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Java > Open Source Codes > com > sleepycat > collections > StoredValueSet


1 /*-
2  * See the file LICENSE for redistribution information.
3  *
4  * Copyright (c) 2000,2006 Oracle. All rights reserved.
5  *
6  * $Id: StoredValueSet.java,v 1.40 2006/10/30 21:14:10 bostic Exp $
7  */
8
9 package com.sleepycat.collections;
10
11 import java.util.Set JavaDoc;
12
13 import com.sleepycat.bind.EntityBinding;
14 import com.sleepycat.bind.EntryBinding;
15 import com.sleepycat.je.Database;
16 import com.sleepycat.je.DatabaseEntry;
17 import com.sleepycat.je.DatabaseException;
18 import com.sleepycat.je.OperationStatus;
19
20 /**
21  * The Set returned by Map.values() and Map.duplicates(), and which can also be
22  * constructed directly if a Map is not needed.
23  * Although this collection is a set it may contain duplicate values. Only if
24  * an entity value binding is used are all elements guaranteed to be unique.
25  *
26  * @author Mark Hayes
27  */
28 public class StoredValueSet extends StoredCollection implements Set JavaDoc {
29
30     /*
31      * This class is also used internally for the set returned by duplicates().
32      */
33
34     /**
35      * Creates a value set view of a {@link Database}.
36      *
37      * @param database is the Database underlying the new collection.
38      *
39      * @param valueBinding is the binding used to translate between value
40      * buffers and value objects.
41      *
42      * @param writeAllowed is true to create a read-write collection or false
43      * to create a read-only collection.
44      *
45      * @throws IllegalArgumentException if formats are not consistently
46      * defined or a parameter is invalid.
47      *
48      * @throws RuntimeExceptionWrapper if a {@link DatabaseException} is
49      * thrown.
50      */
51     public StoredValueSet(Database database,
52                           EntryBinding valueBinding,
53                           boolean writeAllowed) {
54
55         super(new DataView(database, null, valueBinding, null,
56                            writeAllowed, null));
57     }
58
59     /**
60      * Creates a value set entity view of a {@link Database}.
61      *
62      * @param database is the Database underlying the new collection.
63      *
64      * @param valueEntityBinding is the binding used to translate between
65      * key/value buffers and entity value objects.
66      *
67      * @param writeAllowed is true to create a read-write collection or false
68      * to create a read-only collection.
69      *
70      * @throws IllegalArgumentException if formats are not consistently
71      * defined or a parameter is invalid.
72      *
73      * @throws RuntimeExceptionWrapper if a {@link DatabaseException} is
74      * thrown.
75      */
76     public StoredValueSet(Database database,
77                           EntityBinding valueEntityBinding,
78                           boolean writeAllowed) {
79
80         super(new DataView(database, null, null, valueEntityBinding,
81                            writeAllowed, null));
82     }
83
84     StoredValueSet(DataView valueSetView) {
85
86         super(valueSetView);
87     }
88
89     /**
90      * Adds the specified entity to this set if it is not already present
91      * (optional operation).
92      * This method conforms to the {@link Set#add} interface.
93      *
94      * @param entity is the entity to be added.
95      *
96      * @return true if the entity was added, that is the key-value pair
97      * represented by the entity was not previously present in the collection.
98      *
99      * @throws UnsupportedOperationException if the collection is read-only,
100      * if the collection is indexed, or if an entity binding is not used.
101      *
102      * @throws RuntimeExceptionWrapper if a {@link DatabaseException} is
103      * thrown.
104      */
105     public boolean add(Object JavaDoc entity) {
106
107         if (view.isSecondary()) {
108             throw new UnsupportedOperationException JavaDoc(
109                 "add() not allowed with index");
110         } else if (view.range.isSingleKey()) {
111             /* entity is actually just a value in this case */
112             if (!view.dupsAllowed) {
113                 throw new UnsupportedOperationException JavaDoc("duplicates required");
114             }
115             DataCursor cursor = null;
116             boolean doAutoCommit = beginAutoCommit();
117             try {
118                 cursor = new DataCursor(view, true);
119                 cursor.useRangeKey();
120                 OperationStatus status =
121                     cursor.putNoDupData(null, entity, null, true);
122                 closeCursor(cursor);
123                 commitAutoCommit(doAutoCommit);
124                 return (status == OperationStatus.SUCCESS);
125             } catch (Exception JavaDoc e) {
126                 closeCursor(cursor);
127                 throw handleException(e, doAutoCommit);
128             }
129         } else if (view.entityBinding == null) {
130             throw new UnsupportedOperationException JavaDoc(
131                 "add() requires entity binding");
132         } else {
133             return add(null, entity);
134         }
135     }
136
137     /**
138      * Returns true if this set contains the specified element.
139      * This method conforms to the {@link java.util.Set#contains}
140      * interface.
141      *
142      * @param value the value to check.
143      *
144      * @return whether the set contains the given value.
145      */
146     public boolean contains(Object JavaDoc value) {
147
148         return containsValue(value);
149     }
150
151     /**
152      * Removes the specified value from this set if it is present (optional
153      * operation).
154      * If an entity binding is used, the key-value pair represented by the
155      * given entity is removed. If an entity binding is used, the first
156      * occurrence of a key-value pair with the given value is removed.
157      * This method conforms to the {@link Set#remove} interface.
158      *
159      * @throws UnsupportedOperationException if the collection is read-only.
160      *
161      * @throws RuntimeExceptionWrapper if a {@link DatabaseException} is
162      * thrown.
163      */
164     public boolean remove(Object JavaDoc value) {
165
166         return removeValue(value);
167     }
168
169     Object JavaDoc makeIteratorData(BaseIterator iterator,
170                             DatabaseEntry keyEntry,
171                             DatabaseEntry priKeyEntry,
172                             DatabaseEntry valueEntry) {
173
174         return view.makeValue(priKeyEntry, valueEntry);
175     }
176
177     boolean hasValues() {
178
179         return true;
180     }
181 }
182
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