lease

package
v3.5.0-beta.3 Latest Latest
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 Go to latest Published: May 18, 2021 License: Apache-2.0 Imports: 13 Imported by: 17

Documentation

Overview

Package lease provides an interface and implementation for time-limited leases over arbitrary resources.

Index

Constants

View Source 
const MaxLeaseTTL = 9000000000

MaxLeaseTTL is the maximum lease TTL value

View Source 
const NoLease = LeaseID(0)

NoLease is a special LeaseID representing the absence of a lease.

Variables

View Source 
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")
)

Functions

This section is empty.

Types

type Checkpointer 

type Checkpointer func(ctx context.Context, lc *pb.LeaseCheckpointRequest)

Checkpointer permits checkpointing of lease remaining TTLs to the consensus log. Defined here to avoid circular dependency with mvcc.

type FakeLessor 

type FakeLessor struct{}

FakeLessor is a fake implementation of Lessor interface. Used for testing only.

func (*FakeLessor) Attach 

func (fl *FakeLessor) Attach(id LeaseID, items []LeaseItem) error

func (*FakeLessor) Checkpoint 

func (fl *FakeLessor) Checkpoint(id LeaseID, remainingTTL int64) 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) Leases 

func (fl *FakeLessor) Leases() []*Lease

func (*FakeLessor) Lookup 

func (fl *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) SetCheckpointer 

func (fl *FakeLessor) SetCheckpointer(cp Checkpointer)

func (*FakeLessor) SetRangeDeleter 

func (fl *FakeLessor) SetRangeDeleter(dr RangeDeleter)

func (*FakeLessor) Stop 

func (fl *FakeLessor) Stop()

type FakeTxnDelete 

type FakeTxnDelete struct {
	backend.BatchTx
}

func (*FakeTxnDelete) DeleteRange 

func (ftd *FakeTxnDelete) DeleteRange(key, end []byte) (n, rev int64)

func (*FakeTxnDelete) End 

func (ftd *FakeTxnDelete) End()

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) RemainingTTL 

func (l *Lease) RemainingTTL() int64

RemainingTTL returns the last checkpointed remaining TTL of the lease. TODO(jpbetz): do not expose this utility method

func (*Lease) TTL 

func (l *Lease) TTL() int64

TTL returns the TTL of the Lease.

type LeaseExpiredNotifier 

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

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.

func (*LeaseExpiredNotifier) Init 

func (mq *LeaseExpiredNotifier) Init()

func (*LeaseExpiredNotifier) Len 

func (mq *LeaseExpiredNotifier) Len() int

func (*LeaseExpiredNotifier) Poll 

func (mq *LeaseExpiredNotifier) Poll() *LeaseWithTime

func (*LeaseExpiredNotifier) RegisterOrUpdate 

func (mq *LeaseExpiredNotifier) RegisterOrUpdate(item *LeaseWithTime)

func (*LeaseExpiredNotifier) Unregister 

func (mq *LeaseExpiredNotifier) Unregister() *LeaseWithTime

type LeaseID 

type LeaseID int64

type LeaseItem 

type LeaseItem struct {
	Key string
}

type LeaseQueue 

type LeaseQueue []*LeaseWithTime

func (LeaseQueue) Len 

func (pq LeaseQueue) Len() int

func (LeaseQueue) Less 

func (pq LeaseQueue) Less(i, j int) bool

func (*LeaseQueue) Pop 

func (pq *LeaseQueue) Pop() interface{}

func (*LeaseQueue) Push 

func (pq *LeaseQueue) Push(x interface{})

func (LeaseQueue) Swap 

func (pq LeaseQueue) Swap(i, j int)

type LeaseWithTime 

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

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 Lessor 

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()
}

Lessor owns leases. It can grant, revoke, renew and modify leases for lessee.

func NewLessor 

func NewLessor(lg *zap.Logger, b backend.Backend, cfg LessorConfig) Lessor

type LessorConfig 

type LessorConfig struct {
	MinLeaseTTL                int64
	CheckpointInterval         time.Duration
	ExpiredLeasesRetryInterval time.Duration
}

type RangeDeleter 

type RangeDeleter func() TxnDelete

RangeDeleter is a TxnDelete constructor.

type TxnDelete 

type TxnDelete interface {
	DeleteRange(key, end []byte) (n, rev int64)
	End()
}

TxnDelete is a TxnWrite that only permits deletes. Defined here to avoid circular dependency with mvcc.

Source Files

View all Source files

Directories

Path Synopsis
Package leasehttp serves lease renewals made through HTTP requests.
 Package leasehttp serves lease renewals made through HTTP requests.

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