首页 > 解决方案 > NodeJS + Graphql:即使在发送响应后我如何运行代码?

问题描述

我有一个端点,它接收文件并创建一个后台任务来将这些文件上传到 S3。

为了后台文件上传,我使用议程(https://github.com/agenda/agenda)。唯一的限制是我需要以 MongoDB 支持的格式存储文件(这是 Agenda 在后台使用的格式)。为了做到这一点,我将文件转换为缓冲区,然后将其发送到议程。

这是我的代码:

  Mutation: {
    batchCreateProgressPics: combineResolvers(
      isAuthenticated,
      async (parent, { pics }, { models, currentUser }) => {
        return await Promise.all(
          pics.map(async (pic, i) => {
            const { file, bodyPart, localPath } = pic;
            const { createReadStream } = await file;
            const stream = createReadStream();

            console.log("Setting up buffer...");
            const buffer = await new Promise((resolve, reject) => {
              var buffers = [];
              stream.on("data", function(data) {
                buffers.push(data);
              });
              stream.on("end", function() {
                const everything = Buffer.concat(buffers);
                resolve(everything);
              });
              stream.on("error", function(e) {
                reject(e);
              });
            });

            const progressPic = await models.ProgressPic.create({
              bodyPart,
              user: currentUser.id,
              url: localPath,
            });

            console.log("Creating backgruond task...");
            Agenda.now("uploadProgressPic", {
              userId: currentUser.id,
              progressPicId: progressPic.id,
              filename: `${progressPic.id}-${bodyPart}.jpg`,
              buffer,
            });
            console.log("Done.");

            return progressPic;
          })
        );
      }
    ),
  },

这在我的本地开发服务器上很快,但由于缓冲区的原因,需要很长时间才能在生产中运行。以下几行console.log(Setting up buffer...)需要很长时间。

我想做的是:

  1. pics创建并返回一个progressPics数组,数组中的每个元素一个
  2. 在发送响应后执行缓冲区内容,这样它就不会阻碍前端。

这可能吗?

============ 更新 ==========

因此,如果我不await兑现承诺,它会抱怨请求在缓冲区完成之前断开:

const uploadProgressPic = async ({ file, progressPicId, userId, bodyPart }) => {
  try {
    const { createReadStream } = await file;
    const stream = createReadStream();

    console.log("Setting up buffer...");
    const buffer = await new Promise((resolve, reject) => {
      var buffers = [];
      stream.on("data", function(data) {
        buffers.push(data);
      });
      stream.on("end", function() {
        const everything = Buffer.concat(buffers);
        resolve(everything);
      });
      stream.on("error", function(e) {
        reject(e);
      });
    });
    console.log("Done.");

    console.log("Creating backgruond task...");
    Agenda.now("uploadProgressPic", {
      userId,
      progressPicId,
      filename: `${progressPicId}-${bodyPart}.jpg`,
      buffer,
    });
  } catch (error) {
    console.log("ERROR OCCURRED: ", error);
  }
};

export default {
  Mutation: {
    batchCreateProgressPics: combineResolvers(
      isAuthenticated,
      async (parent, { pics }, { models, currentUser }) => {
        return pics.map(async (pic, i) => {
          const { file, bodyPart, localPath } = pic;
          const progressPic = await models.ProgressPic.create({
            bodyPart,
            user: currentUser.id,
            url: localPath,
          });

          uploadProgressPic({
            file,
            progressPicId: progressPic.id,
            userId: currentUser.id,
            bodyPart,
          });

          return progressPic;
        });
      }
    ),
  },
};

错误:

ERROR OCCURRED:  BadRequestError: Request disconnected during file upload stream parsing.
    at IncomingMessage.<anonymous> (/Users/edmundmai/Documents/src/acne-tracker/server/node_modules/graphql-upload/lib/processRequest.js:300:35)
    at Object.onceWrapper (events.js:291:20)
    at IncomingMessage.emit (events.js:203:13)
    at IncomingMessage.EventEmitter.emit (domain.js:471:20)
    at resOnFinish (_http_server.js:614:7)
    at ServerResponse.emit (events.js:208:15)
    at ServerResponse.EventEmitter.emit (domain.js:471:20)
    at onFinish (_http_outgoing.js:649:10)
    at onCorkedFinish (_stream_writable.js:678:5)
    at afterWrite (_stream_writable.js:483:3)
    at processTicksAndRejections (internal/process/task_queues.js:77:11) {
  message: 'Request disconnected during file upload stream parsing.',
  expose: true,
  statusCode: 499,
  status: 499
}

========== 更新 2 ==============

即使尝试 1) 简化它和 2) 移出createReadStream()显示uploadProgressPic相同的错误:

const uploadProgressPic = async ({
  stream,
  progressPicId,
  userId,
  bodyPart,
  models,
}) => {
  try {
    console.log("Uploading to S3...");
    const { Location: url, Key: key, Bucket: bucket } = await S3.upload({
      stream,
      folder: userId,
      filename: `${progressPicId}-${bodyPart}.jpg`,
    });

    if (url && key && bucket) {
      await models.ProgressPic.findOneAndUpdate(
        { _id: progressPicId },
        { $set: { url, key, bucket } },
        { new: true, useFindAndModify: false }
      );
      console.log("Done!");
    }
  } catch (error) {
    console.log("ERROR OCCURRED: ", error);
  }
};

export default {
  Mutation: {
    batchCreateProgressPics: combineResolvers(
      isAuthenticated,
      async (parent, { pics }, { models, currentUser }) => {
        return pics.map(async (pic, i) => {
          const { file, bodyPart, localPath } = pic;
          const progressPic = await models.ProgressPic.create({
            bodyPart,
            user: currentUser.id,
            url: localPath,
          });

          const { createReadStream } = await file;
          const stream = createReadStream();

          uploadProgressPic({
            stream,
            progressPicId: progressPic.id,
            userId: currentUser.id,
            bodyPart,
            models,
          });

          return progressPic;
        });
      }
    ),
  },
};

错误:

Uploading to S3...
Uploading to S3...
Uploading to S3...
ERROR OCCURRED:  BadRequestError: Request disconnected during file upload stream parsing.
    at IncomingMessage.<anonymous> (/Users/edmundmai/Documents/src/acne-tracker/server/node_modules/graphql-upload/lib/processRequest.js:300:35)
    at Object.onceWrapper (events.js:291:20)
    at IncomingMessage.emit (events.js:203:13)
    at IncomingMessage.EventEmitter.emit (domain.js:471:20)
    at resOnFinish (_http_server.js:614:7)
    at ServerResponse.emit (events.js:208:15)
    at ServerResponse.EventEmitter.emit (domain.js:471:20)
    at onFinish (_http_outgoing.js:649:10)
    at onCorkedFinish (_stream_writable.js:678:5)
    at afterWrite (_stream_writable.js:483:3)
    at processTicksAndRejections (internal/process/task_queues.js:77:11) {
  message: 'Request disconnected during file upload stream parsing.',
  expose: true,
  statusCode: 499,
  status: 499
}
Done!

有趣的是Done!,即使它抱怨,我仍然在日志中看到一些 s?

标签: node.jsgraphql

解决方案


不是该主题的专家,但我有一个可行的想法和理论:

  • 想法:如果您要处理大量图像,那么您的问题可能源于 await Promise.all()。我建议您使用async 中的parallelLimit来限制一次执行的并行函数,否则您将遇到性能问题。

  • 理论:也许您可以在每次使用后释放内存分配Buffer以避免内存泄漏问题并使您的服务器性能更高。

如果我错了,请纠正我。我自己对这个问题的结果很感兴趣。


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