Function wrapGenerator

lib/methods/table.js:123–147

(generator, columnMap, moduleName)

}

function wrapGenerator(generator, columnMap, moduleName) {
	return function* virtualTable(...args) {
		/*
			We must defensively clone any buffers in the arguments, because
			otherwise the generator could mutate one of them, which would cause
			us to return incorrect values for hidden columns, potentially
			corrupting the database.
		 */
		const output = args.map(x => Buffer.isBuffer(x) ? Buffer.from(x) : x);
		for (let i = 0; i < columnMap.size; ++i) {
			output.push(null); // Fill with nulls to prevent gaps in array (v8 optimization)
		}
		for (const row of generator(...args)) {
			if (Array.isArray(row)) {
				extractRowArray(row, output, columnMap.size, moduleName);
				yield output;
			} else if (typeof row === 'object' && row !== null) {
				extractRowObject(row, output, columnMap, moduleName);
				yield output;
			} else {
				throw new TypeError(`Virtual table module "${moduleName}" yielded something that isn't a valid row object`);
			}
		}
	};
}

function extractRowArray(row, output, columnCount, moduleName) {
	if (row.length !== columnCount) {