com.facebook.presto.spi.transaction.IsolationLevel Maven / Gradle / Ivy
/*
* 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.
*/
package com.facebook.presto.spi.transaction;
import com.facebook.presto.spi.PrestoException;
import static com.facebook.presto.spi.StandardErrorCode.UNSUPPORTED_ISOLATION_LEVEL;
import static java.lang.String.format;
public enum IsolationLevel
{
SERIALIZABLE,
REPEATABLE_READ,
READ_COMMITTED,
READ_UNCOMMITTED;
public boolean meetsRequirementOf(IsolationLevel requirement)
{
switch (this) {
case READ_UNCOMMITTED:
return requirement == READ_UNCOMMITTED;
case READ_COMMITTED:
return requirement == READ_UNCOMMITTED ||
requirement == READ_COMMITTED;
case REPEATABLE_READ:
return requirement == READ_UNCOMMITTED ||
requirement == READ_COMMITTED ||
requirement == REPEATABLE_READ;
case SERIALIZABLE:
return true;
}
throw new AssertionError("Unhandled isolation level: " + this);
}
@Override
public String toString()
{
return name().replace('_', ' ');
}
public static void checkConnectorSupports(IsolationLevel supportedLevel, IsolationLevel requestedLevel)
{
if (!supportedLevel.meetsRequirementOf(requestedLevel)) {
throw new PrestoException(UNSUPPORTED_ISOLATION_LEVEL, format("Connector supported isolation level %s does not meet requested isolation level %s", supportedLevel, requestedLevel));
}
}
}