Documentation
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Index ¶
- func ClearRejectedSchedulesCache()
- func IsScheduleRejected(schedule string) bool
- type Config
- type Executor
- type Heap
- func (h *Heap[T]) DueState(id string) (present, due bool)
- func (h *Heap[T]) Get(id string) (T, bool)
- func (h *Heap[T]) Len() int
- func (h *Heap[T]) Peek() (T, bool)
- func (h *Heap[T]) Pop() (T, bool)
- func (h *Heap[T]) PopIfDue() (T, bool)
- func (h *Heap[T]) Push(item T)
- func (h *Heap[T]) Remove(id string) bool
- func (h *Heap[T]) Snapshot() []T
- type Item
- type Scheduler
- func (s *Scheduler[T]) Add(item T) error
- func (s *Scheduler[T]) Count() int
- func (s *Scheduler[T]) DueState(id string) (present, due bool)
- func (s *Scheduler[T]) Get(id string) (T, bool)
- func (s *Scheduler[T]) IsLeader() bool
- func (s *Scheduler[T]) Remove(id string)
- func (s *Scheduler[T]) Run(ctx context.Context) error
- func (s *Scheduler[T]) SetIsLeader(fn func() bool)
- func (s *Scheduler[T]) SetItemResolver(fn func(T) T)
- func (s *Scheduler[T]) Snapshot() []T
- func (s *Scheduler[T]) ValidateSchedule(schedule string) error
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func ClearRejectedSchedulesCache ¶
func ClearRejectedSchedulesCache()
ClearRejectedSchedulesCache clears the cache of rejected schedules. This is primarily useful for testing.
func IsScheduleRejected ¶
IsScheduleRejected returns true if the given schedule has been cached as rejected. This is primarily useful for testing.
Types ¶
type Config ¶
type Config struct {
// MissedWindow is how late an item can be before skipping execution (default: 5m)
MissedWindow time.Duration
// IdleInterval is how long to sleep when heap is empty (default: 1m)
IdleInterval time.Duration
}
Config configures the generic scheduler behavior.
func DefaultConfig ¶
func DefaultConfig() Config
DefaultConfig returns the default scheduler configuration.
type Executor ¶
Executor is called when a scheduled item is due for execution. The executor should NOT reschedule the item - that's handled by the scheduler.
type Heap ¶
type Heap[T Item] struct { // contains filtered or unexported fields }
Heap is a generic min-heap ordered by NextExecution time. It is safe for concurrent use.
func (*Heap[T]) DueState ¶ added in v1.1.23
DueState reports whether an item with the given ID is currently in the heap and, if so, whether it is due (NextExecution <= now). An item that has been popped for execution is not in the heap and so reports present=false.
NextExecution is read under the heap lock: indexed items are never mutated in place (updates replace the index entry via Push under the same lock), so this is safe to call concurrently with the scheduler loop.
func (*Heap[T]) Get ¶
Get returns the item with the given ID, or the zero value of T and false if not found.
func (*Heap[T]) Peek ¶
Peek returns the next item without removing it from the heap. Returns the zero value of T and false if the heap is empty.
func (*Heap[T]) Pop ¶
Pop removes and returns the next item from the heap. Returns the zero value of T and false if the heap is empty.
func (*Heap[T]) PopIfDue ¶
PopIfDue removes and returns the next item if it's due (NextExecution <= now). Returns the zero value of T and false if the heap is empty or the next item is not yet due.
func (*Heap[T]) Push ¶
func (h *Heap[T]) Push(item T)
Push adds or updates an item in the heap. If an item with the same ID exists, it updates the entry and fixes the heap position.
type Item ¶
type Item interface {
// ID returns a unique identifier for this item.
ID() string
// Schedule returns the cron expression for this item.
Schedule() string
// NextExecution returns when this item should next execute.
NextExecution() time.Time
// SetNextExecution updates the next execution time.
SetNextExecution(time.Time)
// HeapIndex returns the current index in the heap (-1 if not in heap).
HeapIndex() int
// SetHeapIndex updates the heap index.
SetHeapIndex(int)
}
Item represents anything that can be scheduled. Implementations must be pointer types to support mutation of heap index.
type Scheduler ¶
type Scheduler[T Item] struct { // contains filtered or unexported fields }
Scheduler is a generic cron-based scheduler.
func NewScheduler ¶
NewScheduler creates a new generic scheduler.
func (*Scheduler[T]) Add ¶
Add adds or updates an item in the schedule. The item's Schedule() must return a valid cron expression.
func (*Scheduler[T]) DueState ¶ added in v1.1.23
DueState reports whether an item is currently scheduled (present in the heap) and, if so, whether its execution time has arrived. An item that has been popped for execution reports present=false. See Heap.DueState.
func (*Scheduler[T]) IsLeader ¶ added in v1.1.23
IsLeader reports whether this instance is currently the leader.
func (*Scheduler[T]) SetIsLeader ¶
SetIsLeader sets the leadership check callback. Only the leader actually executes items; non-leaders still maintain the heap.
func (*Scheduler[T]) SetItemResolver ¶
func (s *Scheduler[T]) SetItemResolver(fn func(T) T)
SetItemResolver sets the item resolver callback. When set, the scheduler calls this before rescheduling an item to get the latest version. This helps avoid race conditions where an item is updated while being executed.
func (*Scheduler[T]) Snapshot ¶ added in v1.1.23
func (s *Scheduler[T]) Snapshot() []T
Snapshot returns a copy of all items currently in the heap. Items are returned in arbitrary heap order.
func (*Scheduler[T]) ValidateSchedule ¶
ValidateSchedule checks if a cron schedule expression is valid. Returns nil if valid, or an error describing why it's invalid. Use this to pre-validate schedules before calling Add().
Source Files