51 lines
1.4 KiB
Nim
51 lines
1.4 KiB
Nim
import std/times
|
|
import pkg/ethers
|
|
import pkg/chronos
|
|
import pkg/stint
|
|
import ../clock
|
|
|
|
export clock
|
|
|
|
type
|
|
OnChainClock* = ref object of Clock
|
|
provider: Provider
|
|
subscription: Subscription
|
|
offset: times.Duration
|
|
started: bool
|
|
newBlock: AsyncEvent
|
|
|
|
proc new*(_: type OnChainClock, provider: Provider): OnChainClock =
|
|
OnChainClock(provider: provider, newBlock: newAsyncEvent())
|
|
|
|
proc start*(clock: OnChainClock) {.async.} =
|
|
if clock.started:
|
|
return
|
|
clock.started = true
|
|
|
|
proc onBlock(blck: Block) {.async, upraises:[].} =
|
|
let blockTime = initTime(blck.timestamp.truncate(int64), 0)
|
|
let computerTime = getTime()
|
|
clock.offset = blockTime - computerTime
|
|
clock.newBlock.fire()
|
|
|
|
if latestBlock =? (await clock.provider.getBlock(BlockTag.latest)):
|
|
await onBlock(latestBlock)
|
|
|
|
clock.subscription = await clock.provider.subscribe(onBlock)
|
|
|
|
proc stop*(clock: OnChainClock) {.async.} =
|
|
if not clock.started:
|
|
return
|
|
clock.started = false
|
|
|
|
await clock.subscription.unsubscribe()
|
|
|
|
method now*(clock: OnChainClock): SecondsSince1970 =
|
|
doAssert clock.started, "clock should be started before calling now()"
|
|
toUnix(getTime() + clock.offset)
|
|
|
|
method waitUntil*(clock: OnChainClock, time: SecondsSince1970) {.async.} =
|
|
while (let difference = time - clock.now(); difference > 0):
|
|
clock.newBlock.clear()
|
|
discard await clock.newBlock.wait().withTimeout(chronos.seconds(difference))
|