[PERF] model: export lazily when leaving

Since 7bcff34, the model data is exported every time
the spreadsheet is left.
Exporting the data can be slow though and it's actually not
needed every time.

With this commit, the data is exported lazily, only when
needed.

closes #4848

Task: 4119536
Signed-off-by: Pierre Rousseau (pro) <[email protected]>

src/collaborative/session.ts

@@ -3,7 +3,7 @@ import { UuidGenerator } from "../helpers";
 import { EventBus } from "../helpers/event_bus";
 import { debounce, isDefined } from "../helpers/misc";
 import { SelectiveHistory as RevisionLog } from "../history/selective_history";
-import { CoreCommand, HistoryChange, UID, WorkbookData } from "../types";
+import { CoreCommand, HistoryChange, Lazy, UID, WorkbookData } from "../types";
 import {
   Client,
   ClientId,
@@ -159,9 +159,9 @@ export class Session extends EventBus<CollaborativeEvent> {
   /**
    * Notify the server that the user client left the collaborative session
    */
-  leave(data: WorkbookData) {
+  leave(data: Lazy<WorkbookData>) {
     if (Object.keys(this.clients).length === 1 && this.processedRevisions.size) {
-      this.snapshot(data);
+      this.snapshot(data());
     }
     delete this.clients[this.clientId];
     this.transportService.leave(this.clientId);

src/model.ts

@@ -3,7 +3,7 @@ import { LocalTransportService } from "./collaborative/local_transport_service";
 import { Session } from "./collaborative/session";
 import { DEFAULT_REVISION_ID } from "./constants";
 import { EventBus } from "./helpers/event_bus";
-import { deepCopy, UuidGenerator } from "./helpers/index";
+import { deepCopy, lazy, UuidGenerator } from "./helpers/index";
 import { buildRevisionLog } from "./history/factory";
 import {
   createEmptyExcelWorkbookData,
@@ -289,7 +289,7 @@ export class Model extends EventBus<any> implements CommandDispatcher {
   }
 
   leaveSession() {
-    this.session.leave(this.exportData());
+    this.session.leave(lazy(() => this.exportData()));
   }
 
   private setupUiPlugin(Plugin: UIPluginConstructor) {

tests/collaborative/collaborative_session.test.ts

@@ -1,6 +1,7 @@
 import { Model } from "../../src";
 import { Session } from "../../src/collaborative/session";
 import { DEBOUNCE_TIME, MESSAGE_VERSION } from "../../src/constants";
+import { lazy } from "../../src/helpers";
 import { buildRevisionLog } from "../../src/history/factory";
 import { Client, CommandResult, WorkbookData } from "../../src/types";
 import { MockTransportService } from "../__mocks__/transport_service";
@@ -50,7 +51,7 @@ describe("Collaborative session", () => {
 
   test("local client leaves", () => {
     const spy = jest.spyOn(transport, "sendMessage");
-    session.leave({} as WorkbookData);
+    session.leave(lazy({} as WorkbookData));
     expect(spy).toHaveBeenCalledTimes(1);
     expect(spy).toHaveBeenCalledWith({
       type: "CLIENT_LEFT",
@@ -71,7 +72,7 @@ describe("Collaborative session", () => {
     });
     const spy = jest.spyOn(transport, "sendMessage");
     const data = { sheets: [{}] } as WorkbookData;
-    session.leave(data);
+    session.leave(lazy(data));
     expect(spy).toHaveBeenCalledWith({
       type: "SNAPSHOT",
       version: MESSAGE_VERSION,
@@ -123,7 +124,7 @@ describe("Collaborative session", () => {
     });
     const spy = jest.spyOn(transport, "sendMessage");
     const data = { sheets: [{}] } as WorkbookData;
-    session.leave(data);
+    session.leave(lazy(data));
     expect(spy).toHaveBeenCalledTimes(1);
     expect(spy).toHaveBeenCalledWith({
       type: "CLIENT_LEFT",
@@ -220,7 +221,7 @@ describe("Collaborative session", () => {
 
   test("Leave the session do not crash", () => {
     session.move({ sheetId: "sheetId", col: 1, row: 2 });
-    session.leave({} as WorkbookData);
+    session.leave(lazy({} as WorkbookData));
     jest.advanceTimersByTime(DEBOUNCE_TIME + 100);
   });