methods? ########## File path: shardingsphere-features/shardingsphere-readwrite-splitting/shardingsphere-readwrite-splitting-core/src/main/java/org/apache/shardingsphere/readwritesplitting/algorithm/WeightReplicaLoadBalanceAlgorithm.java ########## @@ -0,0 +1,121 @@ +/* + * 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.shardingsphere.readwritesplitting.algorithm; + +import org.apache.shardingsphere.readwritesplitting.spi.ReplicaLoadBalanceAlgorithm; + +import java.util.Arrays; +import java.util.List; +import java.util.Properties; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.ThreadLocalRandom; + +/** + * Weight replica load-balance algorithm. + */ +public final class WeightReplicaLoadBalanceAlgorithm implements ReplicaLoadBalanceAlgorithm { + + private static final ConcurrentHashMap<String, Double[]> WEIGHT_MAP = new ConcurrentHashMap<>(); + + /** + * Cumulative accuracy loss threshold + */ + private static final double ACCURACY_THRESHOLD = 0.0001; + + private Properties props = new Properties(); + + @Override + public Properties getProps() { + return this.props; + } + + @Override + public void setProps(final Properties props) { + this.props = props; + } + + @Override + public String getType() { + return "WEIGHT"; + } + + @Override + public String getDataSource(final String name, final String writeDataSourceName, final List<String> readDataSourceNames) { + Double[] weight = WEIGHT_MAP.containsKey(name) ? WEIGHT_MAP.get(name) : initWeight(readDataSourceNames); Review comment: @cherubimLV Can we make the ReplicaLoadBalanceAlgorithm interface implement ShardingSphereAlgorithmPostProcessor? So that the weight parameter can be initialized in the init method? ########## File path: shardingsphere-features/shardingsphere-readwrite-splitting/shardingsphere-readwrite-splitting-core/src/main/java/org/apache/shardingsphere/readwritesplitting/algorithm/WeightReplicaLoadBalanceAlgorithm.java ########## @@ -0,0 +1,99 @@ +package org.apache.shardingsphere.readwritesplitting.algorithm; + +import lombok.Getter; +import lombok.Setter; +import org.apache.shardingsphere.readwritesplitting.spi.ReplicaLoadBalanceAlgorithm; + +import java.util.Arrays; +import java.util.List; +import java.util.Properties; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.ThreadLocalRandom; + +/** + * Weight replica load-balance algorithm. + */ +@Getter +@Setter +public class WeightReplicaLoadBalanceAlgorithm implements ReplicaLoadBalanceAlgorithm { + private static final ConcurrentHashMap<String, Double[]> WEIGHT_MAP = new ConcurrentHashMap<>(); Review comment: @cherubimLV Why is the value of this object Double data? Instead of Double? ########## File path: shardingsphere-features/shardingsphere-readwrite-splitting/shardingsphere-readwrite-splitting-core/src/main/java/org/apache/shardingsphere/readwritesplitting/algorithm/WeightReplicaLoadBalanceAlgorithm.java ########## @@ -0,0 +1,121 @@ +/* + * 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.shardingsphere.readwritesplitting.algorithm; + +import org.apache.shardingsphere.readwritesplitting.spi.ReplicaLoadBalanceAlgorithm; + +import java.util.Arrays; +import java.util.List; +import java.util.Properties; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.ThreadLocalRandom; + +/** + * Weight replica load-balance algorithm. + */ +public final class WeightReplicaLoadBalanceAlgorithm implements ReplicaLoadBalanceAlgorithm { + + private static final ConcurrentHashMap<String, Double[]> WEIGHT_MAP = new ConcurrentHashMap<>(); + + /** + * Cumulative accuracy loss threshold Review comment: Hi @cherubimLV, please remove this doc for field. ########## File path: shardingsphere-features/shardingsphere-readwrite-splitting/shardingsphere-readwrite-splitting-core/src/main/java/org/apache/shardingsphere/readwritesplitting/algorithm/WeightReplicaLoadBalanceAlgorithm.java ########## @@ -0,0 +1,99 @@ +package org.apache.shardingsphere.readwritesplitting.algorithm; + +import lombok.Getter; +import lombok.Setter; +import org.apache.shardingsphere.readwritesplitting.spi.ReplicaLoadBalanceAlgorithm; + +import java.util.Arrays; +import java.util.List; +import java.util.Properties; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.ThreadLocalRandom; + +/** + * Weight replica load-balance algorithm. + */ +@Getter +@Setter +public class WeightReplicaLoadBalanceAlgorithm implements ReplicaLoadBalanceAlgorithm { + private static final ConcurrentHashMap<String, Double[]> WEIGHT_MAP = new ConcurrentHashMap<>(); + + private Properties props = new Properties(); + + @Override + public Properties getProps() { + return this.props; + } + + @Override + public void setProps(final Properties props) { Review comment: As @RaigorJiang said, we recommend the lombok method more than the get set method, so please delete these methods. -- This is an automated message from the Apache Git Service. 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