Mercurial > projects > dwt2

annotate org.eclipse.core.jobs/src/org/eclipse/core/internal/jobs/StringPool.d @ 12:bc29606a740c

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Added dwt-addons in original directory structure of eclipse.org
author Frank Benoit <benoit@tionex.de>
date Sat, 14 Mar 2009 18:23:29 +0100
parents
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
12
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
1 /*******************************************************************************
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
2 * Copyright (c) 2005 IBM Corporation and others.
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
3 * All rights reserved. This program and the accompanying materials
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
4 * are made available under the terms of the Eclipse Public License v1.0
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
5 * which accompanies this distribution, and is available at
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
6 * http://www.eclipse.org/legal/epl-v10.html
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
7 *
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
8 * Contributors:
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
9 * IBM - Initial API and implementation
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
10 * Port to the D programming language:
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
11 * Frank Benoit <benoit@tionex.de>
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
12 *******************************************************************************/
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
13 module org.eclipse.core.internal.jobs.StringPool;
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
14
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
15 import java.lang.all;
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
16 import java.util.HashMap;
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
17
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
18 /**
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
19 * A string pool is used for sharing strings in a way that eliminates duplicate
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
20 * equal strings. A string pool instance can be maintained over a long period
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
21 * of time, or used as a temporary structure during a string sharing pass over
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
22 * a data structure.
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
23 * <p>
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
24 * This class is not intended to be subclassed by clients.
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
25 * </p>
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
26 *
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
27 * Note: This class is copied from org.eclipse.core.resources
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
28 *
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
29 * @since 3.1
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
30 */
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
31 public final class StringPool {
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
32 private int savings;
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
33 private const HashMap map;
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
34
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
35 public this(){
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
36 map = new HashMap();
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
37 }
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
38
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
39 /**
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
40 * Adds a <code>String</code> to the pool. Returns a <code>String</code>
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
41 * that is equal to the argument but that is unique within this pool.
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
42 * @param string The string to add to the pool
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
43 * @return A string that is equal to the argument.
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
44 */
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
45 public String add(String string) {
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
46 if (string is null)
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
47 return string;
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
48 Object result = map.get(string);
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
49 if (result !is null) {
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
50 if (stringcast(result) !is string)
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
51 savings += 44 + 2 * string.length;
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
52 return stringcast( result );
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
53 }
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
54 map.put(string, string);
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
55 return string;
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
56 }
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
57
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
58 /**
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
59 * Returns an estimate of the size in bytes that was saved by sharing strings in
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
60 * the pool. In particular, this returns the size of all strings that were added to the
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
61 * pool after an equal string had already been added. This value can be used
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
62 * to estimate the effectiveness of a string sharing operation, in order to
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
63 * determine if or when it should be performed again.
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
64 *
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
65 * In some cases this does not precisely represent the number of bytes that
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
66 * were saved. For example, say the pool already contains string S1. Now
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
67 * string S2, which is equal to S1 but not identical, is added to the pool five
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
68 * times. This method will return the size of string S2 multiplied by the
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
69 * number of times it was added, even though the actual savings in this case
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
70 * is only the size of a single copy of S2.
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
71 */
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
72 public int getSavedStringCount() {
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
73 return savings;
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
74 }
bc29606a740c Added dwt-addons in original directory structure of eclipse.org
Frank Benoit <benoit@tionex.de>
parents:
diff changeset
75 }