Function buildNumericWrapper

lib/internal/ffi-shared-buffer.js:289–523

(
  rawFn, view, argInfos, argOffsets, nargs, retGetter)

// hot path reads a single variable per arg. This is admittedly pretty weird
// but it's the result of lots of perf-hunting.
function buildNumericWrapper(
  rawFn, view, argInfos, argOffsets, nargs, retGetter) {
  // `IsSBEligibleSignature` on the native side rejects 0-arg signatures,
  // so this branch is unreachable today. It's kept as defense-in-depth
  // for when that filter changes or for programmatic callers that hand a
  // 0-arg signature through `wrapWithSharedBuffer` directly.
  /* c8 ignore start */
  if (nargs === 0) {
    if (retGetter === null) {
      return function() {
        if (arguments.length !== 0) {
          throwFFIArgCountError(0, arguments.length);
        }
        rawFn();
      };
    }
    return function() {
      if (arguments.length !== 0) {
        throwFFIArgCountError(0, arguments.length);
      }
      rawFn();
      return retGetter(view, 0, true);
    };
  }
  /* c8 ignore stop */
  if (nargs === 1) {
    const i0 = argInfos[0];
    const o0 = argOffsets[0];
    if (retGetter === null) {
      return function(a0) {
        if (arguments.length !== 1) {
          throwFFIArgCountError(1, arguments.length);
        }
        writeNumericArg(view, i0, o0, a0, 0);
        rawFn();
      };
    }
    return function(a0) {
      if (arguments.length !== 1) {
        throwFFIArgCountError(1, arguments.length);
      }
      writeNumericArg(view, i0, o0, a0, 0);
      rawFn();
      return retGetter(view, 0, true);
    };
  }
  if (nargs === 2) {
    const i0 = argInfos[0];
    const i1 = argInfos[1];
    const o0 = argOffsets[0];
    const o1 = argOffsets[1];
    if (retGetter === null) {
      return function(a0, a1) {
        if (arguments.length !== 2) {
          throwFFIArgCountError(2, arguments.length);
        }
        writeNumericArg(view, i0, o0, a0, 0);
        writeNumericArg(view, i1, o1, a1, 1);