/*
* 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.cql3.statements;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.List;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import org.apache.cassandra.cql3.CQLStatement;
import org.apache.cassandra.auth.Permission;
import org.apache.cassandra.db.migration.*;
import org.apache.cassandra.concurrent.Stage;
import org.apache.cassandra.concurrent.StageManager;
import org.apache.cassandra.config.ConfigurationException;
import org.apache.cassandra.config.Schema;
import org.apache.cassandra.cql3.CFName;
import org.apache.cassandra.service.ClientState;
import org.apache.cassandra.service.StorageProxy;
import org.apache.cassandra.thrift.CqlResult;
import org.apache.cassandra.thrift.InvalidRequestException;
import org.apache.cassandra.thrift.SchemaDisagreementException;
import com.google.common.base.Predicates;
import com.google.common.collect.Maps;
/**
* Abstract class for statements that alter the schema.
*/
public abstract class SchemaAlteringStatement extends CFStatement implements CQLStatement
{
private static final long timeLimitForSchemaAgreement = 10 * 1000;
private final boolean isColumnFamilyLevel;
protected SchemaAlteringStatement()
{
super(null);
this.isColumnFamilyLevel = false;
}
protected SchemaAlteringStatement(CFName name)
{
super(name);
this.isColumnFamilyLevel = true;
}
@Override
public void prepareKeyspace(ClientState state) throws InvalidRequestException
{
if (isColumnFamilyLevel)
super.prepareKeyspace(state);
}
public Prepared prepare() throws InvalidRequestException
{
return new Prepared(this);
}
public abstract void announceMigration() throws InvalidRequestException, ConfigurationException;
public void checkAccess(ClientState state) throws InvalidRequestException
{
if (isColumnFamilyLevel)
state.hasColumnFamilySchemaAccess(keyspace(), Permission.WRITE);
else
state.hasKeyspaceSchemaAccess(Permission.WRITE);
}
@Override
public void validate(ClientState state) throws InvalidRequestException, SchemaDisagreementException
{
validateSchemaAgreement();
}
public CqlResult execute(ClientState state, List<ByteBuffer> variables) throws InvalidRequestException, SchemaDisagreementException
{
try
{
announceMigration();
}
catch (ConfigurationException e)
{
InvalidRequestException ex = new InvalidRequestException(e.toString());
ex.initCause(e);
throw ex;
}
validateSchemaIsSettled();
return null;
}
// Copypasta from CassandraServer (where it is private).
private static void validateSchemaAgreement() throws SchemaDisagreementException
{
if (describeSchemaVersions().size() > 1)
throw new SchemaDisagreementException();
}
private static Map<String, List<String>> describeSchemaVersions()
{
// unreachable hosts don't count towards disagreement
return Maps.filterKeys(StorageProxy.describeSchemaVersions(),
Predicates.not(Predicates.equalTo(StorageProxy.UNREACHABLE)));
}
private static void validateSchemaIsSettled() throws SchemaDisagreementException
{
long limit = System.currentTimeMillis() + timeLimitForSchemaAgreement;
outer:
while (limit - System.currentTimeMillis() >= 0)
{
String currentVersionId = Schema.instance.getVersion().toString();
for (String version : describeSchemaVersions().keySet())
{
if (!version.equals(currentVersionId))
continue outer;
}
// schemas agree
return;
}
throw new SchemaDisagreementException();
}
}