CodegenScalarFromAnnotationsParser.java
/*
* 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.operator.scalar.annotations;
import com.facebook.presto.common.QualifiedObjectName;
import com.facebook.presto.common.type.Type;
import com.facebook.presto.common.type.TypeSignature;
import com.facebook.presto.metadata.BoundVariables;
import com.facebook.presto.metadata.FunctionAndTypeManager;
import com.facebook.presto.metadata.SqlScalarFunction;
import com.facebook.presto.operator.scalar.BuiltInScalarFunctionImplementation;
import com.facebook.presto.operator.scalar.ScalarFunctionImplementationChoice.ArgumentProperty;
import com.facebook.presto.spi.PrestoException;
import com.facebook.presto.spi.function.BlockPosition;
import com.facebook.presto.spi.function.CodegenScalarFunction;
import com.facebook.presto.spi.function.ComplexTypeFunctionDescriptor;
import com.facebook.presto.spi.function.Description;
import com.facebook.presto.spi.function.FunctionKind;
import com.facebook.presto.spi.function.IsNull;
import com.facebook.presto.spi.function.ScalarFunction;
import com.facebook.presto.spi.function.ScalarOperator;
import com.facebook.presto.spi.function.Signature;
import com.facebook.presto.spi.function.SqlFunctionVisibility;
import com.facebook.presto.spi.function.SqlInvokedScalarFunction;
import com.facebook.presto.spi.function.SqlNullable;
import com.facebook.presto.spi.function.SqlType;
import com.facebook.presto.spi.function.TypeParameter;
import com.facebook.presto.sql.gen.lambda.BinaryFunctionInterface;
import com.facebook.presto.sql.gen.lambda.UnaryFunctionInterface;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import java.lang.invoke.MethodHandle;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import static com.facebook.presto.common.type.TypeSignature.parseTypeSignature;
import static com.facebook.presto.metadata.BuiltInTypeAndFunctionNamespaceManager.JAVA_BUILTIN_NAMESPACE;
import static com.facebook.presto.metadata.SignatureBinder.applyBoundVariables;
import static com.facebook.presto.operator.annotations.FunctionsParserHelper.checkPushdownSubfieldArgIndex;
import static com.facebook.presto.operator.annotations.FunctionsParserHelper.findPublicStaticMethods;
import static com.facebook.presto.operator.annotations.FunctionsParserHelper.parseFunctionDescriptor;
import static com.facebook.presto.operator.scalar.ScalarFunctionImplementationChoice.ArgumentProperty.functionTypeArgumentProperty;
import static com.facebook.presto.operator.scalar.ScalarFunctionImplementationChoice.ArgumentProperty.valueTypeArgumentProperty;
import static com.facebook.presto.operator.scalar.ScalarFunctionImplementationChoice.NullConvention.RETURN_NULL_ON_NULL;
import static com.facebook.presto.operator.scalar.ScalarFunctionImplementationChoice.NullConvention.USE_BOXED_TYPE;
import static com.facebook.presto.spi.StandardErrorCode.FUNCTION_IMPLEMENTATION_ERROR;
import static com.facebook.presto.spi.function.Signature.withVariadicBound;
import static com.facebook.presto.util.Failures.checkCondition;
import static com.google.common.collect.ImmutableList.toImmutableList;
import static java.lang.String.format;
public class CodegenScalarFromAnnotationsParser
{
private CodegenScalarFromAnnotationsParser() {}
public static List<SqlScalarFunction> parseFunctionDefinitions(Class<?> clazz)
{
return findScalarsInFunctionDefinitionClass(clazz).stream()
.map(method -> createSqlScalarFunction(method))
.collect(toImmutableList());
}
private static List<Method> findScalarsInFunctionDefinitionClass(Class<?> clazz)
{
Set<Method> methods = findPublicStaticMethods(
clazz,
ImmutableSet.of(CodegenScalarFunction.class),
ImmutableSet.of(ScalarFunction.class, ScalarOperator.class, SqlInvokedScalarFunction.class));
for (Method method : methods) {
checkCondition(
method.isAnnotationPresent(SqlType.class),
FUNCTION_IMPLEMENTATION_ERROR,
"Function-defining method [%s] is missing @SqlType",
method);
checkCondition(method.getReturnType().equals(MethodHandle.class), FUNCTION_IMPLEMENTATION_ERROR, "Function-defining method [%s] must return MethodHandle", method);
}
return ImmutableList.copyOf(methods);
}
private static List<ArgumentProperty> getArgumentProperties(Method method)
{
return Arrays.stream(method.getParameters())
.map(p -> {
checkCondition(p.getType() == Type.class, FUNCTION_IMPLEMENTATION_ERROR, "Codegen scalar function %s must have parameter [%s] of type Type", method, p.getName());
checkCondition(p.getAnnotationsByType(BlockPosition.class).length == 0, FUNCTION_IMPLEMENTATION_ERROR, "Block and Position format is not supported for codegen function %s", method);
checkCondition(p.getAnnotationsByType(IsNull.class).length == 0, FUNCTION_IMPLEMENTATION_ERROR, "Null flag format is not supported for codegen function %s", method);
TypeSignature signature = parseTypeSignature(p.getAnnotation(SqlType.class).value());
if (signature.isFunction()) {
int params = signature.getParameters().size();
checkCondition(params == 2 || params == 3, FUNCTION_IMPLEMENTATION_ERROR, "Only unary and binary functions are supported in codegen function %s", method);
return functionTypeArgumentProperty(params == 2 ? UnaryFunctionInterface.class : BinaryFunctionInterface.class);
}
return valueTypeArgumentProperty(p.getAnnotation(SqlNullable.class) == null ? RETURN_NULL_ON_NULL : USE_BOXED_TYPE);
})
.collect(toImmutableList());
}
private static SqlScalarFunction createSqlScalarFunction(Method method)
{
CodegenScalarFunction codegenScalarFunction = method.getAnnotation(CodegenScalarFunction.class);
Signature signature = new Signature(
QualifiedObjectName.valueOf(JAVA_BUILTIN_NAMESPACE, codegenScalarFunction.value()),
FunctionKind.SCALAR,
Arrays.stream(method.getAnnotationsByType(TypeParameter.class)).map(t -> withVariadicBound(t.value(), t.boundedBy().isEmpty() ? null : t.boundedBy())).collect(toImmutableList()),
ImmutableList.of(),
parseTypeSignature(method.getAnnotation(SqlType.class).value()),
Arrays.stream(method.getParameters()).map(p -> parseTypeSignature(p.getAnnotation(SqlType.class).value())).collect(toImmutableList()),
false);
ComplexTypeFunctionDescriptor descriptor = parseAndCheckFunctionDescriptor(method, signature);
return new SqlScalarFunction(signature)
{
@Override
public BuiltInScalarFunctionImplementation specialize(BoundVariables boundVariables, int arity, FunctionAndTypeManager functionAndTypeManager)
{
Signature boundSignature = applyBoundVariables(signature, boundVariables, arity);
MethodHandle handle;
try {
handle = (MethodHandle) method.invoke(null, boundSignature.getArgumentTypes().stream().map(t -> functionAndTypeManager.getType(t)).toArray());
}
catch (Exception e) {
throw new PrestoException(FUNCTION_IMPLEMENTATION_ERROR, format("Method %s does not return valid MethodHandle", method), e);
}
return new BuiltInScalarFunctionImplementation(
method.getAnnotation(SqlNullable.class) != null,
getArgumentProperties(method),
handle,
Optional.empty());
}
@Override
public SqlFunctionVisibility getVisibility()
{
return codegenScalarFunction.visibility();
}
@Override
public boolean isDeterministic()
{
return codegenScalarFunction.deterministic();
}
@Override
public String getDescription()
{
Description description = method.getAnnotation(Description.class);
return description == null ? "" : description.value();
}
@Override
public boolean isCalledOnNullInput()
{
return codegenScalarFunction.calledOnNullInput();
}
@Override
public ComplexTypeFunctionDescriptor getComplexTypeFunctionDescriptor()
{
return descriptor;
}
};
}
private static ComplexTypeFunctionDescriptor parseAndCheckFunctionDescriptor(Method method, Signature signature)
{
ComplexTypeFunctionDescriptor descriptor = parseFunctionDescriptor(method);
checkPushdownSubfieldArgIndex(method, signature, descriptor.getPushdownSubfieldArgIndex());
return descriptor;
}
}