Use new subscription handling in JSON RPC provider

ethers/providers/jsonrpc.nim

@@ -8,6 +8,7 @@ import ../provider
 import ../signer
 import ./jsonrpc/rpccalls
 import ./jsonrpc/conversions
+import ./jsonrpc/subscriptions
 
 export json
 export basics
@@ -18,10 +19,7 @@ push: {.upraises: [].}
 type
   JsonRpcProvider* = ref object of Provider
     client: Future[RpcClient]
-    subscriptions: Table[JsonNode, SubscriptionHandler]
-  JsonRpcSubscription = ref object of Subscription
-    provider: JsonRpcProvider
-    id: JsonNode
+    subscriptions: Future[JsonRpcSubscriptions]
   JsonRpcSigner* = ref object of Signer
     provider: JsonRpcProvider
     address: ?Address
@@ -53,45 +51,34 @@ const defaultUrl = "http://localhost:8545"
 proc jsonHeaders: seq[(string, string)] =
   @[("Content-Type", "application/json")]
 
-proc connect(_: type RpcClient, url: string): Future[RpcClient] {.async.} =
+proc new*(_: type JsonRpcProvider, url=defaultUrl): JsonRpcProvider =
+  var initialized: Future[void]
+  var client: RpcClient
+  var subscriptions: JsonRpcSubscriptions
+
+  proc initialize {.async.} =
     case parseUri(url).scheme
     of "ws", "wss":
-    let client = newRpcWebSocketClient(getHeaders = jsonHeaders)
-    await client.connect(url)
-    return client
+      let websocket = newRpcWebSocketClient(getHeaders = jsonHeaders)
+      await websocket.connect(url)
+      client = websocket
+      subscriptions = JsonRpcSubscriptions.new(websocket)
     else:
-    let client = newRpcHttpClient(getHeaders = jsonHeaders)
-    await client.connect(url)
+      let http = newRpcHttpClient(getHeaders = jsonHeaders)
+      await http.connect(url)
+      client = http
+      subscriptions = JsonRpcSubscriptions.new(http)
+
+  proc awaitClient: Future[RpcClient] {.async.} =
+    await initialized
     return client
 
-proc connect(provider: JsonRpcProvider, url: string) =
+  proc awaitSubscriptions: Future[JsonRpcSubscriptions] {.async.} =
+    await initialized
+    return subscriptions
 
-  proc getSubscriptionHandler(id: JsonNode): ?SubscriptionHandler =
-    try:
-      if provider.subscriptions.hasKey(id):
-        provider.subscriptions[id].some
-      else:
-        SubscriptionHandler.none
-    except Exception:
-      SubscriptionHandler.none
-
-  proc handleSubscription(arguments: JsonNode) {.upraises: [].} =
-    if id =? arguments["subscription"].catch and
-       handler =? getSubscriptionHandler(id):
-      # fire and forget
-      discard handler(id, arguments)
-
-  proc subscribe: Future[RpcClient] {.async.} =
-    let client = await RpcClient.connect(url)
-    client.setMethodHandler("eth_subscription", handleSubscription)
-    return client
-
-  provider.client = subscribe()
-
-proc new*(_: type JsonRpcProvider, url=defaultUrl): JsonRpcProvider =
-  let provider = JsonRpcProvider()
-  provider.connect(url)
-  provider
+  initialized = initialize()
+  JsonRpcProvider(client: awaitClient(), subscriptions: awaitSubscriptions())
 
 proc send*(provider: JsonRpcProvider,
            call: string,
@@ -171,47 +158,20 @@ method sendTransaction*(provider: JsonRpcProvider, rawTransaction: seq[byte]): F
 
     return TransactionResponse(hash: hash, provider: provider)
 
-proc subscribe(provider: JsonRpcProvider,
-               name: string,
-               filter: ?Filter,
-               handler: SubscriptionHandler): Future[Subscription] {.async.} =
-  convertError:
-    let client = await provider.client
-    doAssert client of RpcWebSocketClient, "subscriptions require websockets"
-
-    var id: JsonNode
-    if filter =? filter:
-      id = await client.eth_subscribe(name, filter)
-    else:
-      id = await client.eth_subscribe(name)
-
-    provider.subscriptions[id] = handler
-
-    return JsonRpcSubscription(id: id, provider: provider)
-
 method subscribe*(provider: JsonRpcProvider,
                   filter: Filter,
-                  callback: LogHandler):
+                  onLog: LogHandler):
                  Future[Subscription] {.async.} =
-  proc handler(id, arguments: JsonNode) {.async.} =
-    if log =? Log.fromJson(arguments["result"]).catch:
-      callback(log)
-  return await provider.subscribe("logs", filter.some, handler)
+  convertError:
+    let subscriptions = await provider.subscriptions
+    return await subscriptions.subscribeLogs(filter, onLog)
 
 method subscribe*(provider: JsonRpcProvider,
-                  callback: BlockHandler):
+                  onBlock: BlockHandler):
                  Future[Subscription] {.async.} =
-  proc handler(id, arguments: JsonNode) {.async.} =
-    if blck =? Block.fromJson(arguments["result"]).catch:
-      await callback(blck)
-  return await provider.subscribe("newHeads", Filter.none, handler)
-
-method unsubscribe*(subscription: JsonRpcSubscription) {.async.} =
   convertError:
-    let provider = subscription.provider
-    provider.subscriptions.del(subscription.id)
-    let client = await provider.client
-    discard await client.eth_unsubscribe(subscription.id)
+    let subscriptions = await provider.subscriptions
+    return await subscriptions.subscribeBlocks(onBlock)
 
 # Signer