Node.js异步函数返回

Question

https://github.com/mapbox/spritezero 我是一个nodejs新手，代码基于此存储库

  q.awaitAll(function (err, buffers) {
    // if(err) return;
    // console.log(buffers);
    [1, 2, 4].forEach(function (pxRatio) {
        var pngPath = destDir + "/sprite@" + pxRatio + ".png";
        var jsonPath = destDir +  "/sprite@" + pxRatio + ".json";

        spritezero.generateLayout(
          { imgs: buffers, pixelRatio: pxRatio, format: true },
          async function(err, dataLayout) {
            if (err) return;
            let result1 = await client.put(
              jsonPath,
              Buffer.from(JSON.stringify(dataLayout, null))
            );
            //console.log(client.signatureUrl(result.name));
          }
        );
        spritezero.generateLayout(
          { imgs: buffers, pixelRatio: pxRatio, format: false },
          function(err, imageLayout) {
            spritezero.generateImage(imageLayout, async function(err, image) {
              if (err) return;
              let result2 = await client.put(pngPath, image);
              //console.log(client.signatureUrl(result.name));
            });
          }
        );
    });


  });

我希望此函数具有上面代码中的返回值， result1和result2来自spritezero.generateLayout中的回调

返回{pxRatio：[result1.name，result2.name}