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 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) 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) 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

                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
                
                	// 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(b backend.Backend, minLeaseTTL int64) Lessor

                  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

                      Directories

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