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128 lines
3.4 KiB
128 lines
3.4 KiB
class FileSystem {
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static get GOOD() { return 0; }
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static get BAD() { return 1; }
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static get BAD_NOTIMPLEMENTED() { return 2; }
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static get BAD_TIMEOUT() { return 3; }
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static get BAD_FORMAT() { return 4; }
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static get BAD_NOENTRY() { return 101; }
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static get BAD_NOACCESS() { return 102; }
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static get O_ACCMODE() { return 0x003; }
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static get O_RDONLY() { return 0x000; }
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static get O_WRONLY() { return 0x001; }
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static get O_RDWR() { return 0x002; }
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static get O_CREAT() { return 0x040; }
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static get O_EXCL() { return 0x080; }
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static get O_TRUNK() { return 0x200; }
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static get O_APPEND() { return 0x400; }
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constructor(root) {
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this.root = root;
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this._inodes = { };
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this._walk(this.root, (entry) => { this._inodes[entry.inode] = entry; });
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}
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_walk(node, callback) {
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callback(node);
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const entries = node.entries;
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if (entries) {
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for(let entry of Object.entries(entries)) {
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this._walk(entry[1], callback);
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}
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}
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}
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lookup(parent, name) {
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const parentEntry = this._inodes[parent];
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const entry = (parentEntry && parentEntry.entries && parentEntry.entries[name]) || null;
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if (entry) {
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return {
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inode: entry.inode,
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mode: entry.mode || parseInt("755", 8),
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type: entry.type || 'file',
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size: entry.size || (entry.contents && entry.contents.length) || 0,
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atime: entry.atime || 0,
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mtime: entry.mtime || 0,
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ctime: entry.ctime || 0
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};
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}
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else {
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return FileSystem.BAD_NOENTRY;
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}
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}
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getattr(inode) {
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let entry = this._inodes[inode];
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if (entry) {
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return {
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mode: entry.mode || parseInt("755", 8),
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type: entry.type || 'file',
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size: entry.size || (entry.contents && entry.contents.length) || 0,
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atime: entry.atime || 0,
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mtime: entry.mtime || 0,
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ctime: entry.ctime || 0
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};
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}
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else {
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return FileSystem.BAD_NOENTRY;
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}
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}
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readdir(inode) {
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let result = FileSystem.BAD_NOENTRY;
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let entry = this._inodes[inode];
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if ((entry) && ("dir" === entry.type)) {
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result = [
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{name: '.', inode: entry.inode},
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{name: '..', inode: entry.inode}
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];
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for(let subdir of Object.entries(entry.entries)) {
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const name = subdir[0];
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const inode = subdir[1].inode;
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result.push({name: name, inode: inode});
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}
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}
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return result;
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}
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open(inode, mode) {
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let result = FileSystem.BAD_NOENTRY;
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let entry = this._inodes[inode];
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if (entry.type == "file") {
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result = ((mode & FileSystem.O_ACCMODE) == FileSystem.O_RDONLY) ? {handle: 1337} : FileSystem.BAD_NOACCESS;
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}
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return result;
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}
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close(inode, handle, mode) {
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// do nothing
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return true;
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}
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read(inode, handle, offset, length) {
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let result = FileSystem.BAD_NOENTRY;
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let entry = this._inodes[inode];
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if (entry.type == "file") {
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let end = Math.min(offset + length, entry.contents.length);
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let data = (offset < entry.contents.length) ? entry.contents.substring(offset, end) : "";
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result = {
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data: btoa(data),
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format: "base64",
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count: data.length
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};
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}
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return result;
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}
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} |