96 lines
1.7 KiB
JavaScript
96 lines
1.7 KiB
JavaScript
import FS from "../fs";
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import SuperNode from "../super-node";
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import Node from "../node";
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import UUID from "../../common/uuid";
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import { MODE_DIRECTORY, MODE_FILE, DATA_BLOCK_SEPARATOR } from "../../common/constants";
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import { SUPER_NODE_ID } from "../../common/constants";
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import E from "../../common/errors";
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const __ = new WeakMap();
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/*
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RootFS is a read-only file system containing exactly one
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directory node. It is created automatically by the VFS
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layer. Its only purpose is to allow the VFS to mount another
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file system on top of its only node.
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*/
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class RootFS extends FS
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{
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constructor(options={})
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{
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super(options);
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let superNode = new SuperNode({ fs: this, data: { dev: UUID.short() } });
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let rootNode = new Node({ fs: this, data: { mode: MODE_DIRECTORY, nlinks: 1 } });
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superNode.rnode = rootNode.id;
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let storage = new Map();
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storage.set(superNode.id, superNode.data);
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storage.set(rootNode.id, rootNode.data);
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__.set(this, {
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storage: storage,
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});
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}
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static get type()
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{
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return "rootfs";
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}
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static async mount()
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{
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throw new E.UNKNOWN("mount operation not available for rootfs");
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}
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async umount()
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{
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throw new E.UNKNOWN("umount operation not available for rootfs");
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}
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async readNode(id)
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{
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let node = __.get(this).storage.get(id);
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if(!node) {
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throw new E.ENOENT();
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}
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return node;
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}
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async writeNode(id, node)
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{
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throw new E.EROFS();
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}
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async readData(id, block=0)
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{
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let data = __.get(this).storage.get(`${id}${DATA_BLOCK_SEPARATOR}${block}`);
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if(!data) {
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throw new E.EIO();
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}
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return data;
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}
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async writeData(id, block, data)
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{
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throw new E.EROFS();
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}
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async fsync()
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{
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}
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async validate(id)
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{
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}
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}
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export default RootFS; |