pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / analyzers / common / src / java / org / apache / lucene / analysis / payloads / PayloadHelper.java

diff --git a/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/payloads/PayloadHelper.java b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/payloads/PayloadHelper.java
new file mode 100644 (file)
index 0000000..1c8a2f8
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/contrib/analyzers/common/src/java/org/apache/lucene/analysis/payloads/PayloadHelper.java
@@ -0,0 +1,74 @@
+package org.apache.lucene.analysis.payloads;
+/**
+ * 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.
+ */
+
+
+/**
+ * Utility methods for encoding payloads.
+ *
+ **/
+public class PayloadHelper {
+
+  public static byte[] encodeFloat(float payload) {
+    return encodeFloat(payload, new byte[4], 0);
+  }
+
+  public static byte[] encodeFloat(float payload, byte[] data, int offset){
+    return encodeInt(Float.floatToIntBits(payload), data, offset);
+  }
+
+  public static byte[] encodeInt(int payload){
+    return encodeInt(payload, new byte[4], 0);
+  }
+
+  public static byte[] encodeInt(int payload, byte[] data, int offset){
+    data[offset] = (byte)(payload >> 24);
+    data[offset + 1] = (byte)(payload >> 16);
+    data[offset + 2] = (byte)(payload >>  8);
+    data[offset + 3] = (byte) payload;
+    return data;
+  }
+
+  /**
+   * @param bytes
+   * @see #decodeFloat(byte[], int)
+   * @see #encodeFloat(float)
+   * @return the decoded float
+   */
+  public static float decodeFloat(byte [] bytes){
+    return decodeFloat(bytes, 0);
+  }
+
+  /**
+   * Decode the payload that was encoded using {@link #encodeFloat(float)}.
+   * NOTE: the length of the array must be at least offset + 4 long.
+   * @param bytes The bytes to decode
+   * @param offset The offset into the array.
+   * @return The float that was encoded
+   *
+   * @see #encodeFloat(float)
+   */
+  public static final float decodeFloat(byte [] bytes, int offset){
+
+    return Float.intBitsToFloat(decodeInt(bytes, offset));
+  }
+
+  public static final int decodeInt(byte [] bytes, int offset){
+    return ((bytes[offset] & 0xFF) << 24) | ((bytes[offset + 1] & 0xFF) << 16)
+         | ((bytes[offset + 2] & 0xFF) <<  8) |  (bytes[offset + 3] & 0xFF);
+  }
+}