MaxLeaseTTL is the maximum lease TTL value
const MaxLeaseTTL = 9000000000
NoLease is a special LeaseID representing the absence of a lease.
const NoLease = LeaseID(0)
var (
ErrNotPrimary = errors.New("not a primary lessor")
ErrLeaseNotFound = errors.New("lease not found")
ErrLeaseExists = errors.New("lease already exists")
ErrLeaseTTLTooLarge = errors.New("too large lease TTL")
)
Checkpointer permits checkpointing of lease remaining TTLs to the consensus log. Defined here to avoid circular dependency with mvcc.
type Checkpointer func(ctx context.Context, lc *pb.LeaseCheckpointRequest) error
FakeLessor is a fake implementation of Lessor interface. Used for testing only.
type FakeLessor struct{}
func (fl *FakeLessor) Attach(id LeaseID, items []LeaseItem) error
func (fl *FakeLessor) Checkpoint(id LeaseID, remainingTTL int64) error
func (fl *FakeLessor) Demote()
func (fl *FakeLessor) Detach(id LeaseID, items []LeaseItem) error
func (fl *FakeLessor) ExpiredLeasesC() <-chan []*Lease
func (fl *FakeLessor) GetLease(item LeaseItem) LeaseID
func (fl *FakeLessor) Grant(id LeaseID, ttl int64) (*Lease, error)
func (fl *FakeLessor) Leases() []*Lease
func (fl *FakeLessor) Lookup(id LeaseID) *Lease
func (fl *FakeLessor) Promote(extend time.Duration)
func (fl *FakeLessor) Recover(b backend.Backend, rd RangeDeleter)
func (fl *FakeLessor) Renew(id LeaseID) (int64, error)
func (fl *FakeLessor) Revoke(id LeaseID) error
func (fl *FakeLessor) SetCheckpointer(cp Checkpointer)
func (fl *FakeLessor) SetRangeDeleter(dr RangeDeleter)
func (fl *FakeLessor) Stop()
type FakeTxnDelete struct {
backend.BatchTx
}
func (ftd *FakeTxnDelete) DeleteRange(key, end []byte) (n, rev int64)
func (ftd *FakeTxnDelete) End()
type Lease struct {
ID LeaseID
// contains filtered or unexported fields
}
func NewLease(id LeaseID, ttl int64) *Lease
func (l *Lease) Keys() []string
Keys returns all the keys attached to the lease.
func (l *Lease) Remaining() time.Duration
Remaining returns the remaining time of the lease.
func (l *Lease) RemainingTTL() int64
RemainingTTL returns the last checkpointed remaining TTL of the lease. TODO(jpbetz): do not expose this utility method
func (l *Lease) SetLeaseItem(item LeaseItem)
SetLeaseItem sets the given lease item, this func is thread-safe
func (l *Lease) TTL() int64
TTL returns the TTL of the Lease.
LeaseExpiredNotifier is a queue used to notify lessor to revoke expired lease. Only save one item for a lease, `Register` will update time of the corresponding lease.
type LeaseExpiredNotifier struct {
// contains filtered or unexported fields
}
func (mq *LeaseExpiredNotifier) Init()
func (mq *LeaseExpiredNotifier) Len() int
func (mq *LeaseExpiredNotifier) Poll() *LeaseWithTime
func (mq *LeaseExpiredNotifier) RegisterOrUpdate(item *LeaseWithTime)
func (mq *LeaseExpiredNotifier) Unregister() *LeaseWithTime
type LeaseID int64
type LeaseItem struct {
Key string
}
type LeaseQueue []*LeaseWithTime
func (pq LeaseQueue) Len() int
func (pq LeaseQueue) Less(i, j int) bool
func (pq *LeaseQueue) Pop() interface{}
func (pq *LeaseQueue) Push(x interface{})
func (pq LeaseQueue) Swap(i, j int)
LeaseWithTime contains lease object with a time. For the lessor's lease heap, time identifies the lease expiration time. For the lessor's lease checkpoint heap, the time identifies the next lease checkpoint time.
type LeaseWithTime struct {
// contains filtered or unexported fields
}
Lessor owns leases. It can grant, revoke, renew and modify leases for lessee.
type Lessor interface {
// SetRangeDeleter lets the lessor create TxnDeletes to the store.
// Lessor deletes the items in the revoked or expired lease by creating
// new TxnDeletes.
SetRangeDeleter(rd RangeDeleter)
SetCheckpointer(cp Checkpointer)
// Grant grants a lease that expires at least after TTL seconds.
Grant(id LeaseID, ttl int64) (*Lease, error)
// Revoke revokes a lease with given ID. The item attached to the
// given lease will be removed. If the ID does not exist, an error
// will be returned.
Revoke(id LeaseID) error
// Checkpoint applies the remainingTTL of a lease. The remainingTTL is used in Promote to set
// the expiry of leases to less than the full TTL when possible.
Checkpoint(id LeaseID, remainingTTL int64) error
// Attach attaches given leaseItem to the lease with given LeaseID.
// If the lease does not exist, an error will be returned.
Attach(id LeaseID, items []LeaseItem) error
// GetLease returns LeaseID for given item.
// If no lease found, NoLease value will be returned.
GetLease(item LeaseItem) LeaseID
// Detach detaches given leaseItem from the lease with given LeaseID.
// If the lease does not exist, an error will be returned.
Detach(id LeaseID, items []LeaseItem) error
// Promote promotes the lessor to be the primary lessor. Primary lessor manages
// the expiration and renew of leases.
// Newly promoted lessor renew the TTL of all lease to extend + previous TTL.
Promote(extend time.Duration)
// Demote demotes the lessor from being the primary lessor.
Demote()
// Renew renews a lease with given ID. It returns the renewed TTL. If the ID does not exist,
// an error will be returned.
Renew(id LeaseID) (int64, error)
// Lookup gives the lease at a given lease id, if any
Lookup(id LeaseID) *Lease
// Leases lists all leases.
Leases() []*Lease
// ExpiredLeasesC returns a chan that is used to receive expired leases.
ExpiredLeasesC() <-chan []*Lease
// Recover recovers the lessor state from the given backend and RangeDeleter.
Recover(b backend.Backend, rd RangeDeleter)
// Stop stops the lessor for managing leases. The behavior of calling Stop multiple
// times is undefined.
Stop()
}
func NewLessor(lg *zap.Logger, b backend.Backend, cluster cluster, cfg LessorConfig) Lessor
type LessorConfig struct {
MinLeaseTTL int64
CheckpointInterval time.Duration
ExpiredLeasesRetryInterval time.Duration
CheckpointPersist bool
}
RangeDeleter is a TxnDelete constructor.
type RangeDeleter func() TxnDelete
TxnDelete is a TxnWrite that only permits deletes. Defined here to avoid circular dependency with mvcc.
type TxnDelete interface {
DeleteRange(key, end []byte) (n, rev int64)
End()
}