/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.index;
import org.elasticsearch.common.lucene.uid.Versions;
/**
*
*/
public enum VersionType {
INTERNAL((byte) 0) {
@Override
public boolean isVersionConflictForWrites(long currentVersion, long expectedVersion) {
return isVersionConflict(currentVersion, expectedVersion);
}
@Override
public boolean isVersionConflictForReads(long currentVersion, long expectedVersion) {
return isVersionConflict(currentVersion, expectedVersion);
}
private boolean isVersionConflict(long currentVersion, long expectedVersion) {
if (currentVersion == Versions.NOT_SET) {
return false;
}
if (expectedVersion == Versions.MATCH_ANY) {
return false;
}
if (currentVersion == Versions.NOT_FOUND) {
return true;
}
if (currentVersion != expectedVersion) {
return true;
}
return false;
}
@Override
public long updateVersion(long currentVersion, long expectedVersion) {
return (currentVersion == Versions.NOT_SET || currentVersion == Versions.NOT_FOUND) ? 1 : currentVersion + 1;
}
@Override
public boolean validateVersionForWrites(long version) {
// not allowing Versions.NOT_FOUND as it is not a valid input value.
return version > 0L || version == Versions.MATCH_ANY;
}
@Override
public boolean validateVersionForReads(long version) {
// not allowing Versions.NOT_FOUND as it is not a valid input value.
return version > 0L || version == Versions.MATCH_ANY;
}
@Override
public VersionType versionTypeForReplicationAndRecovery() {
// replicas get the version from the primary after increment. The same version is stored in
// the transaction log. -> the should use the external semantics.
return EXTERNAL;
}
},
EXTERNAL((byte) 1) {
@Override
public boolean isVersionConflictForWrites(long currentVersion, long expectedVersion) {
if (currentVersion == Versions.NOT_SET) {
return false;
}
if (currentVersion == Versions.NOT_FOUND) {
return false;
}
if (expectedVersion == Versions.MATCH_ANY) {
return true;
}
if (currentVersion >= expectedVersion) {
return true;
}
return false;
}
@Override
public boolean isVersionConflictForReads(long currentVersion, long expectedVersion) {
if (currentVersion == Versions.NOT_SET) {
return false;
}
if (expectedVersion == Versions.MATCH_ANY) {
return false;
}
if (currentVersion == Versions.NOT_FOUND) {
return true;
}
if (currentVersion != expectedVersion) {
return true;
}
return false;
}
@Override
public long updateVersion(long currentVersion, long expectedVersion) {
return expectedVersion;
}
@Override
public boolean validateVersionForWrites(long version) {
return version >= 0L;
}
@Override
public boolean validateVersionForReads(long version) {
return version >= 0L || version == Versions.MATCH_ANY;
}
},
EXTERNAL_GTE((byte) 2) {
@Override
public boolean isVersionConflictForWrites(long currentVersion, long expectedVersion) {
if (currentVersion == Versions.NOT_SET) {
return false;
}
if (currentVersion == Versions.NOT_FOUND) {
return false;
}
if (expectedVersion == Versions.MATCH_ANY) {
return true;
}
if (currentVersion > expectedVersion) {
return true;
}
return false;
}
@Override
public boolean isVersionConflictForReads(long currentVersion, long expectedVersion) {
if (currentVersion == Versions.NOT_SET) {
return false;
}
if (expectedVersion == Versions.MATCH_ANY) {
return false;
}
if (currentVersion == Versions.NOT_FOUND) {
return true;
}
if (currentVersion != expectedVersion) {
return true;
}
return false;
}
@Override
public long updateVersion(long currentVersion, long expectedVersion) {
return expectedVersion;
}
@Override
public boolean validateVersionForWrites(long version) {
return version >= 0L;
}
@Override
public boolean validateVersionForReads(long version) {
return version >= 0L || version == Versions.MATCH_ANY;
}
},
/**
* Warning: this version type should be used with care. Concurrent indexing may result in loss of data on replicas
*/
FORCE((byte) 3) {
@Override
public boolean isVersionConflictForWrites(long currentVersion, long expectedVersion) {
if (currentVersion == Versions.NOT_SET) {
return false;
}
if (currentVersion == Versions.NOT_FOUND) {
return false;
}
if (expectedVersion == Versions.MATCH_ANY) {
return true;
}
return false;
}
@Override
public boolean isVersionConflictForReads(long currentVersion, long expectedVersion) {
return false;
}
@Override
public long updateVersion(long currentVersion, long expectedVersion) {
return expectedVersion;
}
@Override
public boolean validateVersionForWrites(long version) {
return version >= 0L;
}
@Override
public boolean validateVersionForReads(long version) {
return version >= 0L || version == Versions.MATCH_ANY;
}
};
private final byte value;
VersionType(byte value) {
this.value = value;
}
public byte getValue() {
return value;
}
/**
* Checks whether the current version conflicts with the expected version, based on the current version type.
*
* @return true if versions conflict false o.w.
*/
public abstract boolean isVersionConflictForWrites(long currentVersion, long expectedVersion);
/**
* Checks whether the current version conflicts with the expected version, based on the current version type.
*
* @return true if versions conflict false o.w.
*/
public abstract boolean isVersionConflictForReads(long currentVersion, long expectedVersion);
/**
* Returns the new version for a document, based on its current one and the specified in the request
*
* @return new version
*/
public abstract long updateVersion(long currentVersion, long expectedVersion);
/**
* validate the version is a valid value for this type when writing.
*
* @return true if valid, false o.w
*/
public abstract boolean validateVersionForWrites(long version);
/**
* validate the version is a valid value for this type when reading.
*
* @return true if valid, false o.w
*/
public abstract boolean validateVersionForReads(long version);
/**
* Some version types require different semantics for primary and replicas. This version allows
* the type to override the default behavior.
*/
public VersionType versionTypeForReplicationAndRecovery() {
return this;
}
public static VersionType fromString(String versionType) {
if ("internal".equals(versionType)) {
return INTERNAL;
} else if ("external".equals(versionType)) {
return EXTERNAL;
} else if ("external_gt".equals(versionType)) {
return EXTERNAL;
} else if ("external_gte".equals(versionType)) {
return EXTERNAL_GTE;
} else if ("force".equals(versionType)) {
return FORCE;
}
throw new IllegalArgumentException("No version type match [" + versionType + "]");
}
public static VersionType fromString(String versionType, VersionType defaultVersionType) {
if (versionType == null) {
return defaultVersionType;
}
return fromString(versionType);
}
public static VersionType fromValue(byte value) {
if (value == 0) {
return INTERNAL;
} else if (value == 1) {
return EXTERNAL;
} else if (value == 2) {
return EXTERNAL_GTE;
} else if (value == 3) {
return FORCE;
}
throw new IllegalArgumentException("No version type match [" + value + "]");
}
}