/*
* 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.snappy.SnappyBlock;
import com.facebook.presto.block.snappy.SnappyBlockEncoding;
import com.facebook.presto.spi.block.Block;
import com.facebook.presto.spi.block.BlockBuilder;
import com.facebook.presto.spi.block.BlockBuilderStatus;
import com.facebook.presto.spi.block.BlockEncoding;
import io.airlift.slice.SliceOutput;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
public class SnappyEncoder
implements Encoder
{
private final SliceOutput sliceOutput;
private SnappyBlockEncoding encoding;
private BlockBuilder blockBuilder;
private boolean finished;
public SnappyEncoder(SliceOutput sliceOutput)
{
this.sliceOutput = checkNotNull(sliceOutput, "sliceOutput is null");
}
@Override
public Encoder append(Block block)
{
checkNotNull(block, "block is null");
checkState(!finished, "already finished");
if (encoding == null) {
encoding = new SnappyBlockEncoding(block.getType(), block.getEncoding());
blockBuilder = block.getType().createBlockBuilder(new BlockBuilderStatus());
}
for (int position = 0; position < block.getPositionCount(); position++) {
block.appendTo(position, blockBuilder);
if (blockBuilder.isFull()) {
flushBlock();
}
}
return this;
}
@Override
public BlockEncoding finish()
{
checkState(encoding != null, "nothing appended");
checkState(!finished, "already finished");
finished = true;
if (!blockBuilder.isEmpty()) {
flushBlock();
}
return encoding;
}
private void flushBlock()
{
SnappyBlock snappyBlock = new SnappyBlock(blockBuilder.build());
encoding.writeBlock(sliceOutput, snappyBlock);
blockBuilder = snappyBlock.getType().createBlockBuilder(new BlockBuilderStatus());
}
}