Refactored Directory to extend Map

Author: james-pre

jest.config.json

@@ -2,40 +2,40 @@ import { DirectoryRecord, ISODirectoryRecord, JolietDirectoryRecord } from './Di
 import { FileFlags } from './constants.js';
 import { CLEntry, REEntry } from './entries.js';
 
-export abstract class Directory<T extends DirectoryRecord> {
-	protected _record: T;
-	private _fileList: string[] = [];
-	private _fileMap: { [name: string]: T } = {};
+export abstract class Directory<T extends DirectoryRecord> extends Map<string, T> {
+	//public readonly files: string[] = [];
+	//private fileMap = new Map<string, T>();
 
-	public constructor(record: T, isoData: Uint8Array) {
-		this._record = record;
+	public constructor(
+		protected record: T,
+		isoData: Uint8Array
+	) {
+		super();
 		let i = record.lba;
 		let limit = i + record.dataLength;
 		if (!(record.fileFlags & FileFlags.Directory)) {
 			// Must have a CL entry.
-			const cl = record.getSUEntries(isoData).filter(e => e instanceof CLEntry)[0] as CLEntry;
+			const cl = record.getSUEntries(isoData).find(e => e instanceof CLEntry);
+			if (!cl) {
+				throw new ReferenceError('No CL entry');
+			}
 			i = cl.childDirectoryLba * 2048;
 			limit = Infinity;
 		}
 
 		while (i < limit) {
-			const len = isoData[i];
+			const length = isoData[i];
 			// Zero-padding between sectors.
-			// TODO: Could optimize this to seek to nearest-sector upon
-			// seeing a 0.
-			if (len === 0) {
+			// Could optimize this to seek to nearest-sector upon seeing a 0.
+			if (!length) {
 				i++;
 				continue;
 			}
 			const r = this._constructDirectoryRecord(isoData.slice(i));
 			const fname = r.fileName(isoData);
 			// Skip '.' and '..' entries.
-			if (fname !== '\u0000' && fname !== '\u0001') {
-				// Skip relocated entries.
-				if (!r.hasRockRidge || r.getSUEntries(isoData).filter(e => e instanceof REEntry).length === 0) {
-					this._fileMap[fname] = r;
-					this._fileList.push(fname);
-				}
+			if (fname !== '\u0000' && fname !== '\u0001' && (!r.hasRockRidge || !r.getSUEntries(isoData).filter(e => e instanceof REEntry).length)) {
+				this.set(fname, r);
 			} else if (limit === Infinity) {
 				// First entry contains needed data.
 				limit = i + r.dataLength;
@@ -44,40 +44,21 @@ export abstract class Directory<T extends DirectoryRecord> {
 		}
 	}
 
-	/**
-	 * Get the record with the given name.
-	 * Returns undefined if not present.
-	 */
-	public getRecord(name: string): DirectoryRecord {
-		return this._fileMap[name];
-	}
-
-	public get fileList(): string[] {
-		return this._fileList;
-	}
-
 	public getDotEntry(isoData: Uint8Array): T {
-		return this._constructDirectoryRecord(isoData.slice(this._record.lba));
+		return this._constructDirectoryRecord(isoData.slice(this.record.lba));
 	}
 
 	protected abstract _constructDirectoryRecord(data: Uint8Array): T;
 }
-export class ISODirectory extends Directory<ISODirectoryRecord> {
-	public constructor(record: ISODirectoryRecord, isoData: Uint8Array) {
-		super(record, isoData);
-	}
 
+export class ISODirectory extends Directory<ISODirectoryRecord> {
 	protected _constructDirectoryRecord(data: Uint8Array): ISODirectoryRecord {
-		return new ISODirectoryRecord(data, this._record.rockRidgeOffset);
+		return new ISODirectoryRecord(data, this.record.rockRidgeOffset);
 	}
 }
 
 export class JolietDirectory extends Directory<JolietDirectoryRecord> {
-	public constructor(record: JolietDirectoryRecord, isoData: Uint8Array) {
-		super(record, isoData);
-	}
-
 	protected _constructDirectoryRecord(data: Uint8Array): JolietDirectoryRecord {
-		return new JolietDirectoryRecord(data, this._record.rockRidgeOffset);
+		return new JolietDirectoryRecord(data, this.record.rockRidgeOffset);
 	}
 }

src/Directory.ts

@@ -135,7 +135,7 @@ export class IsoFS extends Readonly(Sync(FileSystem)) {
 		}
 
 		if (record.isDirectory(this.data)) {
-			return record.getDirectory(this.data).fileList.slice(0);
+			return Array.from(record.getDirectory(this.data).keys());
 		}
 
 		throw ErrnoError.With('ENOTDIR', path, 'readdir');
@@ -146,13 +146,13 @@ export class IsoFS extends Readonly(Sync(FileSystem)) {
 		if (path === '/') {
 			return this._root;
 		}
-		const components = path.split('/').slice(1);
-		let dir = this._root;
-		for (const component of components) {
+		const parts = path.split('/').slice(1);
+		let dir: DirectoryRecord | undefined = this._root;
+		for (const part of parts) {
 			if (!dir.isDirectory(this.data)) {
 				return;
 			}
-			dir = dir.getDirectory(this.data).getRecord(component);
+			dir = dir.getDirectory(this.data).get(part);
 			if (!dir) {
 				return;
 			}