:WIP: Draft implementation to support events when http-api enabled

services/blockchain-connector/shared/sdk/client.js

@@ -108,7 +108,7 @@ const instantiateAndCacheClient = async () => {
 
 const getApiClient = async () => {
 	if (cachedApiClients.length === 0) {
-		throw new Error(`No API client is alive!`);
+		await instantiateAndCacheClient();
 	}
 	return cachedApiClients[0];
 };
@@ -222,12 +222,14 @@ Signals.get('resetApiClient').add(resetApiClientListener);
 
 // Check periodically for client aliveness and refill cached clients pool
 (async () => {
+	if (config.useHttpApi) return;
+
 	// eslint-disable-next-line no-constant-condition
 	while (true) {
 		const cacheRefreshStartTime = Date.now();
 		await refreshClientsCache();
 		logger.debug(
-			`Refreshed API client cached in ${Date.now() - cacheRefreshStartTime}ms. There are ${
+			`Refreshed API client cache in ${Date.now() - cacheRefreshStartTime}ms. There are ${
 				cachedApiClients.length
 			} API client(s) in the pool.`,
 		);

services/blockchain-connector/shared/sdk/events.js

@@ -21,8 +21,15 @@ const config = require('../../config');
 
 const { getApiClient } = require('./client');
 const { formatEvent } = require('./formatter');
-const { getRegisteredEvents, getEventsByHeight, getNodeInfo } = require('./endpoints');
+const {
+	getRegisteredEvents,
+	getEventsByHeight,
+	getNodeInfo,
+	getBlockByHeight,
+	getGenerators,
+} = require('./endpoints');
 const { updateTokenInfo } = require('./token');
+const { getPosConstants } = require('./pos');
 
 const logger = Logger();
 
@@ -41,13 +48,16 @@ const events = [
 ];
 
 let eventsCounter;
+let lastBlockHeightEvent;
 
 const logError = (method, err) => {
 	logger.warn(`Invocation for ${method} failed with error: ${err.message}`);
 	logger.debug(err.stack);
 };
 
 const subscribeToAllRegisteredEvents = async () => {
+	if (!config.useHttpApi) return;
+
 	// Reset eventsCounter first
 	eventsCounter = 0;
 
@@ -122,6 +132,36 @@ const genesisBlockDownloadedListener = () => {
 Signals.get('nodeIsSynced').add(nodeIsSyncedListener);
 Signals.get('genesisBlockDownloaded').add(genesisBlockDownloadedListener);
 
+const emitNodeEvents = async nodeInfo => {
+	if (config.useHttpApi) {
+		setInterval(async () => {
+			const latestNodeInfo = await getNodeInfo(true);
+			const { syncing } = latestNodeInfo;
+			const isNodeSyncComplete = !syncing;
+
+			if (isNodeSyncComplete) {
+				if (!lastBlockHeightEvent || latestNodeInfo.height > lastBlockHeightEvent) {
+					lastBlockHeightEvent = latestNodeInfo.height;
+					const newBlock = await getBlockByHeight(latestNodeInfo.height);
+					Signals.get(EVENT_CHAIN_BLOCK_NEW).dispatch({ blockHeader: newBlock.header });
+
+					const posConstants = await getPosConstants();
+					if (
+						(latestNodeInfo.height - latestNodeInfo.genesisHeight) % posConstants.roundLength ===
+						1
+					) {
+						const { list: validators } = await getGenerators();
+						Signals.get(EVENT_CHAIN_VALIDATORS_CHANGE).dispatch({ nextValidators: validators });
+					}
+				}
+			}
+		}, nodeInfo.genesis.blockTime * 1000);
+	}
+};
+
+// TODO: Add retry logic in case of failure
+getNodeInfo().then(nodeInfo => emitNodeEvents(nodeInfo));
+
 module.exports = {
 	events,