@awayfl/avm2/lib/abc/lazy/Namespace.ts

Virtual machine for executing AS3 code

import { NamespaceType, getNamespaceTypeName } from './NamespaceType';
import { assert } from '@awayjs/graphics';
import { release } from '@awayfl/swf-loader';
import { StringUtilities } from '@awayfl/swf-loader';
import { HashUtilities } from '@awayfl/swf-loader';
import { namespaceHashingBuffer } from './namespaceHashingBuffer';

export class Namespace {
	public mangledName: string = null;
	constructor(public type: NamespaceType, public uri: string, public prefix: string) {
		assert (type !== undefined);
		this.mangleName();
		if (!release) {
			Object.freeze(this);
		}
	}

	toString() {
		return getNamespaceTypeName(this.type) + (this.uri !== '' ? ':' + this.uri : '');
	}

	private static _knownNames = [
		''
	];

	private static _hashNamespace(type: NamespaceType, uri: string, prefix: string) {
		uri = uri + '';
		prefix = prefix + '';
		const index = Namespace._knownNames.indexOf(uri);
		if (index >= 0) {
			return type << 2 | index;
		}
		const length = 1 + uri.length + prefix.length;
		const data: Uint8Array = length < 101 ? namespaceHashingBuffer : new Uint8Array(length);
		let j = 0;
		data[j++] = type;
		for (let i = 0; i < uri.length; i++) {
			data[j++] = uri.charCodeAt(i);
		}
		for (let i = 0; i < prefix.length; i++) {
			data[j++] = prefix.charCodeAt(i);
		}
		return HashUtilities.hashBytesTo32BitsMD5(data, 0, j);
	}

	private mangleName() {
		if (this.type === NamespaceType.Public && this.uri === '') {
			this.mangledName = 'Bg';
			return;
		}
		const nsHash = Namespace._hashNamespace(this.type, this.uri, this.prefix);
		this.mangledName = StringUtilities.variableLengthEncodeInt32(nsHash);
	}

	public isPublic(): boolean {
		return this.type === NamespaceType.Public;
	}

	public get reflectedURI() {
		// For public names without a URI, Tamarin uses `null`, we use `""`.
		// Hence: special-casing for reflection.
		return this.uri || (this.type === NamespaceType.Public ? null : this.uri);
	}

	public static PUBLIC: Namespace;
}