com.facebook.presto.jdbc.internal.common.block.ColumnarRow Maven / Gradle / Ivy
/*
* 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.jdbc.internal.common.block;
import com.facebook.presto.jdbc.internal.jol.info.ClassLayout;
import static com.facebook.presto.jdbc.internal.io.airlift.slice.SizeOf.sizeOf;
import static java.util.Objects.requireNonNull;
public final class ColumnarRow
{
private static final int INSTANCE_SIZE = ClassLayout.parseClass(ColumnarRow.class).instanceSize();
private final Block nullCheckBlock;
private final Block[] fields;
private final long retainedSizeInBytes;
private final long estimatedSerializedSizeInBytes;
public static ColumnarRow toColumnarRow(Block block)
{
requireNonNull(block, "block is null");
if (block instanceof DictionaryBlock) {
return toColumnarRow((DictionaryBlock) block);
}
if (block instanceof RunLengthEncodedBlock) {
return toColumnarRow((RunLengthEncodedBlock) block);
}
if (!(block instanceof AbstractRowBlock)) {
throw new IllegalArgumentException("Invalid row block: " + block.getClass().getName());
}
AbstractRowBlock rowBlock = (AbstractRowBlock) block;
// get fields for visible region
int firstRowPosition = rowBlock.getFieldBlockOffset(0);
int totalRowCount = rowBlock.getFieldBlockOffset(block.getPositionCount()) - firstRowPosition;
Block[] fieldBlocks = new Block[rowBlock.numFields];
for (int i = 0; i < fieldBlocks.length; i++) {
fieldBlocks[i] = rowBlock.getRawFieldBlocks()[i].getRegion(firstRowPosition, totalRowCount);
}
return new ColumnarRow(block, fieldBlocks, block.getRetainedSizeInBytes(), block.getSizeInBytes());
}
private static ColumnarRow toColumnarRow(DictionaryBlock dictionaryBlock)
{
// build a mapping from the old dictionary to a new dictionary with nulls removed
Block dictionary = dictionaryBlock.getDictionary();
int[] newDictionaryIndex = new int[dictionary.getPositionCount()];
int nextNewDictionaryIndex = 0;
for (int position = 0; position < dictionary.getPositionCount(); position++) {
if (!dictionary.isNull(position)) {
newDictionaryIndex[position] = nextNewDictionaryIndex;
nextNewDictionaryIndex++;
}
}
// reindex the dictionary
int positionCount = dictionaryBlock.getPositionCount();
int[] dictionaryIds = new int[positionCount];
int nonNullPositionCount = 0;
for (int position = 0; position < positionCount; position++) {
if (!dictionaryBlock.isNull(position)) {
int oldDictionaryId = dictionaryBlock.getId(position);
dictionaryIds[nonNullPositionCount] = newDictionaryIndex[oldDictionaryId];
nonNullPositionCount++;
}
}
ColumnarRow columnarRow = toColumnarRow(dictionary);
Block[] fields = new Block[columnarRow.getFieldCount()];
long averageRowSize = 0;
for (int i = 0; i < columnarRow.getFieldCount(); i++) {
Block field = columnarRow.getField(i);
fields[i] = new DictionaryBlock(nonNullPositionCount, field, dictionaryIds);
averageRowSize += field.getPositionCount() == 0 ? 0 : field.getSizeInBytes() / field.getPositionCount();
}
return new ColumnarRow(
dictionaryBlock,
fields,
INSTANCE_SIZE + dictionaryBlock.getRetainedSizeInBytes() + sizeOf(dictionaryIds),
// The estimated serialized size is the sum of the following:
// 1) the offsets size: Integer.BYTES * positionCount. Note that even though ColumnarRow doesn't have the offsets array, the serialized RowBlock still has it. Please see RowBlockEncodingBuffer.
// 2) nulls array size: Byte.BYTES * positionCount
// 3) the estimated serialized size for the fields Blocks which were just constructed as new DictionaryBlocks:
// the average row size: averageRowSize * the number of rows: nonNullPositionCount
(Integer.BYTES + Byte.BYTES) * positionCount + averageRowSize * nonNullPositionCount);
}
private static ColumnarRow toColumnarRow(RunLengthEncodedBlock rleBlock)
{
Block rleValue = rleBlock.getValue();
int positionCount = rleBlock.getPositionCount();
ColumnarRow columnarRow = toColumnarRow(rleValue);
Block[] fields = new Block[columnarRow.getFieldCount()];
long averageRowSize = 0;
for (int i = 0; i < columnarRow.getFieldCount(); i++) {
Block nullSuppressedField = columnarRow.getField(i);
if (rleValue.isNull(0)) {
// the rle value is a null row so, all null-suppressed fields should empty
if (nullSuppressedField.getPositionCount() != 0) {
throw new IllegalArgumentException("Invalid row block");
}
fields[i] = nullSuppressedField;
}
else {
fields[i] = new RunLengthEncodedBlock(nullSuppressedField, positionCount);
averageRowSize += nullSuppressedField.getSizeInBytes() / nullSuppressedField.getPositionCount();
}
}
return new ColumnarRow(
rleBlock,
fields,
INSTANCE_SIZE + rleBlock.getRetainedSizeInBytes(),
// The estimated serialized size is the sum of the following:
// 1) the offsets size: Integer.BYTES * positionCount. Note that even though ColumnarRow doesn't have the offsets array, the serialized RowBlock still has it. Please see RowBlockEncodingBuffer.
// 2) nulls array size: Byte.BYTES * positionCount
// 3) the estimated serialized size for the fields Blocks which were just constructed as new RunLengthEncodedBlocks:
// the average row size: averageRowSize * the number of rows: positionCount
(Integer.BYTES + Byte.BYTES) * positionCount + averageRowSize * positionCount);
}
private ColumnarRow(Block nullCheckBlock, Block[] fields, long retainedSizeInBytes, long estimatedSerializedSizeInBytes)
{
this.nullCheckBlock = nullCheckBlock;
this.fields = fields.clone();
this.retainedSizeInBytes = retainedSizeInBytes;
this.estimatedSerializedSizeInBytes = estimatedSerializedSizeInBytes;
}
public int getPositionCount()
{
return nullCheckBlock.getPositionCount();
}
public int getNonNullPositionCount()
{
if (!nullCheckBlock.mayHaveNull()) {
return getPositionCount();
}
int count = 0;
for (int i = 0; i < getPositionCount(); i++) {
if (!isNull(i)) {
count++;
}
}
return count;
}
public boolean isNull(int position)
{
return nullCheckBlock.isNull(position);
}
public int getFieldCount()
{
return fields.length;
}
/**
* Gets the specified field for all rows as a column.
*
* Note: A null row will not have an entry in the block, so the block
* will be the size of the non-null rows. This block may still contain
* null values when the row is non-null but the field value is null.
*/
public Block getField(int index)
{
return fields[index];
}
public int getOffset(int position)
{
return ((AbstractRowBlock) nullCheckBlock).getFieldBlockOffset(position);
}
public Block getNullCheckBlock()
{
return nullCheckBlock;
}
public long getRetainedSizeInBytes()
{
return retainedSizeInBytes;
}
public long getEstimatedSerializedSizeInBytes()
{
return estimatedSerializedSizeInBytes;
}
@Override
public String toString()
{
StringBuilder sb = new StringBuilder(getClass().getSimpleName()).append("{");
sb.append("positionCount=").append(getPositionCount()).append(",");
sb.append("fieldsCount=").append(fields.length).append(",");
for (int i = 0; i < fields.length; i++) {
sb.append("field_").append(i).append("=").append(fields[i].toString()).append(",");
}
sb.append('}');
return sb.toString();
}
}
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