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1 // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file | |
2 // for details. All rights reserved. Use of this source code is governed by a | |
3 // BSD-style license that can be found in the LICENSE file. | |
4 | |
5 library services.src.index.store.collection; | |
6 | |
7 import 'dart:collection'; | |
8 import 'dart:typed_data'; | |
9 | |
10 | |
11 /** | |
12 * A hash map with `List<int>` keys and [int] values. | |
13 */ | |
14 class IntArrayToIntMap { | |
15 final Map<Int32List, int> map = new HashMap<Int32List, int>(equals: | |
16 _intArrayEquals, hashCode: _intArrayHashCode); | |
17 | |
18 /** | |
19 * Returns the value for the given [key] or null if [key] is not in the map. | |
20 */ | |
21 int operator [](List<int> key) { | |
22 Int32List typedKey = _getTypedKey(key); | |
23 return map[typedKey]; | |
24 } | |
25 | |
26 /** | |
27 * Associates the [key] with the given [value]. | |
28 * | |
29 * If the key was already in the map, its associated value is changed. | |
30 * Otherwise the key-value pair is added to the map. | |
31 */ | |
32 void operator []=(List<int> key, int value) { | |
33 Int32List typedKey = _getTypedKey(key); | |
34 map[typedKey] = value; | |
35 } | |
36 | |
37 /** | |
38 * Returns an [Int32List] version of the given `List<int>` key. | |
39 */ | |
40 static Int32List _getTypedKey(List<int> key) { | |
41 if (key is Int32List) { | |
42 return key; | |
43 } | |
44 return new Int32List.fromList(key); | |
45 } | |
46 | |
47 static bool _intArrayEquals(List<int> a, List<int> b) { | |
48 int length = a.length; | |
49 if (length != b.length) { | |
50 return false; | |
51 } | |
52 for (int i = 0; i < length; i++) { | |
53 if (a[i] != b[i]) { | |
54 return false; | |
55 } | |
56 } | |
57 return true; | |
58 } | |
59 | |
60 static int _intArrayHashCode(List<int> key) { | |
61 return key.fold(0, (int result, int item) { | |
62 return 31 * result + item; | |
63 }); | |
64 } | |
65 } | |
66 | |
67 | |
68 /** | |
69 * A table mapping [int] keys to sets of [int]s. | |
70 */ | |
71 class IntToIntSetMap { | |
72 final Map<int, Int32List> _map = new HashMap<int, Int32List>(); | |
73 | |
74 /** | |
75 * The number of key-value pairs in the map. | |
76 */ | |
77 int get length => _map.length; | |
78 | |
79 /** | |
80 * Adds the [value] to the set associated with the given [value]. | |
81 */ | |
82 void add(int key, int value) { | |
83 Int32List values = _map[key]; | |
84 if (values == null) { | |
85 values = new Int32List(1); | |
86 values[0] = value; | |
87 _map[key] = values; | |
88 } | |
89 if (values.indexOf(value) == -1) { | |
90 int length = values.length; | |
91 Int32List newSet = new Int32List(length + 1); | |
92 newSet.setRange(0, length, values); | |
93 newSet[length] = value; | |
94 _map[key] = newSet; | |
95 } | |
96 } | |
97 | |
98 /** | |
99 * Removes all pairs from the map. | |
100 */ | |
101 void clear() { | |
102 _map.clear(); | |
103 } | |
104 | |
105 /** | |
106 * Returns the set of [int]s for the given [key] or an empty list if [key] is | |
107 * not in the map. | |
108 */ | |
109 List<int> get(int key) { | |
110 List<int> values = _map[key]; | |
111 if (values == null) { | |
112 values = <int>[]; | |
113 } | |
114 return values; | |
115 } | |
116 } | |
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