读取多部分/窗体数据是不直接保存的

我正在尝试从http图像文件上传读取数据。它似乎读取了文件,但由于某种原因,输出文件的大小大约是原始文件的两倍。

原稿:94.7KB

当我在文本编辑器中打开这两个文件时,它们的行数相同,起始字符和结束字符相同。这让我相信上传的文件被保存为字符串而不是二进制数据。

数据的读取:

let body = ''
req.on('data', data => {
  body += data.toString()
}).on('end', data => {
  if (data) body += data.toString()
  // Rest of block
})

数据的保存:

// If there is a filename grab the file data
if (result.filename.length > 0) {
  // Create a temporary url
  let temp = join(os.tmpdir(), (Math.random() * 10000).toString(12).substr(5, 10))

  // Get the data between the blocks after the first two newlines
  let matches = item.match(/^.+?(\r\n\r\n|\n\n)(.+)/s)

  // Write the data to file
  fs.createWriteStream(temp).write(matches[2])
}

下面是数据的完整解析:

http.createServer((req, res) => {
  let body = ''
  req.on('data', data => {
    body += data.toString()
  }).on('end', data => {
    if (data) body += data.toString()
    let boundary = req.headers['content-type'].split('boundary=')[1]

    // Split all the boundary items and loop over them
    body.split(new RegExp(`(--${boundary}|--${boundary}--)`)).forEach(item => {
      if (item.trim().toLowerCase().startsWith('content-disposition')) {
        item = item.trim()
        // Find the name and filename
        let result = item.split(':')[1].split(';').map(i => i.trim()).reduce((obj, itm) => {
          if (itm.startsWith('name=')) obj.name = itm.match(/^name="(.+)"/)[1]
          if (itm.startsWith('filename=')) obj.filename = itm.match(/^filename="(.+)"/)[1]
          return obj
        }, { name: '', filename: '' })

        // If there is a filename grab the file data
        if (result.filename.length > 0) {
          // Create a temporary url
          let temp = join(os.tmpdir(), (Math.random() * 10000).toString(12).substr(5, 10))

          // Get the data
          let matches = item.match(/^.+?(\r\n\r\n|\n\n)(.+)/s)

          // Write the data to file
          fs.createWriteStream(temp).write(matches[2])
        }
      }
    })
  })
})