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1
21 package com.db4o.inside.ix;
22
23 import com.db4o.*;
24 import com.db4o.foundation.*;
25
26
30 public class Index4 {
31
32 public final Indexable4 _handler;
33
34 static private int _version;
35
36 public final MetaIndex _metaIndex;
37
38 private IndexTransaction _globalIndexTransaction;
39
40 private Collection4 _indexTransactions;
41
42 private IxFileRangeReader _fileRangeReader;
43
44 final boolean _nullHandling;
45
46 public Index4(Transaction systemTrans, Indexable4 handler, MetaIndex metaIndex, boolean nullHandling) {
47 _metaIndex = metaIndex;
48 _handler = handler;
49 _globalIndexTransaction = new IndexTransaction(systemTrans, this);
50 _nullHandling = nullHandling;
51 createGlobalFileRange();
52 }
53
54 public IndexTransaction dirtyIndexTransaction(Transaction a_trans) {
55 IndexTransaction ift = new IndexTransaction(a_trans, this);
56 if (_indexTransactions == null) {
57 _indexTransactions = new Collection4();
58 } else {
59 IndexTransaction iftExisting = (IndexTransaction) _indexTransactions.get(ift);
60 if (iftExisting != null) {
61 return iftExisting;
62 }
63 }
64 a_trans.addDirtyFieldIndex(ift);
65 ift.setRoot(Tree.deepClone(_globalIndexTransaction.getRoot(), ift));
66 ift.i_version = ++_version;
67 _indexTransactions.add(ift);
68 return ift;
69 }
70
71 public IndexTransaction globalIndexTransaction(){
72 return _globalIndexTransaction;
73 }
74
75 public IndexTransaction indexTransactionFor(Transaction a_trans) {
76 if (_indexTransactions != null) {
77 IndexTransaction ift = new IndexTransaction(a_trans, this);
78 ift = (IndexTransaction) _indexTransactions.get(ift);
79 if (ift != null) {
80 return ift;
81 }
82 }
83 return _globalIndexTransaction;
84 }
85
86 private int[] freeForMetaIndex(){
87 return new int[] {
88 _metaIndex.indexAddress,
89 _metaIndex.indexLength,
90 };
93 }
94
95 private void doFree(int[] addressLength){
96 YapFile yf = file();
97 for(int i = 0; i < addressLength.length; i += 2){
98 yf.free(addressLength[i], addressLength[i + 1]);
99 }
100 }
101
102
103
108 public void commitFreeSpace(Index4 other){
109
110 int entries = countEntries();
111
112
118
121
122 int length = (entries + 4) * lengthPerEntry();
123
124 int mySlot = getSlot(length);
125 int otherSlot = getSlot(length);
126 doFree(freeForMetaIndex());
127 doFree(other.freeForMetaIndex());
128
129 entries = writeToNewSlot(mySlot);
130 metaIndexSetMembers(entries, length, mySlot);
131 createGlobalFileRange();
132
133 int otherEntries = other.writeToNewSlot(otherSlot);
134
135 if(Deploy.debug){
136 if(entries != otherEntries){
137 throw new RuntimeException  ("Should never happen");
138 }
139 }
140
141 other.metaIndexSetMembers(entries, length, otherSlot);
142 other.createGlobalFileRange();
143 }
144
145 private int lengthPerEntry(){
146 return _handler.linkLength() + YapConst.INT_LENGTH;
147 }
148
149 private void metaIndexStore(int entries, int length, int address){
150 Transaction transact = trans();
151 metaIndexSetMembers(entries, length, address);
152 transact.stream().setInternal(transact, _metaIndex, 1, false);
153 }
154
155 private void metaIndexSetMembers(int entries, int length, int address){
156 _metaIndex.indexEntries = entries;
157 _metaIndex.indexLength = length;
158 _metaIndex.indexAddress = address;
159 }
160
161 private int writeToNewSlot(int slot){
162 Tree root = getRoot();
163 final YapWriter writer = new YapWriter(trans(),slot, lengthPerEntry());
164 final int[] entries = new int[] {0};
165 if (root != null) {
166 root.traverse(new Visitor4() {
167 public void visit(Object a_object) {
168 entries[0] += ((IxTree) a_object).write(_handler, writer);
169 }
170 });
171 }
172 return entries[0];
173 }
174
175
176 void commit(IndexTransaction ixTrans) {
177
178 _indexTransactions.remove(ixTrans);
179 _globalIndexTransaction.merge(ixTrans);
180
181
182
185
188
189 boolean createNewFileRange = true;
190
191 if (createNewFileRange) {
192
193 int entries = countEntries();
194 int length = countEntries() * lengthPerEntry();
195 int slot = getSlot(length);
196
197 int[] free = freeForMetaIndex();
198
199 metaIndexStore(entries, length, slot);
200
201 writeToNewSlot(slot);
202
203 IxFileRange newFileRange = createGlobalFileRange();
204
205 if(_indexTransactions != null){
206 Iterator4 i = _indexTransactions.iterator();
207 while (i.moveNext()) {
208 final IndexTransaction ft = (IndexTransaction) i.current();
209 Tree clonedTree = newFileRange;
210 if (clonedTree != null) {
211 clonedTree = (Tree)clonedTree.deepClone(ft);
212 }
213 final Tree.ByRef tree = new Tree.ByRef(clonedTree);
214 ft.getRoot().traverseFromLeaves((new Visitor4() {
215
216 public void visit(Object a_object) {
217 IxTree ixTree = (IxTree) a_object;
218 if (ixTree._version == ft.i_version) {
219 if (!(ixTree instanceof IxFileRange)) {
220 ixTree.beginMerge();
221 tree.value = Tree.add(tree.value, ixTree);
222 }
223 }
224 }
225 }));
226 ft.setRoot(tree.value);
227 }
228 }
229
230 doFree(free);
231
232 } else {
233 Iterator4 i = _indexTransactions.iterator();
234 while (i.moveNext()) {
235 ((IndexTransaction) i.current()).merge(ixTrans);
236 }
237 }
238 }
239
240 private IxFileRange createGlobalFileRange() {
241 IxFileRange fr = null;
242 if (_metaIndex.indexEntries > 0) {
243 fr = new IxFileRange(_globalIndexTransaction,
244 _metaIndex.indexAddress, 0, _metaIndex.indexEntries);
245 }
246 _globalIndexTransaction.setRoot(fr);
247 return fr;
248 }
249
250 void rollback(IndexTransaction a_ft) {
251 _indexTransactions.remove(a_ft);
252 }
253
254 IxFileRangeReader fileRangeReader() {
255 if (_fileRangeReader == null) {
256 _fileRangeReader = new IxFileRangeReader(_handler);
257 }
258 return _fileRangeReader;
259 }
260
261 public String toString() {
262 if(! Debug4.prettyToStrings){
263 return super.toString();
264 }
265 StringBuffer sb = new StringBuffer ();
266 sb.append("IxField " + System.identityHashCode(this));
267 if (_globalIndexTransaction != null) {
268 sb.append("\n Global \n ");
269 sb.append(_globalIndexTransaction.toString());
270 } else {
271 sb.append("\n no global index \n ");
272 }
273 if (_indexTransactions != null) {
274 Iterator4 i = _indexTransactions.iterator();
275 while (i.moveNext()) {
276 sb.append("\n");
277 sb.append(i.current().toString());
278 }
279 }
280 return sb.toString();
281 }
282
283 private Transaction trans(){
284 return _globalIndexTransaction.i_trans;
285 }
286
287 private YapFile file(){
288 return trans().i_file;
289 }
290
291 private int getSlot(int length){
292 return file().getSlot(length);
293 }
294
295 private Tree getRoot(){
296 return _globalIndexTransaction.getRoot();
297 }
298
299 private int countEntries(){
300 Tree root = getRoot();
301 return root == null ? 0 : root.size();
302 }
303
304
305 }
306 |
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