blob: df9d8ede472c03e43cb7ba7c6604cff76d0b6205 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
|
/*******************************************************************************
* Copyright (c) 2009 EclipseSource and others. All rights reserved. This
* program and the accompanying materials are made available under the terms of
* the Eclipse Public License v1.0 which accompanies this distribution, and is
* available at http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* EclipseSource - initial API and implementation
******************************************************************************/
package org.eclipse.equinox.p2.query;
import java.util.Iterator;
import org.eclipse.equinox.internal.p2.query.QueryHelpers;
/**
* ContextQuery is the abstract superclass for Queries that require the entire
* input to evaluate the results. Queries must consider the group of elements before
* processing the results. <P>
*
* ContextQueries must also be transitive. That is, if run on a subset of the
* input, the order in which they are executed must not matter. If there is the
* need for a non-transitive query, please see:
* https://bugs.eclipse.org/bugs/show_bug.cgi?id=261403
* <p>
* Users of this query must call {@link #perform(Iterator)} to compute
* the results. <P>
* This class may be subclassed by clients. Subclasses should specify the type
* of object they support querying on. Subclasses are also encouraged to clearly
* specify their match algorithm, and expose the parameters involved in the match
* computation, to allow {@link IQueryable} implementations to optimize their
* execution of the query. <P>
*
*/
public abstract class ContextQuery<T> implements IQuery<T> {
/**
* Evaluates the query for a specific input.
*
* @param iterator The elements for which to evaluate the query on
* @return The results of the query. The collector returned must be
* the collector passed in.
*/
public abstract IQueryResult<T> perform(Iterator<T> iterator);
/**
* Gets the ID for this Query.
*/
public String getId() {
return QueryHelpers.getId(this);
}
/**
* Gets a particular property of the query.
* @param property The property to retrieve
*/
public Object getProperty(String property) {
return QueryHelpers.getProperty(this, property);
}
}
|