pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / src / java / org / apache / lucene / store / ChecksumIndexInput.java

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/store/ChecksumIndexInput.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/store/ChecksumIndexInput.java
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+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/store/ChecksumIndexInput.java
@@ -0,0 +1,77 @@
+package org.apache.lucene.store;
+
+/**
+ * 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 java.util.zip.CRC32;
+import java.util.zip.Checksum;
+
+/** Writes bytes through to a primary IndexOutput, computing
+ *  checksum as it goes. Note that you cannot use seek().
+ *
+ * @lucene.internal
+ */
+public class ChecksumIndexInput extends IndexInput {
+  IndexInput main;
+  Checksum digest;
+
+  public ChecksumIndexInput(IndexInput main) {
+    super("ChecksumIndexInput(" + main + ")");
+    this.main = main;
+    digest = new CRC32();
+  }
+
+  @Override
+  public byte readByte() throws IOException {
+    final byte b = main.readByte();
+    digest.update(b);
+    return b;
+  }
+
+  @Override
+  public void readBytes(byte[] b, int offset, int len)
+    throws IOException {
+    main.readBytes(b, offset, len);
+    digest.update(b, offset, len);
+  }
+
+  
+  public long getChecksum() {
+    return digest.getValue();
+  }
+
+  @Override
+  public void close() throws IOException {
+    main.close();
+  }
+
+  @Override
+  public long getFilePointer() {
+    return main.getFilePointer();
+  }
+
+  @Override
+  public void seek(long pos) {
+    throw new RuntimeException("not allowed");
+  }
+
+  @Override
+  public long length() {
+    return main.length();
+  }
+}