class Faulty::Storage::Interface
The interface required for a storage backend implementation
This is for documentation only and is not loaded
Public Instance Methods
Set the circuit state to closed
If multiple parallel processes close the circuit simultaneously, close may be called more than once. If so, this method should return true only once, when the circuit transitions from open to closed.
If the backend does not support locking or atomic operations, then it may always return true, but that could result in duplicate close notifications.
@return [Boolean] True if the circuit transitioned from open to closed
# File lib/faulty/storage/interface.rb, line 74 def close(circuit) raise NotImplementedError end
Add a circuit run entry to storage
The backend may choose to store this in whatever manner it chooses as long as it can implement the other read methods.
@param circuit [Circuit] The circuit that ran @param time [Integer] The unix timestamp for the run @param success [Boolean] True if the run succeeded @return [Array<Array>] An array of the new history tuples after adding
the new entry, see {#history}
# File lib/faulty/storage/interface.rb, line 19 def entry(circuit, time, success) raise NotImplementedError end
Can this storage backend raise an error?
If the storage backend returns false from this method, it will be wrapped in a {FaultTolerantProxy}, otherwise it will be used as-is.
@return [Boolean] True if this cache backend is fault tolerant
# File lib/faulty/storage/interface.rb, line 157 def fault_tolerant? raise NotImplementedError end
Get the entry history of a circuit
No concurrency gurantees are provided for getting status. It's possible that status may represent a circuit in the middle of modification.
A storage backend may choose not to implement this method and instead return an empty array.
Each item in the history array is an array of two items (a tuple) of `[run_time, succeeded]`, where `run_time` is a unix timestamp, and `succeeded` is a boolean, true if the run succeeded.
@param circuit [Circuit] The circuit to get history for @return [Array<Array>] An array of history tuples
# File lib/faulty/storage/interface.rb, line 137 def history(circuit) raise NotImplementedError end
Get a list of all circuit names
If the storage backend does not support listing circuits, this may return an empty array.
@return [Array<String>]
# File lib/faulty/storage/interface.rb, line 147 def list raise NotImplementedError end
Lock the circuit in a given state
No concurrency gurantees are provided for locking
@param circuit [Circuit] The circuit to lock @param state [:open, :closed] The state to lock the circuit in @return [void]
# File lib/faulty/storage/interface.rb, line 85 def lock(circuit, state) raise NotImplementedError end
Set the circuit state to open
If multiple parallel processes open the circuit simultaneously, open may be called more than once. If so, this method should return true only once, when the circuit transitions from closed to open.
If the backend does not support locking or atomic operations, then it may always return true, but that could result in duplicate open notifications.
If returning true, this method also updates opened_at to the current time.
@param circuit [Circuit] The circuit to open @param opened_at [Integer] The timestmp the circuit was opened at @return [Boolean] True if the circuit transitioned from closed to open
# File lib/faulty/storage/interface.rb, line 39 def open(circuit, opened_at) raise NotImplementedError end
Reset the opened_at time for a half_open circuit
If multiple parallel processes open the circuit simultaneously, reopen may be called more than once. If so, this method should return true only once, when the circuit updates the opened_at value. It can use the value from previous_opened_at to do a compare-and-set operation.
If the backend does not support locking or atomic operations, then it may always return true, but that could result in duplicate reopen notifications.
@param circuit [Circuit] The circuit to reopen @param opened_at [Integer] The timestmp the circuit was opened at @param previous_opened_at [Integer] The last known value of opened_at.
Can be used to comare-and-set.
@return [Boolean] True if the opened_at time was updated
# File lib/faulty/storage/interface.rb, line 59 def reopen(circuit, opened_at, previous_opened_at) raise NotImplementedError end
Reset the circuit to a fresh state
Clears all circuit status including entries, state, locks, opened_at, and any other values that would affect Status.
No concurrency gurantees are provided for resetting
@param circuit [Circuit] The circuit to unlock @return [void]
# File lib/faulty/storage/interface.rb, line 108 def reset(circuit) raise NotImplementedError end
Get the status object for a circuit
No concurrency gurantees are provided for getting status. It's possible that status may represent a circuit in the middle of modification.
@param circuit [Circuit] The circuit to get status for @return [Status] The current status
# File lib/faulty/storage/interface.rb, line 119 def status(circuit) raise NotImplementedError end
Unlock the circuit from any state
No concurrency gurantees are provided for locking
@param circuit [Circuit] The circuit to unlock @return [void]
# File lib/faulty/storage/interface.rb, line 95 def unlock(circuit) raise NotImplementedError end