public static void SetCapacity(UnsafeList *list, int capacity)
{
Assert.Check(list != null);
if (list->_items.Dynamic == false)
{
throw new InvalidOperationException(LIST_FIXED_CANT_CHANGE_CAPACITY);
}
// no change in capacity
if (capacity == list->_items.Length)
{
return;
}
// tried to set to zero or negative, so free items
if (capacity <= 0)
{
// have to make sure to set count to 0
list->_count = 0;
// and clear memory for items
if (list->_items.Ptr != null)
{
UnsafeBuffer.Free(&list->_items);
}
return;
}
// allocate new items
UnsafeBuffer newItems = default;
UnsafeBuffer.InitDynamic(&newItems, capacity, list->_items.Stride);
// if have anything in list, copy it
if (list->_count > 0)
{
// also make sure that count is
// not larger than the new capacity
if (list->_count > capacity)
{
list->_count = capacity;
}
// copy over elements
UnsafeBuffer.Copy(list->_items, 0, newItems, 0, list->_count);
}
// if an existing buffer was here, free it
if (list->_items.Ptr != null)
{
UnsafeBuffer.Free(&list->_items);
}
// assign new buffer
list->_items = newItems;
}
static void Expand(UnsafeHashCollection *collection)
{
Assert.Check(collection->Entries.Dynamic == 1);
var capacity = GetNextPrime(collection->Entries.Length);
Assert.Check(capacity >= collection->Entries.Length);
var newBuckets = (Entry **)Native.MallocAndClear(capacity * sizeof(Entry * *), sizeof(Entry * *));
var newEntries = default(UnsafeBuffer);
UnsafeBuffer.InitDynamic(&newEntries, capacity, collection->Entries.Stride);
UnsafeBuffer.Copy(collection->Entries, 0, newEntries, 0, collection->Entries.Length);
collection->FreeHead = null;
collection->FreeCount = 0;
for (int i = collection->Entries.Length - 1; i >= 0; --i)
{
var entry = (Entry *)((byte *)newEntries.Ptr + (i * newEntries.Stride));
if (entry->State == EntryState.Used)
{
var bucketHash = entry->Hash % capacity;
// assign current entry in buckets as next
entry->Next = newBuckets[bucketHash];
// assign entry as new bucket head
newBuckets[bucketHash] = entry;
}
// entry is in free list
else if (entry->State == EntryState.Free)
{
// assign free list as next
entry->Next = collection->FreeHead;
// re-assign free list to entry
collection->FreeHead = entry;
collection->FreeCount = collection->FreeCount + 1;
}
}
// free old memory
Native.Free(collection->Buckets);
UnsafeBuffer.Free(&collection->Entries);
// new storage
collection->Buckets = newBuckets;
collection->Entries = newEntries;
}
static void Expand(UnsafeStack *stack)
{
// new buffer for elements
UnsafeBuffer newItems = default;
// initialize to double size of existing one
UnsafeBuffer.InitDynamic(&newItems, stack->_items.Length * 2, stack->_items.Stride);
// copy memory over from previous items
UnsafeBuffer.Copy(stack->_items, 0, newItems, 0, stack->_items.Length);
// free old buffer
UnsafeBuffer.Free(&stack->_items);
// replace buffer with new
stack->_items = newItems;
}
static void Expand(UnsafeOrderedCollection *collection)
{
Assert.Check(collection->Entries.Dynamic == 1);
Assert.Check(collection->FreeCount == 0);
Assert.Check(collection->FreeHead == 0);
var capacity = collection->Entries.Length * 2;
var newEntries = default(UnsafeBuffer);
UnsafeBuffer.InitDynamic(&newEntries, capacity, collection->Entries.Stride);
UnsafeBuffer.Copy(collection->Entries, 0, newEntries, 0, collection->Entries.Length);
// free old memory
UnsafeBuffer.Free(&collection->Entries);
// new storage
collection->Entries = newEntries;
}
static void ExpandHeap(UnsafeHeapMin *heap)
{
Assert.Check(heap->_items.Dynamic == 1);
// new buffer for elements
UnsafeBuffer newItems = default;
// initialize to double size of existing one
UnsafeBuffer.InitDynamic(&newItems, heap->_items.Length * 2, heap->_items.Stride);
// copy memory over from previous items
UnsafeBuffer.Copy(heap->_items, 0, newItems, 0, heap->_items.Length);
// free old buffer
UnsafeBuffer.Free(&heap->_items);
// replace buffer with new
heap->_items = newItems;
}
// expand algorithm from first answer here: https://codereview.stackexchange.com/questions/129819/queue-resizing-array-implementation
static void Expand(UnsafeQueue *queue, int capacity)
{
Assert.Check(capacity > 0);
// queue has to be dynamic and capacity we're going to have to be larger
Assert.Check(queue->_items.Dynamic == 1);
Assert.Check(queue->_items.Length < capacity);
// new buffer for elements
UnsafeBuffer newItems = default;
// initialize to double size of existing one
UnsafeBuffer.InitDynamic(&newItems, capacity, queue->_items.Stride);
if (queue->_count > 0)
{
// when head is 'ahead' or at tail it means that we're wrapping around
if (queue->_head >= queue->_tail)
{
// so we need to copy head first, from (head, length-head) into (0, length-head)
UnsafeBuffer.Copy(queue->_items, queue->_head, newItems, 0, queue->_items.Length - queue->_head);
// and then copy tail, from (0, tail) into (length-head, tail)
UnsafeBuffer.Copy(queue->_items, 0, newItems, queue->_items.Length - queue->_head, queue->_tail);
}
else
{
// if not, we can just copy from (tail, count) into (0, count)
UnsafeBuffer.Copy(queue->_items, queue->_head, newItems, 0, queue->_count);
}
}
// free existing buffer
UnsafeBuffer.Free(&queue->_items);
queue->_items = newItems;
queue->_head = 0;
queue->_tail = queue->_count % queue->_items.Length;
}