/**
* Copyright [2012] [Datasalt Systems S.L.]
*
* Licensed 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 com.datasalt.pangool.tuplemr.serialization;
import java.io.DataOutput;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import org.apache.hadoop.io.DataOutputBuffer;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableUtils;
import org.apache.hadoop.io.serializer.Serializer;
import com.datasalt.pangool.io.DatumWrapper;
import com.datasalt.pangool.io.ITuple;
import com.datasalt.pangool.io.Schema;
import com.datasalt.pangool.io.Utf8;
import com.datasalt.pangool.io.Schema.Field;
import com.datasalt.pangool.io.Schema.Field.Type;
import com.datasalt.pangool.serialization.HadoopSerialization;
import com.datasalt.pangool.tuplemr.SerializationInfo;
import com.datasalt.pangool.tuplemr.TupleMRConfig;
public class TupleSerializer implements Serializer<DatumWrapper<ITuple>> {
private final HadoopSerialization ser;
private DataOutputStream out;
private final TupleMRConfig tupleMRConfig;
private final Utf8 HELPER_TEXT = new Utf8();
private boolean isMultipleSources = false;
private final DataOutputBuffer tmpOutputBuffer = new DataOutputBuffer();
private final SerializationInfo serInfo;
private final Schema commonSchema;
public TupleSerializer(HadoopSerialization ser, TupleMRConfig tupleMRConfig) {
this.ser = ser;
this.tupleMRConfig = tupleMRConfig;
this.serInfo = tupleMRConfig.getSerializationInfo();
this.commonSchema = this.serInfo.getCommonSchema();
this.isMultipleSources = (tupleMRConfig.getNumIntermediateSchemas() >= 2);
}
public void open(OutputStream out) {
if (out instanceof DataOutputStream) {
this.out = (DataOutputStream) out;
} else {
this.out = new DataOutputStream(out);
}
}
public void serialize(DatumWrapper<ITuple> wrapper) throws IOException {
ITuple tuple = wrapper.datum();
if (isMultipleSources) {
multipleSourcesSerialization(tuple);
} else {
oneSourceSerialization(tuple);
}
}
private void oneSourceSerialization(ITuple tuple) throws IOException {
int[] commonTranslation = serInfo.getCommonSchemaIndexTranslation(0);
//tuple schema is not checked here
write(commonSchema, tuple, commonTranslation, out);
}
private void multipleSourcesSerialization(ITuple tuple) throws IOException {
String sourceName = tuple.getSchema().getName();
Integer schemaId = tupleMRConfig.getSchemaIdByName(sourceName);
if (schemaId == null){
throw new IOException("Schema '" + tuple.getSchema() +"' is not a valid intermediate schema");
}
int[] commonTranslation = serInfo.getCommonSchemaIndexTranslation(schemaId);
// serialize common
write(commonSchema, tuple, commonTranslation, out);
// serialize source id
WritableUtils.writeVInt(out, schemaId);
// serialize rest of the fields
Schema specificSchema = serInfo.getSpecificSchema(schemaId);
int[] specificTranslation = serInfo
.getSpecificSchemaIndexTranslation(schemaId);
write(specificSchema, tuple, specificTranslation, out);
}
public void close() throws IOException {
this.out.close();
}
/**
*
* The size of the translation table matches the destinationSchema fields
* size.
*
* @param destinationSchema
* @param tuple
* @param translationTable
* If null then no translation is performed
* @param output
* @throws IOException
*/
private void write(Schema destinationSchema, ITuple tuple,
int[] translationTable, DataOutput output) throws IOException {
for (int i = 0; i < destinationSchema.getFields().size(); i++) {
Field field = destinationSchema.getField(i);
Type fieldType = field.getType();
Object element = tuple.get(translationTable[i]);
try {
switch(fieldType){
case INT:
WritableUtils.writeVInt(output, (Integer) element); break;
case LONG:
WritableUtils.writeVLong(output, (Long) element);break;
case DOUBLE:
output.writeDouble((Double) element); break;
case FLOAT:
output.writeFloat((Float) element);break;
case STRING:
if (element instanceof Text){
((Text)element).write(output);
} else if (element instanceof String){
HELPER_TEXT.set((String)element);
HELPER_TEXT.write(output);
} else {
raiseClassCastException(null,field,element);
}
break;
case BOOLEAN:
output.write((Boolean) element ? 1 : 0); break;
case ENUM:
writeEnum((Enum<?>) element, field, output); break;
case OBJECT:
writeCustomObject(element,output); break;
default:
throw new IOException("Not supported type:" + fieldType);
}
} catch(ClassCastException e) {
raiseClassCastException(e, field,element);
} catch(NullPointerException e) {
raiseNullInstanceException(e, field, element);
}
} // end for
}
private void writeCustomObject(Object element, DataOutput output) throws IOException{
tmpOutputBuffer.reset();
ser.ser(element, tmpOutputBuffer);
WritableUtils.writeVInt(output, tmpOutputBuffer.getLength());
output.write(tmpOutputBuffer.getData(), 0, tmpOutputBuffer.getLength());
}
private void writeEnum(Enum<?> element, Field field, DataOutput output) throws IOException {
Enum<?> e = (Enum<?>) element;
Class<?> expectedType = field.getObjectClass();
if (e.getClass() != expectedType) {
throw new IOException("Field '" + field.getName() + "' contains '" + element
+ "' which is " + element.getClass().getName()
+ ".The expected type is " + expectedType.getName());
}
WritableUtils.writeVInt(output, e.ordinal());
}
private void raiseClassCastException(ClassCastException cause,Field field,Object element)
throws IOException {
throw new IOException("Field '" + field.getName() + "' with type: '" +
field.getType() + "' can't contain '" + element + "' which is "
+ element.getClass().getName(),cause);
}
private void raiseNullInstanceException(NullPointerException cause, Field field,Object element)
throws IOException {
throw new IOException("Field '" + field.getName() + "' with type " +
field.getType() +" can't contain null value",cause);
}
}