from __future__ import annotations
import json as _json
import logging
import typing
from contextlib import contextmanager
from dataclasses import dataclass
from http.client import HTTPException as HTTPException
from io import BytesIO, IOBase
from ...exceptions import InvalidHeader, TimeoutError
from ...response import BaseHTTPResponse
from ...util.retry import Retry
from .request import EmscriptenRequest
if typing.TYPE_CHECKING:
from ..._base_connection import BaseHTTPConnection, BaseHTTPSConnection
log = logging.getLogger(__name__)
@dataclass
class EmscriptenResponse:
status_code: int
headers: dict[str, str]
body: IOBase | bytes
request: EmscriptenRequest
class EmscriptenHttpResponseWrapper(BaseHTTPResponse):
def __init__(
self,
internal_response: EmscriptenResponse,
url: str | None = None,
connection: BaseHTTPConnection | BaseHTTPSConnection | None = None,
):
self._pool = None # set by pool class
self._body = None
self._response = internal_response
self._url = url
self._connection = connection
self._closed = False
super().__init__(
headers=internal_response.headers,
status=internal_response.status_code,
request_url=url,
version=0,
version_string="HTTP/?",
reason="",
decode_content=True,
)
self.length_remaining = self._init_length(self._response.request.method)
self.length_is_certain = False
@property
def url(self) -> str | None:
return self._url
@url.setter
def url(self, url: str | None) -> None:
self._url = url
@property
def connection(self) -> BaseHTTPConnection | BaseHTTPSConnection | None:
return self._connection
@property
def retries(self) -> Retry | None:
return self._retries
@retries.setter
def retries(self, retries: Retry | None) -> None:
# Override the request_url if retries has a redirect location.
self._retries = retries
def stream(
self, amt: int | None = 2**16, decode_content: bool | None = None
) -> typing.Generator[bytes]:
"""
A generator wrapper for the read() method. A call will block until
``amt`` bytes have been read from the connection or until the
connection is closed.
:param amt:
How much of the content to read. The generator will return up to
much data per iteration, but may return less. This is particularly
likely when using compressed data. However, the empty string will
never be returned.
:param decode_content:
If True, will attempt to decode the body based on the
'content-encoding' header.
"""
while True:
data = self.read(amt=amt, decode_content=decode_content)
if data:
yield data
else:
break
def _init_length(self, request_method: str | None) -> int | None:
length: int | None
content_length: str | None = self.headers.get("content-length")
if content_length is not None:
try:
# RFC 7230 section 3.3.2 specifies multiple content lengths can
# be sent in a single Content-Length header
# (e.g. Content-Length: 42, 42). This line ensures the values
# are all valid ints and that as long as the `set` length is 1,
# all values are the same. Otherwise, the header is invalid.
lengths = {int(val) for val in content_length.split(",")}
if len(lengths) > 1:
raise InvalidHeader(
"Content-Length contained multiple "
"unmatching values (%s)" % content_length
)
length = lengths.pop()
except ValueError:
length = None
else:
if length < 0:
length = None
else: # if content_length is None
length = None
# Check for responses that shouldn't include a body
if (
self.status in (204, 304)
or 100 <= self.status < 200
or request_method == "HEAD"
):
length = 0
return length
def read(
self,
amt: int | None = None,
decode_content: bool | None = None, # ignored because browser decodes always
cache_content: bool = False,
) -> bytes:
if (
self._closed
or self._response is None
or (isinstance(self._response.body, IOBase) and self._response.body.closed)
):
return b""
with self._error_catcher():
# body has been preloaded as a string by XmlHttpRequest
if not isinstance(self._response.body, IOBase):
self.length_remaining = len(self._response.body)
self.length_is_certain = True
# wrap body in IOStream
self._response.body = BytesIO(self._response.body)
if amt is not None and amt >= 0:
# don't cache partial content
cache_content = False
data = self._response.body.read(amt)
if self.length_remaining is not None:
self.length_remaining = max(self.length_remaining - len(data), 0)
if (self.length_is_certain and self.length_remaining == 0) or len(
data
) < amt:
# definitely finished reading, close response stream
self._response.body.close()
return typing.cast(bytes, data)
else: # read all we can (and cache it)
data = self._response.body.read()
if cache_content:
self._body = data
if self.length_remaining is not None:
self.length_remaining = max(self.length_remaining - len(data), 0)
if len(data) == 0 or (
self.length_is_certain and self.length_remaining == 0
):
# definitely finished reading, close response stream
self._response.body.close()
return typing.cast(bytes, data)
def read_chunked(
self,
amt: int | None = None,
decode_content: bool | None = None,
) -> typing.Generator[bytes]:
# chunked is handled by browser
while True:
bytes = self.read(amt, decode_content)
if not bytes:
break
yield bytes
def release_conn(self) -> None:
if not self._pool or not self._connection:
return None
self._pool._put_conn(self._connection)
self._connection = None
def drain_conn(self) -> None:
self.close()
@property
def data(self) -> bytes:
if self._body:
return self._body
else:
return self.read(cache_content=True)
def json(self) -> typing.Any:
"""
Deserializes the body of the HTTP response as a Python object.
The body of the HTTP response must be encoded using UTF-8, as per
`RFC 8529 Section 8.1 <https://www.rfc-editor.org/rfc/rfc8259#section-8.1>`_.
To use a custom JSON decoder pass the result of :attr:`HTTPResponse.data` to
your custom decoder instead.
If the body of the HTTP response is not decodable to UTF-8, a
`UnicodeDecodeError` will be raised. If the body of the HTTP response is not a
valid JSON document, a `json.JSONDecodeError` will be raised.
Read more :ref:`here <json_content>`.
:returns: The body of the HTTP response as a Python object.
"""
data = self.data.decode("utf-8")
return _json.loads(data)
def close(self) -> None:
if not self._closed:
if isinstance(self._response.body, IOBase):
self._response.body.close()
if self._connection:
self._connection.close()
self._connection = None
self._closed = True
@contextmanager
def _error_catcher(self) -> typing.Generator[None]:
"""
Catch Emscripten specific exceptions thrown by fetch.py,
instead re-raising urllib3 variants, so that low-level exceptions
are not leaked in the high-level api.
On exit, release the connection back to the pool.
"""
from .fetch import _RequestError, _TimeoutError # avoid circular import
clean_exit = False
try:
yield
# If no exception is thrown, we should avoid cleaning up
# unnecessarily.
clean_exit = True
except _TimeoutError as e:
raise TimeoutError(str(e))
except _RequestError as e:
raise HTTPException(str(e))
finally:
# If we didn't terminate cleanly, we need to throw away our
# connection.
if not clean_exit:
# The response may not be closed but we're not going to use it
# anymore so close it now
if (
isinstance(self._response.body, IOBase)
and not self._response.body.closed
):
self._response.body.close()
# release the connection back to the pool
self.release_conn()
else:
# If we have read everything from the response stream,
# return the connection back to the pool.
if (
isinstance(self._response.body, IOBase)
and self._response.body.closed
):
self.release_conn()
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