Stores reactivity messages in memory for the lifetime of the application process.
Defines storage operations for chat messages displayed in the reactivity feed.
void Add(MessageItemModel message)
Adds a message to the store.
messageThe message item to persist.IReadOnlyList<MessageItemModel> GetAll()
Returns the current messages ordered from newest to oldest.
A read-only snapshot of stored messages.
An in-memory implementation of IUserPresenceService using a thread-safe dictionary to track user activity.
int RecordActivity(string username)
Records the current UTC time as the specified user's last activity in the in-memory store.
usernameThe username to record; cannot be null, empty, or whitespace.The number of users whose last activity is within the current ActiveWindow.
System.ArgumentExceptionThrown when username is null, empty, or consists only of whitespace.IEnumerable<UserPresenceInfo> GetActiveUsers()
Lists users whose last recorded activity falls within the current ActiveWindow.
A collection of UserPresenceInfo for users with last activity at or after (now - ActiveWindow), ordered by Username.
(IReadOnlyList<UserPresenceInfo> Removed, int ActiveCount) Pulse()
Removes users whose last activity is older than the sliding ActiveWindow and returns the removed entries along with the current count of active users.
`Removed`: a read-only list of user presence entries that were removed because their last activity preceded the ActiveWindow; `ActiveCount`: the number of users whose last activity is within the ActiveWindow.
TimeSpan ActiveWindow { get; set; }
Gets or sets the time window within which a user is considered active since their last recorded activity. Must be a positive duration.
ArgumentOutOfRangeExceptionThrown when the value is less than or equal to TimeSpan.Zero.Represents current presence information for a user.
UsernameThe unique username.SafeUsernameA simplified version of the username safe for use in UI identifiers.LastSeenThe timestamp of the user's last recorded activity.Defines a service for tracking and managing user presence.
int RecordActivity(string username)
Record activity for the specified user and update their presence tracking.
usernameThe username whose activity should be recorded.The current number of active users after recording the activity.
IEnumerable<UserPresenceInfo> GetActiveUsers()
Retrieve presence information for users currently considered active.
A collection of UserPresenceInfo objects for users considered active at the time of the call.
(IReadOnlyList<UserPresenceInfo> Removed, int ActiveCount) Pulse()
Advance presence tracking and expire users considered inactive during this pulse.
A tuple where Removed is a read-only list of users removed during this pulse, and ActiveCount is the current number of active users after the pulse.
A background service that periodically pulses the user presence service and publishes updates to connected clients.
Task RunAsync(CancellationToken stoppingToken)
Periodically pulses user presence, removes departed users from the reactive stream, and publishes updates to connected clients.
stoppingTokenCancellation token used to stop the background loop.A task that completes when the background loop stops.