如何用busboy检测上传流意外停止

Question

我有一个上传文件到mongodb的过程，运行良好。但我有一个大问题。如果由于某种原因连接丢失(客户端浏览器关闭，互联网连接不良，断电等)，我没有任何指示，并且服务生/请求流在一段时间后不会触发导致promise not handled错误的事件。当我通过立即上传和关闭浏览器来测试它的时候。我发现上传到mongodb的文件很少。大概每100个文件中就有10个。我不知道最后一个是否完全上传，也没有事件响应resolve/reject。代码：

static upload (req) {
    return new Promise((resolve, reject) => {

        const docIds = [];
        const busboy = new Busboy({ headers: req.headers });

        const gridFSBucket = MongoDb.GridFSBucket({
            chunkSizeBytes: 64 * 1024,
            bucketName: 'bucketFiles',
            writeConcern: {w: 1}
        });

        busboy.on('file', function (fieldName, file, fileName, encoding, mimeType) {

            const bucketStream = gridFSBucket.openUploadStream(fileName, { metadata: { encoding,  mimeType} });

            file.on('error', function () {
                // Never hitting that
                reject(error);
            });
            file.pipe(bucketStream)
                .on('error', function (error) {
                    // Never hitting that
                    reject(error);
                })
                .on('finish', function (doc) {
                    docIds.push(doc._id);
                });
        });
        busboy.on('error', function (error) {
            // Never hitting that
            reject(error);
        });
        busboy.on('finish', function () {
            //Everything uploaded BUT
            //if connection lost never hitting that
            resolve(docIds);
        });

        req.on('error', function (error) {
            // Never hitting that
            reject(error);
        });
        req.pipe(busboy);
    });
}

Answer 1

我就知道了。要知道是否发生了意外的流/请求结束，您需要侦听错误(‘req.connection’...)事件，如：

req.connection.on('error', function (error) {
    //do something like cancelling the mongodb session ...
    reject(error)
});