package FlexibleEncoding.Parquet;
/*
* adapted from Parquet*
*/
import java.io.IOException;
/**
* Write lengths of byte-arrays using delta encoding, followed by concatenated byte-arrays
* <pre>
* {@code
* delta-length-byte-array : length* byte-array*
* }
* </pre>
* @author Aniket Mokashi
*
*/
public class DeltaLengthByteArrayValuesWriter extends ValuesWriter {
private static final Log LOG = Log.getLog(DeltaLengthByteArrayValuesWriter.class);
private ValuesWriter lengthWriter;
private CapacityByteArrayOutputStream arrayOut;
private LittleEndianDataOutputStream out;
public DeltaLengthByteArrayValuesWriter(int initialSize) {
arrayOut = new CapacityByteArrayOutputStream(initialSize);
out = new LittleEndianDataOutputStream(arrayOut);
lengthWriter = new DeltaBinaryPackingValuesWriter(
DeltaBinaryPackingValuesWriter.DEFAULT_NUM_BLOCK_VALUES,
DeltaBinaryPackingValuesWriter.DEFAULT_NUM_MINIBLOCKS,
initialSize);
}
@Override
public void writeBytes(Binary v) {
try {
lengthWriter.writeInteger(v.length());
out.write(v.getBytes());
} catch (IOException e) {
throw new ParquetEncodingException("could not write bytes", e);
}
}
@Override
public long getBufferedSize() {
return lengthWriter.getBufferedSize() + arrayOut.size();
}
@Override
public BytesInput getBytes() {
try {
out.flush();
} catch (IOException e) {
throw new ParquetEncodingException("could not write page", e);
}
if (Log.DEBUG) LOG.debug("writing a buffer of size " + arrayOut.size());
return BytesInput.concat(lengthWriter.getBytes(), BytesInput.from(arrayOut));
}
// @Override
// public Encoding getEncoding() {
// return Encoding.DELTA_LENGTH_BYTE_ARRAY;
// }
@Override
public void reset() {
lengthWriter.reset();
arrayOut.reset();
}
@Override
public long getAllocatedSize() {
return lengthWriter.getAllocatedSize() + arrayOut.getCapacity();
}
@Override
public String memUsageString(String prefix) {
return arrayOut.memUsageString(lengthWriter.memUsageString(prefix) + " DELTA_LENGTH_BYTE_ARRAY");
}
@Override
public Encoding getEncoding() {
// TODO Auto-generated method stub
return null;
}
}