scouter.agent.asm.AddFieldASM.java Source code

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Here is the source code for scouter.agent.asm.AddFieldASM.java

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/*
 *  Copyright 2015 the original author or authors. 
 *  @https://github.com/scouter-project/scouter
 *
 *  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 scouter.agent.asm;

import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import scouter.agent.ClassDesc;
import scouter.agent.Configure;
import scouter.agent.Logger;
import scouter.agent.asm.util.HookingSet;

import java.util.Map;

public class AddFieldASM implements IASM, Opcodes {
    public final Map<String, String> target = HookingSet.getClassFieldSet(Configure.getInstance().hook_add_fields);

    public AddFieldASM() {
    }

    Configure conf = Configure.getInstance();

    public ClassVisitor transform(ClassVisitor cv, String className, ClassDesc classDesc) {
        if (Configure.getInstance()._hook_async_enabled == false) {
            return cv;
        }
        String field = target.get(className);
        if (field != null) {
            return new AddFieldCV(cv, className, field);
        }
        return cv;
    }
}

class AddFieldCV extends ClassVisitor implements Opcodes {
    private String field;
    private String className;

    public AddFieldCV(ClassVisitor cv, String className, String field) {
        super(ASM7, cv);
        this.field = field;
        this.className = className;
    }

    boolean exist = false;

    @Override
    public void visit(int version, int access, String name, String signature, String superName,
            String[] interfaces) {
        super.visit(version, access, name, signature, superName, interfaces);
        if (exist == false) {
            super.visitField(ACC_PUBLIC, field, Type.getDescriptor(Object.class), null, null).visitEnd();
        }
    }

    @Override
    public FieldVisitor visitField(int access, String name, String desc, String signature, Object value) {
        if (name.equals(field)) {
            exist = true;
            Logger.println("A901", "fail to add the field " + name + " on " + className);
        }
        return super.visitField(access, name, desc, signature, value);
    }
}