[1.7.0-feature] ASM示例

Author: crazyqiang

lib_bytecode/src/main/groovy/com.performance.optimize/ATransform.groovy

@@ -3,8 +3,8 @@ package com.performance.optimize
 import com.android.build.api.transform.*
 import com.android.build.gradle.internal.pipeline.TransformManager
 import groovy.io.FileType
-import org.ninetripods.lib_bytecode.asm.AClassVisitor
 import org.ninetripods.lib_bytecode.BConstant
+import org.ninetripods.lib_bytecode.asm.demo.ATimeCostClassVisitor
 import org.objectweb.asm.ClassReader
 import org.objectweb.asm.ClassVisitor
 import org.objectweb.asm.ClassWriter
@@ -28,21 +28,43 @@ class ATransform extends Transform {
                 File dir = dInput.file
                 if (dir) {
                     dir.traverse(type: FileType.FILES, nameFilter: ~/.*\.class/) { File file ->
+                        /**
+                         * 1、ClassReader: 它负责读取我们传入的类文件中的字节流数据，并提供解析流中包含的一切类属性信息的操作。
+                         * 2、ClassVisitor: 当在 accept 方法中 ClassVisitor 访问 ClassReader 时，ClassReader 便会先开始字节码的解析工作，并将保存在内存中的结果源源不断地通过调用各种 visitxxx 方法传入到 ClassVisitor 之中。
+                         * 3、ClassWriter: 是 ClassVisitor 的一个子类，它并不会储存信息，而是马上会将传入的信息转译成字节码，并在之后随时输出它们。
+                         */
                         ClassReader classReader = new ClassReader(file.bytes)
-                        ClassVisitor classVisitor = new AClassVisitor(BConstant.ASM9, new ClassWriter(ClassWriter.COMPUTE_MAXS))
+                        //ClassWriter.COMPUTE_MAXS 自动计算帧栈信息（操作数栈 & 局部变量表）
+                        //ClassVisitor classVisitor = new AClassVisitor(BConstant.ASM9, new ClassWriter(ClassWriter.COMPUTE_MAXS))
+                        ClassVisitor classVisitor = new ATimeCostClassVisitor(BConstant.ASM9, new ClassWriter(classReader,ClassWriter.COMPUTE_FRAMES))
+                        //访问者模式：将ClassVisitor传入ClassReader中，从而可以访问ClassReader中的私有信息；类似一个接口回调。
                         classReader.accept(classVisitor, ClassReader.EXPAND_FRAMES)
                         System.out.println("find class: " + file.name)
                     }
                 }
-
                 //处理完文件把输出传给下一个文件
                 def dest = invocation.outputProvider.getContentLocation(dInput.name,
                         dInput.contentTypes, dInput.scopes, Format.DIRECTORY)
                 FileUtils.copyDirectory(dInput.file, dest)
             }
 
             //jarInputs表示以jar包方式参与项目编译的文件
-            input.jarInputs.each { JarInput jarInput -> }
+//            input.jarInputs.each { JarInput jarInput ->
+//                File jar = jarInput.file
+//                if (jar) {
+//                    jar.traverse(type: FileType.FILES, nameFilter: ~/.*\.class/) { File file ->
+//                        ClassReader classReader = new ClassReader(file.bytes)
+//                        ClassVisitor classVisitor = new AClassVisitor(BConstant.ASM9, new ClassWriter(ClassWriter.COMPUTE_MAXS))
+//                        classReader.accept(classVisitor, ClassReader.EXPAND_FRAMES)
+//                        System.out.println("find class1: " + file.name)
+//                    }
+//                }
+//
+//                //处理完文件把输出传给下一个文件
+//                def dest = invocation.outputProvider.getContentLocation(dInput.name,
+//                        dInput.contentTypes, dInput.scopes, Format.DIRECTORY)
+//                FileUtils.copyDirectory(dInput.file, dest)
+//            }
         }
     }
 

lib_bytecode/src/main/java/org/ninetripods/lib_bytecode/asm/demo/AAdviceAdapter.kt

@@ -107,11 +107,28 @@ class CustomAdviceAdapter(
         super.visitFieldInsn(opcode, owner, name, descriptor)
     }
 
+    override fun visitVarInsn(opcode: Int, `var`: Int) {
+        super.visitVarInsn(opcode, `var`)
+    }
+
     override fun onMethodEnter() {
         log("onMethodEnter():")
+        /**
+         * @see FIELD_NAME_ADD
+         * 1、访问FIELD_NAME_ADD变量
+         */
         mv.visitFieldInsn(GETSTATIC, owner, FIELD_NAME_ADD, "J")
+        /**
+         * 2、System.currentTimeMillis()
+         */
         mv.visitMethodInsn(INVOKESTATIC, "java/lang/System", "currentTimeMillis", "()J", false)
+        /**
+         * 上述1、2步的值进行相减
+         */
         mv.visitInsn(LSUB)
+        /**
+         * @see FIELD_NAME_ADD 将相减的结果重新赋值给变量FIELD_NAME_ADD
+         */
         mv.visitFieldInsn(PUTSTATIC, owner, FIELD_NAME_ADD, "J")
     }
 

lib_bytecode/src/main/java/org/ninetripods/lib_bytecode/asm/demo/ATimeCostClassVisitor.kt

@@ -7,7 +7,7 @@ import org.objectweb.asm.ClassWriter
 import org.objectweb.asm.Opcodes.*
 
 /**
- * ASM使用示例
+ * ASM自动生成代码示例
  */
 object ProduceClz {
 
@@ -22,20 +22,20 @@ object ProduceClz {
 
     /**
      * 产生类
-    package pkg;
-    public interface Comparable extends Mesurable {
-    int LESS = -1;
-    int EQUAL = 0;
-    int GREATER = 1;
-    int compareTo(Object o);
-    }
+      package pkg;
+      public interface Comparable extends Measurable {
+         int LESS = -1;
+         int EQUAL = 0;
+         int GREATER = 1;
+         int compareTo(Object o);
+      }
      */
     private fun produceClass() {
         val cw = ClassWriter(0)
         //access：修饰字段
         //signature: 泛型
         cw.visit(V1_8, ACC_PUBLIC + ACC_ABSTRACT + ACC_INTERFACE,
-            "pkg/Comparable", null, "java/lang/Object", arrayOf("pkg/Mesurable"))
+            "pkg/Comparable", null, "java/lang/Object", arrayOf("pkg/Measurable"))
         cw.visitField(ACC_PUBLIC + ACC_FINAL + ACC_STATIC, "LESS", "I",
             null, -1).visitEnd()
         cw.visitField(ACC_PUBLIC + ACC_FINAL + ACC_STATIC, "EQUAL", "I",
@@ -46,6 +46,6 @@ object ProduceClz {
         cw.visitMethod(ACC_PUBLIC + ACC_ABSTRACT, "compareTo",
             "(Ljava/lang/Object;)I", null, null).visitEnd()
         cw.visitEnd()
-        FileUtil.byte2File("AndroidStudy/build/demo/GenerAuto.java",cw.toByteArray())
+        FileUtil.byte2File("lib_bytecode/files/Comparable.class",cw.toByteArray())
     }
 }

lib_bytecode/src/main/java/org/ninetripods/lib_bytecode/asm/demo/ProduceClz.kt

@@ -15,6 +15,7 @@ object FileUtil {
             if (file.exists()) {
                 file.delete()
             } else {
+                file.parentFile.mkdir()
                 file.createNewFile()
             }