pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / src / java / org / apache / lucene / index / TermPositions.java

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/index/TermPositions.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/index/TermPositions.java
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+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/index/TermPositions.java
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+package org.apache.lucene.index;
+
+/**
+ * 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;
+
+/**
+ * TermPositions provides an interface for enumerating the <document,
+ * frequency, &lt;position&gt;* &gt; tuples for a term.  <p> The document and
+ * frequency are the same as for a TermDocs.  The positions portion lists the ordinal
+ * positions of each occurrence of a term in a document.
+ *
+ * @see IndexReader#termPositions()
+ */
+
+public interface TermPositions
+    extends TermDocs
+{
+    /** Returns next position in the current document.  It is an error to call
+    this more than {@link #freq()} times
+    without calling {@link #next()}<p> This is
+    invalid until {@link #next()} is called for
+    the first time.
+    */
+    int nextPosition() throws IOException;
+    
+    /** 
+     * Returns the length of the payload at the current term position.
+     * This is invalid until {@link #nextPosition()} is called for
+     * the first time.<br>
+     * @return length of the current payload in number of bytes
+     */
+    int getPayloadLength();
+    
+    /** 
+     * Returns the payload data at the current term position.
+     * This is invalid until {@link #nextPosition()} is called for
+     * the first time.
+     * This method must not be called more than once after each call
+     * of {@link #nextPosition()}. However, payloads are loaded lazily,
+     * so if the payload data for the current position is not needed,
+     * this method may not be called at all for performance reasons.<br>
+     * 
+     * @param data the array into which the data of this payload is to be
+     *             stored, if it is big enough; otherwise, a new byte[] array
+     *             is allocated for this purpose. 
+     * @param offset the offset in the array into which the data of this payload
+     *               is to be stored.
+     * @return a byte[] array containing the data of this payload
+     * @throws IOException
+     */
+    byte[] getPayload(byte[] data, int offset) throws IOException;
+
+  /**
+   * Checks if a payload can be loaded at this position.
+   * <p>
+   * Payloads can only be loaded once per call to 
+   * {@link #nextPosition()}.
+   * 
+   * @return true if there is a payload available at this position that can be loaded
+   */
+    public boolean isPayloadAvailable();
+
+}