OODeepCopy.m

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/*
 
OODeepCopy.m
 
 
Copyright (C) 2009-2013 Jens Ayton
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
 
*/
 
#import "OODeepCopy.h"
 
 
id OODeepCopy(id object)
{
    NSAutoreleasePool           *pool = nil;
    NSMutableSet                *objects = nil;
    
    if (object == nil)  return nil;
    
    pool = [[NSAutoreleasePool alloc] init];
    objects = [NSMutableSet set];
    
    object = [object ooDeepCopyWithSharedObjects:objects];
    
    [pool release];
    
    return object;
}
id OODeepCopy(id object) {…}
 
 
@implementation NSObject (OODeepCopy)
 
- (id) ooDeepCopyWithSharedObjects:(NSMutableSet *)objects
{
    if ([self conformsToProtocol:@protocol(NSCopying)])
    {
        return [self copy];
    }
    else
    {
        return [self retain];
    }
}
- (id) ooDeepCopyWithSharedObjects:(NSMutableSet *)objects {…}
 
@end
 
 
@implementation NSString (OODeepCopy)
 
- (id) ooDeepCopyWithSharedObjects:(NSMutableSet *)objects
{
    NSUInteger length = [self length];
    if (length == 0)  return [[NSString string] retain];
    if (length > 128)  return [self copy];
    
    id object = [objects member:self];
    if (object != nil && [object isKindOfClass:[NSString class]])
    {
        return [object retain];
    }
    else
    {
        object = [self copy];
        [objects addObject:object];
        return object;
    }
}
- (id) ooDeepCopyWithSharedObjects:(NSMutableSet *)objects {…}
 
@end
 
 
@implementation NSValue (OODeepCopy)    // Includes NSNumber
 
- (id) ooDeepCopyWithSharedObjects:(NSMutableSet *)objects
{
    id object = [objects member:self];
    if (object != nil && [object isKindOfClass:[NSValue class]])
    {
        return [object retain];
    }
    else
    {
        object = [self copy];
        [objects addObject:object];
        return object;
    }
}
- (id) ooDeepCopyWithSharedObjects:(NSMutableSet *)objects {…}
 
@end
 
 
@implementation NSArray (OODeepCopy)
 
- (id) ooDeepCopyWithSharedObjects:(NSMutableSet *)objects
{
    NSUInteger              i, count;
    id                      *members = NULL;
    NSArray                 *result = nil;
    BOOL                    tempObjects = NO;
    
    count = [self count];
    if (count == 0)  return [[NSArray array] retain];
    
    members = calloc(sizeof *members, count);
    if (members == NULL)
    {
        [NSException raise:NSMallocException format:@"Failed to allocate space for %lu objects in %s.", (unsigned long)count, __PRETTY_FUNCTION__];
    }
    
    // Ensure there's an objects set even if passed nil.
    if (objects == nil)
    {
        objects = [[NSMutableSet alloc] init];
        tempObjects = YES;
    }
    
    [self getObjects:members];
    @try
    {
        // Deep copy members.
        for (i = 0; i < count; i++)
        {
            members[i] = [members[i] ooDeepCopyWithSharedObjects:objects];
        }
        
        // Make NSArray of results.
        result = [[NSArray alloc] initWithObjects:members count:count];
    }
    @finally
    {
        // Release objects.
        for (i = 0; i < count; i++)
        {
            [members[i] release];
        }
        
        free(members);
        if (tempObjects)  [objects release];
    }
    
    // Collections are not reused because comparing them is arbitrarily slow.
    return result;
}
- (id) ooDeepCopyWithSharedObjects:(NSMutableSet *)objects {…}
 
@end
 
 
@implementation NSSet (OODeepCopy)
 
- (id) ooDeepCopyWithSharedObjects:(NSMutableSet *)objects
{
    NSUInteger              i, count;
    id                      *members = NULL;
    NSSet                   *result = nil;
    BOOL                    tempObjects = NO;
    
    count = [self count];
    if (count == 0)  return [[NSSet set] retain];
    
    members = malloc(sizeof *members * count);
    if (members == NULL)
    {
        [NSException raise:NSMallocException format:@"Failed to allocate space for %lu objects in %s.", (unsigned long)count, __PRETTY_FUNCTION__];
    }
    
    // Ensure there's an objects set even if passed nil.
    if (objects == nil)
    {
        objects = [[NSMutableSet alloc] init];
        tempObjects = YES;
    }
    
    @try
    {
        i = 0;
        id member = nil;
        // Deep copy members.
        foreach (member, self)
        {
            members[i] = [member ooDeepCopyWithSharedObjects:objects];
            i++;
        }
        
        // Make NSSet of results.
        result = [[NSSet alloc] initWithObjects:members count:count];
    }
    @finally
    {
        // Release objects.
        for (i = 0; i < count; i++)
        {
            [members[i] release];
        }
        
        free(members);
        if (tempObjects)  [objects release];
    }
    
    // Collections are not reused because comparing them is arbitrarily slow.
    return result;
}
- (id) ooDeepCopyWithSharedObjects:(NSMutableSet *)objects {…}
 
@end
 
 
@implementation NSDictionary (OODeepCopy)
 
- (id) ooDeepCopyWithSharedObjects:(NSMutableSet *)objects
{
    NSUInteger              i, count;
    id                      *keys = NULL;
    id                      *values = NULL;
    NSDictionary            *result = nil;
    BOOL                    tempObjects = NO;
    
    count = [self count];
    if (count == 0)  return [[NSDictionary dictionary] retain];
    
    keys = malloc(sizeof *keys * count);
    values = malloc(sizeof *values * count);
    if (keys == NULL || values == NULL)
    {
        free(keys);
        free(values);
        [NSException raise:NSMallocException format:@"Failed to allocate space for %lu objects in %s.", (unsigned long)count, __PRETTY_FUNCTION__];
    }
    
    // Ensure there's an objects set even if passed nil.
    if (objects == nil)
    {
        objects = [[NSMutableSet alloc] init];
        tempObjects = YES;
    }
    
    @try
    {
        i = 0;
        id key = nil;
        // Deep copy members.
        foreachkey (key, self)
        {
            keys[i] = [key ooDeepCopyWithSharedObjects:objects];
            values[i] = [[self objectForKey:key] ooDeepCopyWithSharedObjects:objects];
            i++;
        }
        
        // Make NSDictionary of results.
        result = [[NSDictionary alloc] initWithObjects:values forKeys:keys count:count];
    }
    @finally
    {
        // Release objects.
        for (i = 0; i < count; i++)
        {
            [keys[i] release];
            [values[i] release];
        }
        
        free(keys);
        free(values);
        if (tempObjects)  [objects release];
    }
    
    // Collections are not reused because comparing them is arbitrarily slow.
    return result;
}
- (id) ooDeepCopyWithSharedObjects:(NSMutableSet *)objects {…}
 
@end