org.apache.jackrabbit.oak.query.ast.JoinConditionImpl Maven / Gradle / Ivy
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* 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
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* governing permissions and limitations under the License.
*/
package org.apache.jackrabbit.oak.query.ast;
import java.util.Set;
import org.apache.jackrabbit.oak.query.index.FilterImpl;
/**
* The base class for join conditions.
*/
public abstract class JoinConditionImpl extends AstElement {
/**
* The prefix for known paths.
*/
public static final String SPECIAL_PATH_PREFIX = "//";
/**
* A path for a join.
*/
protected static final String KNOWN_PATH = "//path/from/join";
/**
* The parent path of the joined selector
*/
protected static final String KNOWN_PARENT_PATH = "//parent/of/join";
protected static final String KNOWN_VALUE = "valueFromTheJoinSelector";
/**
* Evaluate the result using the currently set values.
*
* @return true if the constraint matches
*/
public abstract boolean evaluate();
/**
* Apply the condition to the filter, further restricting the filter if
* possible. This may also verify the data types are compatible, and that
* paths are valid.
*
* @param f the filter
*/
public abstract void restrict(FilterImpl f);
/**
* Push as much of the condition down to this selector, further restricting
* the selector condition if possible.
*
* @param s the selector
*/
public abstract void restrictPushDown(SelectorImpl s);
/**
* Check whether the given source is the parent of the join condition, as
* selector "[b]" is the parent of the join condition
* "isdescendantnode([a], [b])".
*
* @param source the source
* @return true if the source is the parent
*/
public abstract boolean isParent(SourceImpl source);
/**
* Whether the join condition can be evaluated if the given selectors are able to retrieve data.
*
* @param available the available selectors
* @return true if the condition can be evaluated
*/
public abstract boolean canEvaluate(Set available);
}