pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / facet / src / java / org / apache / lucene / util / encoding / SortingIntEncoder.java

diff --git a/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/util/encoding/SortingIntEncoder.java b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/util/encoding/SortingIntEncoder.java
new file mode 100644 (file)
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+++ b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/util/encoding/SortingIntEncoder.java
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+package org.apache.lucene.util.encoding;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.Arrays;
+
+/**
+ * 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.
+ */
+
+/**
+ * An {@link IntEncoderFilter} which sorts the values to encode in ascending
+ * order before encoding them. Encoding therefore happens upon calling
+ * {@link #close()}. Since this encoder is usually chained with another encoder
+ * that relies on sorted values, it does not offer a default constructor.
+ * 
+ * @lucene.experimental
+ */
+public class SortingIntEncoder extends IntEncoderFilter {
+
+  private float grow = 2.0f;
+  private int index = 0;
+  private int[] set = new int[1024];
+
+  /** Initializes with the given encoder. */
+  public SortingIntEncoder(IntEncoder encoder) {
+    super(encoder);
+  }
+
+  @Override
+  public void close() throws IOException {
+    if (index == 0) {
+      return;
+    }
+
+    Arrays.sort(set, 0, index);
+    for (int i = 0; i < index; i++) {
+      encoder.encode(set[i]);
+    }
+    encoder.close();
+    index = 0;
+
+    super.close();
+  }
+
+  @Override
+  public void encode(int value) throws IOException {
+    if (index == set.length) {
+      int[] newSet = new int[(int) (set.length * grow)];
+      System.arraycopy(set, 0, newSet, 0, set.length);
+      set = newSet;
+    }
+    set[index++] = value;
+  }
+
+  @Override
+  public IntDecoder createMatchingDecoder() {
+    return encoder.createMatchingDecoder();
+  }
+  
+  @Override
+  public void reInit(OutputStream out) {
+    super.reInit(out);
+    index = 0;
+  }
+
+  @Override
+  public String toString() {
+    return "Sorting (" + encoder.toString() + ")";
+  }
+  
+}