protected override void PerformWork(ref List <ArraySegment <Message> > items, out string nextCursor, ref int totalCount, out object state)
{
var cursors = new List <Cursor>();
lock (_lockObj)
{
items = new List <ArraySegment <Message> >(_cursors.Count);
for (int i = 0; i < _cursors.Count; i++)
{
Cursor cursor = Cursor.Clone(_cursors[i]);
cursors.Add(cursor);
MessageStoreResult <Message> storeResult = _cursorTopics[i].Store.GetMessages(cursor.Id, MaxMessages);
ulong next = storeResult.FirstMessageId + (ulong)storeResult.Messages.Count;
cursor.Id = next;
if (storeResult.Messages.Count > 0)
{
items.Add(storeResult.Messages);
totalCount += storeResult.Messages.Count;
}
}
nextCursor = Cursor.MakeCursor(cursors);
// Return the state as a list of cursors
state = cursors;
}
}
protected override void PerformWork(ref List <ArraySegment <Message> > items, out string nextCursor, ref int totalCount, out object state)
{
// The list of cursors represent (streamid, payloadid)
var cursors = new List <Cursor>();
foreach (var stream in _streams)
{
// Get the mapping for this stream
Linktionary <ulong, ScaleoutMapping> mapping = stream.Value;
// See if we have a cursor for this key
Cursor cursor = null;
// REVIEW: We should optimize this
int index = _cursors.FindIndex(c => c.Key == stream.Key);
bool consumed = true;
if (index != -1)
{
cursor = Cursor.Clone(_cursors[index]);
// If there's no node for this cursor id it's likely because we've
// had an app domain restart and the cursor position is now invalid.
if (mapping[cursor.Id] == null)
{
// Set it to the first id in this mapping
cursor.Id = stream.Value.MinKey;
// Mark this cursor as unconsumed
consumed = false;
}
}
else
{
// Create a cursor and add it to the list.
// Point the Id to the first value
cursor = new Cursor
{
Id = stream.Value.MinKey,
Key = stream.Key
};
consumed = false;
}
cursors.Add(cursor);
// Try to find a local mapping for this payload
LinkedListNode <KeyValuePair <ulong, ScaleoutMapping> > node = mapping[cursor.Id];
// Skip this node only if this isn't a new cursor
if (node != null && consumed)
{
// Skip this node since we've already consumed it
node = node.Next;
}
while (node != null)
{
KeyValuePair <ulong, ScaleoutMapping> pair = node.Value;
// Stop if we got more than max messages
if (totalCount >= MaxMessages)
{
break;
}
// It should be ok to lock here since groups aren't modified that often
lock (EventKeys)
{
// For each of the event keys we care about, extract all of the messages
// from the payload
foreach (var eventKey in EventKeys)
{
LocalEventKeyInfo info;
if (pair.Value.EventKeyMappings.TryGetValue(eventKey, out info))
{
int maxMessages = Math.Min(info.Count, MaxMessages);
MessageStoreResult <Message> storeResult = info.Store.GetMessages(info.MinLocal, maxMessages);
if (storeResult.Messages.Count > 0)
{
items.Add(storeResult.Messages);
totalCount += storeResult.Messages.Count;
}
}
}
}
// Update the cursor id
cursor.Id = pair.Key;
node = node.Next;
}
}
nextCursor = Cursor.MakeCursor(cursors);
state = cursors;
}
private void WorkImpl(ConcurrentDictionary <string, Topic> topics, TaskCompletionSource <object> taskCompletionSource)
{
Process:
int totalCount = 0;
string nextCursor = null;
List <ArraySegment <Message> > items = null;
lock (_lockObj)
{
items = new List <ArraySegment <Message> >(Cursors.Count);
for (int i = 0; i < Cursors.Count; i++)
{
Cursor cursor = Cursors[i];
MessageStoreResult <Message> storeResult = cursor.Topic.Store.GetMessages(cursor.Id, _maxMessages);
ulong next = storeResult.FirstMessageId + (ulong)storeResult.Messages.Count;
cursor.Id = next;
if (storeResult.Messages.Count > 0)
{
items.Add(storeResult.Messages);
totalCount += storeResult.Messages.Count;
}
}
nextCursor = Cursor.MakeCursor(Cursors);
}
if (Alive && items.Count > 0)
{
var messageResult = new MessageResult(items, nextCursor, totalCount);
Task <bool> callbackTask = Invoke(messageResult);
if (callbackTask.IsCompleted)
{
try
{
// Make sure exceptions propagate
callbackTask.Wait();
if (callbackTask.Result)
{
// Sync path
goto Process;
}
else
{
// If the callback said it's done then stop
taskCompletionSource.TrySetResult(null);
}
}
catch (Exception ex)
{
taskCompletionSource.TrySetException(ex);
}
}
else
{
WorkImplAsync(callbackTask, topics, taskCompletionSource);
}
}
else
{
taskCompletionSource.TrySetResult(null);
}
}
