/// <summary>
/// Constructor
/// </summary>
/// <param name="capacity">Max capacity, after surpassing it elements will be removed based on last by <see cref="comparer"/>.</param>
/// <param name="comparer">Comparer to sort items.</param>
protected SortedPool(int capacity, IComparer <TValue> comparer)
{
_capacity = capacity;
// ReSharper disable once VirtualMemberCallInConstructor
_comparer = GetUniqueComparer(comparer ?? throw new ArgumentNullException(nameof(comparer)));
_cacheMap = new Dictionary <TKey, TValue>(); // do not initialize it at the full capacity
_buckets = new Dictionary <TGroupKey, ICollection <TValue> >();
_sortedValues = new DictionarySortedSet <TValue, TKey>(_comparer);
}
private IEnumerable <Transaction> Order(
IEnumerable <IEnumerable <Transaction> > transactionsBySenderOrderedByNonce,
IComparer <Transaction> comparer)
{
IEnumerator <Transaction>[] bySenderEnumerators = transactionsBySenderOrderedByNonce
.Select(g => g.GetEnumerator())
.ToArray();
try
{
// we create a sorted list of head of each group of transactions. From:
// A -> N0_P3, N1_P1, N1_P0, N3_P5...
// B -> N4_P4, N5_P3, N6_P3...
// We construct [N4_P4 (B), N0_P3 (A)] in sorted order by priority
var transactions = new DictionarySortedSet <Transaction, IEnumerator <Transaction> >(comparer);
for (int i = 0; i < bySenderEnumerators.Length; i++)
{
IEnumerator <Transaction> enumerator = bySenderEnumerators[i];
if (enumerator.MoveNext())
{
transactions.Add(enumerator.Current !, enumerator);
}
}
// while there are still unreturned transactions
while (transactions.Count > 0)
{
// we take first transaction from sorting order, on first call: N4_P4 from B
var(tx, enumerator) = transactions.Min;
// we replace it by next transaction from same sender, on first call N5_P3 from B
transactions.Remove(tx);
if (enumerator.MoveNext())
{
transactions.Add(enumerator.Current !, enumerator);
}
// we return transactions in lazy manner, no need to sort more than will be taken into block
yield return(tx);
}
}
finally
{
// disposing enumerators
for (int i = 0; i < bySenderEnumerators.Length; i++)
{
bySenderEnumerators[i].Dispose();
}
}
}