/*
* 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.block.snappy;
import com.facebook.presto.block.Block;
import com.facebook.presto.block.BlockCursor;
import com.facebook.presto.block.uncompressed.UncompressedBlockCursor;
import com.facebook.presto.block.uncompressed.UncompressedBooleanBlockCursor;
import com.facebook.presto.block.uncompressed.UncompressedDoubleBlockCursor;
import com.facebook.presto.block.uncompressed.UncompressedLongBlockCursor;
import com.facebook.presto.block.uncompressed.UncompressedSliceBlockCursor;
import com.facebook.presto.serde.SnappyBlockEncoding;
import com.facebook.presto.tuple.TupleInfo;
import com.facebook.presto.tuple.TupleInfo.Type;
import com.google.common.base.Objects;
import com.google.common.base.Preconditions;
import io.airlift.slice.Slice;
import io.airlift.slice.Slices;
import io.airlift.units.DataSize;
import io.airlift.units.DataSize.Unit;
import org.iq80.snappy.Snappy;
import javax.annotation.concurrent.GuardedBy;
import static com.google.common.base.Preconditions.checkState;
public class SnappyBlock
implements Block
{
private final int positionCount;
private final TupleInfo tupleInfo;
private final Slice compressedSlice;
@GuardedBy("this")
private Slice uncompressedSlice = null;
public SnappyBlock(int positionCount, TupleInfo tupleInfo, Slice compressedSlice)
{
Preconditions.checkArgument(positionCount >= 0, "positionCount is negative");
Preconditions.checkNotNull(tupleInfo, "tupleInfo is null");
Preconditions.checkNotNull(compressedSlice, "compressedSlice is null");
this.tupleInfo = tupleInfo;
this.compressedSlice = compressedSlice;
this.positionCount = positionCount;
}
@Override
public TupleInfo getTupleInfo()
{
return tupleInfo;
}
public Slice getCompressedSlice()
{
return compressedSlice;
}
public synchronized Slice getUncompressedSlice()
{
if (uncompressedSlice == null) {
int uncompressedLength = Snappy.getUncompressedLength(compressedSlice.getBytes(), 0);
checkState(uncompressedLength > 0, "Empty block encountered!");
byte[] output = new byte[uncompressedLength];
Snappy.uncompress(compressedSlice.getBytes(), 0, compressedSlice.length(), output, 0);
uncompressedSlice = Slices.wrappedBuffer(output);
}
return uncompressedSlice;
}
public int getSliceOffset()
{
return 0;
}
@Override
public int getPositionCount()
{
return positionCount;
}
@Override
public DataSize getDataSize()
{
return new DataSize(getUncompressedSlice().length(), Unit.BYTE);
}
@Override
public BlockCursor cursor()
{
if (tupleInfo.getFieldCount() == 1) {
Type type = tupleInfo.getTypes().get(0);
if (type == Type.BOOLEAN) {
return new UncompressedBooleanBlockCursor(positionCount, getUncompressedSlice());
}
if (type == Type.FIXED_INT_64) {
return new UncompressedLongBlockCursor(positionCount, getUncompressedSlice());
}
if (type == Type.DOUBLE) {
return new UncompressedDoubleBlockCursor(positionCount, getUncompressedSlice());
}
if (type == Type.VARIABLE_BINARY) {
return new UncompressedSliceBlockCursor(positionCount, getUncompressedSlice());
}
}
return new UncompressedBlockCursor(tupleInfo, positionCount, getUncompressedSlice());
}
@Override
public SnappyBlockEncoding getEncoding()
{
return new SnappyBlockEncoding(tupleInfo);
}
@Override
public Block getRegion(int positionOffset, int length)
{
Preconditions.checkPositionIndexes(positionOffset, positionOffset + length, positionCount);
return cursor().getRegionAndAdvance(length);
}
@Override
public String toString()
{
return Objects.toStringHelper(this)
.add("positionCount", positionCount)
.add("tupleInfo", tupleInfo)
.add("compressedSlice", compressedSlice)
.toString();
}
}