platform-impl/src/com/intellij/util/InstanceofCheckerGeneratorImpl.java

   1 /*
   2  * Copyright (c) 2000-2005 by JetBrains s.r.o. All Rights Reserved.
   3  * Use is subject to license terms.
   4  */
   5 package com.intellij.util;
   6
   7 import com.intellij.openapi.util.Condition;
   8 import com.intellij.util.containers.ConcurrentFactoryMap;
   9 import net.sf.cglib.asm.ClassVisitor;
  10 import net.sf.cglib.asm.Label;
  11 import net.sf.cglib.asm.Type;
  12 import net.sf.cglib.core.*;
  13
  14 import java.lang.reflect.Modifier;
  15
  16 /**
  17  * @author peter
  18  */
  19 public class InstanceofCheckerGeneratorImpl extends InstanceofCheckerGenerator {
  20   private final ConcurrentFactoryMap<Class, Condition<Object>> myCache = new ConcurrentFactoryMap<Class, Condition<Object>>() {
  21     @Override
  22     protected Condition<Object> create(Class key) {
  23       return new InstanceofClassGenerator(key).createClass();
  24     }
  25   };
  26
  27   public Condition<Object> getInstanceofChecker(final Class<?> someClass) {
  28     return myCache.get(someClass);
  29   }
  30
  31   private static String toInternalName(Class<?> someClass) {
  32     return someClass.getName().replace('.', '/');
  33   }
  34
  35   private static class InstanceofClassGenerator extends AbstractClassGenerator {
  36     private static final Source SOURCE = new Source("IntellijInstanceof");
  37     private final Class<?> myCheckedClass;
  38
  39     public InstanceofClassGenerator(Class<?> checkedClass) {
  40       super(SOURCE);
  41       myCheckedClass = checkedClass;
  42     }
  43
  44     @Override
  45     protected ClassLoader getDefaultClassLoader() {
  46       return myCheckedClass.getClassLoader();
  47     }
  48
  49     public Condition<Object> createClass() {
  50       return (Condition<Object>)super.create(myCheckedClass);
  51     }
  52
  53     @Override
  54     protected Object firstInstance(Class type) throws Exception {
  55       return type.newInstance();
  56     }
  57
  58     @Override
  59     protected Object nextInstance(Object instance) throws Exception {
  60       return instance;
  61     }
  62
  63     public void generateClass(ClassVisitor classVisitor) throws Exception {
  64       ClassEmitter cv = new ClassEmitter(classVisitor);
  65
  66       cv.visit(Constants.V1_2, Modifier.PUBLIC, "com/intellij/util/InstanceofChecker$$$$$" + myCheckedClass.getName().replace('.', '$'), toInternalName(Object.class), new String[]{toInternalName(Condition.class)}, Constants.SOURCE_FILE);
  67       final Signature signature = new Signature("<init>", "()V");
  68       final CodeEmitter cons = cv.begin_method(Modifier.PUBLIC, signature, new Type[0], null);
  69       cons.load_this();
  70       cons.dup();
  71       cons.super_invoke_constructor(signature);
  72       cons.return_value();
  73       cons.end_method();
  74
  75       final CodeEmitter e = cv.begin_method(Modifier.PUBLIC, new Signature("value", "(L" + toInternalName(Object.class) + ";)Z"), new Type[0], null);
  76       e.load_arg(0);
  77       e.instance_of(Type.getType(myCheckedClass));
  78
  79       Label fail = e.make_label();
  80       e.if_jump(CodeEmitter.EQ, fail);
  81       e.push(true);
  82       e.return_value();
  83
  84       e.mark(fail);
  85       e.push(false);
  86       e.return_value();
  87       e.end_method();
  88
  89       cv.visitEnd();
  90     }
  91   }
  92 }