python - python中的可恢复文件上传

Question

我正在尝试在 python 中上传文件，我想以可恢复模式上传文件，即当互联网连接恢复时，文件上传从前一阶段恢复。

是否有特定的协议(protocol)支持断点续传。

提前致谢

Answer 1

所以您需要的是查找文件并发送 REST 命令来告诉服务器从正确的位置下载。

这里的代码会尝试直到它完成上传并恢复，同时调试已开启，因此您可以按照以下步骤操作:

#!/usr/bin/env python3
import ftplib
import os
import sys
import time
import socket

class FtpUploadTracker:
    sizeWritten = 0
    totalSize = 0.0
    lastShownPercent = 0

    def __init__(self, totalSize):
        self.totalSize = totalSize

    def handle(self, block):
        self.sizeWritten += 1024
        percentComplete = round((self.sizeWritten / self.totalSize) * 100)

        if (self.lastShownPercent != percentComplete):
            self.lastShownPercent = percentComplete
            print(str(percentComplete) + "% complete ramaing: " + str(self.totalSize - self.sizeWritten), flush=True)



if __name__ == "__main__":
    Server="servername.com"
    Username="username"
    Password="secret password"
    filename = "/path/to/folder"
    Directory="/path/on/server"

    tries = 0
    done = False

    print("Uploading " + str(filename) + " to " + str(Directory), flush=True)

    while tries < 50 and not done:
        try:
            tries += 1
            with ftplib.FTP(Server) as ftp:
                ftp.set_debuglevel(2)
                print("login", flush=True)
                ftp.login(Username, Password)
                # ftp.set_pasv(False)
                ftp.cwd(Directory)
                with open(filename, 'rb') as f:
                    totalSize = os.path.getsize(filename)
                    print('Total file size : ' + str(round(totalSize / 1024 / 1024 ,1)) + ' Mb', flush=True)
                    uploadTracker = FtpUploadTracker(int(totalSize))

                    # Get file size if exists
                    files_list = ftp.nlst()
                    print(files_list, flush=True)
                    if os.path.basename(filename) in files_list:
                        print("Resuming", flush=True)
                        ftp.voidcmd('TYPE I')
                        rest_pos = ftp.size(os.path.basename(filename))
                        f.seek(rest_pos, 0)
                        print("seek to " + str(rest_pos))
                        uploadTracker.sizeWritten = rest_pos
                        print(ftp.storbinary('STOR ' + os.path.basename(filename), f, blocksize=1024, callback=uploadTracker.handle, rest=rest_pos), flush=True)
                    else:
                        print(ftp.storbinary('STOR ' + os.path.basename(filename), f, 1024, uploadTracker.handle), flush=True)
                        done = True

        except (BrokenPipeError, ftplib.error_temp, socket.gaierror) as e:
            print(str(type(e)) + ": " + str(e))
            print("connection died, trying again")
            time.sleep(30)


    print("Done")

魔术线是:

print(ftp.storbinary('STOR ' + os.path.basename(filename), f, blocksize=1024, callback=uploadTracker.handle, rest=rest_pos), flush=True)

其中有 rest=rest_pos。

If optional rest is given, a REST command is sent to the server, passing rest as an argument. rest is usually a byte offset into the requested file, telling the server to restart sending the file’s bytes at the requested offset, skipping over the initial bytes. Note however that RFC 959 requires only that rest be a string containing characters in the printable range from ASCII code 33 to ASCII code 126. The transfercmd() method, therefore, converts rest to a string, but no check is performed on the string’s contents. If the server does not recognize the REST command, an error_reply exception will be raised. If this happens, simply call transfercmd() without a rest argument

Source
还有一些代码 taken from here