Java tutorial
/** * Copyright 2015 Palantir Technologies * * Licensed under the BSD-3 License (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://opensource.org/licenses/BSD-3-Clause * * 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 com.palantir.atlasdb.cleaner; import java.util.Collection; import java.util.Set; import com.google.common.base.Preconditions; import com.google.common.collect.ImmutableMultimap; import com.google.common.collect.Lists; import com.google.common.collect.Multimap; import com.palantir.atlasdb.cleaner.api.OnCleanupTask; import com.palantir.atlasdb.keyvalue.api.Cell; import com.palantir.atlasdb.table.description.Schema; import com.palantir.atlasdb.transaction.api.Transaction; import com.palantir.atlasdb.transaction.api.Transaction.TransactionType; import com.palantir.atlasdb.transaction.api.TransactionManager; import com.palantir.atlasdb.transaction.api.TransactionTask; public class CleanupFollower implements Follower { private final ImmutableMultimap<String, OnCleanupTask> cleanupTasksByTable; public static CleanupFollower create(Iterable<Schema> schemas) { ImmutableMultimap.Builder<String, OnCleanupTask> cleanupTasksByTable = ImmutableMultimap.builder(); for (Schema schema : schemas) { cleanupTasksByTable.putAll(schema.getCleanupTasksByTable()); } return new CleanupFollower(cleanupTasksByTable.build()); } public static CleanupFollower create(Schema schema) { return new CleanupFollower(schema.getCleanupTasksByTable()); } private CleanupFollower(Multimap<String, OnCleanupTask> cleanupTasksByTable) { this.cleanupTasksByTable = ImmutableMultimap.copyOf(cleanupTasksByTable); } @Override public void run(TransactionManager txManager, String tableName, final Set<Cell> cells, final TransactionType transactionType) { Collection<OnCleanupTask> nextTasks = cleanupTasksByTable.get(tableName); while (!nextTasks.isEmpty()) { final Collection<OnCleanupTask> cleanupTasks = nextTasks; nextTasks = txManager .runTaskWithRetry(new TransactionTask<Collection<OnCleanupTask>, RuntimeException>() { @Override public Collection<OnCleanupTask> execute(Transaction t) { Collection<OnCleanupTask> toRetry = Lists.newArrayList(); Preconditions.checkArgument(transactionType == TransactionType.HARD_DELETE || transactionType == TransactionType.AGGRESSIVE_HARD_DELETE); t.setTransactionType(transactionType); for (OnCleanupTask task : cleanupTasks) { boolean needsRetry = task.cellsCleanedUp(t, cells); if (needsRetry) { toRetry.add(task); } } return toRetry; } }); } } }