| /* |
| * 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.cassandra.triggers; |
| |
| import java.io.File; |
| import java.nio.ByteBuffer; |
| import java.util.*; |
| |
| import com.google.common.collect.Iterables; |
| import com.google.common.collect.Lists; |
| import com.google.common.collect.Maps; |
| |
| import org.apache.cassandra.config.TriggerDefinition; |
| import org.apache.cassandra.cql3.QueryProcessor; |
| import org.apache.cassandra.db.*; |
| import org.apache.cassandra.db.marshal.AbstractType; |
| import org.apache.cassandra.exceptions.InvalidRequestException; |
| import org.apache.cassandra.utils.FBUtilities; |
| import org.apache.cassandra.utils.Pair; |
| |
| public class TriggerExecutor |
| { |
| public static final TriggerExecutor instance = new TriggerExecutor(); |
| |
| private final Map<String, ITrigger> cachedTriggers = Maps.newConcurrentMap(); |
| private final ClassLoader parent = Thread.currentThread().getContextClassLoader(); |
| private volatile ClassLoader customClassLoader; |
| |
| private TriggerExecutor() |
| { |
| reloadClasses(); |
| } |
| |
| /** |
| * Reload the triggers which is already loaded, Invoking this will update |
| * the class loader so new jars can be loaded. |
| */ |
| public void reloadClasses() |
| { |
| File triggerDirectory = FBUtilities.cassandraTriggerDir(); |
| if (triggerDirectory == null) |
| return; |
| customClassLoader = new CustomClassLoader(parent, triggerDirectory); |
| cachedTriggers.clear(); |
| } |
| |
| /** |
| * Augment a partition update by executing triggers to generate an intermediate |
| * set of mutations, then merging the ColumnFamily from each mutation with those |
| * supplied. This is called from @{link org.apache.cassandra.service.StorageProxy#cas} |
| * which is scoped for a single partition. For that reason, any mutations generated |
| * by triggers are checked to ensure that they are for the same table and partition |
| * key as the primary update; if not, InvalidRequestException is thrown. If no |
| * additional mutations are generated, the original updates are returned unmodified. |
| * |
| * @param key partition key for the update |
| * @param updates partition update to be applied, contains the merge of the original |
| * update and any generated mutations |
| * @return the final update to be applied, the original update merged with any |
| * additional mutations generated by configured triggers |
| * @throws InvalidRequestException if any mutation generated by a trigger does not |
| * apply to the exact same partition as the initial update |
| */ |
| public ColumnFamily execute(ByteBuffer key, ColumnFamily updates) throws InvalidRequestException |
| { |
| List<Mutation> intermediate = executeInternal(key, updates); |
| if (intermediate == null || intermediate.isEmpty()) |
| return updates; |
| |
| validateForSinglePartition(updates.metadata().getKeyValidator(), updates.id(), key, intermediate); |
| |
| for (Mutation mutation : intermediate) |
| { |
| for (ColumnFamily cf : mutation.getColumnFamilies()) |
| { |
| updates.addAll(cf); |
| } |
| } |
| return updates; |
| } |
| |
| /** |
| * Takes a collection of mutations and possibly augments it by adding extra mutations |
| * generated by configured triggers. If no additional mutations are created |
| * this returns null, signalling to the caller that only the initial set of |
| * mutations should be applied. If additional mutations <i>are</i> generated, |
| * the total set (i.e. the original plus the additional mutations) are applied |
| * together in a logged batch. Should this not be possible because the initial |
| * mutations contain counter updates, InvalidRequestException is thrown. |
| * |
| * @param mutations initial collection of mutations |
| * @return augmented mutations. Either the union of the initial and additional |
| * mutations or null if no additional mutations were generated |
| * @throws InvalidRequestException if additional mutations were generated, but |
| * the initial mutations contains counter updates |
| */ |
| public Collection<Mutation> execute(Collection<? extends IMutation> mutations) throws InvalidRequestException |
| { |
| boolean hasCounters = false; |
| List<Mutation> augmentedMutations = null; |
| |
| for (IMutation mutation : mutations) |
| { |
| if (mutation instanceof CounterMutation) |
| hasCounters = true; |
| |
| for (ColumnFamily cf : mutation.getColumnFamilies()) |
| { |
| List<Mutation> augmentations = executeInternal(mutation.key(), cf); |
| if (augmentations == null || augmentations.isEmpty()) |
| continue; |
| |
| validate(augmentations); |
| |
| if (augmentedMutations == null) |
| augmentedMutations = new LinkedList<>(); |
| augmentedMutations.addAll(augmentations); |
| } |
| } |
| |
| if (augmentedMutations == null) |
| return null; |
| |
| if (hasCounters) |
| throw new InvalidRequestException("Counter mutations and trigger mutations cannot be applied together atomically."); |
| |
| @SuppressWarnings("unchecked") |
| Collection<Mutation> originalMutations = (Collection<Mutation>) mutations; |
| |
| return mergeMutations(Iterables.concat(originalMutations, augmentedMutations)); |
| } |
| |
| private Collection<Mutation> mergeMutations(Iterable<Mutation> mutations) |
| { |
| Map<Pair<String, ByteBuffer>, Mutation> groupedMutations = new HashMap<>(); |
| |
| for (Mutation mutation : mutations) |
| { |
| Pair<String, ByteBuffer> key = Pair.create(mutation.getKeyspaceName(), mutation.key()); |
| Mutation current = groupedMutations.get(key); |
| if (current == null) |
| { |
| // copy in case the mutation's modifications map is backed by an immutable Collections#singletonMap(). |
| groupedMutations.put(key, mutation.copy()); |
| } |
| else |
| { |
| current.addAll(mutation); |
| } |
| } |
| |
| return groupedMutations.values(); |
| } |
| |
| private void validateForSinglePartition(AbstractType<?> keyValidator, |
| UUID cfId, |
| ByteBuffer key, |
| Collection<Mutation> tmutations) |
| throws InvalidRequestException |
| { |
| for (Mutation mutation : tmutations) |
| { |
| if (keyValidator.compare(mutation.key(), key) != 0) |
| throw new InvalidRequestException("Partition key of additional mutation does not match primary update key"); |
| |
| for (ColumnFamily cf : mutation.getColumnFamilies()) |
| { |
| if (! cf.id().equals(cfId)) |
| throw new InvalidRequestException("table of additional mutation does not match primary update table"); |
| } |
| } |
| validate(tmutations); |
| } |
| |
| private void validate(Collection<Mutation> tmutations) throws InvalidRequestException |
| { |
| for (Mutation mutation : tmutations) |
| { |
| QueryProcessor.validateKey(mutation.key()); |
| for (ColumnFamily tcf : mutation.getColumnFamilies()) |
| for (Cell cell : tcf) |
| cell.validateFields(tcf.metadata()); |
| } |
| } |
| |
| /** |
| * Switch class loader before using the triggers for the column family, if |
| * not loaded them with the custom class loader. |
| */ |
| private List<Mutation> executeInternal(ByteBuffer key, ColumnFamily columnFamily) |
| { |
| Map<String, TriggerDefinition> triggers = columnFamily.metadata().getTriggers(); |
| if (triggers.isEmpty()) |
| return null; |
| List<Mutation> tmutations = Lists.newLinkedList(); |
| Thread.currentThread().setContextClassLoader(customClassLoader); |
| try |
| { |
| for (TriggerDefinition td : triggers.values()) |
| { |
| ITrigger trigger = cachedTriggers.get(td.classOption); |
| if (trigger == null) |
| { |
| trigger = loadTriggerInstance(td.classOption); |
| cachedTriggers.put(td.classOption, trigger); |
| } |
| Collection<Mutation> temp = trigger.augment(key, columnFamily); |
| if (temp != null) |
| tmutations.addAll(temp); |
| } |
| return tmutations; |
| } |
| catch (Exception ex) |
| { |
| throw new RuntimeException(String.format("Exception while creating trigger on table with ID: %s", columnFamily.id()), ex); |
| } |
| finally |
| { |
| Thread.currentThread().setContextClassLoader(parent); |
| } |
| } |
| |
| public synchronized ITrigger loadTriggerInstance(String triggerName) throws Exception |
| { |
| // double check. |
| if (cachedTriggers.get(triggerName) != null) |
| return cachedTriggers.get(triggerName); |
| return (ITrigger) customClassLoader.loadClass(triggerName).getConstructor().newInstance(); |
| } |
| } |