bazarr/libs/requests_toolbelt/downloadutils/tee.py

124 lines
4.3 KiB
Python

"""Tee function implementations."""
import io
_DEFAULT_CHUNKSIZE = 65536
__all__ = ['tee', 'tee_to_file', 'tee_to_bytearray']
def _tee(response, callback, chunksize, decode_content):
for chunk in response.raw.stream(amt=chunksize,
decode_content=decode_content):
callback(chunk)
yield chunk
def tee(response, fileobject, chunksize=_DEFAULT_CHUNKSIZE,
decode_content=None):
"""Stream the response both to the generator and a file.
This will stream the response body while writing the bytes to
``fileobject``.
Example usage:
.. code-block:: python
resp = requests.get(url, stream=True)
with open('save_file', 'wb') as save_file:
for chunk in tee(resp, save_file):
# do stuff with chunk
.. code-block:: python
import io
resp = requests.get(url, stream=True)
fileobject = io.BytesIO()
for chunk in tee(resp, fileobject):
# do stuff with chunk
:param response: Response from requests.
:type response: requests.Response
:param fileobject: Writable file-like object.
:type fileobject: file, io.BytesIO
:param int chunksize: (optional), Size of chunk to attempt to stream.
:param bool decode_content: (optional), If True, this will decode the
compressed content of the response.
:raises: TypeError if the fileobject wasn't opened with the right mode
or isn't a BytesIO object.
"""
# We will be streaming the raw bytes from over the wire, so we need to
# ensure that writing to the fileobject will preserve those bytes. On
# Python3, if the user passes an io.StringIO, this will fail, so we need
# to check for BytesIO instead.
if not ('b' in getattr(fileobject, 'mode', '') or
isinstance(fileobject, io.BytesIO)):
raise TypeError('tee() will write bytes directly to this fileobject'
', it must be opened with the "b" flag if it is a file'
' or inherit from io.BytesIO.')
return _tee(response, fileobject.write, chunksize, decode_content)
def tee_to_file(response, filename, chunksize=_DEFAULT_CHUNKSIZE,
decode_content=None):
"""Stream the response both to the generator and a file.
This will open a file named ``filename`` and stream the response body
while writing the bytes to the opened file object.
Example usage:
.. code-block:: python
resp = requests.get(url, stream=True)
for chunk in tee_to_file(resp, 'save_file'):
# do stuff with chunk
:param response: Response from requests.
:type response: requests.Response
:param str filename: Name of file in which we write the response content.
:param int chunksize: (optional), Size of chunk to attempt to stream.
:param bool decode_content: (optional), If True, this will decode the
compressed content of the response.
"""
with open(filename, 'wb') as fd:
for chunk in tee(response, fd, chunksize, decode_content):
yield chunk
def tee_to_bytearray(response, bytearr, chunksize=_DEFAULT_CHUNKSIZE,
decode_content=None):
"""Stream the response both to the generator and a bytearray.
This will stream the response provided to the function, add them to the
provided :class:`bytearray` and yield them to the user.
.. note::
This uses the :meth:`bytearray.extend` by default instead of passing
the bytearray into the ``readinto`` method.
Example usage:
.. code-block:: python
b = bytearray()
resp = requests.get(url, stream=True)
for chunk in tee_to_bytearray(resp, b):
# do stuff with chunk
:param response: Response from requests.
:type response: requests.Response
:param bytearray bytearr: Array to add the streamed bytes to.
:param int chunksize: (optional), Size of chunk to attempt to stream.
:param bool decode_content: (optional), If True, this will decode the
compressed content of the response.
"""
if not isinstance(bytearr, bytearray):
raise TypeError('tee_to_bytearray() expects bytearr to be a '
'bytearray')
return _tee(response, bytearr.extend, chunksize, decode_content)