Java tutorial
/* * 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 io.prestosql.sql.gen; import com.google.common.base.Joiner; import com.google.common.collect.ImmutableList; import com.google.common.primitives.Primitives; import io.airlift.bytecode.BytecodeNode; import io.airlift.bytecode.FieldDefinition; import io.airlift.bytecode.MethodGenerationContext; import io.airlift.bytecode.Scope; import io.airlift.bytecode.expression.BytecodeExpression; import io.prestosql.operator.scalar.ScalarFunctionImplementation; import java.util.List; import java.util.Optional; import static com.google.common.collect.ImmutableList.toImmutableList; import static io.airlift.bytecode.ParameterizedType.type; import static io.prestosql.sql.gen.BytecodeUtils.generateInvocation; import static java.util.Objects.requireNonNull; public class InvokeFunctionBytecodeExpression extends BytecodeExpression { public static BytecodeExpression invokeFunction(Scope scope, CachedInstanceBinder cachedInstanceBinder, String name, ScalarFunctionImplementation function, BytecodeExpression... parameters) { return invokeFunction(scope, cachedInstanceBinder, name, function, ImmutableList.copyOf(parameters)); } public static BytecodeExpression invokeFunction(Scope scope, CachedInstanceBinder cachedInstanceBinder, String name, ScalarFunctionImplementation function, List<BytecodeExpression> parameters) { requireNonNull(scope, "scope is null"); requireNonNull(function, "function is null"); Optional<BytecodeNode> instance = Optional.empty(); if (function.getInstanceFactory().isPresent()) { FieldDefinition field = cachedInstanceBinder.getCachedInstance(function.getInstanceFactory().get()); instance = Optional.of(scope.getThis().getField(field)); } return new InvokeFunctionBytecodeExpression(scope, cachedInstanceBinder.getCallSiteBinder(), name, function, instance, parameters); } private final BytecodeNode invocation; private final String oneLineDescription; private InvokeFunctionBytecodeExpression(Scope scope, CallSiteBinder binder, String name, ScalarFunctionImplementation function, Optional<BytecodeNode> instance, List<BytecodeExpression> parameters) { super(type(Primitives.unwrap(function.getMethodHandle().type().returnType()))); this.invocation = generateInvocation(scope, name, function, instance, parameters.stream().map(BytecodeNode.class::cast).collect(toImmutableList()), binder); this.oneLineDescription = name + "(" + Joiner.on(", ").join(parameters) + ")"; } @Override public BytecodeNode getBytecode(MethodGenerationContext generationContext) { return invocation; } @Override public List<BytecodeNode> getChildNodes() { return ImmutableList.of(); } @Override protected String formatOneLine() { return oneLineDescription; } }