/// <summary>
/// Not allowed to set data larger than the buffer size
/// </summary>
public void Put(T[] dataToSet)
{
var sourceDataLength = dataToSet.Length;
if (sourceDataLength > _capacity)
{
throw new ArgumentException("Amount of data that is trying to be set is larger than the capacity of this buffer");
}
bool isOverflowed;
int nextTail;
lock (_lockObj)
{
// Calculate the amount of data (including the data being read at the moment, if a read is ongoing)
var capacityInUse = BufferLogicHelper.CalculateUsedCapacity(_isEmpty, _head, _tail, _capacity);
if (BufferLogicHelper.WillDataBeOverwritten(sourceDataLength, capacityInUse, _capacity))
{
// We just throw away a chunk if there is no room
LostData += sourceDataLength;
}
// Calculate the next tail, this way we also know whether we are overflowing
nextTail = BufferLogicHelper.CalculateNextIndex(_tail, sourceDataLength, _capacity, out isOverflowed);
}
if (isOverflowed)
{
// Data spans across the end and beginning of the storage array, we need to do two copies
var itemsToWriteAtEnd = _capacity - _tail;
Array.Copy(dataToSet, 0, _storage, _tail, itemsToWriteAtEnd);
var itemsToWriteAtBeginning = sourceDataLength - itemsToWriteAtEnd;
Array.Copy(dataToSet, itemsToWriteAtEnd, _storage, 0, itemsToWriteAtBeginning);
}
else
{
Array.Copy(dataToSet, 0, _storage, _tail, sourceDataLength);
}
lock (_lockObj)
{
_tail = nextTail;
// We just added data, the storage can never be empty now
_isEmpty = false;
// Check if we need to set the event
if (_notifyEventEnabled && !_notifyEvent.IsSet && BufferLogicHelper.CalculateUsedCapacity(_isEmpty, _head, _tail, _capacity) >= _notifyThreshold)
{
// There is not enough data anymore, reset the event
_notifyEvent.Set();
}
}
}
public void Test_CalculateUsedCapacity()
{
Assert.AreEqual(0, BufferLogicHelper.CalculateUsedCapacity(true, 0, 0, 10));
Assert.AreEqual(10, BufferLogicHelper.CalculateUsedCapacity(false, 0, 0, 10));
Assert.AreEqual(9, BufferLogicHelper.CalculateUsedCapacity(false, 0, 9, 10));
Assert.AreEqual(4, BufferLogicHelper.CalculateUsedCapacity(false, 5, 9, 10));
Assert.AreEqual(10, BufferLogicHelper.CalculateUsedCapacity(false, 9, 9, 10));
Assert.AreEqual(0, BufferLogicHelper.CalculateUsedCapacity(true, 9, 9, 10));
Assert.AreEqual(2, BufferLogicHelper.CalculateUsedCapacity(false, 9, 1, 10));
Assert.AreEqual(9, BufferLogicHelper.CalculateUsedCapacity(false, 9, 8, 10));
}
public T[] Get()
{
bool isOverflowed;
int nextHead;
lock (_lockObj)
{
if (BufferLogicHelper.CalculateUsedCapacity(_isEmpty, _head, _tail, _capacity) < _notifyThreshold)
{
// We do not have enough data
throw new Exception("A get should never be done when there is not enough available data! Use the NotifyEvent.");
}
nextHead = BufferLogicHelper.CalculateNextIndex(_head, _notifyThreshold, _capacity, out isOverflowed);
}
var getValues = new T[_notifyThreshold];
if (isOverflowed)
{
// Data spans across the end and beginning of the storage array, we need to do two copies
var itemsToReadFromEnd = _capacity - _head;
Array.Copy(_storage, _head, getValues, 0, itemsToReadFromEnd);
var itemsToReadFromBeginning = _notifyThreshold - itemsToReadFromEnd;
Array.Copy(_storage, 0, getValues, itemsToReadFromEnd, itemsToReadFromBeginning);
}
else
{
Array.Copy(_storage, _head, getValues, 0, _notifyThreshold);
}
lock (_lockObj)
{
_head = nextHead;
// Check if we just read the last available data
_isEmpty = _head == _tail;
// Check if we need to reset the event
if (_notifyEventEnabled && _notifyEvent.IsSet &&
BufferLogicHelper.CalculateUsedCapacity(_isEmpty, _head, _tail, _capacity) < _notifyThreshold)
{
// There is not enough data anymore, reset the event
_notifyEvent.Reset();
}
}
return(getValues);
}
public void Test_CalculateNextIndex()
{
// Simple start case
Assert.AreEqual(2, BufferLogicHelper.CalculateNextIndex(0, 2, 10, out var isOverFlowed));
Assert.IsFalse(isOverFlowed);
// Fully fill the end
Assert.AreEqual(0, BufferLogicHelper.CalculateNextIndex(7, 3, 10, out isOverFlowed));
Assert.IsTrue(isOverFlowed);
// Overflow
Assert.AreEqual(2, BufferLogicHelper.CalculateNextIndex(7, 5, 10, out isOverFlowed));
Assert.IsTrue(isOverFlowed);
}
public void Test_WillDataBeOverwritten()
{
Assert.IsFalse(BufferLogicHelper.WillDataBeOverwritten(10, 0, 10));
Assert.IsTrue(BufferLogicHelper.WillDataBeOverwritten(5, 6, 10));
Assert.IsFalse(BufferLogicHelper.WillDataBeOverwritten(5, 5, 10));
}
