added backend to cache manga updates requests

2023-11-20 17:01:37 +01:00
parent 34b0135da7
commit 29e1d2e499
19 changed files with 699 additions and 20 deletions
--- a/backend/src/cache/MangaUpdatesCache.ts
+++ b/backend/src/cache/MangaUpdatesCache.ts
@@ -0,0 +1,98 @@
+import * as fs from 'fs';
+
+type CacheEntry = { data: string, lastUpdateMs: number }
+
+export class MangaUpdatesCache {
+  private readonly FILE_CACHE_DIR = 'cache';
+  private readonly FILE_SEARCH_BY_TITLE = this.FILE_CACHE_DIR + '/searchByTitle.json';
+  private readonly FILE_SERIES_BY_ID = this.FILE_CACHE_DIR + '/seriesById.json';
+  private readonly FILE_SERIES_GROUPS_BY_ID = this.FILE_CACHE_DIR + '/seriesGroupsById.json';
+
+  private readonly MAX_CACHE_AGE_SEARCH_BY_TITLE = 7 * 24 * 60 * 60 * 1000;
+  private readonly MAX_CACHE_AGE_SERIES_BY_ID = 30 * 24 * 60 * 60 * 1000;
+  private readonly MAX_CACHE_AGE_SERIES_GROUPS_BY_ID = 1 * 24 * 60 * 60 * 1000;
+
+  private _searchByTitle = new Map<string, CacheEntry>();
+  private _seriesById = new Map<string, CacheEntry>();
+  private _seriesGroupsById = new Map<string, CacheEntry>();
+
+  constructor() {
+    this.load();
+  }
+
+  private load(): void {
+    try {
+      fs.mkdirSync(this.FILE_CACHE_DIR);
+    } catch (_) {
+    }
+    this._searchByTitle = this.loadJson(this.FILE_SEARCH_BY_TITLE);
+    this._seriesById = this.loadJson(this.FILE_SERIES_BY_ID);
+    this._seriesGroupsById = this.loadJson(this.FILE_SERIES_GROUPS_BY_ID);
+  }
+
+  private loadJson(file: string): Map<string, CacheEntry> {
+    try {
+      const data = fs.readFileSync(file, {encoding: 'utf8', flag: 'r'});
+      const json = JSON.parse(data);
+      return new Map<string, CacheEntry>(Object.entries(json));
+    } catch (err) {
+      console.error('Failed to load cache from ' + file + ':' + (err as Error).message);
+      return new Map();
+    }
+  }
+
+  private saveJson(file: string, map: Map<string, CacheEntry>): void {
+    try {
+      const data = JSON.stringify(Object.fromEntries(map.entries()));
+      fs.writeFileSync(file, data, {encoding: 'utf8', flag: 'w'});
+    } catch (err) {
+      console.error(err);
+    }
+  }
+
+  getSearchByTitle(title: string): string | undefined {
+    const entry = this._searchByTitle.get(title);
+    return !entry || entry.lastUpdateMs + this.MAX_CACHE_AGE_SEARCH_BY_TITLE < Date.now() ? undefined : entry.data;
+  }
+
+  getSeriesById(id: string): string | undefined {
+    const entry = this._seriesById.get(id);
+    return !entry || entry.lastUpdateMs + this.MAX_CACHE_AGE_SERIES_BY_ID < Date.now() ? undefined : entry.data;
+  }
+
+  getSeriesGroupsById(id: string): string | undefined {
+    const entry = this._seriesGroupsById.get(id);
+    return !entry || entry.lastUpdateMs + this.MAX_CACHE_AGE_SERIES_GROUPS_BY_ID < Date.now() ? undefined : entry.data;
+  }
+
+  putSearchByTitle(title: string, value: string): void {
+    this._searchByTitle.set(title, {data: value, lastUpdateMs: Date.now()});
+    this.saveJson(this.FILE_SEARCH_BY_TITLE, this._searchByTitle);
+  }
+
+  putSeriesById(id: string, value: string): void {
+    this._seriesById.set(id, {data: value, lastUpdateMs: Date.now()});
+    this.saveJson(this.FILE_SERIES_BY_ID, this._seriesById);
+  }
+
+  putSeriesGroupsById(id: string, value: string): void {
+    this._seriesGroupsById.set(id, {data: value, lastUpdateMs: Date.now()});
+    this.saveJson(this.FILE_SERIES_GROUPS_BY_ID, this._seriesGroupsById);
+  }
+
+  getOutOfDateSearch(): string[] {
+    return Array.from(this._searchByTitle.entries())
+      .filter(([title, entry]) => entry.lastUpdateMs + this.MAX_CACHE_AGE_SEARCH_BY_TITLE < Date.now())
+      .map(([title, entry]) => title);
+  }
+  getOutOfDateSeries(): string[] {
+    return Array.from(this._seriesById.entries())
+      .filter(([title, entry]) => entry.lastUpdateMs + this.MAX_CACHE_AGE_SERIES_BY_ID < Date.now())
+      .map(([title, entry]) => title);
+  }
+  getOutOfDateSeriesGroups(): string[] {
+    return Array.from(this._seriesGroupsById.entries())
+      .filter(([title, entry]) => entry.lastUpdateMs + this.MAX_CACHE_AGE_SERIES_GROUPS_BY_ID < Date.now())
+      .map(([title, entry]) => title);
+  }
+}