pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / facet / src / java / org / apache / lucene / facet / enhancements / EnhancementsCategoryTokenizer.java

diff --git a/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/enhancements/EnhancementsCategoryTokenizer.java b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/enhancements/EnhancementsCategoryTokenizer.java
new file mode 100644 (file)
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+++ b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/enhancements/EnhancementsCategoryTokenizer.java
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+package org.apache.lucene.facet.enhancements;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.lucene.analysis.TokenStream;
+
+import org.apache.lucene.facet.enhancements.params.EnhancementsIndexingParams;
+import org.apache.lucene.facet.index.streaming.CategoryTokenizer;
+import org.apache.lucene.util.Vint8;
+
+/**
+ * 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.
+ */
+
+/**
+ * A tokenizer which adds to each category token payload according to the
+ * {@link CategoryEnhancement}s defined in the given
+ * {@link EnhancementsIndexingParams}.
+ * 
+ * @lucene.experimental
+ */
+public class EnhancementsCategoryTokenizer extends CategoryTokenizer {
+
+  /**
+   * The data buffer used for payload instance.
+   */
+  protected byte[] payloadBytes;
+
+  /**
+   * The category enhancements to handle
+   */
+  protected List<CategoryEnhancement> enhancements;
+
+  /**
+   * Buffers for enhancement payload bytes
+   */
+  protected byte[][] enhancementBytes;
+
+  private int nStart;
+
+  /**
+   * Constructor.
+   * 
+   * @param input
+   *            The stream of category tokens.
+   * @param indexingParams
+   *            The indexing params to use.
+   * @throws IOException
+   */
+  public EnhancementsCategoryTokenizer(TokenStream input,
+      EnhancementsIndexingParams indexingParams) throws IOException {
+    super(input, indexingParams);
+    payloadBytes = new byte[Vint8.MAXIMUM_BYTES_NEEDED
+        * (indexingParams.getCategoryEnhancements().size() + 1)];
+    enhancements = indexingParams.getCategoryEnhancements();
+    if (enhancements != null) {
+      // create array of bytes per enhancement
+      enhancementBytes = new byte[enhancements.size()][];
+      // write once the number of enhancements in the payload bytes
+      nStart = Vint8.encode(enhancements.size(), payloadBytes, 0);
+    }
+  }
+
+  @Override
+  protected void setPayload() {
+    this.payloadAttribute.setPayload(null);
+    if (enhancements == null) {
+      return;
+    }
+    // clear previous payload content
+    int nBytes = nStart;
+    int i = 0;
+    int nEnhancementBytes = 0;
+    for (CategoryEnhancement enhancement : enhancements) {
+      // get payload bytes from each enhancement
+      enhancementBytes[i] = enhancement
+          .getCategoryTokenBytes(categoryAttribute);
+      // write the number of bytes in the payload
+      if (enhancementBytes[i] == null) {
+        nBytes += Vint8.encode(0, payloadBytes, nBytes);
+      } else {
+        nBytes += Vint8.encode(enhancementBytes[i].length,
+            payloadBytes, nBytes);
+        nEnhancementBytes += enhancementBytes[i].length;
+      }
+      i++;
+    }
+    if (nEnhancementBytes > 0) {
+      // make sure we have space for all bytes
+      if (payloadBytes.length < nBytes + nEnhancementBytes) {
+        byte[] temp = new byte[(nBytes + nEnhancementBytes) * 2];
+        System.arraycopy(payloadBytes, 0, temp, 0, nBytes);
+        payloadBytes = temp;
+      }
+      for (i = 0; i < enhancementBytes.length; i++) {
+        // add the enhancement payload bytes after the existing bytes
+        if (enhancementBytes[i] != null) {
+          System.arraycopy(enhancementBytes[i], 0, payloadBytes,
+              nBytes, enhancementBytes[i].length);
+          nBytes += enhancementBytes[i].length;
+        }
+      }
+      payload.setData(payloadBytes, 0, nBytes);
+      payloadAttribute.setPayload(payload);
+    }
+  }
+}