scouter.agent.asm.ApicallSpringHandleResponseASM.java Source code

Introduction

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

Source

/*
 *  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 scouter.agent.ClassDesc;
import scouter.agent.Configure;
import scouter.agent.asm.util.AsmUtil;
import scouter.agent.asm.util.HookingSet;
import scouter.agent.trace.TraceApiCall;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.commons.LocalVariablesSorter;

import java.util.HashMap;
import java.util.Map;

public class ApicallSpringHandleResponseASM implements IASM, Opcodes {

    private Map<String, HookingSet> reserved = new HashMap<String, HookingSet>();

    public ApicallSpringHandleResponseASM() {
        AsmUtil.add(reserved, "org/springframework/web/client/RestTemplate",
                "handleResponse(Ljava/net/URI;Lorg/springframework/http/HttpMethod;Lorg/springframework/http/client/ClientHttpResponse;)V");
        AsmUtil.add(reserved, "org/springframework/web/client/AsyncRestTemplate",
                "handleResponseError(Lorg/springframework/http/HttpMethod;Ljava/net/URI;Lorg/springframework/http/client/ClientHttpResponse;)V");
        AsmUtil.add(reserved, "org/springframework/web/client/AsyncRestTemplate$ResponseExtractorFuture",
                "convertResponse(Lorg/springframework/http/client/ClientHttpResponse;)Ljava/lang/Object;");
    }

    @Override
    public ClassVisitor transform(ClassVisitor cv, String className, ClassDesc classDesc) {
        if (Configure.getInstance()._hook_apicall_enabled == false) {
            return cv;
        }

        HookingSet mset = reserved.get(className);
        if (mset != null)
            return new RestTemplateResponseHandlerCV(cv, mset, className);
        return cv;
    }
}

class RestTemplateResponseHandlerCV extends ClassVisitor implements Opcodes {
    public String className;
    private HookingSet mset;

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

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

        }
        if (AsmUtil.isSpecial(methodName)) {
            return mv;
        }
        return new RestTemplateResponseHandlerMV(access, methodName, desc, mv);
    }
}

class RestTemplateResponseHandlerMV extends LocalVariablesSorter implements Opcodes {
    private static final String TARGET = TraceApiCall.class.getName().replace('.', '/');
    private static final String START_METHOD = "setCalleeToCtxInSpringClientHttpResponse";
    private static final String START_SIGNATURE = "(Ljava/lang/Object;Ljava/lang/Object;)V";

    String name;
    String desc;
    int respIdx;

    public RestTemplateResponseHandlerMV(int access, String name, String desc, MethodVisitor mv) {
        super(ASM7, access, desc, mv);
        this.name = name;
        this.desc = desc;
        this.respIdx = AsmUtil.getIdxByType(access, desc,
                Type.getType("Lorg/springframework/http/client/ClientHttpResponse;"));
    }

    @Override
    public void visitCode() {
        mv.visitVarInsn(ALOAD, 0);
        mv.visitVarInsn(ALOAD, respIdx);
        mv.visitMethodInsn(Opcodes.INVOKESTATIC, TARGET, START_METHOD, START_SIGNATURE, false);

        mv.visitCode();
    }
}