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
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
//
// GTMNSArray+Merge.m
//
// Copyright 2008 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy
// of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations
// under the License.
//
#import "GTMNSArray+Merge.h"
#import "GTMDefines.h"
#if GTM_IPHONE_SDK
#import <objc/message.h>
#else // GTM_IPHONE_SDK
#import <objc/objc-runtime.h>
#endif // GTM_IPHONE_SDK
@implementation NSArray (GTMNSArrayMergingAdditions)
- (NSArray *)gtm_mergeArray:(NSArray *)newArray
mergeSelector:(SEL)merger {
return [self gtm_mergeArray:newArray
compareSelector:@selector(compare:)
mergeSelector:merger];
}
- (NSArray *)gtm_mergeArray:(NSArray *)newArray
compareSelector:(SEL)comparer
mergeSelector:(SEL)merger {
// must have a compare selector
if (!comparer) return nil;
// Sort and merge the contents of |self| with |newArray|.
NSArray *sortedMergedArray = nil;
if ([self count] && [newArray count]) {
NSMutableArray *mergingArray = [NSMutableArray arrayWithArray:self];
[mergingArray sortUsingSelector:comparer];
NSArray *sortedNewArray
= [newArray sortedArrayUsingSelector:comparer];
NSUInteger oldIndex = 0;
NSUInteger oldCount = [mergingArray count];
id oldItem = (oldIndex < oldCount)
? [mergingArray objectAtIndex:0]
: nil;
id newItem = nil;
GTM_FOREACH_OBJECT(newItem, sortedNewArray) {
BOOL stillLooking = YES;
while (oldIndex < oldCount && stillLooking) {
// We must take care here, since Intel leaves junk in high bytes of
// return register for predicates that return BOOL.
// For details see:
// http://developer.apple.com/documentation/MacOSX/Conceptual/universal_binary/universal_binary_tips/chapter_5_section_23.html
// and
// http://www.red-sweater.com/blog/320/abusing-objective-c-with-class#comment-83187
NSComparisonResult result
= ((NSComparisonResult (*)(id, SEL, id))objc_msgSend)(newItem, comparer, oldItem);
if (result == NSOrderedSame && merger) {
// It's a match!
id repItem = [oldItem performSelector:merger
withObject:newItem];
[mergingArray replaceObjectAtIndex:oldIndex
withObject:repItem];
++oldIndex;
oldItem = (oldIndex < oldCount)
? [mergingArray objectAtIndex:oldIndex]
: nil;
stillLooking = NO;
} else if (result == NSOrderedAscending
|| (result == NSOrderedSame && !merger)) {
// This is either a new item and belongs right here, or it's
// a match to an existing item but we're not merging.
[mergingArray insertObject:newItem
atIndex:oldIndex];
++oldIndex;
++oldCount;
stillLooking = NO;
} else {
++oldIndex;
oldItem = (oldIndex < oldCount)
? [mergingArray objectAtIndex:oldIndex]
: nil;
}
}
if (stillLooking) {
// Once we get here, the rest of the new items get appended.
[mergingArray addObject:newItem];
}
}
sortedMergedArray = mergingArray;
} else if ([self count]) {
sortedMergedArray = [self sortedArrayUsingSelector:comparer];
} else if ([newArray count]) {
sortedMergedArray = [newArray sortedArrayUsingSelector:comparer];
}
return sortedMergedArray;
}
@end
|
