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983 lines
33 KiB
983 lines
33 KiB
3 years ago
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import io
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import re
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import typing as t
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from functools import partial
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from functools import update_wrapper
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from itertools import chain
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from ._internal import _make_encode_wrapper
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from ._internal import _to_bytes
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from ._internal import _to_str
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from .sansio import utils as _sansio_utils
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from .sansio.utils import host_is_trusted # noqa: F401 # Imported as part of API
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from .urls import _URLTuple
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from .urls import uri_to_iri
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from .urls import url_join
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from .urls import url_parse
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from .urls import url_quote
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if t.TYPE_CHECKING:
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from _typeshed.wsgi import WSGIApplication
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from _typeshed.wsgi import WSGIEnvironment
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def responder(f: t.Callable[..., "WSGIApplication"]) -> "WSGIApplication":
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"""Marks a function as responder. Decorate a function with it and it
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will automatically call the return value as WSGI application.
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Example::
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@responder
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def application(environ, start_response):
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return Response('Hello World!')
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"""
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return update_wrapper(lambda *a: f(*a)(*a[-2:]), f)
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def get_current_url(
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environ: "WSGIEnvironment",
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root_only: bool = False,
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strip_querystring: bool = False,
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host_only: bool = False,
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trusted_hosts: t.Optional[t.Iterable[str]] = None,
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) -> str:
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"""Recreate the URL for a request from the parts in a WSGI
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environment.
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The URL is an IRI, not a URI, so it may contain Unicode characters.
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Use :func:`~werkzeug.urls.iri_to_uri` to convert it to ASCII.
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:param environ: The WSGI environment to get the URL parts from.
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:param root_only: Only build the root path, don't include the
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remaining path or query string.
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:param strip_querystring: Don't include the query string.
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:param host_only: Only build the scheme and host.
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:param trusted_hosts: A list of trusted host names to validate the
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host against.
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"""
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parts = {
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"scheme": environ["wsgi.url_scheme"],
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"host": get_host(environ, trusted_hosts),
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}
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if not host_only:
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parts["root_path"] = environ.get("SCRIPT_NAME", "")
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if not root_only:
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parts["path"] = environ.get("PATH_INFO", "")
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if not strip_querystring:
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parts["query_string"] = environ.get("QUERY_STRING", "").encode("latin1")
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return _sansio_utils.get_current_url(**parts)
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def _get_server(
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environ: "WSGIEnvironment",
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) -> t.Optional[t.Tuple[str, t.Optional[int]]]:
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name = environ.get("SERVER_NAME")
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if name is None:
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return None
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try:
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port: t.Optional[int] = int(environ.get("SERVER_PORT", None))
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except (TypeError, ValueError):
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# unix socket
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port = None
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return name, port
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def get_host(
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environ: "WSGIEnvironment", trusted_hosts: t.Optional[t.Iterable[str]] = None
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) -> str:
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"""Return the host for the given WSGI environment.
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The ``Host`` header is preferred, then ``SERVER_NAME`` if it's not
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set. The returned host will only contain the port if it is different
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than the standard port for the protocol.
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Optionally, verify that the host is trusted using
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:func:`host_is_trusted` and raise a
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:exc:`~werkzeug.exceptions.SecurityError` if it is not.
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:param environ: A WSGI environment dict.
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:param trusted_hosts: A list of trusted host names.
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:return: Host, with port if necessary.
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:raise ~werkzeug.exceptions.SecurityError: If the host is not
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trusted.
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"""
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return _sansio_utils.get_host(
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environ["wsgi.url_scheme"],
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environ.get("HTTP_HOST"),
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_get_server(environ),
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trusted_hosts,
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)
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def get_content_length(environ: "WSGIEnvironment") -> t.Optional[int]:
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"""Returns the content length from the WSGI environment as
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integer. If it's not available or chunked transfer encoding is used,
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``None`` is returned.
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.. versionadded:: 0.9
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:param environ: the WSGI environ to fetch the content length from.
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"""
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if environ.get("HTTP_TRANSFER_ENCODING", "") == "chunked":
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return None
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content_length = environ.get("CONTENT_LENGTH")
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if content_length is not None:
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try:
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return max(0, int(content_length))
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except (ValueError, TypeError):
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pass
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return None
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def get_input_stream(
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environ: "WSGIEnvironment", safe_fallback: bool = True
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) -> t.BinaryIO:
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"""Returns the input stream from the WSGI environment and wraps it
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in the most sensible way possible. The stream returned is not the
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raw WSGI stream in most cases but one that is safe to read from
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without taking into account the content length.
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If content length is not set, the stream will be empty for safety reasons.
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If the WSGI server supports chunked or infinite streams, it should set
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the ``wsgi.input_terminated`` value in the WSGI environ to indicate that.
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.. versionadded:: 0.9
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:param environ: the WSGI environ to fetch the stream from.
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:param safe_fallback: use an empty stream as a safe fallback when the
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content length is not set. Disabling this allows infinite streams,
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which can be a denial-of-service risk.
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"""
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stream = t.cast(t.BinaryIO, environ["wsgi.input"])
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content_length = get_content_length(environ)
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# A wsgi extension that tells us if the input is terminated. In
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# that case we return the stream unchanged as we know we can safely
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# read it until the end.
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if environ.get("wsgi.input_terminated"):
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return stream
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# If the request doesn't specify a content length, returning the stream is
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# potentially dangerous because it could be infinite, malicious or not. If
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# safe_fallback is true, return an empty stream instead for safety.
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if content_length is None:
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return io.BytesIO() if safe_fallback else stream
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# Otherwise limit the stream to the content length
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return t.cast(t.BinaryIO, LimitedStream(stream, content_length))
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def get_query_string(environ: "WSGIEnvironment") -> str:
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"""Returns the ``QUERY_STRING`` from the WSGI environment. This also
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takes care of the WSGI decoding dance. The string returned will be
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restricted to ASCII characters.
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:param environ: WSGI environment to get the query string from.
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.. versionadded:: 0.9
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"""
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qs = environ.get("QUERY_STRING", "").encode("latin1")
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# QUERY_STRING really should be ascii safe but some browsers
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# will send us some unicode stuff (I am looking at you IE).
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# In that case we want to urllib quote it badly.
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return url_quote(qs, safe=":&%=+$!*'(),")
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def get_path_info(
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environ: "WSGIEnvironment", charset: str = "utf-8", errors: str = "replace"
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) -> str:
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"""Return the ``PATH_INFO`` from the WSGI environment and decode it
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unless ``charset`` is ``None``.
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:param environ: WSGI environment to get the path from.
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:param charset: The charset for the path info, or ``None`` if no
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decoding should be performed.
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:param errors: The decoding error handling.
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.. versionadded:: 0.9
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"""
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path = environ.get("PATH_INFO", "").encode("latin1")
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return _to_str(path, charset, errors, allow_none_charset=True) # type: ignore
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def get_script_name(
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environ: "WSGIEnvironment", charset: str = "utf-8", errors: str = "replace"
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) -> str:
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"""Return the ``SCRIPT_NAME`` from the WSGI environment and decode
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it unless `charset` is set to ``None``.
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:param environ: WSGI environment to get the path from.
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:param charset: The charset for the path, or ``None`` if no decoding
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should be performed.
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:param errors: The decoding error handling.
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.. versionadded:: 0.9
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"""
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path = environ.get("SCRIPT_NAME", "").encode("latin1")
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return _to_str(path, charset, errors, allow_none_charset=True) # type: ignore
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def pop_path_info(
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environ: "WSGIEnvironment", charset: str = "utf-8", errors: str = "replace"
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) -> t.Optional[str]:
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"""Removes and returns the next segment of `PATH_INFO`, pushing it onto
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`SCRIPT_NAME`. Returns `None` if there is nothing left on `PATH_INFO`.
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If the `charset` is set to `None` bytes are returned.
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If there are empty segments (``'/foo//bar``) these are ignored but
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properly pushed to the `SCRIPT_NAME`:
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>>> env = {'SCRIPT_NAME': '/foo', 'PATH_INFO': '/a/b'}
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>>> pop_path_info(env)
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'a'
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>>> env['SCRIPT_NAME']
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'/foo/a'
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>>> pop_path_info(env)
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'b'
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>>> env['SCRIPT_NAME']
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'/foo/a/b'
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.. versionadded:: 0.5
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.. versionchanged:: 0.9
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The path is now decoded and a charset and encoding
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parameter can be provided.
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|
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:param environ: the WSGI environment that is modified.
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:param charset: The ``encoding`` parameter passed to
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:func:`bytes.decode`.
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:param errors: The ``errors`` paramater passed to
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:func:`bytes.decode`.
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"""
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path = environ.get("PATH_INFO")
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if not path:
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return None
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script_name = environ.get("SCRIPT_NAME", "")
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|
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# shift multiple leading slashes over
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old_path = path
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path = path.lstrip("/")
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if path != old_path:
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script_name += "/" * (len(old_path) - len(path))
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if "/" not in path:
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environ["PATH_INFO"] = ""
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environ["SCRIPT_NAME"] = script_name + path
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rv = path.encode("latin1")
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else:
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segment, path = path.split("/", 1)
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environ["PATH_INFO"] = f"/{path}"
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environ["SCRIPT_NAME"] = script_name + segment
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rv = segment.encode("latin1")
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return _to_str(rv, charset, errors, allow_none_charset=True) # type: ignore
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|
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def peek_path_info(
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environ: "WSGIEnvironment", charset: str = "utf-8", errors: str = "replace"
|
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) -> t.Optional[str]:
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"""Returns the next segment on the `PATH_INFO` or `None` if there
|
||
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is none. Works like :func:`pop_path_info` without modifying the
|
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|
|
environment:
|
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|
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>>> env = {'SCRIPT_NAME': '/foo', 'PATH_INFO': '/a/b'}
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>>> peek_path_info(env)
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'a'
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|
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>>> peek_path_info(env)
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'a'
|
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|
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|
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If the `charset` is set to `None` bytes are returned.
|
||
|
|
|
||
|
|
.. versionadded:: 0.5
|
||
|
|
|
||
|
|
.. versionchanged:: 0.9
|
||
|
|
The path is now decoded and a charset and encoding
|
||
|
|
parameter can be provided.
|
||
|
|
|
||
|
|
:param environ: the WSGI environment that is checked.
|
||
|
|
"""
|
||
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|
segments = environ.get("PATH_INFO", "").lstrip("/").split("/", 1)
|
||
|
|
if segments:
|
||
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return _to_str( # type: ignore
|
||
|
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segments[0].encode("latin1"), charset, errors, allow_none_charset=True
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||
|
|
)
|
||
|
|
return None
|
||
|
|
|
||
|
|
|
||
|
|
def extract_path_info(
|
||
|
|
environ_or_baseurl: t.Union[str, "WSGIEnvironment"],
|
||
|
|
path_or_url: t.Union[str, _URLTuple],
|
||
|
|
charset: str = "utf-8",
|
||
|
|
errors: str = "werkzeug.url_quote",
|
||
|
|
collapse_http_schemes: bool = True,
|
||
|
|
) -> t.Optional[str]:
|
||
|
|
"""Extracts the path info from the given URL (or WSGI environment) and
|
||
|
|
path. The path info returned is a string. The URLs might also be IRIs.
|
||
|
|
|
||
|
|
If the path info could not be determined, `None` is returned.
|
||
|
|
|
||
|
|
Some examples:
|
||
|
|
|
||
|
|
>>> extract_path_info('http://example.com/app', '/app/hello')
|
||
|
|
'/hello'
|
||
|
|
>>> extract_path_info('http://example.com/app',
|
||
|
|
... 'https://example.com/app/hello')
|
||
|
|
'/hello'
|
||
|
|
>>> extract_path_info('http://example.com/app',
|
||
|
|
... 'https://example.com/app/hello',
|
||
|
|
... collapse_http_schemes=False) is None
|
||
|
|
True
|
||
|
|
|
||
|
|
Instead of providing a base URL you can also pass a WSGI environment.
|
||
|
|
|
||
|
|
:param environ_or_baseurl: a WSGI environment dict, a base URL or
|
||
|
|
base IRI. This is the root of the
|
||
|
|
application.
|
||
|
|
:param path_or_url: an absolute path from the server root, a
|
||
|
|
relative path (in which case it's the path info)
|
||
|
|
or a full URL.
|
||
|
|
:param charset: the charset for byte data in URLs
|
||
|
|
:param errors: the error handling on decode
|
||
|
|
:param collapse_http_schemes: if set to `False` the algorithm does
|
||
|
|
not assume that http and https on the
|
||
|
|
same server point to the same
|
||
|
|
resource.
|
||
|
|
|
||
|
|
.. versionchanged:: 0.15
|
||
|
|
The ``errors`` parameter defaults to leaving invalid bytes
|
||
|
|
quoted instead of replacing them.
|
||
|
|
|
||
|
|
.. versionadded:: 0.6
|
||
|
|
"""
|
||
|
|
|
||
|
|
def _normalize_netloc(scheme: str, netloc: str) -> str:
|
||
|
|
parts = netloc.split("@", 1)[-1].split(":", 1)
|
||
|
|
port: t.Optional[str]
|
||
|
|
|
||
|
|
if len(parts) == 2:
|
||
|
|
netloc, port = parts
|
||
|
|
if (scheme == "http" and port == "80") or (
|
||
|
|
scheme == "https" and port == "443"
|
||
|
|
):
|
||
|
|
port = None
|
||
|
|
else:
|
||
|
|
netloc = parts[0]
|
||
|
|
port = None
|
||
|
|
|
||
|
|
if port is not None:
|
||
|
|
netloc += f":{port}"
|
||
|
|
|
||
|
|
return netloc
|
||
|
|
|
||
|
|
# make sure whatever we are working on is a IRI and parse it
|
||
|
|
path = uri_to_iri(path_or_url, charset, errors)
|
||
|
|
if isinstance(environ_or_baseurl, dict):
|
||
|
|
environ_or_baseurl = get_current_url(environ_or_baseurl, root_only=True)
|
||
|
|
base_iri = uri_to_iri(environ_or_baseurl, charset, errors)
|
||
|
|
base_scheme, base_netloc, base_path = url_parse(base_iri)[:3]
|
||
|
|
cur_scheme, cur_netloc, cur_path = url_parse(url_join(base_iri, path))[:3]
|
||
|
|
|
||
|
|
# normalize the network location
|
||
|
|
base_netloc = _normalize_netloc(base_scheme, base_netloc)
|
||
|
|
cur_netloc = _normalize_netloc(cur_scheme, cur_netloc)
|
||
|
|
|
||
|
|
# is that IRI even on a known HTTP scheme?
|
||
|
|
if collapse_http_schemes:
|
||
|
|
for scheme in base_scheme, cur_scheme:
|
||
|
|
if scheme not in ("http", "https"):
|
||
|
|
return None
|
||
|
|
else:
|
||
|
|
if not (base_scheme in ("http", "https") and base_scheme == cur_scheme):
|
||
|
|
return None
|
||
|
|
|
||
|
|
# are the netlocs compatible?
|
||
|
|
if base_netloc != cur_netloc:
|
||
|
|
return None
|
||
|
|
|
||
|
|
# are we below the application path?
|
||
|
|
base_path = base_path.rstrip("/")
|
||
|
|
if not cur_path.startswith(base_path):
|
||
|
|
return None
|
||
|
|
|
||
|
|
return f"/{cur_path[len(base_path) :].lstrip('/')}"
|
||
|
|
|
||
|
|
|
||
|
|
class ClosingIterator:
|
||
|
|
"""The WSGI specification requires that all middlewares and gateways
|
||
|
|
respect the `close` callback of the iterable returned by the application.
|
||
|
|
Because it is useful to add another close action to a returned iterable
|
||
|
|
and adding a custom iterable is a boring task this class can be used for
|
||
|
|
that::
|
||
|
|
|
||
|
|
return ClosingIterator(app(environ, start_response), [cleanup_session,
|
||
|
|
cleanup_locals])
|
||
|
|
|
||
|
|
If there is just one close function it can be passed instead of the list.
|
||
|
|
|
||
|
|
A closing iterator is not needed if the application uses response objects
|
||
|
|
and finishes the processing if the response is started::
|
||
|
|
|
||
|
|
try:
|
||
|
|
return response(environ, start_response)
|
||
|
|
finally:
|
||
|
|
cleanup_session()
|
||
|
|
cleanup_locals()
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(
|
||
|
|
self,
|
||
|
|
iterable: t.Iterable[bytes],
|
||
|
|
callbacks: t.Optional[
|
||
|
|
t.Union[t.Callable[[], None], t.Iterable[t.Callable[[], None]]]
|
||
|
|
] = None,
|
||
|
|
) -> None:
|
||
|
|
iterator = iter(iterable)
|
||
|
|
self._next = t.cast(t.Callable[[], bytes], partial(next, iterator))
|
||
|
|
if callbacks is None:
|
||
|
|
callbacks = []
|
||
|
|
elif callable(callbacks):
|
||
|
|
callbacks = [callbacks]
|
||
|
|
else:
|
||
|
|
callbacks = list(callbacks)
|
||
|
|
iterable_close = getattr(iterable, "close", None)
|
||
|
|
if iterable_close:
|
||
|
|
callbacks.insert(0, iterable_close)
|
||
|
|
self._callbacks = callbacks
|
||
|
|
|
||
|
|
def __iter__(self) -> "ClosingIterator":
|
||
|
|
return self
|
||
|
|
|
||
|
|
def __next__(self) -> bytes:
|
||
|
|
return self._next()
|
||
|
|
|
||
|
|
def close(self) -> None:
|
||
|
|
for callback in self._callbacks:
|
||
|
|
callback()
|
||
|
|
|
||
|
|
|
||
|
|
def wrap_file(
|
||
|
|
environ: "WSGIEnvironment", file: t.BinaryIO, buffer_size: int = 8192
|
||
|
|
) -> t.Iterable[bytes]:
|
||
|
|
"""Wraps a file. This uses the WSGI server's file wrapper if available
|
||
|
|
or otherwise the generic :class:`FileWrapper`.
|
||
|
|
|
||
|
|
.. versionadded:: 0.5
|
||
|
|
|
||
|
|
If the file wrapper from the WSGI server is used it's important to not
|
||
|
|
iterate over it from inside the application but to pass it through
|
||
|
|
unchanged. If you want to pass out a file wrapper inside a response
|
||
|
|
object you have to set :attr:`Response.direct_passthrough` to `True`.
|
||
|
|
|
||
|
|
More information about file wrappers are available in :pep:`333`.
|
||
|
|
|
||
|
|
:param file: a :class:`file`-like object with a :meth:`~file.read` method.
|
||
|
|
:param buffer_size: number of bytes for one iteration.
|
||
|
|
"""
|
||
|
|
return environ.get("wsgi.file_wrapper", FileWrapper)( # type: ignore
|
||
|
|
file, buffer_size
|
||
|
|
)
|
||
|
|
|
||
|
|
|
||
|
|
class FileWrapper:
|
||
|
|
"""This class can be used to convert a :class:`file`-like object into
|
||
|
|
an iterable. It yields `buffer_size` blocks until the file is fully
|
||
|
|
read.
|
||
|
|
|
||
|
|
You should not use this class directly but rather use the
|
||
|
|
:func:`wrap_file` function that uses the WSGI server's file wrapper
|
||
|
|
support if it's available.
|
||
|
|
|
||
|
|
.. versionadded:: 0.5
|
||
|
|
|
||
|
|
If you're using this object together with a :class:`Response` you have
|
||
|
|
to use the `direct_passthrough` mode.
|
||
|
|
|
||
|
|
:param file: a :class:`file`-like object with a :meth:`~file.read` method.
|
||
|
|
:param buffer_size: number of bytes for one iteration.
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(self, file: t.BinaryIO, buffer_size: int = 8192) -> None:
|
||
|
|
self.file = file
|
||
|
|
self.buffer_size = buffer_size
|
||
|
|
|
||
|
|
def close(self) -> None:
|
||
|
|
if hasattr(self.file, "close"):
|
||
|
|
self.file.close()
|
||
|
|
|
||
|
|
def seekable(self) -> bool:
|
||
|
|
if hasattr(self.file, "seekable"):
|
||
|
|
return self.file.seekable()
|
||
|
|
if hasattr(self.file, "seek"):
|
||
|
|
return True
|
||
|
|
return False
|
||
|
|
|
||
|
|
def seek(self, *args: t.Any) -> None:
|
||
|
|
if hasattr(self.file, "seek"):
|
||
|
|
self.file.seek(*args)
|
||
|
|
|
||
|
|
def tell(self) -> t.Optional[int]:
|
||
|
|
if hasattr(self.file, "tell"):
|
||
|
|
return self.file.tell()
|
||
|
|
return None
|
||
|
|
|
||
|
|
def __iter__(self) -> "FileWrapper":
|
||
|
|
return self
|
||
|
|
|
||
|
|
def __next__(self) -> bytes:
|
||
|
|
data = self.file.read(self.buffer_size)
|
||
|
|
if data:
|
||
|
|
return data
|
||
|
|
raise StopIteration()
|
||
|
|
|
||
|
|
|
||
|
|
class _RangeWrapper:
|
||
|
|
# private for now, but should we make it public in the future ?
|
||
|
|
|
||
|
|
"""This class can be used to convert an iterable object into
|
||
|
|
an iterable that will only yield a piece of the underlying content.
|
||
|
|
It yields blocks until the underlying stream range is fully read.
|
||
|
|
The yielded blocks will have a size that can't exceed the original
|
||
|
|
iterator defined block size, but that can be smaller.
|
||
|
|
|
||
|
|
If you're using this object together with a :class:`Response` you have
|
||
|
|
to use the `direct_passthrough` mode.
|
||
|
|
|
||
|
|
:param iterable: an iterable object with a :meth:`__next__` method.
|
||
|
|
:param start_byte: byte from which read will start.
|
||
|
|
:param byte_range: how many bytes to read.
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(
|
||
|
|
self,
|
||
|
|
iterable: t.Union[t.Iterable[bytes], t.BinaryIO],
|
||
|
|
start_byte: int = 0,
|
||
|
|
byte_range: t.Optional[int] = None,
|
||
|
|
):
|
||
|
|
self.iterable = iter(iterable)
|
||
|
|
self.byte_range = byte_range
|
||
|
|
self.start_byte = start_byte
|
||
|
|
self.end_byte = None
|
||
|
|
|
||
|
|
if byte_range is not None:
|
||
|
|
self.end_byte = start_byte + byte_range
|
||
|
|
|
||
|
|
self.read_length = 0
|
||
|
|
self.seekable = (
|
||
|
|
hasattr(iterable, "seekable") and iterable.seekable() # type: ignore
|
||
|
|
)
|
||
|
|
self.end_reached = False
|
||
|
|
|
||
|
|
def __iter__(self) -> "_RangeWrapper":
|
||
|
|
return self
|
||
|
|
|
||
|
|
def _next_chunk(self) -> bytes:
|
||
|
|
try:
|
||
|
|
chunk = next(self.iterable)
|
||
|
|
self.read_length += len(chunk)
|
||
|
|
return chunk
|
||
|
|
except StopIteration:
|
||
|
|
self.end_reached = True
|
||
|
|
raise
|
||
|
|
|
||
|
|
def _first_iteration(self) -> t.Tuple[t.Optional[bytes], int]:
|
||
|
|
chunk = None
|
||
|
|
if self.seekable:
|
||
|
|
self.iterable.seek(self.start_byte) # type: ignore
|
||
|
|
self.read_length = self.iterable.tell() # type: ignore
|
||
|
|
contextual_read_length = self.read_length
|
||
|
|
else:
|
||
|
|
while self.read_length <= self.start_byte:
|
||
|
|
chunk = self._next_chunk()
|
||
|
|
if chunk is not None:
|
||
|
|
chunk = chunk[self.start_byte - self.read_length :]
|
||
|
|
contextual_read_length = self.start_byte
|
||
|
|
return chunk, contextual_read_length
|
||
|
|
|
||
|
|
def _next(self) -> bytes:
|
||
|
|
if self.end_reached:
|
||
|
|
raise StopIteration()
|
||
|
|
chunk = None
|
||
|
|
contextual_read_length = self.read_length
|
||
|
|
if self.read_length == 0:
|
||
|
|
chunk, contextual_read_length = self._first_iteration()
|
||
|
|
if chunk is None:
|
||
|
|
chunk = self._next_chunk()
|
||
|
|
if self.end_byte is not None and self.read_length >= self.end_byte:
|
||
|
|
self.end_reached = True
|
||
|
|
return chunk[: self.end_byte - contextual_read_length]
|
||
|
|
return chunk
|
||
|
|
|
||
|
|
def __next__(self) -> bytes:
|
||
|
|
chunk = self._next()
|
||
|
|
if chunk:
|
||
|
|
return chunk
|
||
|
|
self.end_reached = True
|
||
|
|
raise StopIteration()
|
||
|
|
|
||
|
|
def close(self) -> None:
|
||
|
|
if hasattr(self.iterable, "close"):
|
||
|
|
self.iterable.close() # type: ignore
|
||
|
|
|
||
|
|
|
||
|
|
def _make_chunk_iter(
|
||
|
|
stream: t.Union[t.Iterable[bytes], t.BinaryIO],
|
||
|
|
limit: t.Optional[int],
|
||
|
|
buffer_size: int,
|
||
|
|
) -> t.Iterator[bytes]:
|
||
|
|
"""Helper for the line and chunk iter functions."""
|
||
|
|
if isinstance(stream, (bytes, bytearray, str)):
|
||
|
|
raise TypeError(
|
||
|
|
"Passed a string or byte object instead of true iterator or stream."
|
||
|
|
)
|
||
|
|
if not hasattr(stream, "read"):
|
||
|
|
for item in stream:
|
||
|
|
if item:
|
||
|
|
yield item
|
||
|
|
return
|
||
|
|
stream = t.cast(t.BinaryIO, stream)
|
||
|
|
if not isinstance(stream, LimitedStream) and limit is not None:
|
||
|
|
stream = t.cast(t.BinaryIO, LimitedStream(stream, limit))
|
||
|
|
_read = stream.read
|
||
|
|
while True:
|
||
|
|
item = _read(buffer_size)
|
||
|
|
if not item:
|
||
|
|
break
|
||
|
|
yield item
|
||
|
|
|
||
|
|
|
||
|
|
def make_line_iter(
|
||
|
|
stream: t.Union[t.Iterable[bytes], t.BinaryIO],
|
||
|
|
limit: t.Optional[int] = None,
|
||
|
|
buffer_size: int = 10 * 1024,
|
||
|
|
cap_at_buffer: bool = False,
|
||
|
|
) -> t.Iterator[bytes]:
|
||
|
|
"""Safely iterates line-based over an input stream. If the input stream
|
||
|
|
is not a :class:`LimitedStream` the `limit` parameter is mandatory.
|
||
|
|
|
||
|
|
This uses the stream's :meth:`~file.read` method internally as opposite
|
||
|
|
to the :meth:`~file.readline` method that is unsafe and can only be used
|
||
|
|
in violation of the WSGI specification. The same problem applies to the
|
||
|
|
`__iter__` function of the input stream which calls :meth:`~file.readline`
|
||
|
|
without arguments.
|
||
|
|
|
||
|
|
If you need line-by-line processing it's strongly recommended to iterate
|
||
|
|
over the input stream using this helper function.
|
||
|
|
|
||
|
|
.. versionchanged:: 0.8
|
||
|
|
This function now ensures that the limit was reached.
|
||
|
|
|
||
|
|
.. versionadded:: 0.9
|
||
|
|
added support for iterators as input stream.
|
||
|
|
|
||
|
|
.. versionadded:: 0.11.10
|
||
|
|
added support for the `cap_at_buffer` parameter.
|
||
|
|
|
||
|
|
:param stream: the stream or iterate to iterate over.
|
||
|
|
:param limit: the limit in bytes for the stream. (Usually
|
||
|
|
content length. Not necessary if the `stream`
|
||
|
|
is a :class:`LimitedStream`.
|
||
|
|
:param buffer_size: The optional buffer size.
|
||
|
|
:param cap_at_buffer: if this is set chunks are split if they are longer
|
||
|
|
than the buffer size. Internally this is implemented
|
||
|
|
that the buffer size might be exhausted by a factor
|
||
|
|
of two however.
|
||
|
|
"""
|
||
|
|
_iter = _make_chunk_iter(stream, limit, buffer_size)
|
||
|
|
|
||
|
|
first_item = next(_iter, "")
|
||
|
|
if not first_item:
|
||
|
|
return
|
||
|
|
|
||
|
|
s = _make_encode_wrapper(first_item)
|
||
|
|
empty = t.cast(bytes, s(""))
|
||
|
|
cr = t.cast(bytes, s("\r"))
|
||
|
|
lf = t.cast(bytes, s("\n"))
|
||
|
|
crlf = t.cast(bytes, s("\r\n"))
|
||
|
|
|
||
|
|
_iter = t.cast(t.Iterator[bytes], chain((first_item,), _iter))
|
||
|
|
|
||
|
|
def _iter_basic_lines() -> t.Iterator[bytes]:
|
||
|
|
_join = empty.join
|
||
|
|
buffer: t.List[bytes] = []
|
||
|
|
while True:
|
||
|
|
new_data = next(_iter, "")
|
||
|
|
if not new_data:
|
||
|
|
break
|
||
|
|
new_buf: t.List[bytes] = []
|
||
|
|
buf_size = 0
|
||
|
|
for item in t.cast(
|
||
|
|
t.Iterator[bytes], chain(buffer, new_data.splitlines(True))
|
||
|
|
):
|
||
|
|
new_buf.append(item)
|
||
|
|
buf_size += len(item)
|
||
|
|
if item and item[-1:] in crlf:
|
||
|
|
yield _join(new_buf)
|
||
|
|
new_buf = []
|
||
|
|
elif cap_at_buffer and buf_size >= buffer_size:
|
||
|
|
rv = _join(new_buf)
|
||
|
|
while len(rv) >= buffer_size:
|
||
|
|
yield rv[:buffer_size]
|
||
|
|
rv = rv[buffer_size:]
|
||
|
|
new_buf = [rv]
|
||
|
|
buffer = new_buf
|
||
|
|
if buffer:
|
||
|
|
yield _join(buffer)
|
||
|
|
|
||
|
|
# This hackery is necessary to merge 'foo\r' and '\n' into one item
|
||
|
|
# of 'foo\r\n' if we were unlucky and we hit a chunk boundary.
|
||
|
|
previous = empty
|
||
|
|
for item in _iter_basic_lines():
|
||
|
|
if item == lf and previous[-1:] == cr:
|
||
|
|
previous += item
|
||
|
|
item = empty
|
||
|
|
if previous:
|
||
|
|
yield previous
|
||
|
|
previous = item
|
||
|
|
if previous:
|
||
|
|
yield previous
|
||
|
|
|
||
|
|
|
||
|
|
def make_chunk_iter(
|
||
|
|
stream: t.Union[t.Iterable[bytes], t.BinaryIO],
|
||
|
|
separator: bytes,
|
||
|
|
limit: t.Optional[int] = None,
|
||
|
|
buffer_size: int = 10 * 1024,
|
||
|
|
cap_at_buffer: bool = False,
|
||
|
|
) -> t.Iterator[bytes]:
|
||
|
|
"""Works like :func:`make_line_iter` but accepts a separator
|
||
|
|
which divides chunks. If you want newline based processing
|
||
|
|
you should use :func:`make_line_iter` instead as it
|
||
|
|
supports arbitrary newline markers.
|
||
|
|
|
||
|
|
.. versionadded:: 0.8
|
||
|
|
|
||
|
|
.. versionadded:: 0.9
|
||
|
|
added support for iterators as input stream.
|
||
|
|
|
||
|
|
.. versionadded:: 0.11.10
|
||
|
|
added support for the `cap_at_buffer` parameter.
|
||
|
|
|
||
|
|
:param stream: the stream or iterate to iterate over.
|
||
|
|
:param separator: the separator that divides chunks.
|
||
|
|
:param limit: the limit in bytes for the stream. (Usually
|
||
|
|
content length. Not necessary if the `stream`
|
||
|
|
is otherwise already limited).
|
||
|
|
:param buffer_size: The optional buffer size.
|
||
|
|
:param cap_at_buffer: if this is set chunks are split if they are longer
|
||
|
|
than the buffer size. Internally this is implemented
|
||
|
|
that the buffer size might be exhausted by a factor
|
||
|
|
of two however.
|
||
|
|
"""
|
||
|
|
_iter = _make_chunk_iter(stream, limit, buffer_size)
|
||
|
|
|
||
|
|
first_item = next(_iter, b"")
|
||
|
|
if not first_item:
|
||
|
|
return
|
||
|
|
|
||
|
|
_iter = t.cast(t.Iterator[bytes], chain((first_item,), _iter))
|
||
|
|
if isinstance(first_item, str):
|
||
|
|
separator = _to_str(separator)
|
||
|
|
_split = re.compile(f"({re.escape(separator)})").split
|
||
|
|
_join = "".join
|
||
|
|
else:
|
||
|
|
separator = _to_bytes(separator)
|
||
|
|
_split = re.compile(b"(" + re.escape(separator) + b")").split
|
||
|
|
_join = b"".join
|
||
|
|
|
||
|
|
buffer: t.List[bytes] = []
|
||
|
|
while True:
|
||
|
|
new_data = next(_iter, b"")
|
||
|
|
if not new_data:
|
||
|
|
break
|
||
|
|
chunks = _split(new_data)
|
||
|
|
new_buf: t.List[bytes] = []
|
||
|
|
buf_size = 0
|
||
|
|
for item in chain(buffer, chunks):
|
||
|
|
if item == separator:
|
||
|
|
yield _join(new_buf)
|
||
|
|
new_buf = []
|
||
|
|
buf_size = 0
|
||
|
|
else:
|
||
|
|
buf_size += len(item)
|
||
|
|
new_buf.append(item)
|
||
|
|
|
||
|
|
if cap_at_buffer and buf_size >= buffer_size:
|
||
|
|
rv = _join(new_buf)
|
||
|
|
while len(rv) >= buffer_size:
|
||
|
|
yield rv[:buffer_size]
|
||
|
|
rv = rv[buffer_size:]
|
||
|
|
new_buf = [rv]
|
||
|
|
buf_size = len(rv)
|
||
|
|
|
||
|
|
buffer = new_buf
|
||
|
|
if buffer:
|
||
|
|
yield _join(buffer)
|
||
|
|
|
||
|
|
|
||
|
|
class LimitedStream(io.IOBase):
|
||
|
|
"""Wraps a stream so that it doesn't read more than n bytes. If the
|
||
|
|
stream is exhausted and the caller tries to get more bytes from it
|
||
|
|
:func:`on_exhausted` is called which by default returns an empty
|
||
|
|
string. The return value of that function is forwarded
|
||
|
|
to the reader function. So if it returns an empty string
|
||
|
|
:meth:`read` will return an empty string as well.
|
||
|
|
|
||
|
|
The limit however must never be higher than what the stream can
|
||
|
|
output. Otherwise :meth:`readlines` will try to read past the
|
||
|
|
limit.
|
||
|
|
|
||
|
|
.. admonition:: Note on WSGI compliance
|
||
|
|
|
||
|
|
calls to :meth:`readline` and :meth:`readlines` are not
|
||
|
|
WSGI compliant because it passes a size argument to the
|
||
|
|
readline methods. Unfortunately the WSGI PEP is not safely
|
||
|
|
implementable without a size argument to :meth:`readline`
|
||
|
|
because there is no EOF marker in the stream. As a result
|
||
|
|
of that the use of :meth:`readline` is discouraged.
|
||
|
|
|
||
|
|
For the same reason iterating over the :class:`LimitedStream`
|
||
|
|
is not portable. It internally calls :meth:`readline`.
|
||
|
|
|
||
|
|
We strongly suggest using :meth:`read` only or using the
|
||
|
|
:func:`make_line_iter` which safely iterates line-based
|
||
|
|
over a WSGI input stream.
|
||
|
|
|
||
|
|
:param stream: the stream to wrap.
|
||
|
|
:param limit: the limit for the stream, must not be longer than
|
||
|
|
what the string can provide if the stream does not
|
||
|
|
end with `EOF` (like `wsgi.input`)
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(self, stream: t.BinaryIO, limit: int) -> None:
|
||
|
|
self._read = stream.read
|
||
|
|
self._readline = stream.readline
|
||
|
|
self._pos = 0
|
||
|
|
self.limit = limit
|
||
|
|
|
||
|
|
def __iter__(self) -> "LimitedStream":
|
||
|
|
return self
|
||
|
|
|
||
|
|
@property
|
||
|
|
def is_exhausted(self) -> bool:
|
||
|
|
"""If the stream is exhausted this attribute is `True`."""
|
||
|
|
return self._pos >= self.limit
|
||
|
|
|
||
|
|
def on_exhausted(self) -> bytes:
|
||
|
|
"""This is called when the stream tries to read past the limit.
|
||
|
|
The return value of this function is returned from the reading
|
||
|
|
function.
|
||
|
|
"""
|
||
|
|
# Read null bytes from the stream so that we get the
|
||
|
|
# correct end of stream marker.
|
||
|
|
return self._read(0)
|
||
|
|
|
||
|
|
def on_disconnect(self) -> bytes:
|
||
|
|
"""What should happen if a disconnect is detected? The return
|
||
|
|
value of this function is returned from read functions in case
|
||
|
|
the client went away. By default a
|
||
|
|
:exc:`~werkzeug.exceptions.ClientDisconnected` exception is raised.
|
||
|
|
"""
|
||
|
|
from .exceptions import ClientDisconnected
|
||
|
|
|
||
|
|
raise ClientDisconnected()
|
||
|
|
|
||
|
|
def exhaust(self, chunk_size: int = 1024 * 64) -> None:
|
||
|
|
"""Exhaust the stream. This consumes all the data left until the
|
||
|
|
limit is reached.
|
||
|
|
|
||
|
|
:param chunk_size: the size for a chunk. It will read the chunk
|
||
|
|
until the stream is exhausted and throw away
|
||
|
|
the results.
|
||
|
|
"""
|
||
|
|
to_read = self.limit - self._pos
|
||
|
|
chunk = chunk_size
|
||
|
|
while to_read > 0:
|
||
|
|
chunk = min(to_read, chunk)
|
||
|
|
self.read(chunk)
|
||
|
|
to_read -= chunk
|
||
|
|
|
||
|
|
def read(self, size: t.Optional[int] = None) -> bytes:
|
||
|
|
"""Read `size` bytes or if size is not provided everything is read.
|
||
|
|
|
||
|
|
:param size: the number of bytes read.
|
||
|
|
"""
|
||
|
|
if self._pos >= self.limit:
|
||
|
|
return self.on_exhausted()
|
||
|
|
if size is None or size == -1: # -1 is for consistence with file
|
||
|
|
size = self.limit
|
||
|
|
to_read = min(self.limit - self._pos, size)
|
||
|
|
try:
|
||
|
|
read = self._read(to_read)
|
||
|
|
except (OSError, ValueError):
|
||
|
|
return self.on_disconnect()
|
||
|
|
if to_read and len(read) != to_read:
|
||
|
|
return self.on_disconnect()
|
||
|
|
self._pos += len(read)
|
||
|
|
return read
|
||
|
|
|
||
|
|
def readline(self, size: t.Optional[int] = None) -> bytes:
|
||
|
|
"""Reads one line from the stream."""
|
||
|
|
if self._pos >= self.limit:
|
||
|
|
return self.on_exhausted()
|
||
|
|
if size is None:
|
||
|
|
size = self.limit - self._pos
|
||
|
|
else:
|
||
|
|
size = min(size, self.limit - self._pos)
|
||
|
|
try:
|
||
|
|
line = self._readline(size)
|
||
|
|
except (ValueError, OSError):
|
||
|
|
return self.on_disconnect()
|
||
|
|
if size and not line:
|
||
|
|
return self.on_disconnect()
|
||
|
|
self._pos += len(line)
|
||
|
|
return line
|
||
|
|
|
||
|
|
def readlines(self, size: t.Optional[int] = None) -> t.List[bytes]:
|
||
|
|
"""Reads a file into a list of strings. It calls :meth:`readline`
|
||
|
|
until the file is read to the end. It does support the optional
|
||
|
|
`size` argument if the underlying stream supports it for
|
||
|
|
`readline`.
|
||
|
|
"""
|
||
|
|
last_pos = self._pos
|
||
|
|
result = []
|
||
|
|
if size is not None:
|
||
|
|
end = min(self.limit, last_pos + size)
|
||
|
|
else:
|
||
|
|
end = self.limit
|
||
|
|
while True:
|
||
|
|
if size is not None:
|
||
|
|
size -= last_pos - self._pos
|
||
|
|
if self._pos >= end:
|
||
|
|
break
|
||
|
|
result.append(self.readline(size))
|
||
|
|
if size is not None:
|
||
|
|
last_pos = self._pos
|
||
|
|
return result
|
||
|
|
|
||
|
|
def tell(self) -> int:
|
||
|
|
"""Returns the position of the stream.
|
||
|
|
|
||
|
|
.. versionadded:: 0.9
|
||
|
|
"""
|
||
|
|
return self._pos
|
||
|
|
|
||
|
|
def __next__(self) -> bytes:
|
||
|
|
line = self.readline()
|
||
|
|
if not line:
|
||
|
|
raise StopIteration()
|
||
|
|
return line
|
||
|
|
|
||
|
|
def readable(self) -> bool:
|
||
|
|
return True
|