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1
17 package org.alfresco.repo.search.impl.lucene.query;
18
19 import java.io.IOException  ;
20 import java.util.Arrays ;
21
22 import org.apache.lucene.index.IndexReader;
23 import org.apache.lucene.index.MultiReader;
24 import org.apache.lucene.index.Term;
25 import org.apache.lucene.index.TermDocs;
26 import org.apache.lucene.index.TermEnum;
27 import org.apache.lucene.index.TermPositions;
28
29 public class DeltaReader extends MultiReader
30 {
31 int[][] deletions;
32
33 Boolean hasExclusions = null;
34
35 private IndexReader[] subReaders;
36
37 private int maxDoc = 0;
38
39 private int[] starts;
40
41 public DeltaReader(IndexReader[] readers, int[][] deletions) throws IOException
42 {
43 super(readers);
44 this.deletions = deletions;
45 initialize(readers);
46 }
47
48 private void initialize(IndexReader[] subReaders) throws IOException
49 {
50 this.subReaders = subReaders;
51 starts = new int[subReaders.length + 1]; for (int i = 0; i < subReaders.length; i++)
53 {
54 starts[i] = maxDoc;
55 maxDoc += subReaders[i].maxDoc(); }
57 starts[subReaders.length] = maxDoc;
58 }
59
60 protected void doCommit() throws IOException
61 {
62 throw new UnsupportedOperationException ();
64 }
65
66 protected void doDelete(int arg0) throws IOException
67 {
68 throw new UnsupportedOperationException ();
70 }
71
72 protected void doUndeleteAll() throws IOException
73 {
74 throw new UnsupportedOperationException ();
76 }
77
78 public boolean hasDeletions()
79 {
80 return super.hasDeletions() || hasSearchExclusions();
81 }
82
83 private boolean hasSearchExclusions()
84 {
85 if (hasExclusions == null)
86 {
87 for (int i = 0; i < deletions.length; i++)
88 {
89 if (deletions[i].length > 0)
90 {
91 hasExclusions = new Boolean (true);
92 break;
93 }
94 }
95 hasExclusions = new Boolean (false);
96 }
97 return hasExclusions.booleanValue();
98 }
99
100 public boolean isDeleted(int docNumber)
101 {
102 int i = readerIndex(docNumber);
103 return super.isDeleted(docNumber) || (Arrays.binarySearch(deletions[i], docNumber - starts[i]) != -1);
104 }
105
106 private int readerIndex(int n)
107 { int lo = 0; int hi = subReaders.length - 1;
111 while (hi >= lo)
112 {
113 int mid = (lo + hi) >> 1;
114 int midValue = starts[mid];
115 if (n < midValue)
116 hi = mid - 1;
117 else if (n > midValue)
118 lo = mid + 1;
119 else
120 { while (mid + 1 < subReaders.length && starts[mid + 1] == midValue)
122 {
123 mid++; }
125 return mid;
126 }
127 }
128 return hi;
129 }
130
131 public TermDocs termDocs() throws IOException
132 {
133 return new DeletingTermDocs(super.termDocs());
134 }
135
136 public TermPositions termPositions() throws IOException
137 {
138 throw new UnsupportedOperationException ();
140 }
141
142 private class DeletingTermDocs implements TermDocs
143 {
144 TermDocs delegate;
145
146 DeletingTermDocs(TermDocs delegate)
147 {
148 super();
149 this.delegate = delegate;
150 }
151
152 public void seek(Term term) throws IOException
153 {
154 delegate.seek(term);
155 }
156
157 public void seek(TermEnum termEnum) throws IOException
158 {
159 delegate.seek(termEnum);
160 }
161
162 public int doc()
163 {
164 return delegate.doc();
165 }
166
167 public int freq()
168 {
169 return delegate.freq();
170 }
171
172 public boolean next() throws IOException
173 {
174 while (delegate.next())
175 {
176 if (!isDeleted(doc()))
177 {
178 return true;
179 }
180 }
181 return false;
182 }
183
184 public int read(int[] docs, int[] freqs) throws IOException
185 {
186 int end;
187 int deletedCount;
188 do
189 {
190 end = delegate.read(docs, freqs);
191 if (end == 0)
192 {
193 return end;
194 }
195 deletedCount = 0;
196 for (int i = 0; i < end; i++)
197 {
198 if (!isDeleted(docs[i]))
199 {
200 deletedCount++;
201 }
202 }
203 }
204 while (end == deletedCount);
205 int position = 0;
207 for(int i = 0; i < end; i++)
208 {
209 if(!isDeleted(i))
210 {
211 docs[position] = docs[i];
212 freqs[position] = freqs[i];
213 position++;
214 }
215 }
216 return position;
217 }
218
219 public boolean skipTo(int docNumber) throws IOException
220 {
221 delegate.skipTo(docNumber);
222 if (!isDeleted(doc()))
223 {
224 return true;
225 }
226 else
227 {
228 return next();
229 }
230 }
231
232 public void close() throws IOException
233 {
234 delegate.close();
235 }
236
237 }
238 }
239 |
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