package com.facebook.presto.operator.scalar;
/*
* 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.
*/
import com.facebook.presto.metadata.BoundVariables;
import com.facebook.presto.metadata.FunctionRegistry;
import com.facebook.presto.metadata.Signature;
import com.facebook.presto.metadata.SqlOperator;
import com.facebook.presto.spi.PrestoException;
import com.facebook.presto.spi.block.Block;
import com.facebook.presto.spi.type.StandardTypes;
import com.facebook.presto.spi.type.Type;
import com.facebook.presto.spi.type.TypeManager;
import com.google.common.base.Throwables;
import com.google.common.collect.ImmutableList;
import java.lang.invoke.MethodHandle;
import java.util.List;
import static com.facebook.presto.metadata.Signature.comparableWithVariadicBound;
import static com.facebook.presto.spi.StandardErrorCode.GENERIC_INTERNAL_ERROR;
import static com.facebook.presto.spi.function.OperatorType.IS_DISTINCT_FROM;
import static com.facebook.presto.spi.type.TypeSignature.parseTypeSignature;
import static com.facebook.presto.spi.type.TypeUtils.readNativeValue;
import static com.facebook.presto.util.Reflection.methodHandle;
import static com.google.common.base.Defaults.defaultValue;
public class RowDistinctFromOperator
extends SqlOperator
{
public static final RowDistinctFromOperator ROW_DISTINCT_FROM = new RowDistinctFromOperator();
private static final MethodHandle METHOD_HANDLE = methodHandle(RowDistinctFromOperator.class, "isDistinctFrom", Type.class, List.class, Block.class, Block.class);
private RowDistinctFromOperator()
{
super(IS_DISTINCT_FROM,
ImmutableList.of(comparableWithVariadicBound("T", "row")),
ImmutableList.of(),
parseTypeSignature(StandardTypes.BOOLEAN),
ImmutableList.of(parseTypeSignature("T"), parseTypeSignature("T")));
}
@Override
public ScalarFunctionImplementation specialize(BoundVariables boundVariables, int arity, TypeManager typeManager, FunctionRegistry functionRegistry)
{
ImmutableList.Builder<MethodHandle> argumentMethods = ImmutableList.builder();
Type type = boundVariables.getTypeVariable("T");
for (Type parameterType : type.getTypeParameters()) {
Signature signature = functionRegistry.resolveOperator(IS_DISTINCT_FROM, ImmutableList.of(parameterType, parameterType));
argumentMethods.add(functionRegistry.getScalarFunctionImplementation(signature).getMethodHandle());
}
return new ScalarFunctionImplementation(
false,
ImmutableList.of(true, true),
METHOD_HANDLE.bindTo(type).bindTo(argumentMethods.build()),
isDeterministic());
}
public static boolean isDistinctFrom(Type rowType, List<MethodHandle> argumentMethods, Block leftRow, Block rightRow)
{
boolean leftNull = leftRow == null;
boolean rightNull = rightRow == null;
if (leftNull != rightNull) {
return true;
}
if (leftNull) {
return false;
}
List<Type> fieldTypes = rowType.getTypeParameters();
for (int i = 0; i < leftRow.getPositionCount(); i++) {
Type type = fieldTypes.get(i);
Object leftValue = readNativeValue(type, leftRow, i);
boolean leftValueNull = leftValue == null;
if (leftValueNull) {
leftValue = defaultValue(type.getJavaType());
}
Object rightValue = readNativeValue(type, rightRow, i);
boolean rightValueNull = rightValue == null;
if (rightValueNull) {
rightValue = defaultValue(type.getJavaType());
}
try {
if ((boolean) argumentMethods.get(i).invoke(
leftValue,
leftValueNull,
rightValue,
rightValueNull)) {
return true;
}
}
catch (Throwable t) {
Throwables.propagateIfInstanceOf(t, Error.class);
Throwables.propagateIfInstanceOf(t, PrestoException.class);
throw new PrestoException(GENERIC_INTERNAL_ERROR, t);
}
}
return false;
}
}