/// <summary>
/// Remove oldest message in the cache, remove oldest block too if the block is empty
/// </summary>
public void RemoveOldestMessage()
{
this.messageBlocks.Last.Value.Remove();
this.ItemCount--;
CachedMessageBlock lastCachedMessageBlock = this.messageBlocks.Last.Value;
// if block is currently empty, but all capacity has been exausted, remove
if (lastCachedMessageBlock.IsEmpty && !lastCachedMessageBlock.HasCapacity)
{
lastCachedMessageBlock.Dispose();
this.messageBlocks.RemoveLast();
}
}
private void PerformBlockPurge(IDisposable purgeRequest)
{
while (!IsEmpty &&
cacheDataAdapter.ShouldPurge(messageBlocks.Last.Value[messageBlocks.Last.Value.OldestMessageIndex], purgeRequest)) // value has the same resource blockId as the one we are purging
{
messageBlocks.Last.Value.Remove();
CachedMessageBlock <TQueueMessage, TCachedMessage> lastCachedMessageBlock = messageBlocks.Last.Value;
// if block is currently empty, but all capacity has been exausted, remove
if (lastCachedMessageBlock.IsEmpty && !lastCachedMessageBlock.HasCapacity)
{
lastCachedMessageBlock.Dispose();
messageBlocks.RemoveLast();
}
}
purgeRequest.Dispose();
}
/// <summary>
/// Allocates a message in a block and returns the block the message is in.
/// </summary>
/// <param name="queueMessage"></param>
/// <returns></returns>
public CachedMessageBlock <TQueueMessage, TCachedMessage> AllocateMessage(TQueueMessage queueMessage)
{
if (queueMessage == null)
{
throw new ArgumentNullException("queueMessage");
}
// allocate new cached message block if needed
if (cachedMessageBlock == null || !cachedMessageBlock.HasCapacity)
{
cachedMessageBlock = cachedMessagePool.Allocate();
}
cachedMessageBlock.Add(queueMessage);
return(cachedMessageBlock);
}
/// <summary>
/// Allocates a message in a block and returns the block the message is in.
/// </summary>
/// <param name="queueMessage"></param>
/// <param name="dequeueTimeUtc"></param>
/// <param name="streamPosition"></param>
/// <returns></returns>
public CachedMessageBlock <TCachedMessage> AllocateMessage(TQueueMessage queueMessage, DateTime dequeueTimeUtc, out StreamPosition streamPosition)
{
streamPosition = default(StreamPosition);
if (queueMessage == null)
{
throw new ArgumentNullException("queueMessage");
}
// allocate new cached message block if needed
if (currentMessageBlock == null || !currentMessageBlock.HasCapacity)
{
currentMessageBlock = messagePool.Allocate();
}
streamPosition = currentMessageBlock.Add(queueMessage, dequeueTimeUtc, dataAdapter);
return(currentMessageBlock);
}
private StreamPosition Add(TQueueMessage message, DateTime dequeueTimeUtc)
{
if (message == null)
{
throw new ArgumentNullException("message");
}
StreamPosition streamPosition;
// allocate message from pool
CachedMessageBlock <TCachedMessage> block = pool.AllocateMessage(message, dequeueTimeUtc, out streamPosition);
// If new block, add message block to linked list
if (block != messageBlocks.FirstOrDefault())
{
messageBlocks.AddFirst(block.Node);
}
itemCount++;
return(streamPosition);
}
public void Add(TQueueMessage message)
{
if (message == null)
{
throw new ArgumentNullException("message");
}
PerformPendingPurges();
// allocate message from pool
CachedMessageBlock <TCachedMessage> block = pool.AllocateMessage(message);
// If new block, add message block to linked list
if (block != messageBlocks.FirstOrDefault())
{
messageBlocks.AddFirst(block.Node);
}
PerformPendingPurges();
}
/// <summary>
/// Allocates a message in a block and returns the block the message is in.
/// </summary>
/// <param name="queueMessage"></param>
/// <param name="dequeueTimeUtc"></param>
/// <param name="streamPosition"></param>
/// <returns></returns>
public CachedMessageBlock <TCachedMessage> AllocateMessage(TQueueMessage queueMessage, DateTime dequeueTimeUtc, out StreamPosition streamPosition)
{
streamPosition = default(StreamPosition);
if (queueMessage == null)
{
throw new ArgumentNullException(nameof(queueMessage));
}
CachedMessageBlock <TCachedMessage> returnBlock = currentMessageBlock ?? (currentMessageBlock = messagePool.Allocate());
streamPosition = returnBlock.Add(queueMessage, dequeueTimeUtc, dataAdapter);
// blocks at capacity are eligable for purge, so we don't want to be holding on to them.
if (!currentMessageBlock.HasCapacity)
{
currentMessageBlock = messagePool.Allocate();
}
return(returnBlock);
}
