ch.sourcepond.utils.podescoin.internal.method.InjectorMethodEnhancer.java Source code

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Here is the source code for ch.sourcepond.utils.podescoin.internal.method.InjectorMethodEnhancer.java

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/*Copyright (C) 2016 Roland Hauser, <sourcepond@gmail.com>
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 ch.sourcepond.utils.podescoin.internal.method;

import static ch.sourcepond.utils.podescoin.internal.Constants.INJECTOR_INTERNAL_NAME;
import static org.objectweb.asm.Opcodes.ALOAD;
import static org.objectweb.asm.Opcodes.ASTORE;
import static org.objectweb.asm.Opcodes.CHECKCAST;
import static org.objectweb.asm.Opcodes.INVOKEINTERFACE;
import static org.objectweb.asm.Opcodes.INVOKESTATIC;
import static org.objectweb.asm.Opcodes.RETURN;
import static org.objectweb.asm.Type.getInternalName;
import static org.objectweb.asm.Type.getMethodDescriptor;
import static org.objectweb.asm.Type.getType;

import java.io.IOException;
import java.io.Serializable;

import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

import ch.sourcepond.utils.podescoin.Container;
import ch.sourcepond.utils.podescoin.internal.Enhancer;
import ch.sourcepond.utils.podescoin.internal.inspector.DefaultStreamCallGenerator;
import ch.sourcepond.utils.podescoin.internal.inspector.Inspector;

abstract class InjectorMethodEnhancer extends Enhancer {
    protected static final String CONTAINER_INTERNAL_NAME = getInternalName(Container.class);
    private static final String GET_CONTAINER_METHOD_NAME = "getContainer";
    private static final String GET_CONTAINER_METHOD_DESC = getMethodDescriptor(getType(Container.class),
            getType(Serializable.class));
    private static final String GET_COMPONENT_BY_ID_NAME = "getComponentById";
    private static final String GET_COMPONENT_BY_ID_DESC = getMethodDescriptor(getType(Object.class),
            getType(String.class), getType(String.class), getType(int.class));
    private static final String GET_COMPONENT_BY_TYPE_NAME_NAME = "getComponentByTypeName";
    private static final String GET_COMPONENT_BY_TYPE_DESC = getMethodDescriptor(getType(Object.class),
            getType(String.class), getType(int.class));
    protected static final String EXCEPTION_INTERNAL_NAME = getInternalName(Exception.class);
    protected static final String IO_EXCEPTION_INTERNAL_NAME = getInternalName(IOException.class);
    protected static final String GET_MESSAGE_NAME = "getMessage";
    protected static final String GET_MESSAGE_DESC = getMethodDescriptor(getType(String.class));
    protected static final String CONSTRUCTOR_DESC = getMethodDescriptor(getType(void.class), getType(String.class),
            getType(Throwable.class));
    private static final int MIN_STACK_SIZE = 4;
    protected final Label l0 = new Label();
    protected final Label l1 = new Label();
    protected final Inspector inspector;

    InjectorMethodEnhancer(final Inspector pInspector, final MethodVisitor pDelegate, final boolean pEnhanceMode,
            final DefaultStreamCallGenerator pDefaultStreamCallGenerator) {
        super(pEnhanceMode, pDefaultStreamCallGenerator, pDelegate);
        inspector = pInspector;
    }

    protected abstract void tryBlock();

    protected abstract void catchBlock();

    @Override
    public final void visitEnhance() {
        visitCode();
        tryBlock();

        // Inserts a call to defaultWriteObject if a new writeObject method is
        // being generated.
        visitStreamDefaultCall();

        visitVarInsn(ALOAD, 0);
        visitMethodInsn(INVOKESTATIC, INJECTOR_INTERNAL_NAME, GET_CONTAINER_METHOD_NAME, GET_CONTAINER_METHOD_DESC,
                false);
        visitVarInsn(ASTORE, 2);
        visitLabel(l0);
        visitVarInsn(ALOAD, 0);

        int stackSize = MIN_STACK_SIZE;
        if (inspector.hasObjectInputStream()) {
            visitVarInsn(ALOAD, 1);
            stackSize++;
        }

        final String[][] components = inspector.getComponents();

        boolean increaseByOne = false;
        for (int i = 0; i < components.length; i++, stackSize++) {
            visitVarInsn(ALOAD, 2);
            if (components[i][0] != null) {
                visitLdcInsn(components[i][0]);
                visitLdcInsn(components[i][1]);
                pushByteConstant(mv, i);
                visitMethodInsn(INVOKEINTERFACE, CONTAINER_INTERNAL_NAME, GET_COMPONENT_BY_ID_NAME,
                        GET_COMPONENT_BY_ID_DESC, true);

                if (!increaseByOne) {
                    increaseByOne = true;
                }
            } else {
                visitLdcInsn(components[i][1]);
                pushByteConstant(mv, i);
                visitMethodInsn(INVOKEINTERFACE, CONTAINER_INTERNAL_NAME, GET_COMPONENT_BY_TYPE_NAME_NAME,
                        GET_COMPONENT_BY_TYPE_DESC, true);
            }
            visitTypeInsn(CHECKCAST, components[i][1].replace('.', '/'));
        }

        visitMethodInsn(Opcodes.INVOKESPECIAL, inspector.getInternalClassName(), inspector.getInjectorMethodName(),
                inspector.getInjectorMethodDesc(), false);

        visitLabel(l1);
        catchBlock();

        visitFrame(Opcodes.F_SAME, 0, null, 0, null);
        visitInsn(RETURN);
        visitMaxs(increaseByOne ? stackSize + 1 : stackSize, 4);
    }
}