pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / src / java / org / apache / lucene / util / DocIdBitSet.java

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/util/DocIdBitSet.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/util/DocIdBitSet.java
new file mode 100644 (file)
index 0000000..28fa7a9
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/util/DocIdBitSet.java
@@ -0,0 +1,83 @@
+package org.apache.lucene.util;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.util.BitSet;
+
+import org.apache.lucene.search.DocIdSet;
+import org.apache.lucene.search.DocIdSetIterator;
+
+
+/** Simple DocIdSet and DocIdSetIterator backed by a BitSet */
+public class DocIdBitSet extends DocIdSet {
+  private BitSet bitSet;
+    
+  public DocIdBitSet(BitSet bitSet) {
+    this.bitSet = bitSet;
+  }
+
+  @Override
+  public DocIdSetIterator iterator() {
+    return new DocIdBitSetIterator(bitSet);
+  }
+
+  /** This DocIdSet implementation is cacheable. */
+  @Override
+  public boolean isCacheable() {
+    return true;
+  }
+  
+  /**
+   * Returns the underlying BitSet. 
+   */
+  public BitSet getBitSet() {
+       return this.bitSet;
+  }
+  
+  private static class DocIdBitSetIterator extends DocIdSetIterator {
+    private int docId;
+    private BitSet bitSet;
+    
+    DocIdBitSetIterator(BitSet bitSet) {
+      this.bitSet = bitSet;
+      this.docId = -1;
+    }
+    
+    @Override
+    public int docID() {
+      return docId;
+    }
+    
+    @Override
+    public int nextDoc() {
+      // (docId + 1) on next line requires -1 initial value for docNr:
+      int d = bitSet.nextSetBit(docId + 1);
+      // -1 returned by BitSet.nextSetBit() when exhausted
+      docId = d == -1 ? NO_MORE_DOCS : d;
+      return docId;
+    }
+  
+    @Override
+    public int advance(int target) {
+      int d = bitSet.nextSetBit(target);
+      // -1 returned by BitSet.nextSetBit() when exhausted
+      docId = d == -1 ? NO_MORE_DOCS : d;
+      return docId;
+    }
+  }
+}