/*
* 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.facebook.presto.serde;
import com.facebook.presto.block.uncompressed.UncompressedBlock;
import com.facebook.presto.tuple.Tuple;
import com.google.common.base.Preconditions;
import io.airlift.slice.DynamicSliceOutput;
import io.airlift.slice.Slice;
import io.airlift.slice.SliceOutput;
import io.airlift.units.DataSize;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static io.airlift.units.DataSize.Unit.KILOBYTE;
public class UncompressedEncoder
implements Encoder
{
private static final int MAX_BLOCK_SIZE = (int) new DataSize(64, KILOBYTE).toBytes();
private final SliceOutput sliceOutput;
private final DynamicSliceOutput buffer = new DynamicSliceOutput(MAX_BLOCK_SIZE);
private UncompressedBlockEncoding encoding;
private boolean finished;
private int tupleCount;
public UncompressedEncoder(SliceOutput sliceOutput)
{
this.sliceOutput = checkNotNull(sliceOutput, "sliceOutput is null");
}
@Override
public Encoder append(Iterable<Tuple> tuples)
{
Preconditions.checkNotNull(tuples, "tuples is null");
checkState(!finished, "already finished");
for (Tuple tuple : tuples) {
if (encoding == null) {
encoding = new UncompressedBlockEncoding(tuple.getTupleInfo());
}
tuple.writeTo(buffer);
tupleCount++;
if (buffer.size() >= MAX_BLOCK_SIZE) {
writeBlock();
}
}
return this;
}
@Override
public BlockEncoding finish()
{
checkState(encoding != null, "nothing appended");
checkState(!finished, "already finished");
finished = true;
if (buffer.size() > 0) {
writeBlock();
}
return encoding;
}
private void writeBlock()
{
Slice slice = buffer.slice();
UncompressedBlock block = new UncompressedBlock(tupleCount, encoding.getTupleInfo(), slice);
encoding.writeBlock(sliceOutput, block);
buffer.reset();
tupleCount = 0;
}
}