/*
* 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.spi.block;
import io.airlift.slice.Slice;
import io.airlift.slice.SliceOutput;
import io.airlift.slice.Slices;
import org.openjdk.jol.info.ClassLayout;
import java.util.Arrays;
import java.util.List;
import static com.facebook.presto.spi.block.BlockUtil.checkValidPositions;
import static com.facebook.presto.spi.block.BlockUtil.checkValidRegion;
import static com.facebook.presto.spi.block.BlockUtil.intSaturatedCast;
import static io.airlift.slice.SizeOf.sizeOf;
public class VariableWidthBlock
extends AbstractVariableWidthBlock
{
private static final int INSTANCE_SIZE = ClassLayout.parseClass(VariableWidthBlock.class).instanceSize();
private final int arrayOffset;
private final int positionCount;
private final Slice slice;
private final int[] offsets;
private final boolean[] valueIsNull;
private final int retainedSizeInBytes;
private final int sizeInBytes;
public VariableWidthBlock(int positionCount, Slice slice, int[] offsets, boolean[] valueIsNull)
{
this(0, positionCount, slice, offsets, valueIsNull);
}
VariableWidthBlock(int arrayOffset, int positionCount, Slice slice, int[] offsets, boolean[] valueIsNull)
{
if (arrayOffset < 0) {
throw new IllegalArgumentException("arrayOffset is negative");
}
this.arrayOffset = arrayOffset;
if (positionCount < 0) {
throw new IllegalArgumentException("positionCount is negative");
}
this.positionCount = positionCount;
if (slice == null) {
throw new IllegalArgumentException("slice is null");
}
this.slice = slice;
if (offsets.length - arrayOffset < (positionCount + 1)) {
throw new IllegalArgumentException("offsets length is less than positionCount");
}
this.offsets = offsets;
if (valueIsNull.length - arrayOffset < positionCount) {
throw new IllegalArgumentException("valueIsNull length is less than positionCount");
}
this.valueIsNull = valueIsNull;
sizeInBytes = intSaturatedCast(offsets[arrayOffset + positionCount] - offsets[arrayOffset] + ((Integer.BYTES + Byte.BYTES) * (long) positionCount));
retainedSizeInBytes = intSaturatedCast(INSTANCE_SIZE + slice.getRetainedSize() + sizeOf(valueIsNull) + sizeOf(offsets));
}
@Override
protected final int getPositionOffset(int position)
{
return offsets[position + arrayOffset];
}
@Override
public int getSliceLength(int position)
{
checkReadablePosition(position);
return getPositionOffset(position + 1) - getPositionOffset(position);
}
@Override
protected boolean isEntryNull(int position)
{
return valueIsNull[position + arrayOffset];
}
@Override
public int getPositionCount()
{
return positionCount;
}
@Override
public int getSizeInBytes()
{
return sizeInBytes;
}
@Override
public int getRegionSizeInBytes(int position, int length)
{
return intSaturatedCast(offsets[arrayOffset + position + length] - offsets[arrayOffset + position] + ((Integer.BYTES + Byte.BYTES) * (long) length));
}
@Override
public int getRetainedSizeInBytes()
{
return retainedSizeInBytes;
}
@Override
public Block copyPositions(List<Integer> positions)
{
checkValidPositions(positions, positionCount);
int finalLength = positions.stream().mapToInt(this::getSliceLength).sum();
SliceOutput newSlice = Slices.allocate(finalLength).getOutput();
int[] newOffsets = new int[positions.size() + 1];
boolean[] newValueIsNull = new boolean[positions.size()];
for (int i = 0; i < positions.size(); i++) {
int position = positions.get(i);
if (isEntryNull(position)) {
newValueIsNull[i] = true;
}
else {
newSlice.appendBytes(slice.getBytes(getPositionOffset(position), getSliceLength(position)));
}
newOffsets[i + 1] = newSlice.size();
}
return new VariableWidthBlock(positions.size(), newSlice.slice(), newOffsets, newValueIsNull);
}
@Override
protected Slice getRawSlice(int position)
{
return slice;
}
@Override
public Block getRegion(int positionOffset, int length)
{
checkValidRegion(getPositionCount(), positionOffset, length);
return new VariableWidthBlock(positionOffset + arrayOffset, length, slice, offsets, valueIsNull);
}
@Override
public Block copyRegion(int positionOffset, int length)
{
checkValidRegion(getPositionCount(), positionOffset, length);
positionOffset += arrayOffset;
int[] newOffsets = Arrays.copyOfRange(offsets, positionOffset, positionOffset + length + 1);
// set new offsets to start from beginning of slice (since we are copying)
for (int i = 0; i < newOffsets.length; i++) {
newOffsets[i] -= offsets[positionOffset];
}
Slice newSlice = Slices.copyOf(slice, offsets[positionOffset], newOffsets[length]);
boolean[] newValueIsNull = Arrays.copyOfRange(valueIsNull, positionOffset, positionOffset + length);
return new VariableWidthBlock(length, newSlice, newOffsets, newValueIsNull);
}
@Override
public String toString()
{
StringBuilder sb = new StringBuilder("VariableWidthBlock{");
sb.append("positionCount=").append(getPositionCount());
sb.append(", slice=").append(slice);
sb.append('}');
return sb.toString();
}
}