com.google.gerrit.index.SchemaDefinitions Maven / Gradle / Ivy
// Copyright (C) 2016 The Android Open Source Project
//
// 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.google.gerrit.index;
import static com.google.common.base.Preconditions.checkArgument;
import static java.util.Objects.requireNonNull;
import com.google.common.collect.ImmutableSortedMap;
import com.google.common.collect.Iterables;
import com.google.gerrit.common.Nullable;
/**
* Definitions of the various schema versions over a given Gerrit data type.
*
* A schema is a description of the fields that are indexed over the given data type.
* This class contains all the versions of a schema defined over its data type, exposed as a map of
* version number to schema definition. If you are interested in the classes responsible for
* backend-specific runtime implementations, see the implementations of {@link IndexDefinition}.
*/
public abstract class SchemaDefinitions {
private final String name;
private final ImmutableSortedMap> schemas;
protected SchemaDefinitions(String name, Class valueClass) {
this.name = requireNonNull(name);
this.schemas = SchemaUtil.schemasFromClass(getClass(), valueClass);
}
public final String getName() {
return name;
}
public final ImmutableSortedMap> getSchemas() {
return schemas;
}
public final Schema get(int version) {
Schema schema = schemas.get(version);
checkArgument(schema != null, "Unrecognized %s schema version: %s", name, version);
return schema;
}
public final Schema getLatest() {
return schemas.lastEntry().getValue();
}
@Nullable
public final Schema getPrevious() {
if (schemas.size() <= 1) {
return null;
}
return Iterables.get(schemas.descendingMap().values(), 1);
}
}