使 Flask send_file 更快答案

【问题标题】：make Flask send_file faster使 Flask send_file 更快
【发布时间】：2019-07-25 16:17:44
【问题描述】：

我想写一个简单的函数。它会从远程服务器获取文件 throw paramiko，然后我想通过将 url 传递给我的浏览器来下载它。但是 flask.send_file 对我来说工作得非常慢。 sftp 连接需要 ~0.5s 但 send_file(io.BytesIO(file_obj.read())) 需要 ~15s。

这里是如何使用它

return send_file(
       io.BytesIO(file_obj.read()),
       mimetype=mimetype,
       as_attachment=True,
       attachment_filename=attachment_filename
   )

import io

from flask import send_file, jsonify
import paramiko


def sftp_conn(remote_path):
   key = paramiko.RSAKey.from_private_key_file(RSA_KEY)
   with paramiko.SSHClient() as client:
       client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
       client.connect(pkey=key, **SERVER_CONN)
       with client.open_sftp() as sftp:
           try:
               file_obj = sftp.file(remote_path, mode='rb')
           except IOError:
               return jsonify({
                   'error': True,
                   'message': 'no such file in directory'
               })
           return send_file(
               io.BytesIO(file_obj.read()),
               mimetype=mimetype,
               as_attachment=True,
               attachment_filename=attachment_filename
           )

【问题讨论】：

标签： python file flask optimization io

【解决方案1】：

好的，我不知道答案，但即使这样也快 4 倍。为子孙后代住在这里

@app.route('/sftp/<path:remote_path>')
@file_cleanup
def file_download(remote_path, local_path, file_name):
key = paramiko.RSAKey.from_private_key_file(RSA_KEY)

with paramiko.SSHClient() as client:
    client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    client.connect(pkey=key, **SERVER_CONN)

    with client.open_sftp() as sftp:
        try:
            sftp.get(remote_path, local_path)
        except IOError:
            return jsonify({
                'error': True,
                'message': 'no such file in directory'
            })

return send_from_directory(
    directory=app.config['UPLOAD_FOLDER'],
    filename=file_name,
    as_attachment=True,
    attachment_filename=file_name,
)

这是@file_cleanup 装饰器

def file_cleanup(func):
def decorated_func(*args, **kwargs):
    file_name = get_file_name(kwargs['remote_path'])
    local_path = Path(app.config['UPLOAD_FOLDER'], file_name)

    kwargs['file_name'] = file_name
    kwargs['local_path'] = local_path

    result = func(*args, **kwargs)

    os.remove(local_path)
    return result
return decorated_func

【讨论】：