ProtocolLib/ProtocolLib/src/main/java/com/comphenix/protocol/reflect/compiler/StructureCompiler.java

461 lines
17 KiB
Java

/*
* ProtocolLib - Bukkit server library that allows access to the Minecraft protocol.
* Copyright (C) 2012 Kristian S. Stangeland
*
* This program is free software; you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with this program;
* if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
* 02111-1307 USA
*/
package com.comphenix.protocol.reflect.compiler;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.comphenix.protocol.reflect.PrimitiveUtils;
import com.comphenix.protocol.reflect.StructureModifier;
import com.google.common.base.Objects;
import net.sf.cglib.asm.*;
// public class CompiledStructureModifierPacket20<TField> extends CompiledStructureModifier<TField> {
//
// private Packet20NamedEntitySpawn typedTarget;
//
// public CompiledStructureModifierPacket20(StructureModifier<TField> other, StructureCompiler compiler) {
// super();
// initialize(other);
// this.target = other.getTarget();
// this.typedTarget = (Packet20NamedEntitySpawn) target;
// this.compiler = compiler;
// }
//
// @Override
// protected Object readGenerated(int fieldIndex) throws FieldAccessException {
//
// Packet20NamedEntitySpawn target = typedTarget;
//
// switch (fieldIndex) {
// case 0: return (Object) target.a;
// case 1: return (Object) target.b;
// case 2: return (Object) target.c;
// case 3: return super.read(fieldIndex);
// case 4: return super.read(fieldIndex);
// case 5: return (Object) target.f;
// case 6: return (Object) target.g;
// case 7: return (Object) target.h;
// default:
// throw new FieldAccessException("Invalid index " + fieldIndex);
// }
// }
//
// @Override
// protected StructureModifier<TField> writeGenerated(int index, Object value) throws FieldAccessException {
//
// Packet20NamedEntitySpawn target = typedTarget;
//
// switch (index) {
// case 0: target.a = (Integer) value; break;
// case 1: target.b = (String) value; break;
// case 2: target.c = (Integer) value; break;
// case 3: target.d = (Integer) value; break;
// case 4: super.write(index, value); break;
// case 5: super.write(index, value); break;
// case 6: target.g = (Byte) value; break;
// case 7: target.h = (Integer) value; break;
// default:
// throw new FieldAccessException("Invalid index " + index);
// }
//
// // Chaining
// return this;
// }
// }
/**
* Represents a StructureModifier compiler.
*
* @author Kristian
*/
public final class StructureCompiler {
// Used to store generated classes of different types
@SuppressWarnings("rawtypes")
private class StructureKey {
private Class targetType;
private Class fieldType;
public StructureKey(Class targetType, Class fieldType) {
this.targetType = targetType;
this.fieldType = fieldType;
}
@Override
public int hashCode() {
return Objects.hashCode(targetType, fieldType);
}
@Override
public boolean equals(Object obj) {
if (obj instanceof StructureKey) {
StructureKey other = (StructureKey) obj;
return Objects.equal(targetType, other.targetType) &&
Objects.equal(fieldType, other.fieldType);
}
return false;
}
}
// Used to load classes
private volatile static Method defineMethod;
@SuppressWarnings("rawtypes")
private Map<StructureKey, Class> compiledCache = new HashMap<StructureKey, Class>();
// The class loader we'll store our classes
private ClassLoader loader;
// References to other classes
private static String PACKAGE_NAME = "com/comphenix/protocol/reflect/compiler";
private static String SUPER_CLASS = "com/comphenix/protocol/reflect/StructureModifier";
private static String COMPILED_CLASS = PACKAGE_NAME + "/CompiledStructureModifier";
private static String FIELD_EXCEPTION_CLASS = "com/comphenix/protocol/reflect/FieldAccessException";
/**
* Construct a structure compiler.
* @param loader - main class loader.
*/
StructureCompiler(ClassLoader loader) {
this.loader = loader;
}
/**
* Compiles the given structure modifier.
* <p>
* WARNING: Do NOT call this method in the main thread. Compiling may easily take 10 ms, which is already
* over 1/4 of a tick (50 ms). Let the background thread automatically compile the structure modifiers instead.
* @param source - structure modifier to compile.
* @return A compiled structure modifier.
*/
@SuppressWarnings("unchecked")
public synchronized <TField> StructureModifier<TField> compile(StructureModifier<TField> source) {
// We cannot optimize a structure modifier with no public fields
if (!isAnyPublic(source.getFields())) {
return source;
}
StructureKey key = new StructureKey(source.getTargetType(), source.getFieldType());
Class<?> compiledClass = compiledCache.get(key);
if (!compiledCache.containsKey(key)) {
compiledClass = generateClass(source);
compiledCache.put(key, compiledClass);
}
// Next, create an instance of this class
try {
return (StructureModifier<TField>) compiledClass.getConstructor(
StructureModifier.class, StructureCompiler.class).
newInstance(source, this);
} catch (IllegalArgumentException e) {
throw new IllegalStateException("Used invalid parameters in instance creation", e);
} catch (SecurityException e) {
throw new RuntimeException("Security limitation!", e);
} catch (InstantiationException e) {
throw new RuntimeException("Error occured while instancing generated class.", e);
} catch (IllegalAccessException e) {
throw new RuntimeException("Security limitation! Cannot create instance of dynamic class.", e);
} catch (InvocationTargetException e) {
throw new RuntimeException("Error occured while instancing generated class.", e);
} catch (NoSuchMethodException e) {
throw new IllegalStateException("Cannot happen.", e);
}
}
private <TField> Class<?> generateClass(StructureModifier<TField> source) {
ClassWriter cw = new ClassWriter(0);
@SuppressWarnings("rawtypes")
Class targetType = source.getTargetType();
String className = "CompiledStructure$" + targetType.getSimpleName() + source.getFieldType().getSimpleName();
String targetSignature = Type.getDescriptor(targetType);
String targetName = targetType.getName().replace('.', '/');
try {
// This class might have been generated before. Try to load it.
Class<?> before = loader.loadClass(PACKAGE_NAME.replace('/', '.') + "." + className);
if (before != null)
return before;
} catch (ClassNotFoundException e) {
// That's ok.
}
cw.visit(Opcodes.V1_6, Opcodes.ACC_PUBLIC + Opcodes.ACC_SUPER, PACKAGE_NAME + "/" + className,
"<TField:Ljava/lang/Object;>L" + COMPILED_CLASS + "<TTField;>;",
COMPILED_CLASS, null);
createFields(cw, targetSignature);
createConstructor(cw, className, targetSignature, targetName);
createReadMethod(cw, className, source.getFields(), targetSignature, targetName);
createWriteMethod(cw, className, source.getFields(), targetSignature, targetName);
cw.visitEnd();
byte[] data = cw.toByteArray();
// Call the define method
try {
if (defineMethod == null) {
Method defined = ClassLoader.class.getDeclaredMethod("defineClass",
new Class<?>[] { String.class, byte[].class, int.class, int.class });
// Awesome. Now, create and return it.
defined.setAccessible(true);
defineMethod = defined;
}
@SuppressWarnings("rawtypes")
Class clazz = (Class) defineMethod.invoke(loader, null, data, 0, data.length);
// DEBUG CODE: Print the content of the generated class.
//org.objectweb.asm.ClassReader cr = new org.objectweb.asm.ClassReader(data);
//cr.accept(new ASMifierClassVisitor(new PrintWriter(System.out)), 0);
return clazz;
} catch (SecurityException e) {
throw new RuntimeException("Cannot use reflection to dynamically load a class.", e);
} catch (NoSuchMethodException e) {
throw new IllegalStateException("Incompatible JVM.", e);
} catch (IllegalArgumentException e) {
throw new IllegalStateException("Cannot call defineMethod - wrong JVM?", e);
} catch (IllegalAccessException e) {
throw new RuntimeException("Security limitation! Cannot dynamically load class.", e);
} catch (InvocationTargetException e) {
throw new RuntimeException("Error occured in code generator.", e);
}
}
/**
* Determine if at least one of the given fields is public.
* @param fields - field to test.
* @return TRUE if one or more field is publically accessible, FALSE otherwise.
*/
private boolean isAnyPublic(List<Field> fields) {
// Are any of the fields public?
for (int i = 0; i < fields.size(); i++) {
if (isPublic(fields.get(i))) {
return true;
}
}
return false;
}
private boolean isPublic(Field field) {
return Modifier.isPublic(field.getModifiers());
}
private void createFields(ClassWriter cw, String targetSignature) {
FieldVisitor typedField = cw.visitField(Opcodes.ACC_PRIVATE, "typedTarget", targetSignature, null, null);
typedField.visitEnd();
}
private void createWriteMethod(ClassWriter cw, String className, List<Field> fields, String targetSignature, String targetName) {
String methodDescriptor = "(ILjava/lang/Object;)L" + SUPER_CLASS + ";";
String methodSignature = "(ITTField;)L" + SUPER_CLASS + "<TTField;>;";
MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PROTECTED, "writeGenerated", methodDescriptor, methodSignature,
new String[] { FIELD_EXCEPTION_CLASS });
BoxingHelper boxingHelper = new BoxingHelper(mv);
mv.visitCode();
mv.visitVarInsn(Opcodes.ALOAD, 0);
mv.visitFieldInsn(Opcodes.GETFIELD, PACKAGE_NAME + "/" + className, "typedTarget", targetSignature);
mv.visitVarInsn(Opcodes.ASTORE, 3);
mv.visitVarInsn(Opcodes.ILOAD, 1);
// The last label is for the default switch
Label[] labels = new Label[fields.size()];
Label errorLabel = new Label();
Label returnLabel = new Label();
// Generate labels
for (int i = 0; i < fields.size(); i++) {
labels[i] = new Label();
}
mv.visitTableSwitchInsn(0, labels.length - 1, errorLabel, labels);
for (int i = 0; i < fields.size(); i++) {
Class<?> outputType = fields.get(i).getType();
Class<?> inputType = PrimitiveUtils.wrap(outputType);
String typeDescriptor = Type.getDescriptor(outputType);
String inputPath = inputType.getName().replace('.', '/');
mv.visitLabel(labels[i]);
// Push the compare object
if (i == 0)
mv.visitFrame(Opcodes.F_APPEND, 1, new Object[] { targetName }, 0, null);
else
mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
// Only write to public fields
if (isPublic(fields.get(i))) {
mv.visitVarInsn(Opcodes.ALOAD, 3);
mv.visitVarInsn(Opcodes.ALOAD, 2);
if (!PrimitiveUtils.isPrimitive(outputType))
mv.visitTypeInsn(Opcodes.CHECKCAST, inputPath);
else
boxingHelper.unbox(Type.getType(outputType));
mv.visitFieldInsn(Opcodes.PUTFIELD, targetName, fields.get(i).getName(), typeDescriptor);
} else {
// Use reflection. We don't have a choice, unfortunately.
mv.visitVarInsn(Opcodes.ALOAD, 0);
mv.visitVarInsn(Opcodes.ILOAD, 1);
mv.visitVarInsn(Opcodes.ALOAD, 2);
mv.visitMethodInsn(Opcodes.INVOKESPECIAL, COMPILED_CLASS, "write", "(ILjava/lang/Object;)L" + SUPER_CLASS + ";");
mv.visitInsn(Opcodes.POP);
}
mv.visitJumpInsn(Opcodes.GOTO, returnLabel);
}
mv.visitLabel(errorLabel);
mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
mv.visitTypeInsn(Opcodes.NEW, FIELD_EXCEPTION_CLASS);
mv.visitInsn(Opcodes.DUP);
mv.visitTypeInsn(Opcodes.NEW, "java/lang/StringBuilder");
mv.visitInsn(Opcodes.DUP);
mv.visitLdcInsn("Invalid index ");
mv.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "(Ljava/lang/String;)V");
mv.visitVarInsn(Opcodes.ILOAD, 1);
mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(I)Ljava/lang/StringBuilder;");
mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;");
mv.visitMethodInsn(Opcodes.INVOKESPECIAL, FIELD_EXCEPTION_CLASS, "<init>", "(Ljava/lang/String;)V");
mv.visitInsn(Opcodes.ATHROW);
mv.visitLabel(returnLabel);
mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
mv.visitVarInsn(Opcodes.ALOAD, 0);
mv.visitInsn(Opcodes.ARETURN);
mv.visitMaxs(5, 4);
mv.visitEnd();
}
private void createReadMethod(ClassWriter cw, String className, List<Field> fields, String targetSignature, String targetName) {
MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PROTECTED, "readGenerated", "(I)Ljava/lang/Object;", null,
new String[] { "com/comphenix/protocol/reflect/FieldAccessException" });
BoxingHelper boxingHelper = new BoxingHelper(mv);
mv.visitCode();
mv.visitVarInsn(Opcodes.ALOAD, 0);
mv.visitFieldInsn(Opcodes.GETFIELD, PACKAGE_NAME + "/" + className, "typedTarget", targetSignature);
mv.visitVarInsn(Opcodes.ASTORE, 2);
mv.visitVarInsn(Opcodes.ILOAD, 1);
// The last label is for the default switch
Label[] labels = new Label[fields.size()];
Label errorLabel = new Label();
// Generate labels
for (int i = 0; i < fields.size(); i++) {
labels[i] = new Label();
}
mv.visitTableSwitchInsn(0, fields.size() - 1, errorLabel, labels);
for (int i = 0; i < fields.size(); i++) {
Class<?> outputType = fields.get(i).getType();
String typeDescriptor = Type.getDescriptor(outputType);
mv.visitLabel(labels[i]);
// Push the compare object
if (i == 0)
mv.visitFrame(Opcodes.F_APPEND, 1, new Object[] { targetName }, 0, null);
else
mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
// Note that byte code cannot access non-public fields
if (isPublic(fields.get(i))) {
mv.visitVarInsn(Opcodes.ALOAD, 2);
mv.visitFieldInsn(Opcodes.GETFIELD, targetName, fields.get(i).getName(), typeDescriptor);
boxingHelper.box(Type.getType(outputType));
} else {
// We have to use reflection for private and protected fields.
mv.visitVarInsn(Opcodes.ALOAD, 0);
mv.visitVarInsn(Opcodes.ILOAD, 1);
mv.visitMethodInsn(Opcodes.INVOKESPECIAL, COMPILED_CLASS, "read", "(I)Ljava/lang/Object;");
}
mv.visitInsn(Opcodes.ARETURN);
}
mv.visitLabel(errorLabel);
mv.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
mv.visitTypeInsn(Opcodes.NEW, FIELD_EXCEPTION_CLASS);
mv.visitInsn(Opcodes.DUP);
mv.visitTypeInsn(Opcodes.NEW, "java/lang/StringBuilder");
mv.visitInsn(Opcodes.DUP);
mv.visitLdcInsn("Invalid index ");
mv.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "(Ljava/lang/String;)V");
mv.visitVarInsn(Opcodes.ILOAD, 1);
mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(I)Ljava/lang/StringBuilder;");
mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;");
mv.visitMethodInsn(Opcodes.INVOKESPECIAL, FIELD_EXCEPTION_CLASS, "<init>", "(Ljava/lang/String;)V");
mv.visitInsn(Opcodes.ATHROW);
mv.visitMaxs(5, 3);
mv.visitEnd();
}
private void createConstructor(ClassWriter cw, String className, String targetSignature, String targetName) {
MethodVisitor mv = cw.visitMethod(Opcodes.ACC_PUBLIC, "<init>",
"(L" + SUPER_CLASS + ";L" + PACKAGE_NAME + "/StructureCompiler;)V",
"(L" + SUPER_CLASS + "<TTField;>;L" + SUPER_CLASS + ";)V", null);
mv.visitCode();
mv.visitVarInsn(Opcodes.ALOAD, 0);
mv.visitMethodInsn(Opcodes.INVOKESPECIAL, COMPILED_CLASS, "<init>", "()V");
mv.visitVarInsn(Opcodes.ALOAD, 0);
mv.visitVarInsn(Opcodes.ALOAD, 1);
mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, PACKAGE_NAME + "/" + className, "initialize", "(L" + SUPER_CLASS + ";)V");
mv.visitVarInsn(Opcodes.ALOAD, 0);
mv.visitVarInsn(Opcodes.ALOAD, 1);
mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, SUPER_CLASS, "getTarget", "()Ljava/lang/Object;");
mv.visitFieldInsn(Opcodes.PUTFIELD, PACKAGE_NAME + "/" + className, "target", "Ljava/lang/Object;");
mv.visitVarInsn(Opcodes.ALOAD, 0);
mv.visitVarInsn(Opcodes.ALOAD, 0);
mv.visitFieldInsn(Opcodes.GETFIELD, PACKAGE_NAME + "/" + className, "target", "Ljava/lang/Object;");
mv.visitTypeInsn(Opcodes.CHECKCAST, targetName);
mv.visitFieldInsn(Opcodes.PUTFIELD, PACKAGE_NAME + "/" + className, "typedTarget", targetSignature);
mv.visitVarInsn(Opcodes.ALOAD, 0);
mv.visitVarInsn(Opcodes.ALOAD, 2);
mv.visitFieldInsn(Opcodes.PUTFIELD, PACKAGE_NAME + "/" + className, "compiler", "L" + PACKAGE_NAME + "/StructureCompiler;");
mv.visitInsn(Opcodes.RETURN);
mv.visitMaxs(2, 3);
mv.visitEnd();
}
}