Implemented support for caseFold parameter on Archives File Systems

.gitignore

@@ -5,4 +5,5 @@ docs
 *.log
 tmp
 build
-.coverage
+.coverage
+.DS_Store

src/zip/fs.ts

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: LGPL-3.0-or-later
 import { FileSystem, Inode, type UsageInfo } from '@zenfs/core';
 import type { Backend } from '@zenfs/core/backends/backend.js';
+import type { CaseFold } from '@zenfs/core/internal/filesystem.js';
 import { S_IFDIR, S_IFREG } from '@zenfs/core/constants';
 import { Readonly } from '@zenfs/core/mixins/readonly.js';
 import { parse } from '@zenfs/core/path';
@@ -34,6 +35,13 @@
 	 * Whether to wait to initialize entries
 	 */
 	lazy?: boolean;
+
+	/**
+	 * Case folding mode for file names (optional).
+	 * Can be 'lower', or 'upper'.
+	 * Default is undefined.
+	 */
+	caseFold?: CaseFold;
 }
 
 /**
@@ -66,6 +74,7 @@
 export class ZipFS<TBuffer extends ArrayBufferLike = ArrayBuffer> extends Readonly(FileSystem) {
 	protected files: Map<string, FileEntry<TBuffer>> = new Map();
 	protected directories: Map<string, Set<string>> = new Map();
+	protected folded: Map<string, string> = new Map();
 
 	protected _time = Date.now();
 	private _ready: boolean = false;
@@ -101,15 +110,17 @@
 				throw withErrno('EPERM', 'Unexpectedly encountered an absolute path in a zip file.');
 			}
 			// Strip the trailing '/' if it exists
-			const name = cd.name.endsWith('/') ? cd.name.slice(0, -1) : cd.name;
-			this.files.set('/' + name, cd);
+			const name = cd.name.endsWith('/') ? '/' + cd.name.slice(0, -1) : '/' + cd.name;
+			this.files.set(this._caseFold(name, true), cd);
 			ptr += cd.size;
 		}
 
 		// Parse directory entries
 		for (const entry of this.files.keys()) {
-			const { dir, base } = parse(entry);
+			const name = this.folded.get(entry) ?? entry;
+			let { dir, base } = parse(name);
 
+			dir = this._caseFold(dir, true);
 			if (!this.directories.has(dir)) {
 				this.directories.set(dir, new Set());
 			}
@@ -119,8 +130,10 @@
 
 		// Add subdirectories to their parent's entries
 		for (const entry of this.directories.keys()) {
-			const { dir, base } = parse(entry);
+			const name = this.folded.get(entry) ?? entry;
+			let { dir, base } = parse(name);
 
+			dir = this._caseFold(dir, true);
 			if (base == '') continue;
 
 			if (!this.directories.has(dir)) {
@@ -134,7 +147,8 @@
 	public constructor(
 		public label: string,
 		protected data: ZipDataSource<TBuffer>,
-		public readonly lazy: boolean = false
+		public readonly lazy: boolean = false,
+		public readonly caseFold?: CaseFold
 	) {
 		super(0x207a6970, 'zipfs');
 	}
@@ -146,13 +160,14 @@
 		};
 	}
 
 	public async stat(path: string): Promise<Inode> {
 		return this.statSync(path);
 	}
 
 	public statSync(path: string): Inode {
+		const folded = this._caseFold(path);
 		// The EOCD/Header does not track directories, so it does not exist in `entries`
-		if (this.directories.has(path)) {
+		if (this.directories.has(folded)) {
 			return new Inode({
 				mode: 0o555 | S_IFDIR,
 				size: 4096,
@@ -163,7 +178,7 @@
 			});
 		}
 
-		const entry = this.files.get(path);
+		const entry = this.files.get(folded);
 
 		if (!entry) throw withErrno('ENOENT');
 
@@ -178,36 +193,42 @@
 		const inode = await this.stat(path);
 		if (!(inode.mode & S_IFDIR)) throw withErrno('ENOTDIR');
 
-		const entries = this.directories.get(path);
+		const entries = this.directories.get(this._caseFold(path));
 		if (!entries) throw withErrno('ENODATA');
 
-		return Array.from(entries);
+		return Array.from(entries).map(entry => {
+			return this.folded.get(entry) ?? entry;
+		});
 	}
 
 	public readdirSync(path: string): string[] {
 		const inode = this.statSync(path);
 		if (!(inode.mode & S_IFDIR)) throw withErrno('ENOTDIR');
 
-		const entries = this.directories.get(path);
+		const entries = this.directories.get(this._caseFold(path));
 		if (!entries) throw withErrno('ENODATA');
 
-		return Array.from(entries);
+		return Array.from(entries).map(entry => {
+			return this.folded.get(entry) ?? entry;
+		});
 	}
 
 	public async read(path: string, buffer: Uint8Array, offset: number, end: number): Promise<void> {
-		if (this.directories.has(path)) throw withErrno('EISDIR');
+		const folded = this._caseFold(path);
+		if (this.directories.has(folded)) throw withErrno('EISDIR');
 
-		const file = this.files.get(path) ?? _throw(withErrno('ENOENT'));
+		const file = this.files.get(folded) ?? _throw(withErrno('ENOENT'));
 
 		if (!file.contents) await file.loadContents();
 
 		buffer.set(file.contents.subarray(offset, end));
 	}
 
 	public readSync(path: string, buffer: Uint8Array, offset: number, end: number): void {
-		if (this.directories.has(path)) throw withErrno('EISDIR');
+		const folded = this._caseFold(path);
+		if (this.directories.has(folded)) throw withErrno('EISDIR');
 
-		const file = this.files.get(path) ?? _throw(withErrno('ENOENT'));
+		const file = this.files.get(folded) ?? _throw(withErrno('ENOENT'));
 
 		if (!file.contents) {
 			void file.loadContents();
@@ -216,6 +237,17 @@
 
 		buffer.set(file.contents.subarray(offset, end));
 	}
+
+	private _caseFold(original: string, update: boolean = false): string {
+		if (this.caseFold) {
+			const folded = this.caseFold == 'upper' ? original.toUpperCase() : original.toLowerCase();
+			if (update && !this.folded.has(folded) && folded !== original) {
+				this.folded.set(folded, original);
+			}
+			return folded;
+		}
+		return original;
+	}
 }
 
 const _isShared = (b: unknown): b is SharedArrayBuffer => typeof b == 'object' && b !== null && b.constructor.name === 'SharedArrayBuffer';
@@ -230,7 +262,7 @@
 		length: number;
 	}>();
 
 	const allDone = (async function __read() {
 		for await (const chunk of stream) {
 			data.set(chunk, bytesRead);
 			bytesRead += chunk.byteLength;
@@ -305,14 +337,15 @@
 		},
 		name: { type: 'string', required: false },
 		lazy: { type: 'boolean', required: false },
+		caseFold: { type: 'string', required: false },
 	},
 
 	isAvailable(): boolean {
 		return true;
 	},
 
 	create<TBuffer extends ArrayBufferLike = ArrayBuffer>(opt: ZipOptions<TBuffer>): ZipFS<TBuffer> {
-		return new ZipFS<TBuffer>(opt.name ?? '', getSource(opt.data), opt.lazy);
+		return new ZipFS<TBuffer>(opt.name ?? '', getSource(opt.data), opt.lazy, opt.caseFold);
 	},
 } satisfies Backend<ZipFS, ZipOptions>;
 type _Zip = typeof _Zip;