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Index ¶
Constants ¶
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const ( // LeaseFieldName is the name of the fields that specifies the lock lease duration for a lock LeaseFieldName = "dynoLockLeaseDuration" // VersionFieldName is the name of the fields that specifies the version of the record used for locking VersionFieldName = "dynoLockVersion" // ExpiresFieldName is the name of the fields that specifies when the lock will expire ExpiresFieldName = "dynoLockExpires" )
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const ( //DefaultTimeout is the default timeout for the lock DefaultTimeout = time.Second //DefaultLeaseDuration is the default lock lease duration DefaultLeaseDuration = time.Millisecond * 500 //DefaultHeartbeatFrequency is the default hertbean freq DefaultHeartbeatFrequency = time.Millisecond * 100 )
Variables ¶
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var ( //ErrLockFailedToAcquire returned by Lock.Acquire if lock could not be acquired ErrLockFailedToAcquire = errors.New("lock failed to be acquired") //ErrLockFailedLeaseRenewal returned by Lock if lock lease could not be renewed ErrLockFailedLeaseRenewal = errors.New("lock failed to renew its lease") //ErrConditionalCheckFailedException returned when lock fails a conditional check ErrConditionalCheckFailedException = errors.New("lock failed on conditional check") // ErrLockTimeout returned when lock cannot be acquired due to a timeout ErrLockTimeout = errors.New("lock timeout") )
Functions ¶
This section is empty.
Types ¶
type Lock ¶
type Lock struct {
DB *dyno.Session
Key map[string]types.AttributeValue // the item that is being locked
TableName string
SessionID *string // this lock sessionId
HasLock bool // whether or not we have a lock
LockTimeout time.Duration // the lock timeout
LockHeartbeatFrequency time.Duration // the lock heartbeat frequency. We will update the lock expiration with every heartbeat
LeaseDuration time.Duration // the lease duration or how much time we will lease the lock for. This must be greater than or equal to heartbeat freq.
Context context.Context // context of the lock, should be released on cancel
// contains filtered or unexported fields
}
Lock is a representation of a lock on a specific record in a table
func Acquire ¶
func Acquire(tableName string, itemKey interface{}, db *dyno.Session, opts ...Opt) (lock *Lock, err error)
Acquire acquires a lock for a given table with a given map of key fields
func MustAcquire ¶
MustAcquire acquires a lock or panics
func (*Lock) Acquire ¶
Acquire the lock by attempting to update release the lock.
will wait for a given time duration to acquire the lock
func (*Lock) MustRelease ¶
func (dl *Lock) MustRelease()
MustRelease attempts to release the lock and panics on error
func (*Lock) StartHeartbeat ¶
func (dl *Lock) StartHeartbeat()
StartHeartbeat starts a go routine that will update the lease no the lock even “freq“
type Opt ¶
type Opt func(*Opts)
Opt is an option
func OptHeartbeatFrequency ¶
OptHeartbeatFrequency sets the heartbeat frequency for the lock
func OptLeaseDuration ¶
OptLeaseDuration sets the lease duration
func OptTimeout ¶
OptTimeout sets the timeout for the lock
type Opts ¶
type Opts struct {
Table *dyno.Table `validate:"required"`
Item interface{} `validate:"required"`
Timeout time.Duration
HeartbeatFrequency time.Duration
LeaseDuration time.Duration
Context context.Context
}
Opts is used as the input for the Acquire func Required:
Document: the record that will be locked KeyValues: the key fields for the record that will be locked
Optional:
Timeout: the timeout as DurationNano for the lock HeartbeatFreq: the freq of the heartbeat to renew the lock lease LeaseDuration: the duration of the lease as a DurationNano
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