diff options
Diffstat (limited to 'paramiko/sftp_file.py')
| -rw-r--r-- | paramiko/sftp_file.py | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/paramiko/sftp_file.py b/paramiko/sftp_file.py index b3c1d648..8d147342 100644 --- a/paramiko/sftp_file.py +++ b/paramiko/sftp_file.py @@ -378,8 +378,8 @@ class SFTPFile (BufferedFile): .. versionadded:: 1.5 """ self.pipelined = pipelined - - def prefetch(self): + + def prefetch(self, file_size=None): """ Pre-fetch the remaining contents of this file in anticipation of future `.read` calls. If reading the entire file, pre-fetching can @@ -391,14 +391,29 @@ class SFTPFile (BufferedFile): data may be read in a random order (using `.seek`); chunks of the buffer that haven't been read will continue to be buffered. + :param int file_size: + When this is ``None`` (the default), this method calls `stat` to + determine the remote file size. In some situations, doing so can + cause exceptions or hangs (see `#562 + <https://github.com/paramiko/paramiko/pull/562>`_); as a + workaround, one may call `stat` explicitly and pass its value in + via this parameter. + .. versionadded:: 1.5.1 + .. versionchanged:: 1.16.0 + The ``file_size`` parameter was added (with no default value). + .. versionchanged:: 1.16.1 + The ``file_size`` parameter was made optional for backwards + compatibility. """ - size = self.stat().st_size + if file_size is None: + file_size = self.stat().st_size; + # queue up async reads for the rest of the file chunks = [] n = self._realpos - while n < size: - chunk = min(self.MAX_REQUEST_SIZE, size - n) + while n < file_size: + chunk = min(self.MAX_REQUEST_SIZE, file_size - n) chunks.append((n, chunk)) n += chunk if len(chunks) > 0: |