nwaku/waku/waku_rln_relay/nonce_manager.nim

60 lines
1.5 KiB
Nim

{.push raises: [].}
import chronos, results, times
import ./constants
export chronos, times, results, constants
# This module contains the NonceManager interface
# The NonceManager is responsible for managing the messageId used to generate RLN proofs
# It should be used to fetch a new messageId every time a proof is generated
# It refreshes the messageId every `epoch` seconds
type
Nonce* = uint64
NonceManager* = ref object of RootObj
epoch*: float64
nextNonce*: Nonce
lastNonceTime*: float64
nonceLimit*: Nonce
NonceManagerErrorKind* = enum
NonceLimitReached
NonceManagerError* = object
kind*: NonceManagerErrorKind
error*: string
NonceManagerResult*[T] = Result[T, NonceManagerError]
proc `$`*(ne: NonceManagerError): string =
case ne.kind
of NonceLimitReached:
return "NonceLimitReached: " & ne.error
proc init*(T: type NonceManager, nonceLimit: Nonce, epoch = 1.float64): T =
return
NonceManager(epoch: epoch, nextNonce: 0, lastNonceTime: 0, nonceLimit: nonceLimit)
proc getNonce*(n: NonceManager): NonceManagerResult[Nonce] =
let now = getTime().toUnixFloat()
var retNonce = n.nextNonce
if now - n.lastNonceTime >= n.epoch:
retNonce = 0
n.lastNonceTime = now
n.nextNonce = retNonce + 1
if retNonce >= n.nonceLimit:
return err(
NonceManagerError(
kind: NonceLimitReached,
error:
"Nonce limit reached. Please wait for the next epoch. requested nonce: " &
$retNonce & " & nonceLimit: " & $n.nonceLimit,
)
)
return ok(retNonce)