/**
* Copyright 2012 Twitter, Inc.
*
* 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 parquet.column.values.bitpacking;
import static parquet.bytes.BytesUtils.getWidthFromMaxInt;
import static parquet.column.Encoding.BIT_PACKED;
import static parquet.column.values.bitpacking.BitPacking.getBitPackingWriter;
import java.io.IOException;
import parquet.bytes.BytesInput;
import parquet.bytes.CapacityByteArrayOutputStream;
import parquet.column.Encoding;
import parquet.column.values.ValuesWriter;
import parquet.column.values.bitpacking.BitPacking.BitPackingWriter;
import parquet.io.ParquetEncodingException;
/**
* a column writer that packs the ints in the number of bits required based on the maximum size.
*
* @author Julien Le Dem
*
*/
public class BitPackingValuesWriter extends ValuesWriter {
private CapacityByteArrayOutputStream out;
private BitPackingWriter bitPackingWriter;
private int bitsPerValue;
/**
* @param bound the maximum value stored by this column
*/
public BitPackingValuesWriter(int bound, int initialCapacity) {
this.bitsPerValue = getWidthFromMaxInt(bound);
this.out = new CapacityByteArrayOutputStream(initialCapacity);
init();
}
private void init() {
this.bitPackingWriter = getBitPackingWriter(bitsPerValue, out);
}
/**
* {@inheritDoc}
* @see parquet.column.values.ValuesWriter#writeInteger(int)
*/
@Override
public void writeInteger(int v) {
try {
bitPackingWriter.write(v);
} catch (IOException e) {
throw new ParquetEncodingException(e);
}
}
/**
* {@inheritDoc}
* @see parquet.column.values.ValuesWriter#getBufferedSize()
*/
@Override
public long getBufferedSize() {
return out.size();
}
/**
* {@inheritDoc}
* @see parquet.column.values.ValuesWriter#getBytes()
*/
@Override
public BytesInput getBytes() {
try {
this.bitPackingWriter.finish();
return BytesInput.from(out);
} catch (IOException e) {
throw new ParquetEncodingException(e);
}
}
/**
* {@inheritDoc}
* @see parquet.column.values.ValuesWriter#reset()
*/
@Override
public void reset() {
out.reset();
init();
}
/**
* {@inheritDoc}
* @see parquet.column.values.ValuesWriter#getAllocatedSize()
*/
@Override
public long getAllocatedSize() {
return out.getCapacity();
}
@Override
public String memUsageString(String prefix) {
return out.memUsageString(prefix);
}
@Override
public Encoding getEncoding() {
return BIT_PACKED;
}
}