libs-base/Source/NSKeyedUnarchiver.m

/** Implementation for NSKeyedUnarchiver for GNUstep
   Copyright (C) 2004 Free Software Foundation, Inc.

   Written by:  Richard Frith-Macdonald <rfm@gnu.org>
   Date: January 2004

   This file is part of the GNUstep Base Library.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 31 Milk Street #960789 Boston, MA 02196 USA.

   */

#import "common.h"
#define	EXPOSE_NSKeyedUnarchiver_IVARS	1
#import "Foundation/NSAutoreleasePool.h"
#import "Foundation/NSData.h"
#import "Foundation/NSDictionary.h"
#import "Foundation/NSException.h"
#import "Foundation/NSMapTable.h"
#import "Foundation/NSNull.h"
#import "Foundation/NSValue.h"

#import "GSPrivate.h"

/*
 *      Setup for inline operation of arrays.
 */
#define GSI_ARRAY_RETAIN(A, X)	[(X).obj retain]
#define GSI_ARRAY_RELEASE(A, X)	[(X).obj release]
#define GSI_ARRAY_TYPES GSUNION_OBJ


#include "GNUstepBase/GSIArray.h"

#define	_IN_NSKEYEDUNARCHIVER_M	1
#import "Foundation/NSKeyedArchiver.h"
#undef	_IN_NSKEYEDUNARCHIVER_M

@interface NilMarker: NSObject
@end
@implementation NilMarker
@end

static NSMapTable	*globalClassMap = 0;

#define	GETVAL \
  id		o; \
  \
  if ([aKey isKindOfClass: [NSString class]] == NO) \
    { \
      [NSException raise: NSInvalidArgumentException \
		  format: @"%@, bad key '%@' in %@", \
	NSStringFromClass([self class]), aKey, NSStringFromSelector(_cmd)]; \
    } \
  if ([aKey hasPrefix: @"$"] == YES) \
    { \
      aKey = [@"$" stringByAppendingString: aKey]; \
    } \
  o = [_keyMap objectForKey: aKey];



@interface NSKeyedUnarchiver (Private)
- (id) _decodeObject: (unsigned)index;
@end

@implementation NSKeyedUnarchiver (Internal)
/**
 * Internal method used to decode an array relatively efficiently.<br />
 * Some MacOS-X library classes seem to use this.
 */
- (id) _decodeArrayOfObjectsForKey: (NSString*)aKey
{
  id	o = [_keyMap objectForKey: aKey];

  if (o != nil)
    {
      if ([o isKindOfClass: [NSArray class]] == YES)
	{
	  unsigned		c = [o count];
	  NSMutableArray	*m = [NSMutableArray arrayWithCapacity: c];
	  unsigned		i;

	  for (i = 0; i < c; i++)
	    {
	      unsigned	ref;
	      id	val;

	      ref = [[[o objectAtIndex: i] objectForKey: @"CF$UID"]
		unsignedIntValue];
	      val = [self _decodeObject: ref];
	      if (val == nil)
		{
		  [NSException raise:
		    NSInvalidUnarchiveOperationException
		    format: @"[%@ +%@]: decoded nil in array",
		    NSStringFromClass([self class]),
		    NSStringFromSelector(_cmd)];
		}
	      [m addObject: val];
	    }
	  o = m;
	}
      else
	{
	  o = nil;
	}
    }
  return o;
}

- (id) _decodePropertyListForKey: (NSString*)aKey
{
  id	o = [_keyMap objectForKey: aKey];

  return o;
}


/**
 * This method is used to replace oldObj with newObj
 * in the map that is maintained in NSKeyedUnarchiver.
 */
- (BOOL) replaceObject: (id)oldObj withObject: (id)newObj
{
  unsigned int i = 0;
  unsigned int count = GSIArrayCount(_objMap);
  for (i = 0; i < count; i++)
    {
      id obj = GSIArrayItemAtIndex(_objMap, i).obj;
      if (obj == oldObj)
        break;
    }

  if (i < count)
    {
      GSIArraySetItemAtIndex(_objMap, (GSIArrayItem)newObj, i);
      return YES;
    }

  return NO;
}
@end

@implementation NSKeyedUnarchiver (Private)
- (id) _decodeObject: (unsigned)index
{
  id	o;
  id	obj;

  /*
   * If the referenced object is already in _objMap
   * we simply return it (the object at index 0 maps to nil)
   */
  obj = GSIArrayItemAtIndex(_objMap, index).obj;
  if (obj != nil)
    {
      if (obj == GSIArrayItemAtIndex(_objMap, 0).obj)
	{
	  return nil;
	}
      return obj;
    }

  /*
   * No mapped object, so we decode from the property list
   * in _objects
   */
  obj = [_objects objectAtIndex: index];
  if ([obj isKindOfClass: [NSDictionary class]] == YES)
    {
      NSString		*classname;
      NSArray		*classes;
      Class		c;
      id		r;
      NSDictionary	*savedKeyMap;
      unsigned		savedCursor;

      /*
       * Fetch the class information from the table.
       */
      o = [obj objectForKey: @"$class"];
      o = [o objectForKey: @"CF$UID"];
      o = [_objects objectAtIndex: [o intValue]];
      classname = [o objectForKey: @"$classname"];
      classes = [o objectForKey: @"$classes"];
      c = [self classForClassName: classname];
      if (c == nil)
	{
	  c = [[self class] classForClassName: classname];
	  if (c == nil)
	    {
	      c = NSClassFromString(classname);
	      if (c == nil)
		{
		  c = [_delegate unarchiver: self
		    cannotDecodeObjectOfClassName: classname
		    originalClasses: classes];
		  if (c == nil)
		    {
		      [NSException raise:
			NSInvalidUnarchiveOperationException
			format: @"[%@ +%@]: no class for name '%@'",
			NSStringFromClass([self class]),
			NSStringFromSelector(_cmd),
			classname];
		    }
		}
	    }
	}

      savedCursor = _cursor;
      savedKeyMap = _keyMap;

      _cursor = 0;			// Starting object decode
      _keyMap = obj;			// Dictionary describing object

      o = [c allocWithZone: _zone];	// Create instance.
      // Store object in map so that decoding of it can be self referential.
      GSIArraySetItemAtIndex(_objMap, (GSIArrayItem)o, index);
      r = [o initWithCoder: self];
      if (r != o)
	{
	  [_delegate unarchiver: self
	      willReplaceObject: o
		     withObject: r];
	  o = r;
	  GSIArraySetItemAtIndex(_objMap, (GSIArrayItem)o, index);
	}
      r = [o awakeAfterUsingCoder: self];
      if (r != o)
	{
	  [_delegate unarchiver: self
	      willReplaceObject: o
		     withObject: r];
	  o = r;
	  GSIArraySetItemAtIndex(_objMap, (GSIArrayItem)o, index);
	}

      if (_delegate != nil)
	{
	  r = [_delegate unarchiver: self didDecodeObject: o];
	  /* Apple documentation says that the delegate may return nil to
	   * indicate that the decoded objects should not be changed.
	   */
	  if (r != nil && r != o)
	    {
	      [_delegate unarchiver: self
		  willReplaceObject: o
			 withObject: r];
	      o = RETAIN(r);
	      GSIArraySetItemAtIndex(_objMap, (GSIArrayItem)o, index);
	    }
	}
      RELEASE(o);	// Retained in array
      obj = o;
      _keyMap = savedKeyMap;
      _cursor = savedCursor;
    }
  else
    {
      // Use the decoded object directly
      GSIArraySetItemAtIndex(_objMap, (GSIArrayItem)obj, index);
    }

  if ((obj == nil) || [@"$null" isEqual: obj])
    {
      // Record NilMarker for decoded object.
      o = GSIArrayItemAtIndex(_objMap, 0).obj;
      GSIArraySetItemAtIndex(_objMap, (GSIArrayItem)o, index);
      obj = nil;
    }

  return obj;
}
@end


@implementation NSKeyedUnarchiver

+ (Class) classForClassName: (NSString*)aString
{
  return (Class)NSMapGet(globalClassMap, (void*)aString);
}

+ (void) initialize
{
  if (globalClassMap == 0)
    {
      globalClassMap =
	NSCreateMapTable(NSObjectMapKeyCallBacks,
			  NSNonOwnedPointerMapValueCallBacks, 0);
      [[NSObject leakAt: &globalClassMap] release];
    }
}

+ (void) setClass: (Class)aClass forClassName: (NSString*)aString
{
  if (aClass == nil)
    {
      NSMapRemove(globalClassMap, (void*)aString);
    }
  else
    {
      NSMapInsert(globalClassMap, (void*)aString, aClass);
    }
}

/*
 * When I tried this on MacOS 10.3 it encoded the object with the key 'root',
 * so this implementation does the same.
 */
+ (id) unarchiveObjectWithData: (NSData*)data
{
  NSKeyedUnarchiver	*u = nil;
  id			o = nil;

  NS_DURING
    {
      u = [[NSKeyedUnarchiver alloc] initForReadingWithData: data];
      o = RETAIN([u decodeObjectForKey: @"root"]);
      [u finishDecoding];
      DESTROY(u);
    }
  NS_HANDLER
    {
      DESTROY(u);
      DESTROY(o);
      [localException raise];
    }
  NS_ENDHANDLER
  return AUTORELEASE(o);
}

+ (id) unarchiveObjectWithFile: (NSString*)aPath
{
  NSData	*d;
  id		o;

  d = [NSData dataWithContentsOfFile: aPath];
  o = [self unarchiveObjectWithData: d];
  return o;
}

+ (id) unarchivedObjectOfClass: (Class)cls
                      fromData: (NSData*)data
                         error: (NSError**)error
{
  return [self unarchivedObjectOfClasses: [NSSet setWithObject:cls]
                                fromData: data
                                   error: error];
}

+ (id) unarchivedObjectOfClasses: (GS_GENERIC_CLASS(NSSet,Class)*)classes
                        fromData: (NSData*)data
                           error: (NSError**)error
{
  /* FIXME: implement proper secure coding support */
  return [self unarchiveObjectWithData: data];
}

+ (NSArray*) unarchivedArrayOfObjectsOfClass: (Class)cls
                                    fromData: (NSData*)data
                                       error: (NSError**)error
{
  return [self unarchivedArrayOfObjectsOfClasses: [NSSet setWithObject:cls]
                                        fromData: data
                                           error: error];
}

+ (NSArray*) unarchivedArrayOfObjectsOfClasses: (GS_GENERIC_CLASS(NSSet,Class)*)classes
                                      fromData: (NSData*)data
                                         error: (NSError**)error
{
  /* FIXME: implement proper secure coding support */
  return [self unarchiveObjectWithData: data];
}

+ (NSDictionary*) unarchivedDictionaryWithKeysOfClass: (Class)keyCls
                                       objectsOfClass: (Class)valueCls
                                             fromData: (NSData*)data
                                                error: (NSError**)error
{
  return [self unarchivedDictionaryWithKeysOfClasses: [NSSet setWithObject:keyCls]
                                    objectsOfClasses: [NSSet setWithObject:valueCls]
                                            fromData: data
                                               error: error];
}

+ (NSDictionary*) unarchivedDictionaryWithKeysOfClasses: (GS_GENERIC_CLASS(NSSet,Class)*)keyClasses
                                       objectsOfClasses: (GS_GENERIC_CLASS(NSSet,Class)*)valueClasses
                                               fromData: (NSData*)data
                                                  error: (NSError**)error
{
  /* FIXME: implement proper secure coding support */
  return [self unarchiveObjectWithData: data];
}


- (BOOL) allowsKeyedCoding
{
  return YES;
}

- (BOOL)requiresSecureCoding
{
  return _requiresSecureCoding;
}

- (void)setRequiresSecureCoding: (BOOL)secure
{
  _requiresSecureCoding = secure;
}

- (Class) classForClassName: (NSString*)aString
{
  return _clsMap == 0 ? Nil : (Class)NSMapGet(_clsMap, (void*)aString);
}

- (BOOL) containsValueForKey: (NSString*)aKey
{
  GETVAL
  if (o != nil)
    {
      return YES;
    }
  return NO;
}

- (void) dealloc
{
  DESTROY(_archive);
  if (_clsMap != 0)
    {
      NSFreeMapTable(_clsMap);
      _clsMap = 0;
    }
  if (_objMap != 0)
    {
      NSZone    *z = _objMap->zone;

      GSIArrayEmpty(_objMap);
      NSZoneFree(z, (void*)_objMap);
    }
  [super dealloc];
}

- (void) decodeArrayOfObjCType: (const char*)type
			 count: (NSUInteger)expected
			    at: (void*)buf
{
  id	 	o = [self decodeObject];
  NSUInteger	size;

  if ([o isKindOfClass: [_NSKeyedCoderOldStyleArray class]] == NO)
    {
      [NSException raise: NSInvalidUnarchiveOperationException
		  format: @"[%@ +%@]: value is '%@'",
	NSStringFromClass([self class]), NSStringFromSelector(_cmd), o];
    }
  if (strcmp([o type], type) != 0)
    {
      [NSException raise: NSInvalidUnarchiveOperationException
		  format: @"[%@ +%@]: type mismatch for %@",
	NSStringFromClass([self class]), NSStringFromSelector(_cmd), o];
    }
  if ([o count] != expected)
    {
      [NSException raise: NSInvalidUnarchiveOperationException
		  format: @"[%@ +%@]: count mismatch for %@",
	NSStringFromClass([self class]), NSStringFromSelector(_cmd), o];
    }
  NSGetSizeAndAlignment(type, &size, NULL);
  memcpy(buf, [o bytes], expected * size);
}

- (BOOL) decodeBoolForKey: (NSString*)aKey
{
  NSString	*oldKey = aKey;
  GETVAL
  if (o != nil)
    {
      if ([o isKindOfClass: [NSNumber class]] == YES)
	{
	  return [o boolValue];
	}
      else
	{
	  [NSException raise: NSInvalidUnarchiveOperationException
		      format: @"[%@ +%@]: value for key(%@) is '%@'",
	    NSStringFromClass([self class]), NSStringFromSelector(_cmd),
	    oldKey, o];
	}
    }
  return NO;
}

- (const uint8_t*) decodeBytesForKey: (NSString*)aKey
		      returnedLength: (NSUInteger*)length
{
  NSString	*oldKey = aKey;
  GETVAL
  if (o != nil)
    {
      if ([o isKindOfClass: [NSData class]] == YES)
	{
	  *length = [o length];
	  return [o bytes];
	}
      else
	{
	  [NSException raise: NSInvalidUnarchiveOperationException
		      format: @"[%@ +%@]: value for key(%@) is '%@'",
	    NSStringFromClass([self class]), NSStringFromSelector(_cmd),
	    oldKey, o];
	}
    }
  *length = 0;
  return 0;
}

- (double) decodeDoubleForKey: (NSString*)aKey
{
  NSString	*oldKey = aKey;
  GETVAL
  if (o != nil)
    {
      if ([o isKindOfClass: [NSNumber class]] == YES)
	{
	  return [o doubleValue];
	}
      else
	{
	  [NSException raise: NSInvalidUnarchiveOperationException
		      format: @"[%@ +%@]: value for key(%@) is '%@'",
	    NSStringFromClass([self class]), NSStringFromSelector(_cmd),
	    oldKey, o];
	}
    }
  return 0.0;
}

- (float) decodeFloatForKey: (NSString*)aKey
{
  NSString	*oldKey = aKey;
  GETVAL
  if (o != nil)
    {
      if ([o isKindOfClass: [NSNumber class]] == YES)
	{
	  return [o floatValue];
	}
      else
	{
	  [NSException raise: NSInvalidUnarchiveOperationException
		      format: @"[%@ +%@]: value for key(%@) is '%@'",
	    NSStringFromClass([self class]), NSStringFromSelector(_cmd),
	    oldKey, o];
	}
    }
  return 0.0;
}

- (int) decodeIntForKey: (NSString*)aKey
{
  int64_t	i = [self decodeInt64ForKey: aKey];

#if	(INT_MAX < INT64_MAX)
  if (i > INT_MAX || i < INT_MIN)
    {
      [NSException raise: NSRangeException
	format: @"[%@ +%@]: value %"PRIu64" for key(%@) is out of range",
        NSStringFromClass([self class]), NSStringFromSelector(_cmd), i, aKey];
    }
#endif
  return (int)i;
}

- (NSInteger) decodeIntegerForKey: (NSString*)aKey
{
  int64_t	i = [self decodeInt64ForKey: aKey];

/* Older Solaris systems define INTPTR_MAX incorrectly ... so we use the
 * void pointer size we determined at configure time to decide whether
 * we need to check for overflow.
 */
#if	(GS_SIZEOF_VOIDP < 8)
  if (i > INT32_MAX || i < INT32_MIN)
    {
      [NSException raise: NSRangeException
	          format: @"[%@ +%@]: value for key(%@) is out of range",
	NSStringFromClass([self class]), NSStringFromSelector(_cmd), aKey];
    }
#endif
  return (NSInteger)i;
}

- (int32_t) decodeInt32ForKey: (NSString*)aKey
{
  int64_t	i = [self decodeInt64ForKey: aKey];

  if (i > INT32_MAX || i < INT32_MIN)
    {
      [NSException raise: NSRangeException
	format: @"[%@ +%@]: value %"PRIu64" for key(%@) is out of range",
	NSStringFromClass([self class]), NSStringFromSelector(_cmd), i, aKey];
    }
  return (int32_t)i;
}

- (int64_t) decodeInt64ForKey: (NSString*)aKey
{
  NSString	*oldKey = aKey;
  GETVAL
  if (o != nil)
    {
      if ([o isKindOfClass: [NSNumber class]] == YES)
	{
	  long long	l = [o longLongValue];

	  return l;
	}
      else
	{
	  [NSException raise: NSInvalidUnarchiveOperationException
		      format: @"[%@ +%@]: value for key(%@) is '%@'",
	    NSStringFromClass([self class]), NSStringFromSelector(_cmd),
	    oldKey, o];
	}
    }
  return 0;
}

- (id) decodeObject
{
  NSString	*key = [NSString stringWithFormat: @"$%d", _cursor++];
  NSNumber	*pos;
  id		o = [_keyMap objectForKey: key];

  if (o != nil)
    {
      if ([o isKindOfClass: [NSDictionary class]] == YES
	&& (pos = [o objectForKey: @"CF$UID"]) != nil)
	{
	  int	index = [pos intValue];

	  return [self _decodeObject: index];
	}
      else
	{
	  [NSException raise: NSInvalidUnarchiveOperationException
		      format: @"[%@ +%@]: value for key(%@) is '%@'",
	    NSStringFromClass([self class]), NSStringFromSelector(_cmd),
	    key, o];
	}
    }
  return nil;
}

- (id) decodeObjectForKey: (NSString*)aKey
{
  NSString	*oldKey = aKey;
  GETVAL
  if (o != nil)
    {
      NSNumber	*pos;

      if ([o isKindOfClass: [NSDictionary class]] == YES
	&& (pos = [o objectForKey: @"CF$UID"]) != nil)
	{
	  int	index = [pos intValue];

	  return [self _decodeObject: index];
	}
      else
	{
	  [NSException raise: NSInvalidUnarchiveOperationException
		      format: @"[%@ +%@]: value for key(%@) is '%@'",
	    NSStringFromClass([self class]), NSStringFromSelector(_cmd),
	    oldKey, o];
	}
    }
  return nil;
}

- (id) decodeObjectOfClasses: (NSSet *)classes forKey: (NSString *)key
{
  return [self decodeObjectForKey: key];
}

- (NSPoint) decodePoint
{
  NSPoint	p;

  [self decodeValueOfObjCType: @encode(CGFloat) at: &p.x];
  [self decodeValueOfObjCType: @encode(CGFloat) at: &p.y];
  return p;
}

- (NSRect) decodeRect
{
  NSRect	r;

  [self decodeValueOfObjCType: @encode(CGFloat) at: &r.origin.x];
  [self decodeValueOfObjCType: @encode(CGFloat) at: &r.origin.y];
  [self decodeValueOfObjCType: @encode(CGFloat) at: &r.size.width];
  [self decodeValueOfObjCType: @encode(CGFloat) at: &r.size.height];
  return r;
}

- (NSSize) decodeSize
{
  NSSize	s;

  [self decodeValueOfObjCType: @encode(CGFloat) at: &s.width];
  [self decodeValueOfObjCType: @encode(CGFloat) at: &s.height];
  return s;
}

- (void) decodeValueOfObjCType: (const char*)type
			    at: (void*)address
{
  NSString	*aKey;
  id		o;

  if (*type == _C_ID || *type == _C_CLASS
    || *type == _C_SEL || *type == _C_CHARPTR)
    {
      o = [self decodeObject];
      if (*type == _C_ID || *type == _C_CLASS)
	{
	  *(id*)address = RETAIN(o);
	}
      else if (*type == _C_SEL)
	{
	  *(SEL*)address = NSSelectorFromString(o);
	}
      else if (*type == _C_CHARPTR)
	{
	  *(const char**)address = [o cString];
	}
      return;
    }

  aKey = [NSString stringWithFormat: @"$%u", _cursor++];
  o = [_keyMap objectForKey: aKey];

  switch (*type)
    {
      case _C_CHR:
	*(char*)address = [o charValue];
	return;

      case _C_UCHR:
	*(unsigned char*)address = [o unsignedCharValue];
	return;

      case _C_SHT:
	*(short*)address = [o shortValue];
	return;

      case _C_USHT:
	*(unsigned short*)address = [o unsignedShortValue];
	return;

      case _C_INT:
	*(int*)address = [o intValue];
	return;

      case _C_UINT:
	*(unsigned int*)address = [o unsignedIntValue];
	return;

      case _C_LNG:
	*(long int*)address = [o longValue];
	return;

      case _C_ULNG:
	*(unsigned long int*)address = [o unsignedLongValue];
	return;

      case _C_LNG_LNG:
	*(long long int*)address = [o longLongValue];
	return;

      case _C_ULNG_LNG:
	*(unsigned long long int*)address = [o unsignedLongLongValue];
	return;

      case _C_FLT:
	*(float*)address = [o floatValue];
	return;

      case _C_DBL:
	*(double*)address = [o doubleValue];
	return;

#if defined(_C_BOOL) && (!defined(__GNUC__) || __GNUC__ > 2)
      case _C_BOOL:
	*(_Bool*)address = (_Bool)[o unsignedCharValue];
	return;
#endif

      case _C_STRUCT_B:
	[NSException raise: NSInvalidArgumentException
		    format: @"-[%@ %@]: this archiver cannote decode structs",
	  NSStringFromClass([self class]), NSStringFromSelector(_cmd)];
	return;

      case _C_ARY_B:
	{
	  int		count = atoi(++type);

	  while (isdigit(*type))
	    {
	      type++;
	    }
	  [self decodeArrayOfObjCType: type count: count at: address];
	}
	return;

      default:
	[NSException raise: NSInvalidArgumentException
		    format: @"-[%@ %@]: unknown type encoding ('%c')",
	  NSStringFromClass([self class]), NSStringFromSelector(_cmd), *type];
	break;
    }
}

- (id) delegate
{
  return _delegate;
}

- (NSString*) description
{
  if (_archive == nil)
    {
      // For consistency with OSX
      [NSException raise: NSInvalidArgumentException
		  format: @"method sent to uninitialised unarchiver"];
    }
  return [super description];
}

- (void) finishDecoding
{
  [_delegate unarchiverWillFinish: self];
  DESTROY(_archive);
  [_delegate unarchiverDidFinish: self];
}

- (id) init
{
  Class c = [self class];
  DESTROY(self);
  [NSException raise: NSInvalidArgumentException
              format: @"-[%@ init]: cannot use -init for initialisation",
              NSStringFromClass(c)];
  return nil;
}

- (id) initForReadingWithData: (NSData*)data
{
  self = [super init];
  if (self)
    {
      NSPropertyListFormat	format;
      NSString			*error;

      _zone = [self zone];
      _archive = [NSPropertyListSerialization propertyListFromData: data
	mutabilityOption: NSPropertyListImmutable
	format: &format
	errorDescription: &error];
      if (_archive == nil)
	{
	  DESTROY(self);
	}
      else
	{
	  unsigned	count;
	  unsigned	i;

	  IF_NO_ARC(RETAIN(_archive);)
	  _archiverClass = [_archive objectForKey: @"$archiver"];
	  _version = [_archive objectForKey: @"$version"];

	  _objects = [_archive objectForKey: @"$objects"];
	  _keyMap = [_archive objectForKey: @"$top"];
	  _objMap = NSZoneMalloc(_zone, sizeof(GSIArray_t));
	  count = [_objects count];
	  GSIArrayInitWithZoneAndCapacity(_objMap, _zone, count);
	  // Add marker for nil object
	  GSIArrayAddItem(_objMap, (GSIArrayItem)((id)[NilMarker class]));
	  // Add markers for unencoded objects.
	  for (i = 1; i < count; i++)
	    {
	      GSIArrayAddItem(_objMap, (GSIArrayItem)(id)nil);
	    }
	}
    }
  return self;
}

- (void) setClass: (Class)aClass forClassName: (NSString*)aString
{
  if (aString == nil)
    {
      if (_clsMap != 0)
	{
          NSMapRemove(_clsMap, (void*)aString);
	}
    }
  else
    {
      if (_clsMap == 0)
	{
	  _clsMap = NSCreateMapTable(NSObjectMapKeyCallBacks,
	    NSNonOwnedPointerMapValueCallBacks, 0);
	}
      NSMapInsert(_clsMap, (void*)aString, (void*)aClass);
    }
}

- (void) setDelegate: (id)delegate
{
  _delegate = delegate;		// Not retained.
}

- (NSInteger) versionForClassName: (NSString*)className
{
  return 0;	// Not used for keyed unarchiving.
}
@end

@implementation NSObject (NSKeyedUnarchiverDelegate)
/** <override-dummy />
 */
- (Class) unarchiver: (NSKeyedUnarchiver*)anUnarchiver
  cannotDecodeObjectOfClassName: (NSString*)aName
  originalClasses: (NSArray*)classNames
{
  return nil;
}
/** <override-dummy />
 */
- (id) unarchiver: (NSKeyedUnarchiver*)anUnarchiver
  didDecodeObject: (id)anObject
{
  return anObject;
}
/** <override-dummy />
 */
- (void) unarchiverDidFinish: (NSKeyedUnarchiver*)anUnarchiver
{
}
/** <override-dummy />
 */
- (void) unarchiverWillFinish: (NSKeyedUnarchiver*)anUnarchiver
{
}
/** <override-dummy />
 */
- (void) unarchiver: (NSKeyedUnarchiver*)anUnarchiver
  willReplaceObject: (id)anObject
	 withObject: (id)newObject
{
}
@end

@implementation NSObject (NSKeyedUnarchiverObjectSubstitution)
+ (Class) classForKeyedUnarchiver
{
  return self;
}
@end