Caching remote JSON requests

src/CLI.ts

@@ -3,6 +3,7 @@ import { CLIWatcher } from "./CLIWatcher.ts";
 import { comMojangFolder, previewComMojangFolder } from "./comMojangFolder.ts";
 import { Dash, isMatch } from "./deps.ts";
 import { DenoFileSystem } from "./FileSystem.ts";
+import { getLocalData, saveLocalData, tryInvalidateLocalData } from "./LocalCache.ts";
 import { FileTypeImpl, PackTypeImpl } from "./McProjectCore.ts";
 
 interface IDashOptions {
@@ -25,13 +26,28 @@ export class CLI {
 			mode,
 			verbose: true,
 
-			requestJsonData: (dataPath: string) =>
-				fetch(
+			requestJsonData: async (dataPath: string) => {
+				const cached = await getLocalData(dataPath);
+
+				if (cached) {
+					try {
+						return JSON.parse(cached);
+					} catch {
+						// empty
+					}
+				}
+
+				const data = await fetch(
 					dataPath.replace(
 						"data/",
 						"https://raw.githubusercontent.com/bridge-core/editor-packages/main/",
 					),
-				).then((resp) => resp.json()),
+				).then((resp) => resp.json());
+
+				saveLocalData(dataPath, JSON.stringify(data));
+
+				return data;
+			},
 		});
 
 		await dash.setup();
@@ -64,13 +80,15 @@ export class CLI {
 	async build(options: IDashOptions) {
 		this.verifyOptions(options);
 
+		await tryInvalidateLocalData();
 		const dash = await this.createDashService(options);
 		await dash.build();
 	}
 	async watch(options: IDashOptions) {
 		this.verifyOptions(options);
-		const dash = await this.createDashService(options);
 
+		await tryInvalidateLocalData();
+		const dash = await this.createDashService(options);
 		await dash.build();
 		await new CLIWatcher(dash).watch(options.reload);
 	}

src/LocalCache.ts

@@ -0,0 +1,71 @@
+import { fs, path } from "./deps.ts";
+
+export async function tryInvalidateLocalData() {
+	const localDataPath = await getLocalDataPath();
+
+	if (!localDataPath) return;
+
+	try {
+		let time = 0;
+
+		const timestampFilePath = path.join(localDataPath, ".timestamp");
+
+		if (await fs.exists(timestampFilePath)) {
+			const lastUpdatedTimestamp = await Deno.readTextFile(timestampFilePath);
+
+			time = parseInt(lastUpdatedTimestamp);
+		}
+
+		const now = Date.now();
+
+		if (now - time > 1000 * 60 * 60 * 24) {
+			console.log("Invalidating local cache of remote data!");
+
+			await fs.emptyDir(localDataPath);
+		}
+	} catch {
+		// empty
+	}
+}
+
+export async function getLocalDataPath(): Promise<string | undefined> {
+	const userDir = Deno.env.get("HOME") || Deno.env.get("USERPROFILE");
+
+	if (!userDir) return undefined;
+
+	const appDataPath = path.join(userDir, ".dash");
+
+	await fs.ensureDir(appDataPath);
+
+	return appDataPath;
+}
+
+export async function saveLocalData(filePath: string, content: string) {
+	const localDataPath = await getLocalDataPath();
+
+	if (!localDataPath) return;
+
+	const fullPath = path.join(localDataPath, filePath);
+
+	await fs.ensureDir(path.dirname(fullPath));
+
+	await Deno.writeTextFile(fullPath, content);
+
+	const timestampFilePath = path.join(localDataPath, ".timestamp");
+
+	if (!await fs.exists(timestampFilePath)) await Deno.writeTextFile(timestampFilePath, Date.now().toString());
+}
+
+export async function getLocalData(filePath: string): Promise<string | undefined> {
+	const localDataPath = await getLocalDataPath();
+
+	if (!localDataPath) return;
+
+	const fullPath = path.join(localDataPath, filePath);
+
+	try {
+		return await Deno.readTextFile(fullPath);
+	} catch {
+		return;
+	}
+}

src/McProjectCore.ts

@@ -1,20 +1,50 @@
 import { FileType, IFileType, PackType } from "./deps.ts";
+import { getLocalData, saveLocalData } from "./LocalCache.ts";
 
 export class PackTypeImpl extends PackType<void> {
 	async setup() {
+		const cached = await getLocalData("packDefinitions.json");
+
+		if (cached) {
+			try {
+				this.packTypes = JSON.parse(cached);
+
+				return;
+			} catch {
+				// empty
+			}
+		}
+
 		this.packTypes = await fetch(
 			"https://raw.githubusercontent.com/bridge-core/editor-packages/main/packages/minecraftBedrock/packDefinitions.json",
 		).then((resp) => resp.json());
+
+		saveLocalData("packDefinitions.json", JSON.stringify(this.packTypes));
 	}
 }
 export class FileTypeImpl extends FileType<void> {
 	protected _cache = new Map<string, IFileType | null>();
 
 	async setup() {
 		this._cache.clear();
+
+		const cached = await getLocalData("fileDefinitions.json");
+
+		if (cached) {
+			try {
+				this.fileTypes = JSON.parse(cached);
+
+				return;
+			} catch {
+				// empty
+			}
+		}
+
 		this.fileTypes = await fetch(
 			"https://raw.githubusercontent.com/bridge-core/editor-packages/main/dist/minecraftBedrock/fileDefinitions.json",
 		).then((resp) => resp.json());
+
+		saveLocalData("fileDefinitions.json", JSON.stringify(this.fileTypes));
 	}
 
 	override addPluginFileType(fileDef: IFileType) {

src/deps.ts

@@ -1,4 +1,5 @@
 export * as path from "jsr:@std/path";
+export * as fs from "https://deno.land/std/fs/mod.ts";
 export {
 	FileType,
 	type IFileType,