响应并行api请求调用以下载zip文件

xzlaal3s  于 2021-09-23  发布在  Java
关注(0)|答案(1)|浏览(463)

我使用的是react ts,以nestjs作为后端。
上下文
我有一个函数 downloadZip(csvProps) :输入-csv文件的参数和api请求的url;输出-包含4个csv文件的zip文件

const downloadZip = async (csvProps: any, urlParams: any) => {
        let zip = new JSZip();

        let csv = zip.folder("csv");

        //English Data CSV
        let enDataBlob = await downloadCSV(`${ServerService.getUrl()}/fetchData`, urlParams,
            {...csvProps, filename: 'Data_en', columns: headers_data_en, wrapColumnChar: '"'})
        csv?.file('Data_en.csv', enDataBlob as Blob, {base64: true})

        //French Data CSV
        let frDataBlob = await downloadCSV(`${ServerService.getUrl()}/fetchData`, urlParams,
            {...csvProps, filename: 'Data_fr', columns: headers_data_fr, wrapColumnChar: '"'})
        csv?.file('Data_fr.csv', frDataBlob as Blob, {base64: true})

        //English Flow CSV
        let enFlowBlob = await downloadCSV(`${ServerService.getUrl()}/fetchFlow`, urlParams,
            {...csvProps, filename: 'Flow_en', columns: headers_flow_en, wrapColumnChar: '"'})
        csv?.file('Flow_en.csv', enFlowBlob as Blob, {base64: true})

        //French Flow CSV
        let frFlowBlob = await downloadCSV(`${ServerService.getUrl()}/fetchFlow`, urlParams,
            {...csvProps, filename: 'Flow_fr', columns: headers_flow_fr, wrapColumnChar: '"'})
        csv?.file('Flow_fr.csv', frFlowBlob as Blob, {base64: true})

        zip.generateAsync(({type: "blob"}))
            .then((content) => {
                saveAs(content, csvProps.filename)
            })
    }

这个 downloadCSV(url: string, urlParams: any, csvProps: any) 上面使用的函数只是向后端发出axios请求,并返回响应生成的csv blob:

export const downloadCSV = async (apiURL: string, urlParams: any, csvProps: any) => {
    let csvBlob: Blob|undefined;
    let api = await axios.get(apiURL, {
        params: urlParams
      })
    .then(async (res) => {
        // handleCSV: Gets all CSV related data and returns a csv Blob
        csvBlob = await handleCSV({...csvProps, datas: res.data});
    })
    return csvBlob
}

因为我正在使用 async-await ,api请求和随后的blob生成过程按顺序进行,性能受到影响。
问题
有没有办法使这些过程并行?我希望所有的文件都被并行处理,然后最终添加到zip中。

gj3fmq9x

gj3fmq9x1#

而不是 await 通过调用每个api,您可以 Promise.all(apiCalls) 并等待结果,让结果成为api返回的值数组。差不多

const downloadZip = async (csvProps: any, urlParams: any) => {
  let zip = new JSZip();

  let csv = zip.folder("csv");
  const apiCalls = [
    downloadCSV(`${ServerService.getUrl()}/fetchData`, urlParams,
      {...csvProps, filename: 'Data_en', columns: headers_data_en, wrapColumnChar: '"'}),
    downloadCSV(`${ServerService.getUrl()}/fetchData`, urlParams,
      {...csvProps, filename: 'Data_fr', columns: headers_data_fr, wrapColumnChar: '"'}),
    downloadCSV(`${ServerService.getUrl()}/fetchFlow`, urlParams,
      {...csvProps, filename: 'Flow_en', columns: headers_flow_en, wrapColumnChar: '"'}),
    downloadCSV(`${ServerService.getUrl()}/fetchFlow`, urlParams,
      {...csvProps, filename: 'Flow_fr', columns: headers_flow_fr, wrapColumnChar: '"'}),
  ];
  const [enDataBlob, frDataBlob, enFlowBlob, frFlowBlob] = await Promise.all(apiCalls);
  //English Data CSV
  csv?.file('Data_en.csv', enDataBlob as Blob, {base64: true})

  //French Data CSV
  csv?.file('Data_fr.csv', frDataBlob as Blob, {base64: true})

  //English Flow CSV
  csv?.file('Flow_en.csv', enFlowBlob as Blob, {base64: true})

  //French Flow CSV
  csv?.file('Flow_fr.csv', frFlowBlob as Blob, {base64: true})

  zip.generateAsync(({type: "blob"}))
    .then((content) => {
      saveAs(content, csvProps.filename)
    })
}

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