Documentation
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Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type AllEventsFilter ¶
type AllEventsFilter struct {
Filter
}
An AllEventsFilter delivers all messages to a subscriber, provided that the subscriber is an administrator.
func (*AllEventsFilter) Matches ¶
func (f *AllEventsFilter) Matches(msg *Message, subscriber *Subscriber) bool
Matches returns whether the current AllEventsFilter matches the provided subscriber.
func (*AllEventsFilter) String ¶
func (f *AllEventsFilter) String() string
type Broadcaster ¶
type Broadcaster struct {
// contains filtered or unexported fields
}
A Broadcaster can send messages to Subscribers.
func NewBroadcaster ¶
func NewBroadcaster(ctx *common.Context, metrics Metrics) *Broadcaster
NewBroadcaster returns a new Broadcaster.
func (*Broadcaster) Broadcast ¶
func (b *Broadcaster) Broadcast(message *Message) bool
Broadcast delivers the provided message to all matching Subscribers.
func (*Broadcaster) Deauthenticate ¶
func (b *Broadcaster) Deauthenticate(user string)
Deauthenticate removes all the Subscribers belonging to the provided user from the Broadcaster.
func (*Broadcaster) Run ¶
func (b *Broadcaster) Run()
Run is the main Broadcaster loop. It listens for subscribe/unsubscribe/deauth events to manage the Subscribers, as well as new incoming messages that will be sent to all matching Subscribers.
func (*Broadcaster) Subscribe ¶
func (b *Broadcaster) Subscribe(subscriber *Subscriber) bool
Subscribe adds one subscriber to the Broadcaster.
func (*Broadcaster) Unsubscribe ¶
func (b *Broadcaster) Unsubscribe(subscriber *Subscriber) bool
Unsubscribe removes one subscriber from the Broadcaster.
type ContestFilter ¶
type ContestFilter struct {
Filter
// contains filtered or unexported fields
}
A ContestFilter is a Filter that only allows Messages that are associated with a particular contest.
func (*ContestFilter) Matches ¶
func (f *ContestFilter) Matches(msg *Message, subscriber *Subscriber) bool
Matches returns whether the current ContestFilter matches the provided message/subscriber combination.
func (*ContestFilter) String ¶
func (f *ContestFilter) String() string
type Filter ¶
type Filter interface {
String() string
Matches(msg *Message, subscriber *Subscriber) bool
}
Filter is used to determine whether messages should be sent to a particular subscriber.
type Message ¶
type Message struct {
Contest string `json:"contest,omitempty"`
Problemset int64 `json:"problemset,omitempty"`
Problem string `json:"problem,omitempty"`
User string `json:"user,omitempty"`
Public bool `json:"public"`
Message string `json:"message"`
}
A Message is a message that will be broadcast to Subscribers.
type Metrics ¶
type Metrics interface {
IncrementWebSocketsCount(delta int)
IncrementSSECount(delta int)
IncrementMessagesCount()
IncrementChannelDropCount()
ObserveDispatchMessageLatency(latency time.Duration)
ObserveProcessMessageLatency(latency time.Duration)
}
Metrics is the interface needed to publish performance metrics.
type ProblemFilter ¶
type ProblemFilter struct {
Filter
// contains filtered or unexported fields
}
A ProblemFilter is a Filter that only allows Messages that are associated with a particular problem.
func (*ProblemFilter) Matches ¶
func (f *ProblemFilter) Matches(msg *Message, subscriber *Subscriber) bool
Matches returns whether the current ProblemFilter matches the provided message/subscriber combination.
func (*ProblemFilter) String ¶
func (f *ProblemFilter) String() string
type ProblemsetFilter ¶ added in v1.1.0
type ProblemsetFilter struct {
Filter
// contains filtered or unexported fields
}
A ProblemsetFilter is a Filter that only allows Messages that are associated with a particular problemset.
func (*ProblemsetFilter) Matches ¶ added in v1.1.0
func (f *ProblemsetFilter) Matches(msg *Message, subscriber *Subscriber) bool
Matches returns whether the current ProblemsetFilter matches the provided message/subscriber combination.
func (*ProblemsetFilter) String ¶ added in v1.1.0
func (f *ProblemsetFilter) String() string
type QueuedMessage ¶
type QueuedMessage struct {
// contains filtered or unexported fields
}
A QueuedMessage is a message that may be broadcast to relevant Subscribers. It also performs latency analysis.
func (*QueuedMessage) Dispatched ¶
func (m *QueuedMessage) Dispatched()
Dispatched signals that this message has been dispatched. It is used to perform latency analysis.
func (*QueuedMessage) Processed ¶
func (m *QueuedMessage) Processed()
Processed signals that this message has been processed and has been enqueued in all the relevant Subscribers' queues.
type SSETransport ¶
type SSETransport struct {
// contains filtered or unexported fields
}
A SSETransport is a Transport that uses Server-Side Events to deliver events.
func (*SSETransport) Init ¶
func (t *SSETransport) Init(close chan<- struct{})
Init sends the necessary headers to signal that this is a SSE response.
func (*SSETransport) Ping ¶
func (t *SSETransport) Ping() error
Ping sends an empty message to prevent the underlying connection from being closed due to inactivity.
func (*SSETransport) ReadLoop ¶
func (t *SSETransport) ReadLoop()
ReadLoop waits until the underlying connection is closed, since the subscriber cannot send anything to us.
func (*SSETransport) Send ¶
func (t *SSETransport) Send(message *QueuedMessage) error
Send sends the provided message.
func (*SSETransport) String ¶
func (t *SSETransport) String() string
type Subscriber ¶
type Subscriber struct {
// contains filtered or unexported fields
}
A Subscriber represents a user that wishes to receive broadcast notifications.
func NewSubscriber ¶
func NewSubscriber( ctx *common.Context, client *http.Client, requestURL *url.URL, authToken string, filterString string, transport Transport, ) (*Subscriber, error)
NewSubscriber creates a new Subscriber.
func (*Subscriber) Matches ¶
func (s *Subscriber) Matches(msg *Message) bool
Matches returns whether the provided message should be sent to the current subscriber.
func (*Subscriber) Run ¶
func (s *Subscriber) Run()
Run loops waiting for one of three events to happen: connection closure, a new message is ready to be delivered to this subscriber, and periodic ping ticks.
func (*Subscriber) Send ¶
func (s *Subscriber) Send() chan<- *QueuedMessage
Send returns the send channel, where messages can be added to.
type Transport ¶
type Transport interface {
fmt.Stringer
// Init performs any initialization and sets a channel that will be closed by
// the Transport if the connection is closed.
Init(close chan<- struct{})
// Close writes the WebSockets Close message to notify the subscriber that
// the socket is going away.
Close()
// Ping sends an empty message to the subscriber, to ensure that the
// underlying channel is not closed due to inactivity.
Ping() error
// ReadLoop consumes any input sent by the subscriber.
ReadLoop()
// Send sends a message to the subscriber.
Send(message *QueuedMessage) error
}
A Transport exposes the interface needed to broadcast events to a subscriber.
func NewSSETransport ¶
func NewSSETransport(w http.ResponseWriter) Transport
NewSSETransport creates a new SSETransport for the provided ResponseWriter.
type UpstreamError ¶
An UpstreamError represents an error that comes from the frontend.
func (*UpstreamError) Error ¶
func (e *UpstreamError) Error() string
type UserFilter ¶
type UserFilter struct {
Filter
// contains filtered or unexported fields
}
A UserFilter is a Filter that only allows Messages that are associated with a particular user.
func (*UserFilter) Matches ¶
func (f *UserFilter) Matches(msg *Message, subscriber *Subscriber) bool
Matches returns whether the current UserFilter matches the provided message/subscriber combination.
func (*UserFilter) String ¶
func (f *UserFilter) String() string
type ValidateFilterResponse ¶
type ValidateFilterResponse struct {
User string `json:"user"`
Admin bool `json:"admin"`
ProblemAdmin []string `json:"problem_admin"`
ContestAdmin []string `json:"contest_admin"`
ProblemsetAdmin []int64 `json:"problemset_admin"`
}
A ValidateFilterResponse holds the results of a Validate request.
type WebSocketTransport ¶
type WebSocketTransport struct {
// contains filtered or unexported fields
}
A WebSocketTransport is a transport that uses WebSockets to deliver events.
func (*WebSocketTransport) Close ¶
func (t *WebSocketTransport) Close()
Close writes the WebSockets Close message to notify the subscriber that the socket is going away. It does not actually signals the close channel, since that will happen as soon as we receive the Close message from the subscriber.
func (*WebSocketTransport) Init ¶
func (t *WebSocketTransport) Init(close chan<- struct{})
Init sets a channel that will be closed by the Transport if the connection is closed.
func (*WebSocketTransport) Ping ¶
func (t *WebSocketTransport) Ping() error
Ping sends a WebSockets Ping message to prevent the underlying socket from being closed due to inactivity.
func (*WebSocketTransport) ReadLoop ¶
func (t *WebSocketTransport) ReadLoop()
ReadLoop reads (and discards) all incoming messages.
func (*WebSocketTransport) Send ¶
func (t *WebSocketTransport) Send(message *QueuedMessage) error
Send sends the provided message.
func (*WebSocketTransport) String ¶
func (t *WebSocketTransport) String() string
Source Files