scouter.agent.asm.CapThisASM.java Source code

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Here is the source code for scouter.agent.asm.CapThisASM.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.MethodVisitor;
import org.objectweb.asm.Opcodes;
import scouter.agent.ClassDesc;
import scouter.agent.Configure;
import scouter.agent.asm.util.AsmUtil;
import scouter.agent.asm.util.HookingSet;
import scouter.agent.trace.TraceMain;

import java.util.List;

public class CapThisASM implements IASM, Opcodes {
    private List<HookingSet> target = HookingSet
            .getHookingMethodSet(Configure.getInstance().hook_constructor_patterns);

    public ClassVisitor transform(ClassVisitor cv, String className, ClassDesc classDesc) {
        if (Configure.getInstance()._hook_cap_enabled == false) {
            return cv;
        }
        for (int i = 0; i < target.size(); i++) {
            HookingSet mset = target.get(i);
            if (mset.classMatch.include(className)) {
                return new CapThisCV(cv, mset, className);
            }
        }
        return cv;
    }
}

// ///////////////////////////////////////////////////////////////////////////
class CapThisCV extends ClassVisitor implements Opcodes {

    private HookingSet mset;
    private String className;

    public CapThisCV(ClassVisitor cv, HookingSet mset, String className) {
        super(ASM7, cv);
        this.mset = mset;
        this.className = className;
    }

    @Override
    public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
        MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
        if (mv == null || mset.isA(name, desc) == false) {
            return mv;
        }
        return new CapThisMV(className, desc, mv);
    }
}

// ///////////////////////////////////////////////////////////////////////////
class CapThisMV extends MethodVisitor implements Opcodes {
    private static final String CLASS = TraceMain.class.getName().replace('.', '/');
    private static final String METHOD = "capThis";
    private static final String SIGNATURE = "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/Object;)V";

    private String className;
    private String methodDesc;

    public CapThisMV(String classname, String methoddesc, MethodVisitor mv) {
        super(ASM7, mv);
        this.className = classname;
        this.methodDesc = methoddesc;
    }

    @Override
    public void visitInsn(int opcode) {
        if ((opcode >= IRETURN && opcode <= RETURN) || opcode == ATHROW) {
            AsmUtil.PUSH(mv, className);
            AsmUtil.PUSH(mv, methodDesc);
            mv.visitVarInsn(Opcodes.ALOAD, 0);
            mv.visitMethodInsn(Opcodes.INVOKESTATIC, CLASS, METHOD, SIGNATURE, false);
        }
        mv.visitInsn(opcode);
    }
}