Author: gdusbabek
Date: Wed Jul 21 15:14:05 2010
New Revision: 966275
URL: http://svn.apache.org/viewvc?rev=966275&view=rev
Log:
avro serialization utility functions. patch by stuhood, reviewed by gdusbabek.
CASSANDRA-1186
Added:
cassandra/trunk/src/java/org/apache/cassandra/io/SerDeUtils.java
Added: cassandra/trunk/src/java/org/apache/cassandra/io/SerDeUtils.java
URL:
http://svn.apache.org/viewvc/cassandra/trunk/src/java/org/apache/cassandra/io/SerDeUtils.java?rev=966275&view=auto
==============================================================================
--- cassandra/trunk/src/java/org/apache/cassandra/io/SerDeUtils.java (added)
+++ cassandra/trunk/src/java/org/apache/cassandra/io/SerDeUtils.java Wed Jul 21
15:14:05 2010
@@ -0,0 +1,109 @@
+/**
+ * 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.cassandra.io;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import org.apache.avro.Schema;
+import org.apache.avro.io.BinaryDecoder;
+import org.apache.avro.io.BinaryEncoder;
+import org.apache.avro.io.Decoder;
+import org.apache.avro.io.DecoderFactory;
+import org.apache.avro.generic.GenericArray;
+import org.apache.avro.generic.GenericData;
+import org.apache.avro.specific.SpecificDatumReader;
+import org.apache.avro.specific.SpecificDatumWriter;
+import org.apache.avro.specific.SpecificRecord;
+import org.apache.avro.util.Utf8;
+
+import org.apache.cassandra.io.util.OutputBuffer;
+
+/**
+ * Static serialization/deserialization utility functions, intended to
eventually replace ICompactSerializers.
+ */
+public final class SerDeUtils
+{
+ // unbuffered decoders
+ private final static DecoderFactory DIRECT_DECODERS = new
DecoderFactory().configureDirectDecoder(true);
+
+ /**
+ * Deserializes a single object based on the given Schema.
+ * @param schema writer's schema
+ * @param bytes Array to deserialize from
+ * @throws IOException
+ */
+ public static <T extends SpecificRecord> T deserialize(Schema schema,
byte[] bytes) throws IOException
+ {
+ BinaryDecoder dec = DIRECT_DECODERS.createBinaryDecoder(bytes, null);
+ return new SpecificDatumReader<T>(schema).read(null, dec);
+ }
+
+ /**
+ * Serializes a single object.
+ * @param o Object to serialize
+ */
+ public static <T extends SpecificRecord> byte[] serialize(T o) throws
IOException
+ {
+ OutputBuffer buff = new OutputBuffer();
+ BinaryEncoder enc = new BinaryEncoder(buff);
+ SpecificDatumWriter<T> writer = new
SpecificDatumWriter<T>(o.getSchema());
+ writer.write(o, enc);
+ enc.flush();
+ return buff.asByteArray();
+ }
+
+ /**
+ * Deserializes a single object as stored along with its Schema by
serialize(T). NB: See warnings on serialize(T).
+ * @param bytes Array to deserialize from
+ * @throws IOException
+ */
+ public static <T extends SpecificRecord> T deserializeWithSchema(byte[]
bytes) throws IOException
+ {
+ BinaryDecoder dec = DIRECT_DECODERS.createBinaryDecoder(bytes, null);
+ Schema schema = Schema.parse(dec.readString(new Utf8()).toString());
+ return new SpecificDatumReader<T>(schema).read(null, dec);
+ }
+
+ /**
+ * Serializes a single object along with its Schema. NB: For performance
critical areas, it is <b>much</b>
+ * more efficient to store the Schema independently.
+ * @param o Object to serialize
+ */
+ public static <T extends SpecificRecord> byte[] serializeWithSchema(T o)
throws IOException
+ {
+ OutputBuffer buff = new OutputBuffer();
+ BinaryEncoder enc = new BinaryEncoder(buff);
+ enc.writeString(new Utf8(o.getSchema().toString()));
+ SpecificDatumWriter<T> writer = new
SpecificDatumWriter<T>(o.getSchema());
+ writer.write(o, enc);
+ enc.flush();
+ return buff.asByteArray();
+ }
+
+ /**
+ * Create a generic array of the given type and size. Mostly to minimize
imports.
+ */
+ public static <T> GenericArray<T> createArray(int size, Schema schema)
+ {
+ return new GenericData.Array<T>(size, Schema.createArray(schema));
+ }
+}
