reverse caching: middleware

js/src/redux/middleware.js

@@ -23,6 +23,7 @@ import SignerMiddleware from './providers/signerMiddleware';
 import statusMiddleware from '~/views/Status/middleware';
 import CertificationsMiddleware from './providers/certifications/middleware';
 import ChainMiddleware from './providers/chainMiddleware';
+import RegistryMiddleware from './providers/registry/middleware';
 
 export default function (api, browserHistory) {
   const errors = new ErrorsMiddleware();
@@ -32,13 +33,15 @@ export default function (api, browserHistory) {
   const certifications = new CertificationsMiddleware();
   const routeMiddleware = routerMiddleware(browserHistory);
   const chain = new ChainMiddleware();
+  const registry = new RegistryMiddleware();
 
   const middleware = [
     settings.toMiddleware(),
     signer.toMiddleware(),
     errors.toMiddleware(),
     certifications.toMiddleware(),
-    chain.toMiddleware()
+    chain.toMiddleware(),
+    registry.toMiddleware()
   ];
 
   return middleware.concat(status, routeMiddleware, thunk);

js/src/redux/providers/registry/middleware.js

@@ -0,0 +1,106 @@
+// Copyright 2015, 2016 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+import Contracts from '~/contracts';
+import subscribeToEvent from '~/util/subscribe-to-event';
+
+import registryABI from '~/contracts/abi/registry.json';
+
+import { setReverse, startCachingReverses } from './actions';
+
+export default class RegistryMiddleware {
+  toMiddleware () {
+    return (store) => {
+      const api = Contracts.get()._api;
+      let contract, confirmedEvents, removedEvents, interval;
+
+      let addressesToCheck = {};
+
+      const onLog = (log) => {
+        switch (log.event) {
+          case 'ReverseConfirmed':
+            addressesToCheck[log.params.reverse.value] = true;
+
+            break;
+          case 'ReverseRemoved':
+            delete addressesToCheck[log.params.reverse.value];
+
+            break;
+        }
+      };
+
+      const checkReverses = () => {
+        Object
+          .keys(addressesToCheck)
+          .forEach((address) => {
+            contract
+              .instance
+              .reverse
+              .call({}, [ address ])
+              .then((reverse) => store.dispatch(setReverse(address, reverse)));
+          });
+
+        addressesToCheck = {};
+      };
+
+      return (next) => (action) => {
+        switch (action.type) {
+          case 'initAll':
+            next(action);
+            store.dispatch(startCachingReverses());
+
+            break;
+          case 'startCachingReverses':
+            const { registry } = Contracts.get();
+
+            registry.getInstance()
+              .then((instance) => api.newContract(registryABI, instance.address))
+              .then((_contract) => {
+                contract = _contract;
+
+                confirmedEvents = subscribeToEvent(_contract, 'ReverseConfirmed');
+                confirmedEvents.on('log', onLog);
+
+                removedEvents = subscribeToEvent(_contract, 'ReverseRemoved');
+                removedEvents.on('log', onLog);
+
+                interval = setInterval(checkReverses, 2000);
+              })
+              .catch((err) => {
+                console.error('Failed to start caching reverses:', err);
+                throw err;
+              });
+
+            break;
+          case 'stopCachingReverses':
+            if (confirmedEvents) {
+              confirmedEvents.unsubscribe();
+            }
+            if (removedEvents) {
+              removedEvents.unsubscribe();
+            }
+            if (interval) {
+              clearInterval(interval);
+            }
+
+            break;
+          default:
+            next(action);
+        }
+      };
+    };
+  }
+};