Question

我想将图片裁剪成各种尺寸并将其上传到AWS S3。裁剪大小存储在数组中。

我正在使用async瀑布和series方法来实现这一目标。

async.each(crop_sizes,function (result,cb) {

            async.waterfall([
                /*
                 * Crop the images to specific size
                 */
                function (callback) {
                    gm(path)
                        .resize(result.width,result.height,'^')
                        .stream(function (err,buffer) {
                            console.log('cropped')
                            callback(null,{'buffer':buffer,'filename':filename,'s3':s3});
                        });
                },
                function (output,callback) {
                    var params ={
                        Bucket:'mybucket',
                        Key:'artwork-croppedimages/'+result.folder+output.filename,
                        Body:output.buffer
                    }

                    var options ={
                        partSize: 5242880, queueSize: 1
                    };

                    s3.upload(params,options,function(err, data) {
                        console.log("upload");

                        callback();
                    });
                }

            ],function (err,result) {
                console.log("one iteration completed");
                cb();
            });
        },function (err,result) {
            console.log("All upload complete");
        });

这是代码的执行方式：

重复async.each中的步骤1和2。

裁剪图像。
将裁剪后的图像上传到AWS S3。

但是在上传大尺寸图片时失败了。这是我得到的输出：

cropped
cropped
cropped
cropped
cropped
cropped
cropped
cropped
cropped
cropped
cropped
cropped
upload
one iteration completed
upload
one iteration completed
upload
one iteration completed
upload
one iteration completed
upload
one iteration completed
upload
one iteration completed
upload
one iteration completed
upload
one iteration completed
upload
one iteration completed
upload
one iteration completed
upload
one iteration completed
upload
one iteration completed
All upload complete

预期产出：

 cropped
   upload
   one iteration completed
  cropped
   upload
   one iteration completed
   .....
  All upload complete

Answer 1

你可以尝试async.eachOfSeries功能吗？我怀疑async.each函数并行运行iteratee（如文档中所述），这必然导致问题。

node.js异步：裁剪图像并上传到服务器

1 个答案: