using SSE instead of socket IO

packages/web/src/utility/api.ts

@@ -1,6 +1,16 @@
 import resolveApi, { resolveApiHeaders } from './resolveApi';
 import { writable } from 'svelte/store';
-import socket from './socket';
+import { cacheClean } from './cache';
+// import socket from './socket';
+
+let eventSource;
+
+function wantEventSource() {
+  if (!eventSource) {
+    eventSource = new EventSource(`${resolveApi()}/stream`);
+    eventSource.addEventListener('clean-cache', e => cacheClean(JSON.parse(e.data)));
+  }
+}
 
 export async function apiCall(route: string, args: {} = undefined) {
   const resp = await fetch(`${resolveApi()}/${route}`, {
@@ -15,16 +25,28 @@ export async function apiCall(route: string, args: {} = undefined) {
   return resp.json();
 }
 
+const apiHandlers = new WeakMap();
+
 export function apiOn(event: string, handler: Function) {
-  socket().on(event, handler);
+  wantEventSource();
+  if (!apiHandlers.has(handler)) {
+    const handlerProxy = e => {
+      // console.log('RECEIVED', e.type, JSON.parse(e.data));
+      handler(JSON.parse(e.data));
+    };
+    apiHandlers.set(handler, handlerProxy);
+  }
+
+  eventSource.addEventListener(event, apiHandlers.get(handler));
 }
 
 export function apiOff(event: string, handler: Function) {
-  socket().off(event, handler);
+  wantEventSource();
+  if (apiHandlers.has(handler)) {
+    eventSource.removeEventListener(event, apiHandlers.get(handler));
+  }
 }
 
-import _ from 'lodash';
-
 export function useApiCall(route, args, defaultValue) {
   const result = writable(defaultValue);
 

packages/web/src/utility/metadataLoaders.ts

@@ -2,7 +2,6 @@ import _ from 'lodash';
 import { cacheGet, cacheSet, getCachedPromise } from './cache';
 import stableStringify from 'json-stable-stringify';
 import { cacheClean } from './cache';
-import socket from './socket';
 import getAsArray from './getAsArray';
 import { DatabaseInfo } from 'dbgate-types';
 import { derived } from 'svelte/store';
@@ -194,11 +193,11 @@ function useCore(loader, args) {
         }
       }
 
-      if (reloadTrigger && !socket) {
-        console.error('Socket not available, reloadTrigger not planned');
-      }
+      // if (reloadTrigger && !socket) {
+      //   console.error('Socket not available, reloadTrigger not planned');
+      // }
       handleReload();
-      if (reloadTrigger && socket) {
+      if (reloadTrigger) {
         for (const item of getAsArray(reloadTrigger)) {
           apiOn(item, handleReload);
         }

packages/web/src/utility/socket.js

@@ -1,23 +0,0 @@
-import io from 'socket.io-client';
-import resolveApi from './resolveApi';
-import { cacheClean } from './cache';
-import { shouldWaitForElectronInitialize } from './getElectron';
-
-let socketInstance;
-
-function recreateSocket() {
-  if (shouldWaitForElectronInitialize()) return;
-
-  socketInstance = io(resolveApi());
-  socketInstance.on('clean-cache', reloadTrigger => cacheClean(reloadTrigger));
-}
-
-window['dbgate_recreateSocket'] = recreateSocket;
-
-recreateSocket();
-
-function socket() {
-  return socketInstance;
-}
-
-export default socket;