87 lines
2.6 KiB
Nim
87 lines
2.6 KiB
Nim
import std/times
|
|
import pkg/stint
|
|
import pkg/chronos
|
|
import pkg/questionable
|
|
import pkg/nimcrypto
|
|
import ./market
|
|
|
|
export questionable
|
|
export market
|
|
|
|
type
|
|
Purchasing* = ref object
|
|
market: Market
|
|
proofProbability*: UInt256
|
|
requestExpiryInterval*: UInt256
|
|
offerExpiryMargin*: UInt256
|
|
Purchase* = ref object
|
|
future: Future[void]
|
|
market: Market
|
|
offerExpiryMargin: UInt256
|
|
request*: StorageRequest
|
|
offers*: seq[StorageOffer]
|
|
selected*: ?StorageOffer
|
|
|
|
const DefaultProofProbability = 100.u256
|
|
const DefaultRequestExpiryInterval = (10 * 60).u256
|
|
const DefaultOfferExpiryMargin = (8 * 60).u256
|
|
|
|
proc start(purchase: Purchase) {.gcsafe.}
|
|
|
|
proc new*(_: type Purchasing, market: Market): Purchasing =
|
|
Purchasing(
|
|
market: market,
|
|
proofProbability: DefaultProofProbability,
|
|
requestExpiryInterval: DefaultRequestExpiryInterval,
|
|
offerExpiryMargin: DefaultOfferExpiryMargin
|
|
)
|
|
|
|
proc populate*(purchasing: Purchasing, request: StorageRequest): StorageRequest =
|
|
result = request
|
|
if result.ask.proofProbability == 0.u256:
|
|
result.ask.proofProbability = purchasing.proofProbability
|
|
if result.expiry == 0.u256:
|
|
result.expiry = (getTime().toUnix().u256 + purchasing.requestExpiryInterval)
|
|
if result.nonce == array[32, byte].default:
|
|
doAssert randomBytes(result.nonce) == 32
|
|
|
|
proc purchase*(purchasing: Purchasing, request: StorageRequest): Purchase =
|
|
let request = purchasing.populate(request)
|
|
let purchase = Purchase(
|
|
request: request,
|
|
market: purchasing.market,
|
|
offerExpiryMargin: purchasing.offerExpiryMargin
|
|
)
|
|
purchase.start()
|
|
purchase
|
|
|
|
proc selectOffer(purchase: Purchase) {.async.} =
|
|
var cheapest: ?StorageOffer
|
|
for offer in purchase.offers:
|
|
without getTime().toUnix().u256 < offer.expiry - purchase.offerExpiryMargin:
|
|
continue
|
|
without current =? cheapest:
|
|
cheapest = some offer
|
|
continue
|
|
if current.price > offer.price:
|
|
cheapest = some offer
|
|
if cheapest =? cheapest:
|
|
await purchase.market.selectOffer(cheapest.id)
|
|
|
|
proc run(purchase: Purchase) {.async.} =
|
|
proc onOffer(offer: StorageOffer) =
|
|
purchase.offers.add(offer)
|
|
let market = purchase.market
|
|
purchase.request = await market.requestStorage(purchase.request)
|
|
let subscription = await market.subscribeOffers(purchase.request.id, onOffer)
|
|
await market.waitUntil(purchase.request.expiry)
|
|
await purchase.selectOffer()
|
|
await subscription.unsubscribe()
|
|
|
|
proc start(purchase: Purchase) =
|
|
purchase.future = purchase.run()
|
|
asyncSpawn purchase.future
|
|
|
|
proc wait*(purchase: Purchase) {.async.} =
|
|
await purchase.future
|