From dece42dce3db0dceff48ad1e7810953554622472 Mon Sep 17 00:00:00 2001
From: RMidhunSuresh <hi@midhun.dev>
Date: Mon, 18 Jul 2022 14:55:13 +0530
Subject: [PATCH] Do not store all the manifests in memory

---
 src/platform/web/ThemeBuilder.ts | 13 +++++--------
 src/platform/web/ThemeLoader.ts  | 18 +++++++++++-------
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/src/platform/web/ThemeBuilder.ts b/src/platform/web/ThemeBuilder.ts
index 85d1e336..2ff4108a 100644
--- a/src/platform/web/ThemeBuilder.ts
+++ b/src/platform/web/ThemeBuilder.ts
@@ -15,29 +15,26 @@ limitations under the License.
 */
 import type {ThemeInformation} from "./ThemeLoader";
 import type {Platform} from "./Platform.js";
+import type {ThemeManifest} from "../types/theme";
 import {ColorSchemePreference} from "./ThemeLoader";
 import {IconColorizer} from "./IconColorizer";
 import {DerivedVariables} from "./DerivedVariables";
-import {ThemeManifest} from "../types/theme";
 import {ILogItem} from "../../logging/types";
 
 export class ThemeBuilder {
-    private _idToManifest: Map<string, {manifest: ThemeManifest, location: string}>;
     private _themeMapping: Record<string, ThemeInformation> = {};
     private _preferredColorScheme?: ColorSchemePreference;
     private _platform: Platform;
     private _injectedVariables?: Record<string, string>;
 
-    constructor(platform: Platform, manifestMap: Map<string, any>, preferredColorScheme?: ColorSchemePreference) {
-        this._idToManifest = manifestMap;
+    constructor(platform: Platform, preferredColorScheme?: ColorSchemePreference) {
         this._preferredColorScheme = preferredColorScheme;
         this._platform = platform;
     }
 
-    async populateDerivedTheme(manifest: ThemeManifest, log: ILogItem): Promise<void> {
+    async populateDerivedTheme(manifest: ThemeManifest, baseManifest: ThemeManifest, baseManifestLocation: string, log: ILogItem): Promise<void> {
         await log.wrap("ThemeBuilder.populateThemeMap", async () => {
-            const {manifest: baseManifest, location} = this._idToManifest.get(manifest.extends!)!;
-            const {cssLocation, derivedVariables, icons} = this._getSourceData(baseManifest, location, log);
+            const {cssLocation, derivedVariables, icons} = this._getSourceData(baseManifest, baseManifestLocation, log);
             const themeName = manifest.name;
             if (!themeName) {
                 throw new Error(`Theme name not found in manifest!`);
@@ -49,7 +46,7 @@ export class ThemeBuilder {
                     const { name: variantName, default: isDefault, dark, variables } = variantDetails;
                     const resolvedVariables = new DerivedVariables(variables, derivedVariables, dark).toVariables();
                     Object.assign(variables, resolvedVariables);
-                    const iconVariables = await new IconColorizer(this._platform, icons, variables, location).toVariables();
+                    const iconVariables = await new IconColorizer(this._platform, icons, variables, baseManifestLocation).toVariables();
                     Object.assign(variables, resolvedVariables, iconVariables);
                     const themeDisplayName = `${themeName} ${variantName}`;
                     if (isDefault) {
diff --git a/src/platform/web/ThemeLoader.ts b/src/platform/web/ThemeLoader.ts
index b899ab5e..81114a54 100644
--- a/src/platform/web/ThemeLoader.ts
+++ b/src/platform/web/ThemeLoader.ts
@@ -15,7 +15,7 @@ limitations under the License.
 */
 
 import type {ILogItem} from "../../logging/types";
-import { ThemeManifest } from "../types/theme";
+import type {ThemeManifest} from "../types/theme";
 import type {Platform} from "./Platform.js";
 import {ThemeBuilder} from "./ThemeBuilder";
 
@@ -52,20 +52,24 @@ export class ThemeLoader {
     }
 
     async init(manifestLocations: string[], log?: ILogItem): Promise<void> {
-        const idToManifest = new Map();
         await this._platform.logger.wrapOrRun(log, "ThemeLoader.init", async (log) => {
             this._themeMapping = {};
             const results = await Promise.all(
-                manifestLocations.map( location => this._platform.request(location, { method: "GET", format: "json", cache: true, }).response())
+                manifestLocations.map(location => this._platform.request(location, { method: "GET", format: "json", cache: true, }).response())
             );
-            results.forEach(({ body }, i) => idToManifest.set(body.id, { manifest: body, location: manifestLocations[i] }));
-            this._themeBuilder = new ThemeBuilder(this._platform, idToManifest, this.preferredColorScheme);
+            this._themeBuilder = new ThemeBuilder(this._platform, this.preferredColorScheme);
             const runtimeThemePromises: Promise<void>[] = [];
             for (let i = 0; i < results.length; ++i) {
                 const { body } = results[i];
                 try {
                     if (body.extends) {
-                        const promise = this._themeBuilder.populateDerivedTheme(body, log);
+                        const indexOfBaseManifest = results.findIndex(manifest => manifest.body.id === body.extends);
+                        if (indexOfBaseManifest === -1) {
+                            throw new Error(`Base manifest for derived theme at ${manifestLocations[i]} not found!`);
+                        }
+                        const {body: baseManifest} = results[indexOfBaseManifest];
+                        const baseManifestLocation = manifestLocations[indexOfBaseManifest];
+                        const promise = this._themeBuilder.populateDerivedTheme(body, baseManifest, baseManifestLocation, log);
                         runtimeThemePromises.push(promise);
                     }
                     else {
@@ -97,7 +101,7 @@ export class ThemeLoader {
     }
 
     private _populateThemeMap(manifest: ThemeManifest, manifestLocation: string, log: ILogItem) {
-        log.wrap("populateThemeMap", () => {
+        log.wrap("ThemeLoader.populateThemeMap", () => {
             /*
             After build has finished, the source section of each theme manifest
             contains `built-assets` which is a mapping from the theme-id to