我的aws-lambda函数中有一个异步函数，效果很好。
这样做：
抓取图片（'下载'功能），
裁剪并将其调整为缩略图（'转换'功能），
将该缩略图上传到新存储区（“上传”功能），
使用该缩略图的网址（'updateVenue'函数）
最后，它创建了一个新的场景对象（这也是一个解析对象）（'saveScene'函数）。
**我省略了代码，指明venueObj和sceneObj是什么让它更简单，因为我不相信这是问题。
我的问题是，在updateVenue函数被记录为成功完成后，下一个日志是：在完成请求之前退出进程。 Aka saveScene函数永远不会被调用。
即使我按翻转updateVenue和saveScene函数的顺序，也会在第一个Parse函数 - saveScene完成后退出该进程。因此，我认为错误是我称之为的方式。
我也在使用 context.succeed（），也许这与它有关？
// Download the image from S3, transform, and upload to a different S3 bucket.
async.waterfall([
function download(next) {
// Download the image from S3 into a buffer.
s3.getObject({
Bucket: srcBucket,
Key: srcKey
},
next);
},
function transform(response, next) {
gm(response.Body).size(function(err, size) {
// Infer the scaling factor to avoid stretching the image unnaturally.
WIDTH = size.width;
HEIGHT = size.height;
if (WIDTH > HEIGHT) {
var side = HEIGHT;
}
else{
var side = WIDTH;
}
var scalingFactor = Math.min(
MAX_WIDTH / side,
MAX_HEIGHT / side
);
var width = scalingFactor * side;
var height = scalingFactor * side;
// Transform the image buffer in memory.
this.gravity("Center").crop(side, side).resize(width, height)
.toBuffer(imageType, function(err, buffer) {
if (err) {
next(err);
console.log(err);
} else {
next(null, response.ContentType, buffer);
}
});
});
},
function upload(contentType, data, next) {
// Stream the transformed image to a different S3 bucket.
s3.putObject({
Bucket: dstBucket,
Key: dstKey,
Body: data,
ContentType: contentType
},
next);
},
function updateVenue(next) {
venueObj.save(null, {
success: function(response){
console.log('Updated Venue thumbnail succesfully: ', response);
context.succeed();
next
},
error: function(response, error){
console.log('Failed to update Venue thumbnail, with error code: ' + error.description);
context.fail();
next
}
}); // end of venueObj.save
},
function saveScene(next) {
sceneObj.save(null, {
success: function(response){
console.log('Saved sceneObj succesfully: ', response);
context.succeed();
next
},
error: function(response, error){
console.log('Failed to create new sceneObj, with error code: ' + error.description);
context.fail();
next
}
}); // end of sceneObj.save
}
], function (err) {
if (err) {
console.error(
'Unable to resize ' + srcBucket + '/' + srcKey +
' and upload to ' + dstBucket + '/' + dstKey +
' due to an error: ' + err
);
} else {
console.log(
'Successfully resized ' + srcBucket + '/' + srcKey +
' and uploaded to ' + dstBucket + '/' + dstKey
);
}
callback(null, "message");
}
);
答案 0 :(得分：0)
我相信你只需要在updateVenue和saveScence中调用if(isChecked){
//do your stuff with the button
}
。 async.waterfall将回调传递给系列中的每个函数，您当前正在使用next。如果需要将数据传递给下一个fn，则将其作为第二个参数传递给回调。
以下是next：
updateVenue希望有所帮助！
答案 1 :(得分：0)
我发现了如何解决这个问题。不幸的是，我无法将功能分开，但是，我能够将第二个功能嵌入到第一个功能的完成块中：
// Download the image from S3, transform, and upload to a different S3 bucket.
async.waterfall([
function download(next) {
// Download the image from S3 into a buffer.
s3.getObject({
Bucket: srcBucket,
Key: srcKey
},
next);
},
function transform(response, next) {
gm(response.Body).size(function(err, size) {
// Infer the scaling factor to avoid stretching the image unnaturally.
WIDTH = size.width;
HEIGHT = size.height;
if (WIDTH > HEIGHT) {
var side = HEIGHT;
}
else{
var side = WIDTH;
}
var scalingFactor = Math.min(
MAX_WIDTH / side,
MAX_HEIGHT / side
);
var width = scalingFactor * side;
var height = scalingFactor * side;
// Transform the image buffer in memory.
this.gravity("Center").crop(side, side).resize(width, height)
.toBuffer(imageType, function(err, buffer) {
if (err) {
next(err);
console.log(err);
} else {
next(null, response.ContentType, buffer);
}
});
});
},
function upload(contentType, data, next) {
// Stream the transformed image to a different S3 bucket.
s3.putObject({
Bucket: dstBucket,
Key: dstKey,
Body: data,
ContentType: contentType
},
next);
},
function updateVenue(next) {
venueObj.save(null, {
success: function(response){
console.log('Updated Venue thumbnail succesfully: ', response);
sceneObj.save(null, {
success: function(response){
console.log('Saved sceneObj succesfully: ', response);
context.succeed();
next
},
error: function(response, error){
console.log('Failed to create new sceneObj, with error code: ' + error.description);
context.fail();
next
}
}); // end of sceneObj.save
},
error: function(response, error){
console.log('Failed to update Venue thumbnail, with error code: ' + error.description);
context.fail();
next
}
}); // end of venueObj.save
}
], function (err) {
if (err) {
console.error(
'Unable to resize ' + srcBucket + '/' + srcKey +
' and upload to ' + dstBucket + '/' + dstKey +
' due to an error: ' + err
);
} else {
console.log(
'Successfully resized ' + srcBucket + '/' + srcKey +
' and uploaded to ' + dstBucket + '/' + dstKey
);
}
callback(null, "message");
}
);