8005801: Refactor findSetMethod
Summary: findSetMethod() was a very large single method, very unreadable and unmaintainable. It was broken into easy-to-understand pieces. The refactoring required introduction of a comand-object like entity, SetMethodCreator, to contain the nontrivial transient state of the algorithm that made the original big method so resistant to refactoring in the first place.
Reviewed-by: lagergren, sundar
--- a/nashorn/src/jdk/nashorn/internal/runtime/ScriptObject.java Tue Jan 08 13:50:11 2013 +0100
+++ b/nashorn/src/jdk/nashorn/internal/runtime/ScriptObject.java Tue Jan 08 14:14:17 2013 +0100
@@ -132,10 +132,11 @@
/** Indexed array data. */
private ArrayData arrayData;
- private static final MethodHandle SETEMBED = findOwnMH("setEmbed", void.class, CallSiteDescriptor.class, PropertyMap.class, PropertyMap.class, MethodHandle.class, int.class, Object.class, Object.class);
- private static final MethodHandle SETSPILL = findOwnMH("setSpill", void.class, CallSiteDescriptor.class, PropertyMap.class, PropertyMap.class, int.class, Object.class, Object.class);
- private static final MethodHandle SETSPILLWITHNEW = findOwnMH("setSpillWithNew", void.class, CallSiteDescriptor.class, PropertyMap.class, PropertyMap.class, int.class, Object.class, Object.class);
- private static final MethodHandle SETSPILLWITHGROW = findOwnMH("setSpillWithGrow", void.class, CallSiteDescriptor.class, PropertyMap.class, PropertyMap.class, int.class, int.class, Object.class, Object.class);
+ static final MethodHandle SETEMBED = findOwnMH("setEmbed", void.class, CallSiteDescriptor.class, PropertyMap.class, PropertyMap.class, MethodHandle.class, int.class, Object.class, Object.class);
+ static final MethodHandle SETSPILL = findOwnMH("setSpill", void.class, CallSiteDescriptor.class, PropertyMap.class, PropertyMap.class, int.class, Object.class, Object.class);
+ static final MethodHandle SETSPILLWITHNEW = findOwnMH("setSpillWithNew", void.class, CallSiteDescriptor.class, PropertyMap.class, PropertyMap.class, int.class, Object.class, Object.class);
+ static final MethodHandle SETSPILLWITHGROW = findOwnMH("setSpillWithGrow", void.class, CallSiteDescriptor.class, PropertyMap.class, PropertyMap.class, int.class, int.class, Object.class, Object.class);
+
private static final MethodHandle TRUNCATINGFILTER = findOwnMH("truncatingFilter", Object[].class, int.class, Object[].class);
private static final MethodHandle KNOWNFUNCPROPGUARD = findOwnMH("knownFunctionPropertyGuard", boolean.class, Object.class, PropertyMap.class, MethodHandle.class, Object.class, ScriptFunction.class);
@@ -218,13 +219,14 @@
}
/**
- * Bind the method handle to the specified receiver.
+ * Bind the method handle to the specified receiver, while preserving its original type (it will just ignore the
+ * first argument in lieu of the bound argument).
* @param methodHandle Method handle to bind to.
* @param receiver Object to bind.
* @return Bound method handle.
*/
- private static MethodHandle bindTo(final MethodHandle methodHandle, final Object receiver) {
- return MH.dropArguments(MH.bindTo(methodHandle, receiver), 0, Object.class);
+ static MethodHandle bindTo(final MethodHandle methodHandle, final Object receiver) {
+ return MH.dropArguments(MH.bindTo(methodHandle, receiver), 0, methodHandle.type().parameterType(0));
}
/**
@@ -1724,138 +1726,43 @@
* @return GuardedInvocation to be invoked at call site.
*/
protected GuardedInvocation findSetMethod(final CallSiteDescriptor desc, final boolean megaMorphic) {
- final String name = desc.getNameToken(2);
+ final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
if(megaMorphic) {
return findMegaMorphicSetMethod(desc, name);
}
- final MethodType callType = desc.getMethodType();
- final PropertyMap oldMap = getMap();
- final Class<?> type = callType.parameterType(1);
-
FindProperty find = findProperty(name, true);
- if (!isScope()) {
- // not a scope search. We don't want any inherited a property
- // unless it happens to be a user defined accessor property.
- if (find != null && find.isInherited()) {
- final Property inherited = find.getProperty();
- if (!(inherited instanceof UserAccessorProperty)) {
- // we should only use inherited user accessor property
- find = null;
- // but we should still check if inherited data property is not writable!
- if (isExtensible() && !inherited.isWritable()) {
- if (NashornCallSiteDescriptor.isStrict(desc)) {
- typeError(Context.getGlobal(), "property.not.writable", name, ScriptRuntime.safeToString((this)));
- }
- assert !NashornCallSiteDescriptor.isFastScope(desc);
- return new GuardedInvocation(Lookup.EMPTY_SETTER, oldMap.getProtoGetSwitchPoint(name),
- NashornGuards.getMapGuard(oldMap));
- }
- }
+ // If it's not a scope search, then we don't want any inherited properties except those with user defined accessors.
+ if (!isScope() && find != null && find.isInherited() && !(find.getProperty() instanceof UserAccessorProperty)) {
+ // We should still check if inherited data property is not writable
+ if (isExtensible() && !find.isWritable()) {
+ return createEmptySetMethod(desc, "property.not.writable", false);
}
+ // Otherwise, forget the found property
+ find = null;
}
- MethodHandle methodHandle = null;
- Property property = null;
- int invokeFlags = 0;
-
if (find != null) {
- if (!find.isWritable()) {
- if (NashornCallSiteDescriptor.isStrict(desc)) {
- typeError(Context.getGlobal(), "property.not.writable", name, ScriptRuntime.safeToString(this));
- }
-
- return new GuardedInvocation(Lookup.EMPTY_SETTER, oldMap.getProtoGetSwitchPoint(name),
- NashornGuards.getMapGuard(oldMap));
- }
-
- property = find.getProperty();
- methodHandle = find.getSetter(type, NashornCallSiteDescriptor.isStrict(desc));
-
- assert methodHandle != null;
- assert property != null;
-
- final ScriptFunction setter = find.getSetterFunction();
-
- invokeFlags = 0;
- if (setter != null && setter.isStrict()) {
- invokeFlags = NashornCallSiteDescriptor.CALLSITE_STRICT;
- }
-
- if (!property.hasSetterFunction() && find.isInherited()) {
- methodHandle = bindTo(methodHandle, find.getOwner());
+ if(!find.isWritable()) {
+ // Existing, non-writable property
+ return createEmptySetMethod(desc, "property.not.writable", true);
}
} else if (!isExtensible()) {
- if (NashornCallSiteDescriptor.isStrict(desc)) {
- typeError(Context.getGlobal(), "object.non.extensible", name, ScriptRuntime.safeToString(this));
- }
-
- assert !NashornCallSiteDescriptor.isFastScope(desc);
- return new GuardedInvocation(Lookup.EMPTY_SETTER, oldMap.getProtoGetSwitchPoint(name), NashornGuards.getMapGuard(oldMap));
+ // Non-existing property on a non-extensible object
+ return createEmptySetMethod(desc, "object.non.extensible", false);
}
- if (methodHandle == null) {
- // In strict mode, assignment can not create a new variable.
- // See also ECMA Annex C item 4. ReferenceError is thrown.
- if (NashornCallSiteDescriptor.isScope(desc) && NashornCallSiteDescriptor.isStrict(desc)) {
- referenceError(Context.getGlobal(), "not.defined", name);
- }
-
- if (isScope()) {
- final ScriptObject global = Context.getGlobal();
- methodHandle = global.addSpill(name);
- methodHandle = bindTo(methodHandle, global);
- } else {
- int i = findEmbed();
-
- if (i >= EMBED_SIZE) {
- i = oldMap.getSpillLength();
-
- final MethodHandle getter =
- MH.asType(
- MH.insertArguments(
- MH.arrayElementGetter(Object[].class),
- 1,
- i),
- Lookup.GET_OBJECT_TYPE);
- final MethodHandle setter =
- MH.asType(
- MH.insertArguments(
- MH.arrayElementSetter(Object[].class),
- 1,
- i),
- Lookup.SET_OBJECT_TYPE);
-
- property = new SpillProperty(name, Property.IS_SPILL, i, getter, setter);
-
- final PropertyMap newMap = oldMap.addProperty(property);
-
- i = property.getSlot();
-
- if (spill == null) {
- methodHandle = MH.insertArguments(SETSPILLWITHNEW, 0, desc, oldMap, newMap, i);
- } else if (i < spill.length) {
- methodHandle = MH.insertArguments(SETSPILL, 0, desc, oldMap, newMap, i);
- } else {
- final int newLength = (i + SPILL_RATE) / SPILL_RATE * SPILL_RATE;
- methodHandle = MH.insertArguments(SETSPILLWITHGROW, 0, desc, oldMap, newMap, i, newLength);
- }
- } else {
- useEmbed(i);
- property = new SpillProperty(name, 0, i, GET_EMBED[i], SET_EMBED[i]);
- final PropertyMap newMap = oldMap.addProperty(property);
- //TODO specfields
- methodHandle = MH.insertArguments(SETEMBED, 0, desc, oldMap, newMap, property.getSetter(Object.class, getMap()), i);
- }
-
- notifyPropertyAdded(this, property);
- }
- }
-
- // the guard has to use old map because the setter is valid only for incoming object with this map
- return new NashornGuardedInvocation(methodHandle, null, ObjectClassGenerator.OBJECT_FIELDS_ONLY &&
- NashornCallSiteDescriptor.isFastScope(desc) && (property == null || !property.canChangeType()) ?
- null : NashornGuards.getMapGuard(oldMap), invokeFlags);
+ return new SetMethodCreator(this, find, desc).createGuardedInvocation();
+ }
+
+ private GuardedInvocation createEmptySetMethod(final CallSiteDescriptor desc, String strictErrorMessage, boolean canBeFastScope) {
+ final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
+ if (NashornCallSiteDescriptor.isStrict(desc)) {
+ typeError(Context.getGlobal(), strictErrorMessage, name, ScriptRuntime.safeToString((this)));
+ }
+ assert canBeFastScope || !NashornCallSiteDescriptor.isFastScope(desc);
+ final PropertyMap map = getMap();
+ return new GuardedInvocation(Lookup.EMPTY_SETTER, map.getProtoGetSwitchPoint(name), NashornGuards.getMapGuard(map));
}
@SuppressWarnings("unused")
@@ -2169,7 +2076,7 @@
return spillProperty.getSetter(type, getMap()); //TODO specfields
}
- private MethodHandle addSpill(final String key) {
+ MethodHandle addSpill(final String key) {
return addSpill(key, 0);
}
@@ -3216,8 +3123,8 @@
/** Embed offset */
public static final int EMBED_OFFSET = 32 - EMBED_SIZE;
- private static final MethodHandle[] GET_EMBED;
- private static final MethodHandle[] SET_EMBED;
+ static final MethodHandle[] GET_EMBED;
+ static final MethodHandle[] SET_EMBED;
static {
GET_EMBED = new MethodHandle[EMBED_SIZE];
@@ -3230,11 +3137,11 @@
}
}
- private void useEmbed(final int i) {
+ void useEmbed(final int i) {
flags |= 1 << (EMBED_OFFSET + i);
}
- private int findEmbed() {
+ int findEmbed() {
final int bits = ~(flags >>> EMBED_OFFSET);
final int least = bits ^ -bits;
final int index = Integer.numberOfTrailingZeros(least) - 1;
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/src/jdk/nashorn/internal/runtime/SetMethodCreator.java Tue Jan 08 14:14:17 2013 +0100
@@ -0,0 +1,236 @@
+/*
+ * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.nashorn.internal.runtime;
+
+import static jdk.nashorn.internal.runtime.ECMAErrors.referenceError;
+import static jdk.nashorn.internal.runtime.linker.Lookup.MH;
+
+import java.lang.invoke.MethodHandle;
+
+import jdk.nashorn.internal.codegen.objects.ObjectClassGenerator;
+import jdk.nashorn.internal.runtime.linker.Lookup;
+import jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor;
+import jdk.nashorn.internal.runtime.linker.NashornGuardedInvocation;
+import jdk.nashorn.internal.runtime.linker.NashornGuards;
+
+import org.dynalang.dynalink.CallSiteDescriptor;
+import org.dynalang.dynalink.linker.GuardedInvocation;
+
+/**
+ * Instances of this class are quite ephemeral; they only exist for the duration of an invocation of
+ * {@link ScriptObject#findSetMethod(CallSiteDescriptor, boolean)} and serve as the actual encapsulation of the
+ * algorithm for creating an appropriate property setter method.
+ */
+class SetMethodCreator {
+ // See constructor parameters for description of fields
+ private final ScriptObject sobj;
+ private final PropertyMap map;
+ private final FindProperty find;
+ private final CallSiteDescriptor desc;
+
+ /**
+ * Creates a new property setter method creator.
+ * @param sobj the object for which we're creating the property setter
+ * @param find a result of a {@link ScriptObject#findProperty(String, boolean)} on the object for the property we
+ * want to create a setter for. Can be null if the property does not yet exist on the object.
+ * @param desc the descriptor of the call site that triggered the property setter lookup
+ */
+ SetMethodCreator(final ScriptObject sobj, final FindProperty find, final CallSiteDescriptor desc) {
+ this.sobj = sobj;
+ this.map = sobj.getMap();
+ this.find = find;
+ this.desc = desc;
+ }
+
+ private String getName() {
+ return desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
+ }
+
+ private PropertyMap getMap() {
+ return map;
+ }
+
+ /**
+ * Creates the actual guarded invocation that represents the dynamic setter method for the property.
+ * @return the actual guarded invocation that represents the dynamic setter method for the property.
+ */
+ GuardedInvocation createGuardedInvocation() {
+ return createSetMethod().createGuardedInvocation();
+ }
+
+ /**
+ * This class encapsulates the results of looking up a setter method; it's basically a triple of a method hanle,
+ * a Property object, and flags for invocation.
+ *
+ */
+ private class SetMethod {
+ private final MethodHandle methodHandle;
+ private final Property property;
+ private final int invokeFlags;
+
+ /**
+ * Creates a new lookup result.
+ * @param methodHandle the actual method handle
+ * @param property the property object. Can be null in case we're creating a new property in the global object.
+ * @param invokeFlags flags for the invocation. Normally either 0, or
+ * {@link NashornCallSiteDescriptor#CALLSITE_STRICT} when an existing property with a strict function for a
+ * property setter is discovered.
+ */
+ SetMethod(final MethodHandle methodHandle, final Property property, final int invokeFlags) {
+ assert methodHandle != null;
+ this.methodHandle = methodHandle;
+ this.property = property;
+ this.invokeFlags = invokeFlags;
+ }
+
+ /**
+ * Composes from its components an actual guarded invocation that represents the dynamic setter method for the property.
+ * @return the composed guarded invocation that represents the dynamic setter method for the property.
+ */
+ GuardedInvocation createGuardedInvocation() {
+ return new NashornGuardedInvocation(methodHandle, null, getGuard(), invokeFlags);
+ }
+
+ private MethodHandle getGuard() {
+ return needsNoGuard() ? null : NashornGuards.getMapGuard(getMap());
+ }
+
+ private boolean needsNoGuard() {
+ return NashornCallSiteDescriptor.isFastScope(desc) &&
+ (ObjectClassGenerator.OBJECT_FIELDS_ONLY || isPropertyTypeStable());
+ }
+
+ private boolean isPropertyTypeStable() {
+ return property == null || !property.canChangeType();
+ }
+ }
+
+ private SetMethod createSetMethod() {
+ if (find != null) {
+ return createExistingPropertySetter();
+ }
+
+ checkStrictCreateNewVariable();
+
+ if (sobj.isScope()) {
+ return createGlobalPropertySetter();
+ }
+
+ return createNewPropertySetter();
+ }
+
+ private void checkStrictCreateNewVariable() {
+ // In strict mode, assignment can not create a new variable.
+ // See also ECMA Annex C item 4. ReferenceError is thrown.
+ if (NashornCallSiteDescriptor.isScope(desc) && NashornCallSiteDescriptor.isStrict(desc)) {
+ referenceError(Context.getGlobal(), "not.defined", getName());
+ }
+ }
+
+ private SetMethod createExistingPropertySetter() {
+ final Property property = find.getProperty();
+ final Class<?> type = desc.getMethodType().parameterType(1);
+ final MethodHandle methodHandle = find.getSetter(type, NashornCallSiteDescriptor.isStrict(desc));
+
+ assert methodHandle != null;
+ assert property != null;
+
+ final MethodHandle boundHandle;
+ if (!property.hasSetterFunction() && find.isInherited()) {
+ boundHandle = ScriptObject.bindTo(methodHandle, find.getOwner());
+ } else {
+ boundHandle = methodHandle;
+ }
+ return new SetMethod(boundHandle, property, getExistingPropertySetterInvokeFlags());
+ }
+
+ private int getExistingPropertySetterInvokeFlags() {
+ final ScriptFunction setter = find.getSetterFunction();
+ if (setter != null && setter.isStrict()) {
+ return NashornCallSiteDescriptor.CALLSITE_STRICT;
+ }
+ return 0;
+ }
+
+ private SetMethod createGlobalPropertySetter() {
+ final ScriptObject global = Context.getGlobal();
+ return new SetMethod(ScriptObject.bindTo(global.addSpill(getName()), global), null, 0);
+ }
+
+ private SetMethod createNewPropertySetter() {
+ final int nextEmbed = sobj.findEmbed();
+ final SetMethod sm;
+ if (nextEmbed >= ScriptObject.EMBED_SIZE) {
+ sm = createNewSpillPropertySetter();
+ } else {
+ sm = createNewEmbedPropertySetter(nextEmbed);
+ }
+
+ sobj.notifyPropertyAdded(sobj, sm.property);
+ return sm;
+ }
+
+ private SetMethod createNewSpillPropertySetter() {
+ final int nextSpill = getMap().getSpillLength();
+
+ final Property property = createSpillProperty(nextSpill);
+ return new SetMethod(createSpillMethodHandle(nextSpill, property), property, 0);
+ }
+
+ private Property createSpillProperty(final int nextSpill) {
+ final MethodHandle getter = MH.asType(MH.insertArguments(MH.arrayElementGetter(Object[].class), 1, nextSpill), Lookup.GET_OBJECT_TYPE);
+ final MethodHandle setter = MH.asType(MH.insertArguments(MH.arrayElementSetter(Object[].class), 1, nextSpill), Lookup.SET_OBJECT_TYPE);
+
+ return new SpillProperty(getName(), Property.IS_SPILL, nextSpill, getter, setter);
+ }
+
+ private MethodHandle createSpillMethodHandle(final int nextSpill, Property property) {
+ final PropertyMap oldMap = getMap();
+ final PropertyMap newMap = getNewMap(property);
+
+ final Object[] spill = sobj.spill;
+ if (spill == null) {
+ return MH.insertArguments(ScriptObject.SETSPILLWITHNEW, 0, desc, oldMap, newMap, nextSpill);
+ } else if (nextSpill < spill.length) {
+ return MH.insertArguments(ScriptObject.SETSPILL, 0, desc, oldMap, newMap, nextSpill);
+ } else {
+ final int newLength = (nextSpill + ScriptObject.SPILL_RATE) / ScriptObject.SPILL_RATE * ScriptObject.SPILL_RATE;
+ return MH.insertArguments(ScriptObject.SETSPILLWITHGROW, 0, desc, oldMap, newMap, nextSpill, newLength);
+ }
+ }
+
+ private SetMethod createNewEmbedPropertySetter(final int nextEmbed) {
+ sobj.useEmbed(nextEmbed);
+ final Property property = new SpillProperty(getName(), 0, nextEmbed, ScriptObject.GET_EMBED[nextEmbed], ScriptObject.SET_EMBED[nextEmbed]);
+ //TODO specfields
+ final MethodHandle methodHandle = MH.insertArguments(ScriptObject.SETEMBED, 0, desc, getMap(), getNewMap(property), property.getSetter(Object.class, getMap()), nextEmbed);
+ return new SetMethod(methodHandle, property, 0);
+ }
+
+ private PropertyMap getNewMap(Property property) {
+ return getMap().addProperty(property);
+ }
+}
--- a/nashorn/src/jdk/nashorn/internal/runtime/SpillProperty.java Tue Jan 08 13:50:11 2013 +0100
+++ b/nashorn/src/jdk/nashorn/internal/runtime/SpillProperty.java Tue Jan 08 14:14:17 2013 +0100
@@ -43,7 +43,7 @@
private static final MethodHandle SPILLGETTER = MH.asType(MH.getter(MethodHandles.lookup(), ScriptObject.class, "spill", Object[].class), Lookup.GET_OBJECT_TYPE);
/** Property slot in spill */
- int slot;
+ private final int slot;
/**
* Constructor
--- a/nashorn/src/jdk/nashorn/internal/runtime/linker/Mangler.java Tue Jan 08 13:50:11 2013 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,140 +0,0 @@
-/*
- * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation. Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code 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
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package jdk.nashorn.internal.runtime.linker;
-
-import java.util.Arrays;
-
-/**
- * Used to mangle java visible names. Currently used only to transform script file
- * name to be safely used as part of generated Script class name.
- */
-public class Mangler {
- /** Beginning of escape sequence (mu as in municode.) */
- private static final char ESCAPE = '\u03BC';
-
- /** Hexadecimal base. */
- private static final char hexBase = 'A';
-
- /** Hexadecimal characters. */
- private static final char[] hexCharacters = new char[] {
- '0',
- '1',
- '2',
- '3',
- '4',
- '5',
- '6',
- '7',
- '8',
- '9',
- hexBase + 0,
- hexBase + 1,
- hexBase + 2,
- hexBase + 3,
- hexBase + 4,
- hexBase + 5
- };
-
- private Mangler() {
- }
-
- /**
- * Mangles a user supplied name so it is java identifier safe.
- * @param name Name to be mangled
- * @return Mangled name or null if not mangled.
- */
- public static String mangle(final String name) {
- final int length = name.length();
- final char[] buffer = new char[length * 5];
- boolean mangled = false;
- int pos = 0;
-
- for (int i = 0; i < length; i++) {
- final char ch = name.charAt(i);
-
- if (! Character.isJavaIdentifierPart(ch)) {
- buffer[pos++] = ESCAPE;
- buffer[pos++] = hexCharacters[(ch >>> 12) & 0xF];
- buffer[pos++] = hexCharacters[(ch >>> 8) & 0xF];
- buffer[pos++] = hexCharacters[(ch >>> 4) & 0xF];
- buffer[pos++] = hexCharacters[ ch & 0xF];
- mangled = true;
- } else if (ch == ESCAPE) {
- buffer[pos++] = ESCAPE;
- buffer[pos++] = ESCAPE;
- mangled = true;
- } else {
- buffer[pos++] = ch;
- }
- }
-
- return mangled ? new String(Arrays.copyOf(buffer, pos)) : null;
- }
-
- /**
- * Convert a character to a hexadecimal digit. Assumes [0-9A-F].
- * @param ch Character to convert.
- * @return Hexadecimal digit.
- */
- private static int fromHex(final char ch) {
- return ch >= hexBase ? ch - hexBase + 10 : ch - '0';
- }
-
- /**
- * Unmangles a name. Assumes name mangled by this package.
- * @param name Mangled name.
- * @return Unmangled name.
- */
- public static String unmangle(final String name) {
- final int length = name.length();
- char[] buffer = new char[length];
- int pos = 0;
-
- for (int i = 0; i < length; ) {
- char ch = name.charAt(i++);
-
- if (ch == ESCAPE) {
- final char ch0 = name.charAt(i++);
-
- if (ch0 == ESCAPE) {
- // pass thru
- } else {
- final char ch1 = name.charAt(i++);
- final char ch2 = name.charAt(i++);
- final char ch3 = name.charAt(i++);
-
- ch = (char)(fromHex(ch0) << 12 | fromHex(ch1) << 8 | fromHex(ch2) << 4 | fromHex(ch3));
- }
- }
-
- buffer[pos++] = ch;
- }
-
- buffer = Arrays.copyOf(buffer, pos);
-
- return new String(buffer);
- }
-}