examples/aqua-examples/decentralized-blockchain-gateway/gateway/aqua/rpc.aqua

import "@fluencelabs/aqua-lib/builtin.aqua"

export randomLoadBalancingEth, roundRobinEth, Counter, Logger

data EthResult:
  value: string
  success: bool
  error: string

service Logger("logger"):
  log(s: []string)
  logCall(s: string)

service NumOp("op"):
  identity(n: u64) -> i64

service Counter("counter"):
  incrementAndReturn() -> u32

func empty() -> EthResult:
  <- EthResult(value = "", success = true, error = "")

service EthCaller:
  eth_call(uri: string, method: string, jsonArgs: []string) -> EthResult

func call(uri: string, method: string, jsonArgs: []string, serviceId: string) -> EthResult:
  EthCaller serviceId
  on HOST_PEER_ID:
    res <- EthCaller.eth_call(uri, method, jsonArgs)
  <- res

func randomLoadBalancing(uris: []string, method: string, jsonArgs: []string, serviceId: string, callFunc: string, string, []string, string -> EthResult) -> EthResult:
  on INIT_PEER_ID:
    time <- NumOp.identity(Peer.timestamp_sec())
    providerNumber = time % Op.array_length(uris)
    Logger.logCall(uris[providerNumber])
  <- callFunc(uris[providerNumber], method, jsonArgs, serviceId)

func randomLoadBalancingEth(uris: []string, method: string, jsonArgs: []string, serviceId: string) -> EthResult:
  <- randomLoadBalancing(uris, method, jsonArgs, serviceId, call)

func roundRobin(uris: []string, method: string, jsonArgs: []string, serviceId: string, counterServiceId: string, counterPeerId: string, callFunc: string, string, []string, string -> EthResult) -> EthResult:
  on counterPeerId:
    Counter counterServiceId
    requestNumber <- Counter.incrementAndReturn()
  on INIT_PEER_ID:
    providerNumber = requestNumber % Op.array_length(uris)
    Logger.logCall(uris[providerNumber])
  <- callFunc(uris[providerNumber], method, jsonArgs, serviceId)

func roundRobinEth(uris: []string, method: string, jsonArgs: []string, serviceId: string, counterServiceId: string, counterPeerId: string) -> EthResult:
  <- roundRobin(uris, method, jsonArgs, serviceId, counterServiceId, counterPeerId, call)