/*
* 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 com.facebook.presto.spi.type.Type;
import java.lang.invoke.MethodHandle;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import static java.util.Objects.requireNonNull;
public abstract class AbstractMapBlock
implements Block
{
// inverse of hash fill ratio, must be integer
static final int HASH_MULTIPLIER = 2;
protected final Type keyType;
protected final MethodHandle keyNativeHashCode;
protected final MethodHandle keyBlockNativeEquals;
public AbstractMapBlock(Type keyType, MethodHandle keyNativeHashCode, MethodHandle keyBlockNativeEquals)
{
this.keyType = requireNonNull(keyType, "keyType is null");
this.keyNativeHashCode = requireNonNull(keyNativeHashCode, "keyNativeHashCode is null");
this.keyBlockNativeEquals = requireNonNull(keyBlockNativeEquals, "keyBlockNativeEquals is null");
}
protected abstract Block getKeys();
protected abstract Block getValues();
protected abstract int[] getHashTables();
/**
* offset is entry-based, not position-based. In other words,
* if offset[1] is 6, it means the first map has 6 key-value pairs,
* not 6 key/values (which would be 3 pairs).
*/
protected abstract int[] getOffsets();
/**
* offset is entry-based, not position-based. (see getOffsets)
*/
protected abstract int getOffsetBase();
protected abstract boolean[] getMapIsNull();
private int getOffset(int position)
{
return getOffsets()[position + getOffsetBase()];
}
@Override
public BlockEncoding getEncoding()
{
return new MapBlockEncoding(keyType, keyBlockNativeEquals, keyNativeHashCode, getKeys().getEncoding(), getValues().getEncoding());
}
@Override
public Block copyPositions(List<Integer> positions)
{
int[] newOffsets = new int[positions.size() + 1];
boolean[] newMapIsNull = new boolean[positions.size()];
List<Integer> entriesPositions = new ArrayList<>();
int newPosition = 0;
for (int position : positions) {
if (isNull(position)) {
newMapIsNull[newPosition] = true;
newOffsets[newPosition + 1] = newOffsets[newPosition];
}
else {
int entriesStartOffset = getOffset(position);
int entriesEndOffset = getOffset(position + 1);
int entryCount = entriesEndOffset - entriesStartOffset;
newOffsets[newPosition + 1] = newOffsets[newPosition] + entryCount;
for (int elementIndex = entriesStartOffset; elementIndex < entriesEndOffset; elementIndex++) {
entriesPositions.add(elementIndex);
}
}
newPosition++;
}
int[] hashTable = getHashTables();
int[] newHashTable = new int[newOffsets[newOffsets.length - 1] * HASH_MULTIPLIER];
int newHashIndex = 0;
for (int position : positions) {
int entriesStartOffset = getOffset(position);
int entriesEndOffset = getOffset(position + 1);
for (int hashIndex = entriesStartOffset * HASH_MULTIPLIER; hashIndex < entriesEndOffset * HASH_MULTIPLIER; hashIndex++) {
newHashTable[newHashIndex] = hashTable[hashIndex];
newHashIndex++;
}
}
Block newKeys = getKeys().copyPositions(entriesPositions);
Block newValues = getValues().copyPositions(entriesPositions);
return new MapBlock(0, positions.size(), newMapIsNull, newOffsets, newKeys, newValues, newHashTable, keyType, keyBlockNativeEquals, keyNativeHashCode);
}
@Override
public Block getRegion(int position, int length)
{
int positionCount = getPositionCount();
if (position < 0 || length < 0 || position + length > positionCount) {
throw new IndexOutOfBoundsException("Invalid position " + position + " in block with " + positionCount + " positions");
}
if (position == 0 && length == positionCount) {
return this;
}
return new MapBlock(
position + getOffsetBase(),
length,
getMapIsNull(),
getOffsets(),
getKeys(),
getValues(),
getHashTables(),
keyType,
keyBlockNativeEquals, keyNativeHashCode
);
}
@Override
public int getRegionSizeInBytes(int position, int length)
{
int positionCount = getPositionCount();
if (position < 0 || length < 0 || position + length > positionCount) {
throw new IndexOutOfBoundsException("Invalid position " + position + " in block with " + positionCount + " positions");
}
int entriesStart = getOffsets()[getOffsetBase() + position];
int entriesEnd = getOffsets()[getOffsetBase() + position + length];
int entryCount = entriesEnd - entriesStart;
return getKeys().getRegionSizeInBytes(entriesStart, entryCount) +
getValues().getRegionSizeInBytes(entriesStart, entryCount) +
(Integer.BYTES + Byte.BYTES) * length +
Integer.BYTES * HASH_MULTIPLIER * entryCount;
}
@Override
public Block copyRegion(int position, int length)
{
int positionCount = getPositionCount();
if (position < 0 || length < 0 || position + length > positionCount) {
throw new IndexOutOfBoundsException("Invalid position " + position + " in block with " + positionCount + " positions");
}
int startValueOffset = getOffset(position);
int endValueOffset = getOffset(position + length);
Block newKeys = getKeys().copyRegion(startValueOffset, endValueOffset - startValueOffset);
Block newValues = getValues().copyRegion(startValueOffset, endValueOffset - startValueOffset);
int[] newOffsets = new int[length + 1];
for (int i = 1; i < newOffsets.length; i++) {
newOffsets[i] = getOffset(position + i) - startValueOffset;
}
boolean[] newValueIsNull = Arrays.copyOfRange(getMapIsNull(), position + getOffsetBase(), position + getOffsetBase() + length);
int[] newHashTable = Arrays.copyOfRange(getHashTables(), startValueOffset * HASH_MULTIPLIER, endValueOffset * HASH_MULTIPLIER);
return new MapBlock(
0,
length,
newValueIsNull,
newOffsets,
newKeys,
newValues,
newHashTable,
keyType,
keyBlockNativeEquals, keyNativeHashCode
);
}
@Override
public <T> T getObject(int position, Class<T> clazz)
{
if (clazz != Block.class) {
throw new IllegalArgumentException("clazz must be Block.class");
}
checkReadablePosition(position);
int startEntryOffset = getOffset(position);
int endEntryOffset = getOffset(position + 1);
return clazz.cast(new SingleMapBlock(
startEntryOffset * 2,
(endEntryOffset - startEntryOffset) * 2,
getKeys(),
getValues(),
getHashTables(),
keyType,
keyNativeHashCode,
keyBlockNativeEquals));
}
@Override
public void writePositionTo(int position, BlockBuilder blockBuilder)
{
checkReadablePosition(position);
BlockBuilder entryBuilder = blockBuilder.beginBlockEntry();
int startValueOffset = getOffset(position);
int endValueOffset = getOffset(position + 1);
for (int i = startValueOffset; i < endValueOffset; i++) {
if (getKeys().isNull(i)) {
entryBuilder.appendNull();
}
else {
getKeys().writePositionTo(i, entryBuilder);
entryBuilder.closeEntry();
}
if (getValues().isNull(i)) {
entryBuilder.appendNull();
}
else {
getValues().writePositionTo(i, entryBuilder);
entryBuilder.closeEntry();
}
}
}
@Override
public Block getSingleValueBlock(int position)
{
checkReadablePosition(position);
int startValueOffset = getOffset(position);
int endValueOffset = getOffset(position + 1);
int valueLength = endValueOffset - startValueOffset;
Block newKeys = getKeys().copyRegion(startValueOffset, valueLength);
Block newValues = getValues().copyRegion(startValueOffset, valueLength);
int[] newHashTable = Arrays.copyOfRange(getHashTables(), startValueOffset * HASH_MULTIPLIER, endValueOffset * HASH_MULTIPLIER);
return new MapBlock(
0,
1,
new boolean[] {isNull(position)},
new int[] {0, valueLength},
newKeys,
newValues,
newHashTable,
keyType,
keyBlockNativeEquals,
keyNativeHashCode);
}
@Override
public boolean isNull(int position)
{
checkReadablePosition(position);
return getMapIsNull()[position + getOffsetBase()];
}
private void checkReadablePosition(int position)
{
if (position < 0 || position >= getPositionCount()) {
throw new IllegalArgumentException("position is not valid");
}
}
}