/**
* Uses the ColumnarSerde to deserialize the buff:BytesRefArrayWritable into a ColumnarStruct
* instance.
*
* @param buff BytesRefArrayWritable
* @return ColumnarStruct
*/
private ColumnarStruct readColumnarStruct(BytesRefArrayWritable buff) {
// use ColumnarSerDe to deserialize row
ColumnarStruct struct = null;
try {
struct = (ColumnarStruct) serde.deserialize(buff);
} catch (SerDeException e) {
LOG.error(e.toString(), e);
throw new RuntimeException(e.toString(), e);
}
return struct;
}
@Override
public void prepareToRead(@SuppressWarnings("rawtypes") RecordReader reader, PigSplit split)
throws IOException {
this.reader = (HiveRCRecordReader) reader;
// check that the required indexes actually exist i.e. the columns that
// should be read.
// assuming this is always defined simplifies the readColumnarTuple
// logic.
int requiredIndexes[] = getRequiredColumns();
if (requiredIndexes == null) {
int fieldLen = pigSchema.getFields().length;
// if any the partition keys should already exist
String[] partitionKeys = getPartitionKeys(null, null);
if (partitionKeys != null) {
fieldLen = partitionKeys.length;
}
requiredIndexes = new int[fieldLen];
for (int i = 0; i < fieldLen; i++) {
requiredIndexes[i] = i;
}
this.requiredColumns = requiredIndexes;
}
try {
serde = new ColumnarSerDe();
serde.initialize(hiveConf, props);
} catch (SerDeException e) {
LOG.error(e.toString(), e);
throw new IOException(e);
}
}