| | | 1 | | using System; |
| | | 2 | | using System.Collections; |
| | | 3 | | using System.Collections.Generic; |
| | | 4 | | |
| | | 5 | | /* |
| | | 6 | | * `KeyValueSet` works as an alternative of `Dictionary` when a iteration through all it values is performed frequently. |
| | | 7 | | * CONS: It's much slower to modify the data compared to a `Dictionary` |
| | | 8 | | * PRO: It's much faster to iterate through all the data compared to a `Dictionary` and |
| | | 9 | | * it doesn't alloc extra memory while doing so. |
| | | 10 | | * Benchmark against a `Dictionary`: |
| | | 11 | | * Adding element: ~32% slower |
| | | 12 | | * Removing element: ~164% slower |
| | | 13 | | * Iterating through all elements: ~34% faster |
| | | 14 | | */ |
| | | 15 | | |
| | | 16 | | public readonly struct KeyValueSetPair<TKey, TValue> |
| | | 17 | | { |
| | | 18 | | public readonly TKey key; |
| | | 19 | | public readonly TValue value; |
| | | 20 | | |
| | | 21 | | public KeyValueSetPair(TKey key, TValue value) |
| | | 22 | | { |
| | 918 | 23 | | this.key = key; |
| | 918 | 24 | | this.value = value; |
| | 918 | 25 | | } |
| | | 26 | | } |
| | | 27 | | |
| | | 28 | | public interface IReadOnlyKeyValueSet<TKey, TValue> : IEnumerable<KeyValueSetPair<TKey, TValue>> |
| | | 29 | | { |
| | | 30 | | TValue this[TKey key] { get; } |
| | | 31 | | int Count { get; } |
| | | 32 | | IReadOnlyList<KeyValueSetPair<TKey, TValue>> Pairs { get; } |
| | | 33 | | bool ContainsKey(TKey key); |
| | | 34 | | bool TryGetValue(TKey key, out TValue value); |
| | | 35 | | } |
| | | 36 | | |
| | | 37 | | public class KeyValueSet<TKey, TValue> : IReadOnlyKeyValueSet<TKey, TValue> |
| | | 38 | | { |
| | | 39 | | private readonly Dictionary<TKey, int> indexer; |
| | | 40 | | private readonly List<KeyValueSetPair<TKey, TValue>> pairs; |
| | | 41 | | |
| | | 42 | | public IReadOnlyList<KeyValueSetPair<TKey, TValue>> Pairs => pairs; |
| | | 43 | | |
| | | 44 | | public int Count => pairs.Count; |
| | | 45 | | |
| | | 46 | | public TValue this[TKey key] |
| | | 47 | | { |
| | | 48 | | set => AddInternal(key, value, false); |
| | | 49 | | get |
| | | 50 | | { |
| | | 51 | | TryGetValue(key, out TValue value); |
| | | 52 | | return value; |
| | | 53 | | } |
| | | 54 | | } |
| | | 55 | | |
| | | 56 | | public KeyValueSet() : this(0) { } |
| | | 57 | | |
| | | 58 | | public KeyValueSet(int capacity) |
| | | 59 | | { |
| | | 60 | | indexer = new Dictionary<TKey, int>(capacity); |
| | | 61 | | pairs = new List<KeyValueSetPair<TKey, TValue>>(capacity); |
| | | 62 | | } |
| | | 63 | | |
| | | 64 | | public bool ContainsKey(TKey key) |
| | | 65 | | { |
| | | 66 | | return indexer.ContainsKey(key); |
| | | 67 | | } |
| | | 68 | | |
| | | 69 | | public bool TryGetValue(TKey key, out TValue value) |
| | | 70 | | { |
| | | 71 | | if (!indexer.TryGetValue(key, out int index)) |
| | | 72 | | { |
| | | 73 | | value = default; |
| | | 74 | | return false; |
| | | 75 | | } |
| | | 76 | | value = pairs[index].value; |
| | | 77 | | return true; |
| | | 78 | | } |
| | | 79 | | |
| | | 80 | | public void Add(TKey key, TValue value) |
| | | 81 | | { |
| | | 82 | | AddInternal(key, value, true); |
| | | 83 | | } |
| | | 84 | | |
| | | 85 | | public void RemoveAt(int index) |
| | | 86 | | { |
| | | 87 | | int count = Count; |
| | | 88 | | if (index >= count || index < 0) |
| | | 89 | | { |
| | | 90 | | throw new IndexOutOfRangeException(); |
| | | 91 | | } |
| | | 92 | | |
| | | 93 | | TKey key = pairs[index].key; |
| | | 94 | | |
| | | 95 | | if (count > 1 && index < count - 1) |
| | | 96 | | { |
| | | 97 | | int lastValueIndex = count - 1; |
| | | 98 | | pairs[index] = pairs[lastValueIndex]; |
| | | 99 | | indexer[pairs[lastValueIndex].key] = index; |
| | | 100 | | pairs.RemoveAt(lastValueIndex); |
| | | 101 | | } |
| | | 102 | | else |
| | | 103 | | { |
| | | 104 | | pairs.RemoveAt(index); |
| | | 105 | | } |
| | | 106 | | |
| | | 107 | | indexer.Remove(key); |
| | | 108 | | } |
| | | 109 | | |
| | | 110 | | public bool Remove(TKey key) |
| | | 111 | | { |
| | | 112 | | if (!indexer.TryGetValue(key, out int index)) |
| | | 113 | | { |
| | | 114 | | return false; |
| | | 115 | | } |
| | | 116 | | |
| | | 117 | | RemoveAt(index); |
| | | 118 | | return true; |
| | | 119 | | } |
| | | 120 | | |
| | | 121 | | public void Clear() |
| | | 122 | | { |
| | | 123 | | indexer.Clear(); |
| | | 124 | | pairs.Clear(); |
| | | 125 | | } |
| | | 126 | | |
| | | 127 | | public IEnumerator<KeyValueSetPair<TKey, TValue>> GetEnumerator() |
| | | 128 | | { |
| | | 129 | | for (int i = 0; i < Count; i++) |
| | | 130 | | { |
| | | 131 | | yield return pairs[i]; |
| | | 132 | | } |
| | | 133 | | } |
| | | 134 | | |
| | | 135 | | IEnumerator IEnumerable.GetEnumerator() |
| | | 136 | | { |
| | | 137 | | return GetEnumerator(); |
| | | 138 | | } |
| | | 139 | | |
| | | 140 | | private void AddInternal(TKey key, TValue value, bool add) |
| | | 141 | | { |
| | | 142 | | if (!add && indexer.TryGetValue(key, out int index)) |
| | | 143 | | { |
| | | 144 | | pairs[index] = new KeyValueSetPair<TKey, TValue>(key, value); |
| | | 145 | | return; |
| | | 146 | | } |
| | | 147 | | indexer.Add(key, pairs.Count); |
| | | 148 | | pairs.Add(new KeyValueSetPair<TKey, TValue>(key, value)); |
| | | 149 | | } |
| | | 150 | | } |