internal static GetInstanceDelegate Search(this ImmutableHashTable <Type, GetInstanceDelegate> hashTable, Type key)
{
var hashCode = key.GetHashCode();
var bucketIndex = hashCode & (hashTable.Divisor - 1);
ImmutableHashTree <Type, GetInstanceDelegate> tree = hashTable.Buckets[bucketIndex];
while (tree.Height != 0 && tree.HashCode != hashCode)
{
tree = hashCode < tree.HashCode ? tree.Left : tree.Right;
}
if (tree.Height != 0 && ReferenceEquals(tree.Key, key))
{
return(tree.Value);
}
if (tree.Duplicates.Items.Length > 0)
{
foreach (var keyValue in tree.Duplicates.Items)
{
if (ReferenceEquals(keyValue.Key, key))
{
return(keyValue.Value);
}
}
}
return(default(GetInstanceDelegate));
}
private void AddExistingValues(ImmutableHashTable <TKey, TValue> previous)
{
foreach (ImmutableHashTree <TKey, TValue> bucket in previous.Buckets)
{
foreach (var keyValue in bucket.InOrder())
{
int hashCode = keyValue.Key.GetHashCode();
int bucketIndex = hashCode & (this.Divisor - 1);
this.Buckets[bucketIndex] = this.Buckets[bucketIndex].Add(keyValue.Key, keyValue.Value);
}
}
}
/// <summary>
/// Initializes a new instance of the <see cref="ImmutableHashTable{TKey,TValue}"/> class.
/// </summary>
/// <param name="previous">The "previous" hash table that contains already existing values.</param>
/// <param name="key">The key to be associated with the value.</param>
/// <param name="value">The value to be added to the tree.</param>
internal ImmutableHashTable(ImmutableHashTable <TKey, TValue> previous, TKey key, TValue value)
{
this.Count = previous.Count + 1;
if (previous.Count >= previous.Divisor)
{
this.Divisor = previous.Divisor * 2;
this.Buckets = new ImmutableHashTree <TKey, TValue> [this.Divisor];
InitializeBuckets(0, this.Divisor);
this.AddExistingValues(previous);
}
else
{
this.Divisor = previous.Divisor;
this.Buckets = new ImmutableHashTree <TKey, TValue> [this.Divisor];
Array.Copy(previous.Buckets, this.Buckets, previous.Divisor);
}
var hashCode = key.GetHashCode();
var bucketIndex = hashCode & (this.Divisor - 1);
this.Buckets[bucketIndex] = this.Buckets[bucketIndex].Add(key, value);
}
/// <summary>
/// Adds a new element to the <see cref="ImmutableHashTree{TKey,TValue}"/>.
/// </summary>
/// <typeparam name="TKey">The type of the key.</typeparam>
/// <typeparam name="TValue">The type of the value.</typeparam>
/// <param name="hashTable">The target <see cref="ImmutableHashTable{TKey,TValue}"/>.</param>
/// <param name="key">The key to be associated with the value.</param>
/// <param name="value">The value to be added to the tree.</param>
/// <returns>A new <see cref="ImmutableHashTree{TKey,TValue}"/> that contains the new key/value pair.</returns>
public static ImmutableHashTable <TKey, TValue> Add <TKey, TValue>(this ImmutableHashTable <TKey, TValue> hashTable, TKey key, TValue value)
{
return(new ImmutableHashTable <TKey, TValue>(hashTable, key, value));
}