pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / src / java / org / apache / lucene / search / PhrasePositions.java

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/PhrasePositions.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/PhrasePositions.java
new file mode 100644 (file)
index 0000000..fd246d8
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/PhrasePositions.java
@@ -0,0 +1,93 @@
+package org.apache.lucene.search;
+
+/**
+ * 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.io.IOException;
+import org.apache.lucene.index.*;
+
+/**
+ * Position of a term in a document that takes into account the term offset within the phrase. 
+ */
+final class PhrasePositions {
+  int doc;                                       // current doc
+  int position;                                          // position in doc
+  int count;                                     // remaining pos in this doc
+  int offset;                                    // position in phrase
+  final int ord;                                  // unique across all PhrasePositions instances
+  TermPositions tp;                              // stream of positions
+  PhrasePositions next;                                  // used to make lists
+  PhrasePositions nextRepeating;                       // link to next repeating pp: standing for same term in different query offsets
+
+  PhrasePositions(TermPositions t, int o, int ord) {
+    tp = t;
+    offset = o;
+    this.ord = ord;
+  }
+
+  final boolean next() throws IOException {      // increments to next doc
+    if (!tp.next()) {
+      tp.close();                                // close stream
+      doc = Integer.MAX_VALUE;                   // sentinel value
+      return false;
+    }
+    doc = tp.doc();
+    position = 0;
+    return true;
+  }
+
+  final boolean skipTo(int target) throws IOException {
+    if (!tp.skipTo(target)) {
+      tp.close();                                // close stream
+      doc = Integer.MAX_VALUE;                   // sentinel value
+      return false;
+    }
+    doc = tp.doc();
+    position = 0;
+    return true;
+  }
+
+
+  final void firstPosition() throws IOException {
+    count = tp.freq();                           // read first pos
+    nextPosition();
+  }
+
+  /**
+   * Go to next location of this term current document, and set 
+   * <code>position</code> as <code>location - offset</code>, so that a 
+   * matching exact phrase is easily identified when all PhrasePositions 
+   * have exactly the same <code>position</code>.
+   */
+  final boolean nextPosition() throws IOException {
+    if (count-- > 0) {                           // read subsequent pos's
+      position = tp.nextPosition() - offset;
+      return true;
+    } else
+      return false;
+  }
+  
+  /** for debug purposes */
+  @Override
+  public String toString() {
+    String s = "d:"+doc+" o:"+offset+" p:"+position+" c:"+count;
+    if (nextRepeating!=null) {
+      s += " rpt[ "+nextRepeating+" ]";
+    }
+    return s;
+  }
+}