mirror of https://github.com/morpheus65535/bazarr
117 lines
3.9 KiB
Python
117 lines
3.9 KiB
Python
![]() |
# -*- coding: utf-8 -*-
|
||
|
"""
|
||
|
|
||
|
requests_toolbelt.streaming_iterator
|
||
|
====================================
|
||
|
|
||
|
This holds the implementation details for the :class:`StreamingIterator`. It
|
||
|
is designed for the case where you, the user, know the size of the upload but
|
||
|
need to provide the data as an iterator. This class will allow you to specify
|
||
|
the size and stream the data without using a chunked transfer-encoding.
|
||
|
|
||
|
"""
|
||
|
from requests.utils import super_len
|
||
|
|
||
|
from .multipart.encoder import CustomBytesIO, encode_with
|
||
|
|
||
|
|
||
|
class StreamingIterator(object):
|
||
|
|
||
|
"""
|
||
|
This class provides a way of allowing iterators with a known size to be
|
||
|
streamed instead of chunked.
|
||
|
|
||
|
In requests, if you pass in an iterator it assumes you want to use
|
||
|
chunked transfer-encoding to upload the data, which not all servers
|
||
|
support well. Additionally, you may want to set the content-length
|
||
|
yourself to avoid this but that will not work. The only way to preempt
|
||
|
requests using a chunked transfer-encoding and forcing it to stream the
|
||
|
uploads is to mimic a very specific interace. Instead of having to know
|
||
|
these details you can instead just use this class. You simply provide the
|
||
|
size and iterator and pass the instance of StreamingIterator to requests
|
||
|
via the data parameter like so:
|
||
|
|
||
|
.. code-block:: python
|
||
|
|
||
|
from requests_toolbelt import StreamingIterator
|
||
|
|
||
|
import requests
|
||
|
|
||
|
# Let iterator be some generator that you already have and size be
|
||
|
# the size of the data produced by the iterator
|
||
|
|
||
|
r = requests.post(url, data=StreamingIterator(size, iterator))
|
||
|
|
||
|
You can also pass file-like objects to :py:class:`StreamingIterator` in
|
||
|
case requests can't determize the filesize itself. This is the case with
|
||
|
streaming file objects like ``stdin`` or any sockets. Wrapping e.g. files
|
||
|
that are on disk with ``StreamingIterator`` is unnecessary, because
|
||
|
requests can determine the filesize itself.
|
||
|
|
||
|
Naturally, you should also set the `Content-Type` of your upload
|
||
|
appropriately because the toolbelt will not attempt to guess that for you.
|
||
|
"""
|
||
|
|
||
|
def __init__(self, size, iterator, encoding='utf-8'):
|
||
|
#: The expected size of the upload
|
||
|
self.size = int(size)
|
||
|
|
||
|
if self.size < 0:
|
||
|
raise ValueError(
|
||
|
'The size of the upload must be a positive integer'
|
||
|
)
|
||
|
|
||
|
#: Attribute that requests will check to determine the length of the
|
||
|
#: body. See bug #80 for more details
|
||
|
self.len = self.size
|
||
|
|
||
|
#: Encoding the input data is using
|
||
|
self.encoding = encoding
|
||
|
|
||
|
#: The iterator used to generate the upload data
|
||
|
self.iterator = iterator
|
||
|
|
||
|
if hasattr(iterator, 'read'):
|
||
|
self._file = iterator
|
||
|
else:
|
||
|
self._file = _IteratorAsBinaryFile(iterator, encoding)
|
||
|
|
||
|
def read(self, size=-1):
|
||
|
return encode_with(self._file.read(size), self.encoding)
|
||
|
|
||
|
|
||
|
class _IteratorAsBinaryFile(object):
|
||
|
def __init__(self, iterator, encoding='utf-8'):
|
||
|
#: The iterator used to generate the upload data
|
||
|
self.iterator = iterator
|
||
|
|
||
|
#: Encoding the iterator is using
|
||
|
self.encoding = encoding
|
||
|
|
||
|
# The buffer we use to provide the correct number of bytes requested
|
||
|
# during a read
|
||
|
self._buffer = CustomBytesIO()
|
||
|
|
||
|
def _get_bytes(self):
|
||
|
try:
|
||
|
return encode_with(next(self.iterator), self.encoding)
|
||
|
except StopIteration:
|
||
|
return b''
|
||
|
|
||
|
def _load_bytes(self, size):
|
||
|
self._buffer.smart_truncate()
|
||
|
amount_to_load = size - super_len(self._buffer)
|
||
|
bytes_to_append = True
|
||
|
|
||
|
while amount_to_load > 0 and bytes_to_append:
|
||
|
bytes_to_append = self._get_bytes()
|
||
|
amount_to_load -= self._buffer.append(bytes_to_append)
|
||
|
|
||
|
def read(self, size=-1):
|
||
|
size = int(size)
|
||
|
if size == -1:
|
||
|
return b''.join(self.iterator)
|
||
|
|
||
|
self._load_bytes(size)
|
||
|
return self._buffer.read(size)
|