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Diffstat (limited to 'sca-java-1.x/branches/sca-java-1.1/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/DataBindingRuntimeWireProcessor.java')
-rw-r--r-- | sca-java-1.x/branches/sca-java-1.1/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/DataBindingRuntimeWireProcessor.java | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/sca-java-1.x/branches/sca-java-1.1/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/DataBindingRuntimeWireProcessor.java b/sca-java-1.x/branches/sca-java-1.1/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/DataBindingRuntimeWireProcessor.java new file mode 100644 index 0000000000..d0a2dbc003 --- /dev/null +++ b/sca-java-1.x/branches/sca-java-1.1/modules/core-databinding/src/main/java/org/apache/tuscany/sca/core/databinding/wire/DataBindingRuntimeWireProcessor.java @@ -0,0 +1,220 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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 org.apache.tuscany.sca.core.databinding.wire; + +import java.lang.reflect.Method; +import java.util.List; + +import org.apache.tuscany.sca.assembly.Implementation; +import org.apache.tuscany.sca.databinding.DataBindingExtensionPoint; +import org.apache.tuscany.sca.databinding.Mediator; +import org.apache.tuscany.sca.interfacedef.DataType; +import org.apache.tuscany.sca.interfacedef.InterfaceContract; +import org.apache.tuscany.sca.interfacedef.Operation; +import org.apache.tuscany.sca.invocation.Interceptor; +import org.apache.tuscany.sca.invocation.InvocationChain; +import org.apache.tuscany.sca.runtime.RuntimeComponent; +import org.apache.tuscany.sca.runtime.RuntimeWire; +import org.apache.tuscany.sca.runtime.RuntimeWireProcessor; + +/** + * This processor is responsible to add an interceptor to invocation chain if + * the source and target operations have different databinding requirements + * + * @version $Rev$ $Date$ + */ +public class DataBindingRuntimeWireProcessor implements RuntimeWireProcessor { + private Mediator mediator; + private DataBindingExtensionPoint dataBindings; + + public DataBindingRuntimeWireProcessor(Mediator mediator, DataBindingExtensionPoint dataBindings) { + super(); + this.mediator = mediator; + this.dataBindings = dataBindings; + } + + public boolean isTransformationRequired(DataType source, DataType target) { + if (source == null || target == null) { // void return type + return false; + } + if (source == target) { + return false; + } + + // Output type can be null + if (source == null && target == null) { + return false; + } else if (source == null || target == null) { + return true; + } + String sourceDataBinding = source.getDataBinding(); + String targetDataBinding = target.getDataBinding(); + if (sourceDataBinding == targetDataBinding) { + return false; + } + if (sourceDataBinding == null || targetDataBinding == null) { + // TODO: If any of the databinding is null, then no transformation + return false; + } + return !sourceDataBinding.equals(targetDataBinding); + } + + public boolean isTransformationRequired(Operation source, Operation target) { + if (source == target) { + return false; + } + + if (source.isWrapperStyle() != target.isWrapperStyle()) { + return true; + } + + // Check output type + DataType sourceOutputType = source.getOutputType(); + DataType targetOutputType = target.getOutputType(); + + // Note the target output type is now the source for checking + // compatibility + if (isTransformationRequired(targetOutputType, sourceOutputType)) { + return true; + } + + List<DataType> sourceInputType = source.getInputType().getLogical(); + List<DataType> targetInputType = target.getInputType().getLogical(); + + int size = sourceInputType.size(); + if (size != targetInputType.size()) { + // TUSCANY-1682: The wrapper style may have different arguments + return true; + } + for (int i = 0; i < size; i++) { + if (isTransformationRequired(sourceInputType.get(i), targetInputType.get(i))) { + return true; + } + } + + return false; + } + + private boolean isTransformationRequired(InterfaceContract sourceContract, + Operation sourceOperation, + InterfaceContract targetContract, + Operation targetOperation) { + if (targetContract == null) { + targetContract = sourceContract; + } + if (sourceContract == targetContract) { + return false; + } + return isTransformationRequired(sourceOperation, targetOperation); + } + + public void process(RuntimeWire wire) { + InterfaceContract sourceContract = wire.getSource().getInterfaceContract(); + InterfaceContract targetContract = wire.getTarget().getInterfaceContract(); + if (targetContract == null) { + targetContract = sourceContract; + } + + if (!sourceContract.getInterface().isRemotable()) { + return; + } + List<InvocationChain> chains = wire.getInvocationChains(); + for (InvocationChain chain : chains) { + Operation sourceOperation = chain.getSourceOperation(); + Operation targetOperation = chain.getTargetOperation(); + + Interceptor interceptor = null; + if (isTransformationRequired(sourceContract, sourceOperation, targetContract, targetOperation)) { + // Add the interceptor to the source side because multiple + // references can be wired to the same service + interceptor = new DataTransformationInterceptor(wire, sourceOperation, targetOperation, mediator); + } else { + // assume pass-by-values copies are required if interfaces are remotable and there is no data binding + // transformation, i.e. a transformation will result in a copy so another pass-by-value copy is unnecessary + if (requiresCopy(wire, sourceOperation, targetOperation)) { + interceptor = new PassByValueInterceptor(dataBindings, targetOperation); + } + } + if (interceptor != null) { + chain.addInterceptor(0, interceptor); + } + } + + } + + /** + * Pass-by-value copies are required if the interfaces are remotable unless the + * implementation uses the @AllowsPassByReference annotation. + */ + protected boolean requiresCopy(RuntimeWire wire, Operation sourceOperation, Operation targetOperation) { + if (!sourceOperation.getInterface().isRemotable()) { + return false; + } + if (!targetOperation.getInterface().isRemotable()) { + return false; + } + + if (allowsPassByReference(wire.getSource().getComponent(), sourceOperation)) { + return false; + } + + if (allowsPassByReference(wire.getTarget().getComponent(), sourceOperation)) { + return false; + } + + return true; + } + + /** + * Does the implementation use the @AllowsPassByReference annotation for the operation. + * Uses reflection to avoid a dependency on JavaImplementation because the isAllowsPassByReference + * and getAllowsPassByReference methods are not on the Implementation interface. + * TODO: move isAllowsPassByReference/getAllowsPassByReference to Implementation interface + */ + protected boolean allowsPassByReference(RuntimeComponent component, Operation operation) { + if (component == null || component.getImplementation() == null) { + return true; // err on the side of no copies + } + Implementation impl = component.getImplementation(); + try { + + Method m = impl.getClass().getMethod("isAllowsPassByReference", new Class[] {}); + if ((Boolean)m.invoke(impl, new Object[]{})) { + return true; + } + + m = impl.getClass().getMethod("getAllowsPassByReferenceMethods", new Class[] {}); + List<Method> ms = (List<Method>)m.invoke(impl, new Object[]{}); + if (ms != null) { + for (Method m2 : ms) { + // simple name matching is ok as its a remote operation so no overloading + if (operation.getName().equals(m2.getName())) + return true; + } + } + + } catch (Exception e) { + // ignore, assume the impl has no isAllowsPassByReference method + } + + return false; + } + +} |