43 lines
1.9 KiB
C#
43 lines
1.9 KiB
C#
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namespace PersistentOrderedMap;
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public sealed class PersistentOrderedMap<TK, TV, TStrategy> : BaseOrderedMap<TK, TV, TStrategy> where TStrategy : IKeyStrategy<TK>
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{
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internal PersistentOrderedMap(Node<TK> root, TStrategy strategy, int count)
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: base(root, strategy, count) { }
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// ---------------------------------------------------------
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// Immutable Write API (Returns new Map)
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// ---------------------------------------------------------
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public PersistentOrderedMap<TK, TV, TStrategy> Set(TK key, TV value)
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{
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// OPTIMIZATION: Use OwnerId.None (0).
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// This signals EnsureEditable to always copy the root path,
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// producing a new tree of nodes that also have OwnerId.None.
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var newRoot = BTreeFunctions.Set(Root, key, value, Strategy, OwnerId.None, out bool countChanged);
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return new PersistentOrderedMap<TK, TV, TStrategy>(newRoot, Strategy, countChanged ? Count + 1 : Count);
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}
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public static PersistentOrderedMap<TK, TV, TStrategy> Empty(TStrategy strategy)
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{
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// Create an empty Leaf Node.
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// 'default(OwnerId)' (usually 0) marks this node as Immutable/Persistent.
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// This ensures that any subsequent Set/Remove will clone this node
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// instead of modifying it in place.
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var emptyRoot = new LeafNode<TK, TV>(default(OwnerId), strategy.UsesPrefixes);
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return new PersistentOrderedMap<TK, TV, TStrategy>(emptyRoot, strategy, 0);
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}
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public PersistentOrderedMap<TK, TV, TStrategy> Remove(TK key)
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{
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var newRoot = BTreeFunctions.Remove<TK,TV, TStrategy>(Root, key, Strategy, OwnerId.None, out bool removed);
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if (!removed) return this;
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return new PersistentOrderedMap<TK, TV, TStrategy>(newRoot, Strategy, Count - 1);
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}
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public TransientOrderedMap<TK, TV, TStrategy> ToTransient()
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{
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return new TransientOrderedMap<TK, TV, TStrategy>(Root, Strategy, Count);
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}
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}
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