feat(gateway): Refactor aqua (#115)

* Add Logger ability

* Rewrote random and round-robin

* Rewrote quorum

* Add comments

* Add config.mode check

* Update README

* Small fixes

* Update js-client

gateway/aqua/balancer.aqua

@@ -0,0 +1,55 @@
+module Balancer declares Balancer, ProviderBalancer, WorkersBalancer, randomBalancer, cycleBalancer
+
+import Worker from "@fluencelabs/aqua-lib/subnet.aqua"
+
+import Counter from "counter.aqua"
+import Random from "random.aqua"
+import Provider from "provider.aqua"
+
+ability WorkersBalancer:
+    nextWorker() -> Worker
+
+ability ProviderBalancer:
+    nextProvider() -> Provider
+
+ability Balancer:
+    nextWorker() -> Worker
+    nextProvider() -> Provider
+    next() -> Worker, Provider
+
+-- Create balancer that returns 
+-- workers and providers in random order
+func randomBalancer{Random}(workers: []Worker, providers: []Provider) -> Balancer:
+    -- closures do not capture topology here
+    nextWorker = func () -> Worker:
+        rand <- Random.next()
+        idx = rand % workers.length
+        <- workers[idx]
+
+    nextProvider = func () -> Provider:
+        rand <- Random.next()
+        idx = rand % providers.length
+        <- providers[idx]
+
+    next = func () -> Worker, Provider:
+        <- nextWorker(), nextProvider()
+
+    <- Balancer(next=next, nextWorker=nextWorker, nextProvider=nextProvider)
+
+-- Create balancer that returns
+-- workers and providers in cycle order
+func cycleBalancer{Counter}(workers: []Worker, providers: []Provider) -> Balancer:
+    next = func () -> Worker, Provider:
+        n <- Counter.incrementAndReturn()
+        idx = n % workers.length
+        <- workers[idx], providers[idx]
+
+    nextWorker = func () -> Worker:
+        w, p <- next()
+        <- w
+
+    nextProvider = func () -> Provider:
+        w, p <- next()
+        <- p
+
+    <- Balancer(next=next, nextWorker=nextWorker, nextProvider=nextProvider)

gateway/aqua/counter.aqua

@@ -0,0 +1,22 @@
+module Counter declares Counter, onPeerCounter
+
+export CounterSrv
+
+ability Counter:
+  incrementAndReturn() -> u32
+
+service CounterSrv("counter"):
+  incrementAndReturn() -> u32
+
+-- Create Counter ability that 
+-- counts on peer through CounterSrv(id)
+func onPeerCounter(peer: string, id: string) -> Counter:
+    -- closure does not capture topology here
+    incAndReturn = func () -> u32:
+        on peer:
+            CounterSrv id
+            res <- CounterSrv.incrementAndReturn()
+        <- res
+
+    <- Counter(incrementAndReturn = incAndReturn)
+

gateway/aqua/eth_rpc.aqua

@@ -0,0 +1,22 @@
+module RPCEth declares RPCEth, fromWorkerProvider
+
+import Worker from "@fluencelabs/aqua-lib/subnet.aqua"
+
+import "services.aqua"
+
+import Provider from "provider.aqua"
+
+-- Ability to call Ethereum JSON RPC methods
+ability RPCEth:
+    call(method: string, jsonArgs: []string) -> JsonString
+
+-- Create RPCEth ability from Worker and Provider
+func fromWorkerProvider(worker: Worker, provider: Provider) -> RPCEth:
+    -- closure does not capture topology here
+    call = func (method: string, jsonArgs: []string) -> JsonString:
+        -- TODO: Handle worker_id == nil?
+        on worker.worker_id! via worker.host_id:
+            res <- EthRpc.eth_call(provider, method, jsonArgs)
+        <- res
+
+    <- RPCEth(call = call)

gateway/aqua/logger.aqua

@@ -0,0 +1,38 @@
+module Logger declares Logger, initPeerLogger
+
+export LoggerSrv
+
+import Worker from "@fluencelabs/aqua-lib/subnet.aqua"
+
+ability Logger:
+  log(s: []string)
+  logNum(n: u32)
+  logCall(s: string)
+  logWorker(w: Worker)
+
+service LoggerSrv("logger"):
+  log(s: []string)
+  logNum(n: u32)
+  logCall(s: string)
+  logWorker(w: Worker)
+
+-- Create Logger ability that logs
+-- on INIT_PEER_ID via HOST_PEER_ID
+-- through LoggerSrv
+func initPeerLogger() -> Logger:
+  -- closures do not capture topology here
+
+  log = func (s: []string):
+    on INIT_PEER_ID via HOST_PEER_ID:
+        LoggerSrv.log(s)
+  logNum = func (n: u32):
+    on INIT_PEER_ID via HOST_PEER_ID:
+        LoggerSrv.logNum(n)
+  logCall = func (s: string):
+    on INIT_PEER_ID via HOST_PEER_ID:
+        LoggerSrv.logCall(s)
+  logWorker = func (w: Worker):
+    on INIT_PEER_ID via HOST_PEER_ID:
+        LoggerSrv.logWorker(w)
+
+  <- Logger(log=log, logNum=logNum, logCall=logCall, logWorker=logWorker)

gateway/aqua/provider.aqua

@@ -0,0 +1,3 @@
+module Provider declares Provider
+
+alias Provider: string

gateway/aqua/quorum.aqua

@@ -0,0 +1,29 @@
+module Quorum declares QuorumChecker, QuorumResult, onPeerQuorumChecker
+
+import JsonString from "services.aqua"
+
+export QuorumCheckerSrv
+
+data QuorumResult:
+  value: string
+  results: []JsonString
+  error: string
+
+-- Ability to check if a quorum on results is reached
+ability QuorumChecker:
+  check(results: []JsonString, minResults: u32) -> QuorumResult
+
+service QuorumCheckerSrv("quorum"):
+  check(results: []JsonString, minResults: u32) -> QuorumResult
+
+-- Create a QuorumChecker ability
+-- that checks quorum on peer through QuorumCheckerSrv(id)
+func onPeerQuorumChecker(peer: string, id: string) -> QuorumChecker:
+  -- closure does not capture topology here
+  check = func (results: []JsonString, minResults: u32) -> QuorumResult:
+    on peer:
+        QuorumCheckerSrv id
+        res <- QuorumCheckerSrv.check(results, minResults)
+    <- res
+
+  <- QuorumChecker(check = check)

gateway/aqua/random.aqua

@@ -0,0 +1,18 @@
+module Random declares Random, timeRandom
+
+import Peer from "@fluencelabs/aqua-lib/builtin.aqua"
+
+import NumOp from "utils.aqua"
+
+ability Random:
+    next() -> i64
+
+-- Create random from timestamp
+func timeRandom() -> Random:
+    -- closure does not capture topology here
+    next = func () -> i64:
+        t <- Peer.timestamp_sec()
+        n <- NumOp.identity(t)
+        <- n
+
+    <- Random(next = next)

gateway/aqua/rpc.aqua

@@ -1,118 +1,108 @@
+aqua RPC
+
 import "@fluencelabs/aqua-lib/builtin.aqua"
 import Subnet, Worker from "@fluencelabs/aqua-lib/subnet.aqua"
+
 import "services.aqua"
 use "deals.aqua"
 
-export randomLoadBalancingEth, roundRobinEth, quorumEth, Counter, Logger
-
-data QuorumResult:
-  value: string
-  results: []JsonString
-  error: string
-
-service Logger("logger"):
-  log(s: []string)
-  logNum(n: u32)
-  logCall(s: string)
-  logWorker(w: Worker)
+import Logger, initPeerLogger from "logger.aqua"
+import Balancer, ProviderBalancer, randomBalancer, cycleBalancer from "balancer.aqua"
+import onPeerCounter from "counter.aqua"
+import QuorumChecker, QuorumResult, onPeerQuorumChecker from "quorum.aqua"
+import timeRandom from "random.aqua"
+import RPCEth, fromWorkerProvider from "eth_rpc.aqua"
 
-service NumOp("op"):
-  identity(n: u64) -> i64
+import NumOp from "utils.aqua"
 
-service Counter("counter"):
-  incrementAndReturn() -> u32
+export randomLoadBalancingEth, roundRobinEth, quorumEth
 
-service QuorumChecker("quorum"):
-  check(results: []JsonString, minResults: u32) -> QuorumResult
+func errorQuorumResult(msg: string) -> QuorumResult:
+  <- QuorumResult(value = "", results = [], error = msg)
 
-func empty() -> JsonString:
-  <- JsonString(value = "", success = true, error = "")
-
-func call(uri: string, method: string, jsonArgs: []string) -> JsonString:
-  res <- EthRpc.eth_call(uri, method, jsonArgs)
-  <- res
+func errorJsonString(msg: string) -> JsonString:
+  <- JsonString(value = "", success = false, error = msg)
 
+-- Get workers participating in deal
 func getWorkers() -> []Worker, ?string:
-  deals <- Deals.get()
+  on INIT_PEER_ID via HOST_PEER_ID:
+    deals <- Deals.get()
   dealId = deals.defaultWorker!.dealIdOriginal
   on HOST_PEER_ID:
     result <- Subnet.resolve(dealId)
-    workers = result.workers
-    error = result.error
-  <- workers, error
+  <- result.workers, result.error
 
-func callOnWorker(worker: Worker, uri: string, method: string, jsonArgs: []string, callFunc: string, string, []string -> JsonString) -> JsonString:
-  on worker.worker_id! via worker.host_id:
-    result <- callFunc(uri, method, jsonArgs)
-  <- result
+-- Call RPC method through ability
+func rpcCall{RPCEth}(method: string, jsonArgs: []string) -> JsonString:
+  <- RPCEth.call(method, jsonArgs)
 
-func randomLoadBalancing(uris: []string, method: string, jsonArgs: []string, callFunc: string, string, []string -> JsonString) -> JsonString:
+-- Call RPC method with load balancing
+func balancedEthCall{Logger, Balancer}(method: string, jsonArgs: []string) -> JsonString:
   on HOST_PEER_ID:
-    workers <- getWorkers()
-    workersNum = workers.length
-    -- choose worker randomly
-    timeW <- NumOp.identity(Peer.timestamp_sec())
-    workerNumber = timeW % workers.length
-    worker = workers[workerNumber]
-    -- choose provider randomly
-    timeP <- NumOp.identity(Peer.timestamp_sec())
-    providerNumber = timeP % uris.length
-    provider = uris[providerNumber]
-    result <- callOnWorker(worker, provider, method, jsonArgs, callFunc)
-  Logger.logWorker(worker)
-  Logger.logCall(uris[providerNumber])
+    worker, provider <- Balancer.next()
+    Logger.logWorker(worker)
+    Logger.logCall(provider)
+    Op.noop() -- dirty hack for topology to converge
+    rpc <- fromWorkerProvider(worker, provider)
+    result <- rpcCall{rpc}(method, jsonArgs)
   <- result
 
+-- Call RPC method with random load balancing
 func randomLoadBalancingEth(uris: []string, method: string, jsonArgs: []string) -> JsonString:
-  <- randomLoadBalancing(uris, method, jsonArgs, call)
-
-func roundRobin(uris: []string, method: string, jsonArgs: []string, counterServiceId: string, counterPeerId: string, callFunc: string, string, []string -> JsonString) -> JsonString:
-  on counterPeerId:
-    Counter counterServiceId
-    requestNumber <- Counter.incrementAndReturn()
-  on HOST_PEER_ID:
-    workers, error <- getWorkers()
-    result: *JsonString
-    if error == nil:
-      workerNumber = requestNumber % workers.length
-      worker = workers[workerNumber]
-      providerNumber = requestNumber % uris.length
-      provider = uris[providerNumber]
-      result <<- callOnWorker(worker, provider, method, jsonArgs, callFunc)
-      Op.noop() -- dirty hack
-      on INIT_PEER_ID:
-        Logger.logWorker(worker)
-        Logger.logCall(uris[providerNumber])
-    else:
-      result <<- JsonString(value = "", success = false, error = error!)
-
+  result: ?JsonString
+
+  workers, error <- getWorkers()
+  if error != nil:
+    result <- errorJsonString(error!)
+  else:
+    log <- initPeerLogger()
+    random <- timeRandom()
+    balancer <- randomBalancer{random}(workers, uris)
+    result <- balancedEthCall{log, balancer}(method, jsonArgs)
+
   <- result!
 
+-- Call RPC method with round-robin load balancing
 func roundRobinEth(uris: []string, method: string, jsonArgs: []string, counterServiceId: string, counterPeerId: string) -> JsonString:
-  <- roundRobin(uris, method, jsonArgs, counterServiceId, counterPeerId, call)
+  result: ?JsonString
+
+  workers, error <- getWorkers()
+  if error != nil:
+    result <- errorJsonString(error!)
+  else:
+    log <- initPeerLogger()
+    counter <- onPeerCounter(counterPeerId, counterServiceId)
+    balancer <- cycleBalancer{counter}(workers, uris)
+    result <- balancedEthCall{log, balancer}(method, jsonArgs)
+
+  <- result!
 
-func quorum(
-  uris: []string, quorumNumber: u32, timeout: u32, method: string, jsonArgs: []string, quorumServiceId: string, quorumPeerId: string,
-  callFunc: string, string, []string -> JsonString
-) -> QuorumResult:
+-- Call RPC method with workers quorum and provider load balancing
+func quorum{ProviderBalancer, QuorumChecker}(workers: []Worker, quorumNumber: u32, timeout: u32, method: string, jsonArgs: []string) -> QuorumResult:
   results: *JsonString
-  on HOST_PEER_ID:
-    workers <- getWorkers()
+  on HOST_PEER_ID:  
     for worker <- workers par:
-      on worker.worker_id! via worker.host_id:
-        -- choose provider randomly
-        timeP <- NumOp.identity(Peer.timestamp_ms())
-        providerNumber = timeP % uris.length
-        provider = uris[providerNumber]
-        results <- callFunc(provider, method, jsonArgs)
-    -- wait all results from all workers with timeout
-    join results[workers.length - 1]
-    par Peer.timeout(timeout, "")
-  on quorumPeerId via HOST_PEER_ID:
-    Counter quorumServiceId
-    -- check all results that we got
-    quorumResult <- QuorumChecker.check(results, quorumNumber)
-  <- quorumResult
+      provider <- ProviderBalancer.nextProvider()
+      rpc <- fromWorkerProvider(worker, provider)
+      results <- rpcCall{rpc}(method, jsonArgs)
+
+  -- wait all results from all workers with timeout
+  join results[workers.length - 1]
+  par Peer.timeout(timeout, "Workers timeout")
+
+  <- QuorumChecker.check(results, quorumNumber)
 
+-- Call RPC method with workers quorum and provider load balancing
 func quorumEth(uris: []string, quorumNumber: u32, timeout: u32, method: string, jsonArgs: []string, quorumServiceId: string, quorumPeerId: string) -> QuorumResult:
-  <- quorum(uris, quorumNumber, timeout, method, jsonArgs, quorumServiceId, quorumPeerId, call)
+  result: *QuorumResult
+
+  workers, error <- getWorkers()
+  if error != nil:
+    result <- errorQuorumResult(error!)
+  else:
+    random <- timeRandom()
+    balancer <- randomBalancer{random}(workers, uris)
+    quorumChecker <- onPeerQuorumChecker(quorumPeerId, quorumServiceId)
+    result <- quorum{balancer, quorumChecker}(workers, quorumNumber, timeout, method, jsonArgs)
+
+  <- result!