Documentation
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Overview ¶
Package notifyqueue is the durable delivery queue: the PostgreSQL implementation of notification.QueueStore over the notifications table, and the LISTEN side of the pg_notify wakeup it fires on every enqueue.
The store and the listener are two halves of one mechanism — the store NOTIFYs on NotifyChannel, the listener LISTENs on it and wakes the send worker — so they share this package and the channel name that binds them.
Index ¶
- Constants
- type Listener
- type PostgresStore
- func (s *PostgresStore) ClaimDigest(ctx context.Context, lease time.Duration) ([]notification.Notification, error)
- func (s *PostgresStore) ClaimImmediate(ctx context.Context, lease time.Duration) (*notification.Notification, error)
- func (s *PostgresStore) Count(ctx context.Context, filter notification.HistoryFilter) (int, error)
- func (s *PostgresStore) CountsByStatus(ctx context.Context, filter notification.HistoryFilter) (map[string]int, error)
- func (s *PostgresStore) Enqueue(ctx context.Context, n notification.Notification) error
- func (s *PostgresStore) Fail(ctx context.Context, ids []int64, sendErr string) error
- func (s *PostgresStore) List(ctx context.Context, filter notification.HistoryFilter) ([]notification.Notification, error)
- func (s *PostgresStore) MarkSent(ctx context.Context, ids []int64) error
- func (s *PostgresStore) PurgeOld(ctx context.Context, resolvedRetention, pendingTTL time.Duration) (int64, error)
- func (s *PostgresStore) Retry(ctx context.Context, ids []int64, sendErr string, backoff time.Duration) error
Constants ¶
const NotifyChannel = "notifications"
NotifyChannel is the pg_notify channel that wakes the send worker when a row is enqueued. Producers fire it best-effort; the worker also polls.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Listener ¶
type Listener struct {
// contains filtered or unexported fields
}
Listener is the LISTEN side of the queue's LISTEN/NOTIFY adapter. Enqueue fires NOTIFY; this goroutine receives it and wakes the worker so immediate notifications go out without waiting for the poll interval.
func NewListener ¶
NewListener constructs a Listener for the supplied DSN. It does not connect until Start is called.
type PostgresStore ¶
type PostgresStore struct {
// contains filtered or unexported fields
}
PostgresStore implements notification.QueueStore backed by the notifications table.
func NewPostgresStore ¶
func NewPostgresStore(db *sql.DB) *PostgresStore
NewPostgresStore creates a PostgreSQL-backed notification queue.
func (*PostgresStore) ClaimDigest ¶
func (s *PostgresStore) ClaimDigest(ctx context.Context, lease time.Duration) ([]notification.Notification, error)
ClaimDigest claims all due digest rows for the recipient with the oldest due digest row. Concurrent workers racing for the same recipient are safe: the loser's UPDATE matches zero rows and reports notification.ErrNoWork.
func (*PostgresStore) ClaimImmediate ¶
func (s *PostgresStore) ClaimImmediate(ctx context.Context, lease time.Duration) (*notification.Notification, error)
ClaimImmediate claims the next due non-digest row.
func (*PostgresStore) Count ¶
func (s *PostgresStore) Count(ctx context.Context, filter notification.HistoryFilter) (int, error)
Count returns how many rows match the filter, ignoring its paging fields.
func (*PostgresStore) CountsByStatus ¶
func (s *PostgresStore) CountsByStatus(ctx context.Context, filter notification.HistoryFilter) (map[string]int, error)
CountsByStatus returns the per-status row counts for the filter. Statuses with no rows are absent from the map; callers render a zero for them.
func (*PostgresStore) Enqueue ¶
func (s *PostgresStore) Enqueue(ctx context.Context, n notification.Notification) error
Enqueue inserts a pending notification row and fires a best-effort pg_notify so a listening worker wakes without waiting for the next poll.
func (*PostgresStore) List ¶
func (s *PostgresStore) List(ctx context.Context, filter notification.HistoryFilter) ([]notification.Notification, error)
List returns one page of notification history, newest first.
func (*PostgresStore) MarkSent ¶
func (s *PostgresStore) MarkSent(ctx context.Context, ids []int64) error
MarkSent transitions claimed rows to sent.
Source Files