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);
}
internal static ArrayPrefix <T> Release <T>(ArrayPrefix <T> arrayPrefix, bool clearArray)
{
// ReSharper disable once PatternAlwaysOfType
if (arrayPrefix.Array is T[] array)
{
ArrayPool <T> .Shared.Return(array, clearArray);
}
return(ArrayPrefix <T> .Empty);
}
internal static ArrayPrefix <T> EnsureSize <T>(ArrayPrefix <T> arrayPrefix, int size, bool clearArray)
{
if (size <= arrayPrefix.Count)
{
return(arrayPrefix);
}
UncheckedGrow(ref arrayPrefix, size, clearArray);
return(arrayPrefix);
}
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);
}
}
internal static ArrayPrefix <T> Add <T>(ArrayPrefix <T> arrayPrefix, T item, bool clearArray)
{
int capacity = (arrayPrefix.Array?.Length).GetValueOrDefault();
if (arrayPrefix.Count == capacity)
{
UncheckedEnsureCapacity(ref arrayPrefix, capacity, arrayPrefix.Count + 1, clearArray);
}
UncheckedAdd(ref arrayPrefix, item);
return(arrayPrefix);
}
internal static ArrayPrefix <T> Resize <T>(ArrayPrefix <T> arrayPrefix, int size, bool clearArray)
{
if (arrayPrefix.Count < size)
{
UncheckedGrow(ref arrayPrefix, size, clearArray);
return(arrayPrefix);
}
if (arrayPrefix.Count > size)
{
UncheckedShrink(ref arrayPrefix, size, clearArray);
return(arrayPrefix);
}
return(arrayPrefix);
}
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);
}