add opfs and api link to it

src/moto/opfs.js

@@ -0,0 +1,121 @@
+const root = await navigator.storage.getDirectory();
+
+function resolvePath(path) {
+    if (!path) {
+        return [];
+    } else if (typeof path === 'string') {
+        path = path.trim();
+        while (path.charAt(0) === '/') {
+            path = path.substring(1);
+        }
+        return path.length ? path.split('/') : [];
+    } else if (Array.isArray(path)) {
+        return path;
+    } else {
+        throw "invalid path value";
+    }
+}
+
+export async function dirHandle(path, options = { create: true }) {
+    path = resolvePath(path);
+    if (path.length === 0) {
+        return root;
+    }
+    let dir = root;
+    for (let tok of path) {
+        try {
+            dir = await dir.getDirectoryHandle(tok, options);
+        } catch (error) {
+            if (options.report) {
+                console.log({ path, error });
+            }
+            return undefined;
+        }
+    }
+    return dir;
+}
+
+export async function fileHandle(path, options = { create: false }) {
+    path = resolvePath(path);
+    if (path.length === 0) {
+        return undefined;
+    }
+    let target = path.pop();
+    let dir = await dirHandle(path);
+    return dir.getFileHandle(target, options);
+}
+
+export async function clear() {
+    for await (let name of root.keys()) {
+        await root.removeEntry(name, { recursive: true });
+    }
+}
+
+export async function remove(path) {
+    path = resolvePath(path);
+    if (path.length === 0) {
+        return clear();
+    }
+    let target = path.pop();
+    let dir = await dirHandle(path);
+    console.log({ dir, target });
+    await dir.removeEntry(target, { recursive: true });
+}
+
+export async function entries(path) {
+    return (await dirHandle(path)).entries();
+}
+
+export async function values(path) {
+    return (await dirHandle(path)).values();
+}
+
+export async function keys(path) {
+    return (await dirHandle(path)).keys();
+}
+
+export async function tree(path) {
+    path = resolvePath(path);
+    let dir = await dirHandle(path);
+    return treeFrom(dir, path, []);
+}
+
+async function treeFrom(dir, path, list) {
+    let entries = await dir.entries()
+    for await (let [ name, handle ] of entries) {
+        path.push(name);
+        if (handle.kind === 'directory') {
+            await treeFrom(handle, path, list);
+        } else {
+            list.push(path.join('/'));
+        }
+        path.pop();
+    }
+    return list;
+}
+
+export async function getText(path) {
+    let handle = await fileHandle(path);
+    let file = await handle.getFile();
+    return file.text();
+}
+
+export async function putText(path, text) {
+    let handle = await fileHandle(path, { create: true });
+    let stream = await handle.createWritable();
+    await stream.write(text);
+    return stream.close();
+}
+
+export const OPFS = {
+    dirHandle,
+    fileHandle,
+    entries,
+    keys,
+    values,
+    tree,
+    clear,
+    remove,
+    getText,
+    putText
+};