/*
* Copyright 1999-2015 dangdang.com.
* <p>
* Licensed 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.
* </p>
*/
package com.dangdang.ddframe.rdb.sharding.example.jdbc.masterslave.algorithm;
import com.dangdang.ddframe.rdb.sharding.api.ShardingValue;
import com.dangdang.ddframe.rdb.sharding.api.strategy.database.SingleKeyDatabaseShardingAlgorithm;
import com.google.common.collect.Range;
import java.util.Collection;
import java.util.LinkedHashSet;
public final class ModuloDatabaseShardingAlgorithm implements SingleKeyDatabaseShardingAlgorithm<Integer> {
@Override
public String doEqualSharding(final Collection<String> dataSourceNames, final ShardingValue<Integer> shardingValue) {
for (String each : dataSourceNames) {
if (each.endsWith(shardingValue.getValue() % 2 + "")) {
return each;
}
}
throw new IllegalArgumentException();
}
@Override
public Collection<String> doInSharding(final Collection<String> dataSourceNames, final ShardingValue<Integer> shardingValue) {
Collection<String> result = new LinkedHashSet<>(dataSourceNames.size());
for (Integer value : shardingValue.getValues()) {
for (String each : dataSourceNames) {
if (each.endsWith(value % 2 + "")) {
result.add(each);
}
}
}
return result;
}
@Override
public Collection<String> doBetweenSharding(final Collection<String> dataSourceNames, final ShardingValue<Integer> shardingValue) {
Collection<String> result = new LinkedHashSet<>(dataSourceNames.size());
Range<Integer> range = shardingValue.getValueRange();
for (Integer value = range.lowerEndpoint(); value <= range.upperEndpoint(); value++) {
for (String each : dataSourceNames) {
if (each.endsWith(value % 2 + "")) {
result.add(each);
}
}
}
return result;
}
}