com.datastax.driver.core.ConsistencyLevel Maven / Gradle / Ivy
/*
* Copyright DataStax, Inc.
*
* 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.
*
* The following only applies to changes made to this file as part of YugaByte development.
*
* Portions Copyright (c) YugaByte, Inc.
*
* 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.datastax.driver.core;
import com.datastax.driver.core.exceptions.DriverInternalError;
public enum ConsistencyLevel {
ANY(0),
ONE(1),
TWO(2),
THREE(3),
QUORUM(4),
ALL(5),
LOCAL_QUORUM(6),
EACH_QUORUM(7),
SERIAL(8),
LOCAL_SERIAL(9),
LOCAL_ONE(10);
// Aliases for YugaByte consistency levels.
public static final ConsistencyLevel YB_CONSISTENT_PREFIX = ONE;
public static final ConsistencyLevel YB_STRONG = QUORUM;
// Used by the native protocol
final int code;
private static final ConsistencyLevel[] codeIdx;
static {
int maxCode = -1;
for (ConsistencyLevel cl : ConsistencyLevel.values()) maxCode = Math.max(maxCode, cl.code);
codeIdx = new ConsistencyLevel[maxCode + 1];
for (ConsistencyLevel cl : ConsistencyLevel.values()) {
if (codeIdx[cl.code] != null) throw new IllegalStateException("Duplicate code");
codeIdx[cl.code] = cl;
}
}
private ConsistencyLevel(int code) {
this.code = code;
}
static ConsistencyLevel fromCode(int code) {
if (code < 0 || code >= codeIdx.length)
throw new DriverInternalError(String.format("Unknown code %d for a consistency level", code));
return codeIdx[code];
}
/**
* Whether or not this consistency level applies to the local data-center only.
*
* @return whether this consistency level is {@code LOCAL_ONE}, {@code LOCAL_QUORUM}, or {@code
* LOCAL_SERIAL}.
*/
public boolean isDCLocal() {
return this == LOCAL_ONE || this == LOCAL_QUORUM || this == LOCAL_SERIAL;
}
/**
* Whether or not this consistency level corresponds to YB strong consistency.
*
* @return whether this consistency level is {@code QUORUM} or {@code LOCAL_ONE}.
*/
public boolean isYBStrong() {
return this == QUORUM || this == LOCAL_ONE;
}
/**
* Whether or not this consistency level is serial, that is, applies only to the "paxos" phase of
* a Lightweight
* transaction.
*
* Serial consistency levels are only meaningful when executing conditional updates ({@code
* INSERT}, {@code UPDATE} or {@code DELETE} statements with an {@code IF} condition).
*
*
Two consistency levels belong to this category: {@link #SERIAL} and {@link #LOCAL_SERIAL}.
*
* @return whether this consistency level is {@link #SERIAL} or {@link #LOCAL_SERIAL}.
* @see Statement#setSerialConsistencyLevel(ConsistencyLevel)
* @see Lightweight
* transactions
*/
public boolean isSerial() {
return this == SERIAL || this == LOCAL_SERIAL;
}
}