Merge pull request #1917 from ably/liveobjects/subscriptions

[DTP-958, DTP-959] Liveobjects/subscriptions

grunt/esbuild/build.js

@@ -82,6 +82,7 @@ const liveObjectsPluginConfig = {
   entryPoints: ['src/plugins/liveobjects/index.ts'],
   plugins: [umdWrapper.default({ libraryName: 'AblyLiveObjectsPlugin', amdNamedModule: false })],
   outfile: 'build/liveobjects.js',
+  external: ['deep-equal'],
 };
 
 const liveObjectsPluginCdnConfig = {

package.json

@@ -47,6 +47,7 @@
   ],
   "dependencies": {
     "@ably/msgpack-js": "^0.4.0",
+    "deep-equal": "^2.2.3",
     "fastestsmallesttextencoderdecoder": "^1.0.22",
     "got": "^11.8.5",
     "ulid": "^2.3.0",
@@ -72,6 +73,7 @@
     "@babel/traverse": "^7.23.7",
     "@testing-library/react": "^13.3.0",
     "@types/cli-table": "^0.3.4",
+    "@types/deep-equal": "^1.0.4",
     "@types/jmespath": "^0.15.2",
     "@types/node": "^18.0.0",
     "@types/request": "^2.48.7",

scripts/moduleReport.ts

@@ -37,6 +37,18 @@ const functions = [
   { name: 'constructPresenceMessage', transitiveImports: [] },
 ];
 
+// List of all buildable plugins available as a separate export
+interface PluginInfo {
+  description: string;
+  path: string;
+  external?: string[];
+}
+
+const buildablePlugins: Record<'push' | 'liveObjects', PluginInfo> = {
+  push: { description: 'Push', path: './build/push.js', external: ['ulid'] },
+  liveObjects: { description: 'LiveObjects', path: './build/liveobjects.js', external: ['deep-equal'] },
+};
+
 function formatBytes(bytes: number) {
   const kibibytes = bytes / 1024;
   const formatted = kibibytes.toFixed(2);
@@ -70,7 +82,7 @@ function getModularBundleInfo(exports: string[]): BundleInfo {
 }
 
 // Uses esbuild to create a bundle containing the named exports from a given module
-function getBundleInfo(modulePath: string, exports?: string[]): BundleInfo {
+function getBundleInfo(modulePath: string, exports?: string[], external?: string[]): BundleInfo {
   const outfile = exports ? exports.join('') : 'all';
   const exportTarget = exports ? `{ ${exports.join(', ')} }` : '*';
   const result = esbuild.buildSync({
@@ -84,7 +96,7 @@ function getBundleInfo(modulePath: string, exports?: string[]): BundleInfo {
     outfile,
     write: false,
     sourcemap: 'external',
-    external: ['ulid'],
+    external,
   });
 
   const pathHasBase = (component: string) => {
@@ -183,9 +195,9 @@ async function calculateAndCheckFunctionSizes(): Promise<Output> {
   return output;
 }
 
-async function calculatePluginSize(options: { path: string; description: string }): Promise<Output> {
+async function calculatePluginSize(options: PluginInfo): Promise<Output> {
   const output: Output = { tableRows: [], errors: [] };
-  const pluginBundleInfo = getBundleInfo(options.path);
+  const pluginBundleInfo = getBundleInfo(options.path, undefined, options.external);
   const sizes = {
     rawByteSize: pluginBundleInfo.byteSize,
     gzipEncodedByteSize: (await promisify(gzip)(pluginBundleInfo.code)).byteLength,
@@ -200,11 +212,11 @@ async function calculatePluginSize(options: { path: string; description: string
 }
 
 async function calculatePushPluginSize(): Promise<Output> {
-  return calculatePluginSize({ path: './build/push.js', description: 'Push' });
+  return calculatePluginSize(buildablePlugins.push);
 }
 
 async function calculateLiveObjectsPluginSize(): Promise<Output> {
-  return calculatePluginSize({ path: './build/liveobjects.js', description: 'LiveObjects' });
+  return calculatePluginSize(buildablePlugins.liveObjects);
 }
 
 async function calculateAndCheckMinimalUsefulRealtimeBundleSize(): Promise<Output> {
@@ -291,7 +303,8 @@ async function checkBaseRealtimeFiles() {
 }
 
 async function checkPushPluginFiles() {
-  const pushPluginBundleInfo = getBundleInfo('./build/push.js');
+  const { path, external } = buildablePlugins.push;
+  const pushPluginBundleInfo = getBundleInfo(path, undefined, external);
 
   // These are the files that are allowed to contribute >= `threshold` bytes to the Push bundle.
   const allowedFiles = new Set([
@@ -305,7 +318,8 @@ async function checkPushPluginFiles() {
 }
 
 async function checkLiveObjectsPluginFiles() {
-  const pluginBundleInfo = getBundleInfo('./build/liveobjects.js');
+  const { path, external } = buildablePlugins.liveObjects;
+  const pluginBundleInfo = getBundleInfo(path, undefined, external);
 
   // These are the files that are allowed to contribute >= `threshold` bytes to the LiveObjects bundle.
   const allowedFiles = new Set([

src/plugins/liveobjects/livecounter.ts

@@ -1,4 +1,4 @@
-import { LiveObject, LiveObjectData } from './liveobject';
+import { LiveObject, LiveObjectData, LiveObjectUpdate, LiveObjectUpdateNoop } from './liveobject';
 import { LiveObjects } from './liveobjects';
 import { StateCounter, StateCounterOp, StateMessage, StateOperation, StateOperationAction } from './statemessage';
 import { Timeserial } from './timeserial';
@@ -7,7 +7,11 @@ export interface LiveCounterData extends LiveObjectData {
   data: number;
 }
 
-export class LiveCounter extends LiveObject<LiveCounterData> {
+export interface LiveCounterUpdate extends LiveObjectUpdate {
+  update: { inc: number };
+}
+
+export class LiveCounter extends LiveObject<LiveCounterData, LiveCounterUpdate> {
   constructor(
     liveObjects: LiveObjects,
     private _created: boolean,
@@ -62,16 +66,19 @@ export class LiveCounter extends LiveObject<LiveCounterData> {
       );
     }
 
+    let update: LiveCounterUpdate | LiveObjectUpdateNoop;
     switch (op.action) {
       case StateOperationAction.COUNTER_CREATE:
-        this._applyCounterCreate(op.counter);
+        update = this._applyCounterCreate(op.counter);
         break;
 
       case StateOperationAction.COUNTER_INC:
         if (this._client.Utils.isNil(op.counterOp)) {
           this._throwNoPayloadError(op);
+          // leave an explicit return here, so that TS knows that update object is always set after the switch statement.
+          return;
         } else {
-          this._applyCounterInc(op.counterOp);
+          update = this._applyCounterInc(op.counterOp);
         }
         break;
 
@@ -84,12 +91,18 @@ export class LiveCounter extends LiveObject<LiveCounterData> {
     }
 
     this.setRegionalTimeserial(opRegionalTimeserial);
+    this.notifyUpdated(update);
   }
 
   protected _getZeroValueData(): LiveCounterData {
     return { data: 0 };
   }
 
+  protected _updateFromDataDiff(currentDataRef: LiveCounterData, newDataRef: LiveCounterData): LiveCounterUpdate {
+    const counterDiff = newDataRef.data - currentDataRef.data;
+    return { update: { inc: counterDiff } };
+  }
+
   private _throwNoPayloadError(op: StateOperation): void {
     throw new this._client.ErrorInfo(
       `No payload found for ${op.action} op for LiveCounter objectId=${this.getObjectId()}`,
@@ -98,7 +111,7 @@ export class LiveCounter extends LiveObject<LiveCounterData> {
     );
   }
 
-  private _applyCounterCreate(op: StateCounter | undefined): void {
+  private _applyCounterCreate(op: StateCounter | undefined): LiveCounterUpdate | LiveObjectUpdateNoop {
     if (this.isCreated()) {
       // skip COUNTER_CREATE op if this counter is already created
       this._client.Logger.logAction(
@@ -107,24 +120,27 @@ export class LiveCounter extends LiveObject<LiveCounterData> {
         'LiveCounter._applyCounterCreate()',
         `skipping applying COUNTER_CREATE op on a counter instance as it is already created; objectId=${this._objectId}`,
       );
-      return;
+      return { noop: true };
     }
 
     if (this._client.Utils.isNil(op)) {
       // if a counter object is missing for the COUNTER_CREATE op, the initial value is implicitly 0 in this case.
       // we need to SUM the initial value to the current value due to the reasons below, but since it's a 0, we can skip addition operation
       this.setCreated(true);
-      return;
+      return { update: { inc: 0 } };
     }
 
     // note that it is intentional to SUM the incoming count from the create op.
     // if we get here, it means that current counter instance wasn't initialized from the COUNTER_CREATE op,
     // so it is missing the initial value that we're going to add now.
     this._dataRef.data += op.count ?? 0;
     this.setCreated(true);
+
+    return { update: { inc: op.count ?? 0 } };
   }
 
-  private _applyCounterInc(op: StateCounterOp): void {
+  private _applyCounterInc(op: StateCounterOp): LiveCounterUpdate {
     this._dataRef.data += op.amount;
+    return { update: { inc: op.amount } };
   }
 }