Function seekSignature

index-native.cjs:4271–4291

(reader, signature, startOffset, minimumBytes, maximumLength)

}

async function seekSignature(reader, signature, startOffset, minimumBytes, maximumLength) {
	const signatureArray = new Uint8Array(4);
	const signatureView = getDataView$1(signatureArray);
	setUint32$1(signatureView, 0, signature);
	const maximumBytes = minimumBytes + maximumLength;
	return (await seek(minimumBytes)) || await seek(Math.min(maximumBytes, startOffset));

	async function seek(length) {
		const offset = startOffset - length;
		const bytes = await readUint8Array(reader, offset, length);
		for (let indexByte = bytes.length - minimumBytes; indexByte >= 0; indexByte--) {
			if (bytes[indexByte] == signatureArray[0] && bytes[indexByte + 1] == signatureArray[1] &&
				bytes[indexByte + 2] == signatureArray[2] && bytes[indexByte + 3] == signatureArray[3]) {
				return {
					offset: offset + indexByte,
					buffer: bytes.slice(indexByte, indexByte + minimumBytes).buffer
				};
			}
		}
	}
}

function getOptionValue$1(zipReader, options, name) {
	return options[name] === UNDEFINED_VALUE ? zipReader.options[name] : options[name];