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
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
|
/*
* Copyright 2017 Google
*
* 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 "FIndexedNode.h"
#import "FImmutableSortedSet.h"
#import "FIndex.h"
#import "FPriorityIndex.h"
#import "FKeyIndex.h"
#import "FChildrenNode.h"
static FImmutableSortedSet *FALLBACK_INDEX;
@interface FIndexedNode ()
@property (nonatomic, strong) id<FNode> node;
/**
* The indexed set is initialized lazily to prevent creation when it is not needed
*/
@property (nonatomic, strong) FImmutableSortedSet *indexed;
@property (nonatomic, strong) id<FIndex> index;
@end
@implementation FIndexedNode
+ (FImmutableSortedSet *)fallbackIndex {
static FImmutableSortedSet *fallbackIndex;
static dispatch_once_t once;
dispatch_once(&once, ^{
fallbackIndex = [[FImmutableSortedSet alloc] init];
});
return fallbackIndex;
}
+ (FIndexedNode *)indexedNodeWithNode:(id<FNode>)node
{
return [[FIndexedNode alloc] initWithNode:node index:[FPriorityIndex priorityIndex]];
}
+ (FIndexedNode *)indexedNodeWithNode:(id<FNode>)node index:(id<FIndex>)index
{
return [[FIndexedNode alloc] initWithNode:node index:index];
}
- (id)initWithNode:(id<FNode>)node index:(id<FIndex>)index
{
// Initialize indexed lazily
return [self initWithNode:node index:index indexed:nil];
}
- (id)initWithNode:(id<FNode>)node index:(id<FIndex>)index indexed:(FImmutableSortedSet *)indexed
{
self = [super init];
if (self != nil) {
self->_node = node;
self->_index = index;
self->_indexed = indexed;
}
return self;
}
- (void)ensureIndexed
{
if (!self.indexed) {
if ([self.index isEqual:[FKeyIndex keyIndex]]) {
self.indexed = [FIndexedNode fallbackIndex];
} else {
__block BOOL sawChild;
[self.node enumerateChildrenUsingBlock:^(NSString *key, id<FNode> node, BOOL *stop) {
sawChild = sawChild || [self.index isDefinedOn:node];
*stop = sawChild;
}];
if (sawChild) {
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
[self.node enumerateChildrenUsingBlock:^(NSString *key, id<FNode> node, BOOL *stop) {
FNamedNode *namedNode = [[FNamedNode alloc] initWithName:key andNode:node];
dict[namedNode] = [NSNull null];
}];
// Make sure to assign index here, because the comparator will be retained and using self will cause a
// cycle
id<FIndex> index = self.index;
self.indexed = [FImmutableSortedSet setWithKeysFromDictionary:dict
comparator:^NSComparisonResult(FNamedNode *namedNode1, FNamedNode *namedNode2) {
return [index compareNamedNode:namedNode1 toNamedNode:namedNode2];
}];
} else {
self.indexed = [FIndexedNode fallbackIndex];
}
}
}
}
- (BOOL)hasIndex:(id<FIndex>)index
{
return [self.index isEqual:index];
}
- (FIndexedNode *)updateChild:(NSString *)key withNewChild:(id<FNode>)newChildNode
{
id<FNode> newNode = [self.node updateImmediateChild:key withNewChild:newChildNode];
if (self.indexed == [FIndexedNode fallbackIndex] && ![self.index isDefinedOn:newChildNode]) {
// doesn't affect the index, no need to create an index
return [[FIndexedNode alloc] initWithNode:newNode index:self.index indexed:[FIndexedNode fallbackIndex]];
} else if (!self.indexed || self.indexed == [FIndexedNode fallbackIndex]) {
// No need to index yet, index lazily
return [[FIndexedNode alloc] initWithNode:newNode index:self.index];
} else {
id<FNode> oldChild = [self.node getImmediateChild:key];
FImmutableSortedSet *newIndexed = [self.indexed removeObject:[FNamedNode nodeWithName:key node:oldChild]];
if (![newChildNode isEmpty]) {
newIndexed = [newIndexed addObject:[FNamedNode nodeWithName:key node:newChildNode]];
}
return [[FIndexedNode alloc] initWithNode:newNode index:self.index indexed:newIndexed];
}
}
- (FIndexedNode *)updatePriority:(id<FNode>)priority
{
return [[FIndexedNode alloc] initWithNode:[self.node updatePriority:priority]
index:self.index
indexed:self.indexed];
}
- (FNamedNode *)firstChild
{
if (![self.node isKindOfClass:[FChildrenNode class]]) {
return nil;
} else {
[self ensureIndexed];
if (self.indexed == [FIndexedNode fallbackIndex]) {
return [((FChildrenNode *)self.node) firstChild];
} else {
return self.indexed.firstObject;
}
}
}
- (FNamedNode *)lastChild
{
if (![self.node isKindOfClass:[FChildrenNode class]]) {
return nil;
} else {
[self ensureIndexed];
if (self.indexed == [FIndexedNode fallbackIndex]) {
return [((FChildrenNode *)self.node) lastChild];
} else {
return self.indexed.lastObject;
}
}
}
- (NSString *)predecessorForChildKey:(NSString *)childKey childNode:(id<FNode>)childNode index:(id<FIndex>)index
{
if (![self.index isEqual:index]) {
[NSException raise:NSInvalidArgumentException format:@"Index not available in IndexedNode!"];
}
[self ensureIndexed];
if (self.indexed == [FIndexedNode fallbackIndex]) {
return [self.node predecessorChildKey:childKey];
} else {
FNamedNode *node = [self.indexed predecessorEntry:[FNamedNode nodeWithName:childKey node:childNode]];
return node.name;
}
}
- (void)enumerateChildrenReverse:(BOOL)reverse usingBlock:(void (^)(NSString *, id<FNode>, BOOL *))block
{
[self ensureIndexed];
if (self.indexed == [FIndexedNode fallbackIndex]) {
[self.node enumerateChildrenReverse:reverse usingBlock:block];
} else {
[self.indexed enumerateObjectsReverse:reverse usingBlock:^(FNamedNode *namedNode, BOOL *stop) {
block(namedNode.name, namedNode.node, stop);
}];
}
}
- (NSEnumerator *)childEnumerator
{
[self ensureIndexed];
if (self.indexed == [FIndexedNode fallbackIndex]) {
return [self.node childEnumerator];
} else {
return [self.indexed objectEnumerator];
}
}
@end
|
