2.2.4. AppendFile

Implement this function:

User.append_file(filename: str, new_data: bytes)

Efficiently appends new_data to the end of the file named filename that is owned by the calling user. However, raises a util.DropboxError in the following circumstances:

  • If no file named filename exists.

  • File appending cannot complete due to malicious action. (This operation is not required to verify the integrity of the existing file data for filename, but it is allowed to perform such checks and raise an error if malicious action has been detected.)

“Efficiently” means that this operation’s bandwidth (as measured by the total size of the data uploaded and downloaded via dataserver.Set and dataserver.Get) must scale linearly in the size of the data being appended and the number of users filename is shared with, and nothing else}. Logarithmic and constant scaling in other terms is acceptable.

Parameters:

  • filename (str) – The name of the file

  • new_data (bytes) – The data to append to the end of the existing file

Returns:

nothing

Raises:

DropboxError – if an error case occurred

Note

Some examples of efficiency requirements: appending 100 bytes to a 10 terabyte file should not use 10 terabytes of bandwidth; similarly, the 1000th append_file operation to filename should not use significantly more bandwidth than the first append_file operation. (This is not an exhaustive list of examples.)