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ActiveGo 1.8Package lease
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Constants
const (
// NoLease is a special LeaseID representing the absence of a lease.
NoLease = LeaseID(0)
)
Variables
var (
ErrNotPrimary = errors.New("not a primary lessor")
ErrLeaseNotFound = errors.New("lease not found")
ErrLeaseExists = errors.New("lease already exists")
)
type FakeLessor ¶
FakeLessor is a fake implementation of Lessor interface. Used for testing only.
type FakeLessor struct{}
func (*FakeLessor) Attach ¶
func (fl *FakeLessor) Attach(id LeaseID, items []LeaseItem) error
func (*FakeLessor) Demote ¶
func (fl *FakeLessor) Demote()
func (*FakeLessor) Detach ¶
func (fl *FakeLessor) Detach(id LeaseID, items []LeaseItem) error
func (*FakeLessor) ExpiredLeasesC ¶
func (fl *FakeLessor) ExpiredLeasesC() <-chan []*Lease
func (*FakeLessor) GetLease ¶
func (fl *FakeLessor) GetLease(item LeaseItem) LeaseID
func (*FakeLessor) Grant ¶
func (fl *FakeLessor) Grant(id LeaseID, ttl int64) (*Lease, error)
func (*FakeLessor) Lookup ¶
func (le *FakeLessor) Lookup(id LeaseID) *Lease
func (*FakeLessor) Promote ¶
func (fl *FakeLessor) Promote(extend time.Duration)
func (*FakeLessor) Recover ¶
func (fl *FakeLessor) Recover(b backend.Backend, rd RangeDeleter)
func (*FakeLessor) Renew ¶
func (fl *FakeLessor) Renew(id LeaseID) (int64, error)
func (*FakeLessor) Revoke ¶
func (fl *FakeLessor) Revoke(id LeaseID) error
func (*FakeLessor) SetRangeDeleter ¶
func (fl *FakeLessor) SetRangeDeleter(dr RangeDeleter)
func (*FakeLessor) Stop ¶
func (fl *FakeLessor) Stop()
type Lease ¶
type Lease struct {
ID LeaseID
// contains filtered or unexported fields
}
func (*Lease) Keys ¶
func (l *Lease) Keys() []string
Keys returns all the keys attached to the lease.
func (*Lease) Remaining ¶
func (l *Lease) Remaining() time.Duration
Remaining returns the remaining time of the lease.
func (*Lease) TTL ¶
func (l *Lease) TTL() int64
TTL returns the TTL of the Lease.
type LeaseID ¶
type LeaseID int64
type LeaseItem ¶
type LeaseItem struct {
Key string
}
type Lessor ¶
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)
// 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
// 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
// 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 ¶
func NewLessor(b backend.Backend, minLeaseTTL int64) Lessor
type RangeDeleter ¶
RangeDeleter is a TxnDelete constructor.
type RangeDeleter func() TxnDelete
type 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()
}