taskdb

type AttachIterator interface {
	// Returns an array of task states. Returns nil when there are no more, safe to call multiple times when empty
	Next() ([]*TaskDBTaskState, error)
}

type BadgerAttachIterator struct {
	// contains filtered or unexported fields
}

type BadgerDrainIterator struct {
	// contains filtered or unexported fields
}

type BadgerTaskDB struct {
	// contains filtered or unexported fields
}

type BadgerTaskStateWithID struct {
	State   *TaskDBTaskState
	ID      []byte
	Payload string
}

type BadgerWriteResult struct {
	// contains filtered or unexported fields
}

type DrainIterator interface {
	// Returns an array of task payloads that can be joined to their current states, and sent to other partitions. Returns nil when there are no more, safe to call multiple times when empty
	Next() ([]*DrainTask, error)
}

type DrainTask struct {
	Topic    string
	Priority int32
	Payload  string
}

type FakeAttachIterator struct{}

type MemoryDrainIterator struct {
	// contains filtered or unexported fields
}

type MemoryTaskDB struct {
	// contains filtered or unexported fields
}

type MemoryWriteResult struct{}

type TaskDB interface {
	// Acquires the TaskDB lock as needed, then returns an AttachIterator
	Attach() AttachIterator

	// A Task will be inserted into the task table, and its first state inserted
	PutPayload(topicName, taskID string, payload string) WriteResult

	// A new task state
	PutState(state *TaskDBTaskState) WriteResult

	// Retrieves the payload for a given task
	GetPayload(topicName, taskID string) (string, error)

	// Deletes all task states for a topic, and removes the topic from the task table. If no more tasks exist then the task will be removed from the task table
	Delete(topicName, taskID string) WriteResult

	// Returns an iterator that will read all payloads from the DB, so they can be drained into other partitions
	Drain() DrainIterator
}

type TaskDBTaskState struct {
	Topic     string
	Partition string

	ID               string
	State            TaskState
	Version          int32
	DeliveryAttempts int32
	CreatedAt        time.Time
	Priority         int32
}

type TaskState int32

type WriteResult interface {
	// Waits for the write to be committed to the TaskDB.
	// Should use a buffered channel to wait for a batch to be committed.
	// If the TaskDB does not batch it should still immediately write to
	// the buffered channel so that function calls are non-blocking and
	// return immediately
	Get() error
}