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1
8
9 package com.sleepycat.persist;
10
11 import java.util.Iterator  ;
12
13 import com.sleepycat.je.DatabaseEntry;
14 import com.sleepycat.je.DatabaseException;
15 import com.sleepycat.je.LockMode;
16 import com.sleepycat.je.OperationStatus;
17 import com.sleepycat.util.keyrange.RangeCursor;
18
19
25 class BasicCursor<V> implements EntityCursor<V> {
26
27 RangeCursor cursor;
28 ValueAdapter<V> adapter;
29 DatabaseEntry key;
30 DatabaseEntry pkey;
31 DatabaseEntry data;
32
33 BasicCursor(RangeCursor cursor, ValueAdapter<V> adapter) {
34 this.cursor = cursor;
35 this.adapter = adapter;
36 key = adapter.initKey();
37 pkey = adapter.initPKey();
38 data = adapter.initData();
39 }
40
41 public V first()
42 throws DatabaseException {
43
44 return first(null);
45 }
46
47 public V first(LockMode lockMode)
48 throws DatabaseException {
49
50 return returnValue(cursor.getFirst(key, pkey, data, lockMode));
51 }
52
53 public V last()
54 throws DatabaseException {
55
56 return last(null);
57 }
58
59 public V last(LockMode lockMode)
60 throws DatabaseException {
61
62 return returnValue(cursor.getLast(key, pkey, data, lockMode));
63 }
64
65 public V next()
66 throws DatabaseException {
67
68 return next(null);
69 }
70
71 public V next(LockMode lockMode)
72 throws DatabaseException {
73
74 return returnValue(cursor.getNext(key, pkey, data, lockMode));
75 }
76
77 public V nextDup()
78 throws DatabaseException {
79
80 return nextDup(null);
81 }
82
83 public V nextDup(LockMode lockMode)
84 throws DatabaseException {
85
86 checkInitialized();
87 return returnValue(cursor.getNextDup(key, pkey, data, lockMode));
88 }
89
90 public V nextNoDup()
91 throws DatabaseException {
92
93 return nextNoDup(null);
94 }
95
96 public V nextNoDup(LockMode lockMode)
97 throws DatabaseException {
98
99 return returnValue(cursor.getNextNoDup(key, pkey, data, lockMode));
100 }
101
102 public V prev()
103 throws DatabaseException {
104
105 return prev(null);
106 }
107
108 public V prev(LockMode lockMode)
109 throws DatabaseException {
110
111 return returnValue(cursor.getPrev(key, pkey, data, lockMode));
112 }
113
114 public V prevDup()
115 throws DatabaseException {
116
117 return prevDup(null);
118 }
119
120 public V prevDup(LockMode lockMode)
121 throws DatabaseException {
122
123 checkInitialized();
124 return returnValue(cursor.getPrevDup(key, pkey, data, lockMode));
125 }
126
127 public V prevNoDup()
128 throws DatabaseException {
129
130 return prevNoDup(null);
131 }
132
133 public V prevNoDup(LockMode lockMode)
134 throws DatabaseException {
135
136 return returnValue(cursor.getPrevNoDup(key, pkey, data, lockMode));
137 }
138
139 public V current()
140 throws DatabaseException {
141
142 return current(null);
143 }
144
145 public V current(LockMode lockMode)
146 throws DatabaseException {
147
148 checkInitialized();
149 return returnValue(cursor.getCurrent(key, pkey, data, lockMode));
150 }
151
152 public int count()
153 throws DatabaseException {
154
155 checkInitialized();
156 return cursor.count();
157 }
158
159 public Iterator <V> iterator() {
160 return iterator(null);
161 }
162
163 public Iterator <V> iterator(LockMode lockMode) {
164 return new BasicIterator(this, lockMode);
165 }
166
167 public boolean update(V entity)
168 throws DatabaseException {
169
170 checkInitialized();
171 adapter.valueToData(entity, data);
172 return cursor.putCurrent(data) == OperationStatus.SUCCESS;
173 }
174
175 public boolean delete()
176 throws DatabaseException {
177
178 checkInitialized();
179 return cursor.delete() == OperationStatus.SUCCESS;
180 }
181
182 public EntityCursor<V> dup()
183 throws DatabaseException {
184
185 return new BasicCursor<V>(cursor.dup(true), adapter);
186 }
187
188 public void close()
189 throws DatabaseException {
190
191 cursor.close();
192 }
193
194 void checkInitialized()
195 throws IllegalStateException {
196
197 if (!cursor.isInitialized()) {
198 throw new IllegalStateException
199 ("Cursor is not initialized at a valid position");
200 }
201 }
202
203 V returnValue(OperationStatus status) {
204 V value;
205 if (status == OperationStatus.SUCCESS) {
206 value = adapter.entryToValue(key, pkey, data);
207 } else {
208 value = null;
209 }
210
211 adapter.clearEntries(key, pkey, data);
212 return value;
213 }
214 }
215 |
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