private static void UncheckedEnsureCapacity <T>(ref ArrayPrefix <T> arrayPrefix, int capacity, int minimum,
bool clearArray)
{
Debug.Assert(minimum > capacity, "minimum > capacity");
int nextCapacity = capacity == 0 ? DefaultCapacity : unchecked (2 * capacity);
if (unchecked ((uint)nextCapacity > MaxCoreClrArrayLength))
{
nextCapacity = Math.Max(capacity + 1, MaxCoreClrArrayLength);
}
nextCapacity = Math.Max(nextCapacity, minimum);
T[] next = ArrayPool <T> .Shared.Rent(nextCapacity);
if (arrayPrefix.Count > 0)
{
Debug.Assert(arrayPrefix.Array != null, "arrayPrefix.Array != null");
Array.Copy(arrayPrefix.Array, 0, next, 0, arrayPrefix.Count);
ArrayPool <T> .Shared.Return(arrayPrefix.Array, clearArray);
}
arrayPrefix = ArrayPrefix.Create(next, arrayPrefix.Count);
}
private const int MaxCoreClrArrayLength = 0x7fefffff; // For byte arrays the limit is slightly larger
internal static ArrayPrefix <T> Create <T>(int capacity)
{
Debug.Assert(capacity >= 0, "capacity >= 0");
T[] array = ArrayPool <T> .Shared.Rent(capacity);
return(ArrayPrefix.Create(array, 0));
}
private static void UncheckedAdd <T>(ref ArrayPrefix <T> arrayPrefix, T item)
{
Debug.Assert(arrayPrefix.Array != null, "arrayPrefix.Array != null");
Debug.Assert(arrayPrefix.Count < arrayPrefix.Array.Length, "arrayPrefix.Count < arrayPrefix.Array.Length");
arrayPrefix.Array[arrayPrefix.Count] = item;
arrayPrefix = ArrayPrefix.Create(arrayPrefix.Array, arrayPrefix.Count + 1);
}
private static void UncheckedShrink <T>(ref ArrayPrefix <T> arrayPrefix, int size, bool clearArray)
{
Debug.Assert(arrayPrefix.Count > size, "arrayPrefix.Count > size");
int oldCount = arrayPrefix.Count;
arrayPrefix = ArrayPrefix.Create(arrayPrefix.Array, size);
if (clearArray)
{
Array.Clear(arrayPrefix.Array, size, oldCount - size);
}
}
private static void UncheckedGrow <T>(ref ArrayPrefix <T> arrayPrefix, int size, bool clearArray)
{
Debug.Assert(arrayPrefix.Count < size, "arrayPrefix.Count < size");
int capacity = (arrayPrefix.Array?.Length).GetValueOrDefault();
if (capacity < size)
{
UncheckedEnsureCapacity(ref arrayPrefix, capacity, size, clearArray);
}
int oldCount = arrayPrefix.Count;
Debug.Assert(arrayPrefix.Array != null, "arrayPrefix.Array != null");
Array.Clear(arrayPrefix.Array, oldCount, size - oldCount);
arrayPrefix = ArrayPrefix.Create(arrayPrefix.Array, size);
}