HADOOP-13019. Implement ErasureCodec for HitchHiker XOR coding. Contributed by Kai Sasaki.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/codec/HHXORErasureCodec.java

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+/**
+ * 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.
+ */
+package org.apache.hadoop.io.erasurecode.codec;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.io.erasurecode.ECSchema;
+import org.apache.hadoop.io.erasurecode.coder.ErasureCoder;
+import org.apache.hadoop.io.erasurecode.coder.HHXORErasureDecoder;
+import org.apache.hadoop.io.erasurecode.coder.HHXORErasureEncoder;
+
+/**
+ * A Hitchhiker-XOR erasure codec.
+ */
+@InterfaceAudience.Private
+public class HHXORErasureCodec extends AbstractErasureCodec {
+
+  public HHXORErasureCodec(ECSchema schema) {
+    super(schema);
+  }
+
+  @Override
+  public ErasureCoder createEncoder() {
+    return new HHXORErasureEncoder(getSchema());
+  }
+
+  @Override
+  public ErasureCoder createDecoder() {
+    return new HHXORErasureDecoder(getSchema());
+  }
+}

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/erasurecode/codec/TestHHXORErasureCodec.java

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+/**
+ * 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.
+ */
+package org.apache.hadoop.io.erasurecode.codec;
+
+import org.apache.hadoop.io.erasurecode.ECSchema;
+import org.apache.hadoop.io.erasurecode.coder.ErasureCoder;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class TestHHXORErasureCodec {
+  private ECSchema schema = new ECSchema("hhxor", 10, 4);
+
+  @Test
+  public void testGoodCodec() {
+    HHXORErasureCodec codec = new HHXORErasureCodec(schema);
+    ErasureCoder encoder = codec.createEncoder();
+    assertEquals(10, encoder.getNumDataUnits());
+    assertEquals(4, encoder.getNumParityUnits());
+
+    ErasureCoder decoder = codec.createDecoder();
+    assertEquals(10, decoder.getNumDataUnits());
+    assertEquals(4, decoder.getNumParityUnits());
+  }
+}