1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
/* Implementation of QuickSort for GNUStep
Copyright (C) 2005-2012 Free Software Foundation, Inc.
Written by: Saso Kiselkov <diablos@manga.sk>
Date: 2005
Modified by: Niels Grewe <niels.grewe@halbordnung.de>
Date: September 2012
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., 51 Franklin Street, Fifth Floor,
Boston, MA 02110 USA.
*/
#import "common.h"
#import "Foundation/NSSortDescriptor.h"
#import "Foundation/NSArray.h"
#import "Foundation/NSObjCRuntime.h"
#import "GSSorting.h"
/**
* Sorts the provided object array's sortRange according to sortDescriptor.
*/
// Quicksort algorithm copied from Wikipedia :-).
static inline void
SwapObjects(id * o1, id * o2)
{
id temp;
temp = *o1;
*o1 = *o2;
*o2 = temp;
}
static void
_GSQuickSort(id *objects,
NSRange sortRange,
id comparisonEntity,
GSComparisonType type,
void *context)
{
if (sortRange.length > 1)
{
id pivot = objects[sortRange.location];
unsigned int left = sortRange.location + 1;
unsigned int right = NSMaxRange(sortRange);
while (left < right)
{
if (GSCompareUsingDescriptorOrComparator(objects[left], pivot,
comparisonEntity, type, context) == NSOrderedDescending)
{
SwapObjects(&objects[left], &objects[--right]);
}
else
{
left++;
}
}
SwapObjects(&objects[--left], &objects[sortRange.location]);
_GSQuickSort(objects,
NSMakeRange(sortRange.location, left - sortRange.location),
comparisonEntity, type, context);
_GSQuickSort(objects,
NSMakeRange(right, NSMaxRange(sortRange) - right),
comparisonEntity, type, context);
}
}
@interface GSQuickSortPlaceHolder : NSObject
+ (void) setUnstable;
@end
@implementation GSQuickSortPlaceHolder
+ (void) setUnstable
{
_GSSortUnstable = _GSQuickSort;
}
@end
|
