From 64a8f353fdc03c74cbc8bd0596ff321ab0cfea0b Mon Sep 17 00:00:00 2001 From: Polina Date: Thu, 2 Jul 2026 18:30:34 +0000 Subject: [PATCH] =?UTF-8?q?=D0=97=D0=B0=D0=B3=D1=80=D1=83=D0=B7=D0=B8?= =?UTF-8?q?=D1=82=D1=8C=20=D1=84=D0=B0=D0=B9=D0=BB=D1=8B=20=D0=B2=20=C2=AB?= =?UTF-8?q?venv/Lib/site-packages/h11=C2=BB?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- venv/Lib/site-packages/h11/_readers.py | 250 +++++++++++++ venv/Lib/site-packages/h11/_receivebuffer.py | 153 ++++++++ venv/Lib/site-packages/h11/_state.py | 365 +++++++++++++++++++ venv/Lib/site-packages/h11/_util.py | 135 +++++++ venv/Lib/site-packages/h11/_version.py | 16 + 5 files changed, 919 insertions(+) create mode 100644 venv/Lib/site-packages/h11/_readers.py create mode 100644 venv/Lib/site-packages/h11/_receivebuffer.py create mode 100644 venv/Lib/site-packages/h11/_state.py create mode 100644 venv/Lib/site-packages/h11/_util.py create mode 100644 venv/Lib/site-packages/h11/_version.py diff --git a/venv/Lib/site-packages/h11/_readers.py b/venv/Lib/site-packages/h11/_readers.py new file mode 100644 index 0000000..576804c --- /dev/null +++ b/venv/Lib/site-packages/h11/_readers.py @@ -0,0 +1,250 @@ +# Code to read HTTP data +# +# Strategy: each reader is a callable which takes a ReceiveBuffer object, and +# either: +# 1) consumes some of it and returns an Event +# 2) raises a LocalProtocolError (for consistency -- e.g. we call validate() +# and it might raise a LocalProtocolError, so simpler just to always use +# this) +# 3) returns None, meaning "I need more data" +# +# If they have a .read_eof attribute, then this will be called if an EOF is +# received -- but this is optional. Either way, the actual ConnectionClosed +# event will be generated afterwards. +# +# READERS is a dict describing how to pick a reader. It maps states to either: +# - a reader +# - or, for body readers, a dict of per-framing reader factories + +import re +from typing import Any, Callable, Dict, Iterable, NoReturn, Optional, Tuple, Type, Union + +from ._abnf import chunk_header, header_field, request_line, status_line +from ._events import Data, EndOfMessage, InformationalResponse, Request, Response +from ._receivebuffer import ReceiveBuffer +from ._state import ( + CLIENT, + CLOSED, + DONE, + IDLE, + MUST_CLOSE, + SEND_BODY, + SEND_RESPONSE, + SERVER, +) +from ._util import LocalProtocolError, RemoteProtocolError, Sentinel, validate + +__all__ = ["READERS"] + +header_field_re = re.compile(header_field.encode("ascii")) +obs_fold_re = re.compile(rb"[ \t]+") + + +def _obsolete_line_fold(lines: Iterable[bytes]) -> Iterable[bytes]: + it = iter(lines) + last: Optional[bytes] = None + for line in it: + match = obs_fold_re.match(line) + if match: + if last is None: + raise LocalProtocolError("continuation line at start of headers") + if not isinstance(last, bytearray): + # Cast to a mutable type, avoiding copy on append to ensure O(n) time + last = bytearray(last) + last += b" " + last += line[match.end() :] + else: + if last is not None: + yield last + last = line + if last is not None: + yield last + + +def _decode_header_lines( + lines: Iterable[bytes], +) -> Iterable[Tuple[bytes, bytes]]: + for line in _obsolete_line_fold(lines): + matches = validate(header_field_re, line, "illegal header line: {!r}", line) + yield (matches["field_name"], matches["field_value"]) + + +request_line_re = re.compile(request_line.encode("ascii")) + + +def maybe_read_from_IDLE_client(buf: ReceiveBuffer) -> Optional[Request]: + lines = buf.maybe_extract_lines() + if lines is None: + if buf.is_next_line_obviously_invalid_request_line(): + raise LocalProtocolError("illegal request line") + return None + if not lines: + raise LocalProtocolError("no request line received") + matches = validate( + request_line_re, lines[0], "illegal request line: {!r}", lines[0] + ) + return Request( + headers=list(_decode_header_lines(lines[1:])), _parsed=True, **matches + ) + + +status_line_re = re.compile(status_line.encode("ascii")) + + +def maybe_read_from_SEND_RESPONSE_server( + buf: ReceiveBuffer, +) -> Union[InformationalResponse, Response, None]: + lines = buf.maybe_extract_lines() + if lines is None: + if buf.is_next_line_obviously_invalid_request_line(): + raise LocalProtocolError("illegal request line") + return None + if not lines: + raise LocalProtocolError("no response line received") + matches = validate(status_line_re, lines[0], "illegal status line: {!r}", lines[0]) + http_version = ( + b"1.1" if matches["http_version"] is None else matches["http_version"] + ) + reason = b"" if matches["reason"] is None else matches["reason"] + status_code = int(matches["status_code"]) + class_: Union[Type[InformationalResponse], Type[Response]] = ( + InformationalResponse if status_code < 200 else Response + ) + return class_( + headers=list(_decode_header_lines(lines[1:])), + _parsed=True, + status_code=status_code, + reason=reason, + http_version=http_version, + ) + + +class ContentLengthReader: + def __init__(self, length: int) -> None: + self._length = length + self._remaining = length + + def __call__(self, buf: ReceiveBuffer) -> Union[Data, EndOfMessage, None]: + if self._remaining == 0: + return EndOfMessage() + data = buf.maybe_extract_at_most(self._remaining) + if data is None: + return None + self._remaining -= len(data) + return Data(data=data) + + def read_eof(self) -> NoReturn: + raise RemoteProtocolError( + "peer closed connection without sending complete message body " + "(received {} bytes, expected {})".format( + self._length - self._remaining, self._length + ) + ) + + +chunk_header_re = re.compile(chunk_header.encode("ascii")) + + +class ChunkedReader: + def __init__(self) -> None: + self._bytes_in_chunk = 0 + # After reading a chunk, we have to throw away the trailing \r\n. + # This tracks the bytes that we need to match and throw away. + self._bytes_to_discard = b"" + self._reading_trailer = False + + def __call__(self, buf: ReceiveBuffer) -> Union[Data, EndOfMessage, None]: + if self._reading_trailer: + lines = buf.maybe_extract_lines() + if lines is None: + return None + return EndOfMessage(headers=list(_decode_header_lines(lines))) + if self._bytes_to_discard: + data = buf.maybe_extract_at_most(len(self._bytes_to_discard)) + if data is None: + return None + if data != self._bytes_to_discard[: len(data)]: + raise LocalProtocolError( + f"malformed chunk footer: {data!r} (expected {self._bytes_to_discard!r})" + ) + self._bytes_to_discard = self._bytes_to_discard[len(data) :] + if self._bytes_to_discard: + return None + # else, fall through and read some more + assert self._bytes_to_discard == b"" + if self._bytes_in_chunk == 0: + # We need to refill our chunk count + chunk_header = buf.maybe_extract_next_line() + if chunk_header is None: + return None + matches = validate( + chunk_header_re, + chunk_header, + "illegal chunk header: {!r}", + chunk_header, + ) + # XX FIXME: we discard chunk extensions. Does anyone care? + self._bytes_in_chunk = int(matches["chunk_size"], base=16) + if self._bytes_in_chunk == 0: + self._reading_trailer = True + return self(buf) + chunk_start = True + else: + chunk_start = False + assert self._bytes_in_chunk > 0 + data = buf.maybe_extract_at_most(self._bytes_in_chunk) + if data is None: + return None + self._bytes_in_chunk -= len(data) + if self._bytes_in_chunk == 0: + self._bytes_to_discard = b"\r\n" + chunk_end = True + else: + chunk_end = False + return Data(data=data, chunk_start=chunk_start, chunk_end=chunk_end) + + def read_eof(self) -> NoReturn: + raise RemoteProtocolError( + "peer closed connection without sending complete message body " + "(incomplete chunked read)" + ) + + +class Http10Reader: + def __call__(self, buf: ReceiveBuffer) -> Optional[Data]: + data = buf.maybe_extract_at_most(999999999) + if data is None: + return None + return Data(data=data) + + def read_eof(self) -> EndOfMessage: + return EndOfMessage() + + +def expect_nothing(buf: ReceiveBuffer) -> None: + if buf: + raise LocalProtocolError("Got data when expecting EOF") + return None + + +ReadersType = Dict[ + Union[Type[Sentinel], Tuple[Type[Sentinel], Type[Sentinel]]], + Union[Callable[..., Any], Dict[str, Callable[..., Any]]], +] + +READERS: ReadersType = { + (CLIENT, IDLE): maybe_read_from_IDLE_client, + (SERVER, IDLE): maybe_read_from_SEND_RESPONSE_server, + (SERVER, SEND_RESPONSE): maybe_read_from_SEND_RESPONSE_server, + (CLIENT, DONE): expect_nothing, + (CLIENT, MUST_CLOSE): expect_nothing, + (CLIENT, CLOSED): expect_nothing, + (SERVER, DONE): expect_nothing, + (SERVER, MUST_CLOSE): expect_nothing, + (SERVER, CLOSED): expect_nothing, + SEND_BODY: { + "chunked": ChunkedReader, + "content-length": ContentLengthReader, + "http/1.0": Http10Reader, + }, +} diff --git a/venv/Lib/site-packages/h11/_receivebuffer.py b/venv/Lib/site-packages/h11/_receivebuffer.py new file mode 100644 index 0000000..e5c4e08 --- /dev/null +++ b/venv/Lib/site-packages/h11/_receivebuffer.py @@ -0,0 +1,153 @@ +import re +import sys +from typing import List, Optional, Union + +__all__ = ["ReceiveBuffer"] + + +# Operations we want to support: +# - find next \r\n or \r\n\r\n (\n or \n\n are also acceptable), +# or wait until there is one +# - read at-most-N bytes +# Goals: +# - on average, do this fast +# - worst case, do this in O(n) where n is the number of bytes processed +# Plan: +# - store bytearray, offset, how far we've searched for a separator token +# - use the how-far-we've-searched data to avoid rescanning +# - while doing a stream of uninterrupted processing, advance offset instead +# of constantly copying +# WARNING: +# - I haven't benchmarked or profiled any of this yet. +# +# Note that starting in Python 3.4, deleting the initial n bytes from a +# bytearray is amortized O(n), thanks to some excellent work by Antoine +# Martin: +# +# https://bugs.python.org/issue19087 +# +# This means that if we only supported 3.4+, we could get rid of the code here +# involving self._start and self.compress, because it's doing exactly the same +# thing that bytearray now does internally. +# +# BUT unfortunately, we still support 2.7, and reading short segments out of a +# long buffer MUST be O(bytes read) to avoid DoS issues, so we can't actually +# delete this code. Yet: +# +# https://pythonclock.org/ +# +# (Two things to double-check first though: make sure PyPy also has the +# optimization, and benchmark to make sure it's a win, since we do have a +# slightly clever thing where we delay calling compress() until we've +# processed a whole event, which could in theory be slightly more efficient +# than the internal bytearray support.) +blank_line_regex = re.compile(b"\n\r?\n", re.MULTILINE) + + +class ReceiveBuffer: + def __init__(self) -> None: + self._data = bytearray() + self._next_line_search = 0 + self._multiple_lines_search = 0 + + def __iadd__(self, byteslike: Union[bytes, bytearray]) -> "ReceiveBuffer": + self._data += byteslike + return self + + def __bool__(self) -> bool: + return bool(len(self)) + + def __len__(self) -> int: + return len(self._data) + + # for @property unprocessed_data + def __bytes__(self) -> bytes: + return bytes(self._data) + + def _extract(self, count: int) -> bytearray: + # extracting an initial slice of the data buffer and return it + out = self._data[:count] + del self._data[:count] + + self._next_line_search = 0 + self._multiple_lines_search = 0 + + return out + + def maybe_extract_at_most(self, count: int) -> Optional[bytearray]: + """ + Extract a fixed number of bytes from the buffer. + """ + out = self._data[:count] + if not out: + return None + + return self._extract(count) + + def maybe_extract_next_line(self) -> Optional[bytearray]: + """ + Extract the first line, if it is completed in the buffer. + """ + # Only search in buffer space that we've not already looked at. + search_start_index = max(0, self._next_line_search - 1) + partial_idx = self._data.find(b"\r\n", search_start_index) + + if partial_idx == -1: + self._next_line_search = len(self._data) + return None + + # + 2 is to compensate len(b"\r\n") + idx = partial_idx + 2 + + return self._extract(idx) + + def maybe_extract_lines(self) -> Optional[List[bytearray]]: + """ + Extract everything up to the first blank line, and return a list of lines. + """ + # Handle the case where we have an immediate empty line. + if self._data[:1] == b"\n": + self._extract(1) + return [] + + if self._data[:2] == b"\r\n": + self._extract(2) + return [] + + # Only search in buffer space that we've not already looked at. + match = blank_line_regex.search(self._data, self._multiple_lines_search) + if match is None: + self._multiple_lines_search = max(0, len(self._data) - 2) + return None + + # Truncate the buffer and return it. + idx = match.span(0)[-1] + out = self._extract(idx) + lines = out.split(b"\n") + + for line in lines: + if line.endswith(b"\r"): + del line[-1] + + assert lines[-2] == lines[-1] == b"" + + del lines[-2:] + + return lines + + # In theory we should wait until `\r\n` before starting to validate + # incoming data. However it's interesting to detect (very) invalid data + # early given they might not even contain `\r\n` at all (hence only + # timeout will get rid of them). + # This is not a 100% effective detection but more of a cheap sanity check + # allowing for early abort in some useful cases. + # This is especially interesting when peer is messing up with HTTPS and + # sent us a TLS stream where we were expecting plain HTTP given all + # versions of TLS so far start handshake with a 0x16 message type code. + def is_next_line_obviously_invalid_request_line(self) -> bool: + try: + # HTTP header line must not contain non-printable characters + # and should not start with a space + return self._data[0] < 0x21 + except IndexError: + return False diff --git a/venv/Lib/site-packages/h11/_state.py b/venv/Lib/site-packages/h11/_state.py new file mode 100644 index 0000000..3ad444b --- /dev/null +++ b/venv/Lib/site-packages/h11/_state.py @@ -0,0 +1,365 @@ +################################################################ +# The core state machine +################################################################ +# +# Rule 1: everything that affects the state machine and state transitions must +# live here in this file. As much as possible goes into the table-based +# representation, but for the bits that don't quite fit, the actual code and +# state must nonetheless live here. +# +# Rule 2: this file does not know about what role we're playing; it only knows +# about HTTP request/response cycles in the abstract. This ensures that we +# don't cheat and apply different rules to local and remote parties. +# +# +# Theory of operation +# =================== +# +# Possibly the simplest way to think about this is that we actually have 5 +# different state machines here. Yes, 5. These are: +# +# 1) The client state, with its complicated automaton (see the docs) +# 2) The server state, with its complicated automaton (see the docs) +# 3) The keep-alive state, with possible states {True, False} +# 4) The SWITCH_CONNECT state, with possible states {False, True} +# 5) The SWITCH_UPGRADE state, with possible states {False, True} +# +# For (3)-(5), the first state listed is the initial state. +# +# (1)-(3) are stored explicitly in member variables. The last +# two are stored implicitly in the pending_switch_proposals set as: +# (state of 4) == (_SWITCH_CONNECT in pending_switch_proposals) +# (state of 5) == (_SWITCH_UPGRADE in pending_switch_proposals) +# +# And each of these machines has two different kinds of transitions: +# +# a) Event-triggered +# b) State-triggered +# +# Event triggered is the obvious thing that you'd think it is: some event +# happens, and if it's the right event at the right time then a transition +# happens. But there are somewhat complicated rules for which machines can +# "see" which events. (As a rule of thumb, if a machine "sees" an event, this +# means two things: the event can affect the machine, and if the machine is +# not in a state where it expects that event then it's an error.) These rules +# are: +# +# 1) The client machine sees all h11.events objects emitted by the client. +# +# 2) The server machine sees all h11.events objects emitted by the server. +# +# It also sees the client's Request event. +# +# And sometimes, server events are annotated with a _SWITCH_* event. For +# example, we can have a (Response, _SWITCH_CONNECT) event, which is +# different from a regular Response event. +# +# 3) The keep-alive machine sees the process_keep_alive_disabled() event +# (which is derived from Request/Response events), and this event +# transitions it from True -> False, or from False -> False. There's no way +# to transition back. +# +# 4&5) The _SWITCH_* machines transition from False->True when we get a +# Request that proposes the relevant type of switch (via +# process_client_switch_proposals), and they go from True->False when we +# get a Response that has no _SWITCH_* annotation. +# +# So that's event-triggered transitions. +# +# State-triggered transitions are less standard. What they do here is couple +# the machines together. The way this works is, when certain *joint* +# configurations of states are achieved, then we automatically transition to a +# new *joint* state. So, for example, if we're ever in a joint state with +# +# client: DONE +# keep-alive: False +# +# then the client state immediately transitions to: +# +# client: MUST_CLOSE +# +# This is fundamentally different from an event-based transition, because it +# doesn't matter how we arrived at the {client: DONE, keep-alive: False} state +# -- maybe the client transitioned SEND_BODY -> DONE, or keep-alive +# transitioned True -> False. Either way, once this precondition is satisfied, +# this transition is immediately triggered. +# +# What if two conflicting state-based transitions get enabled at the same +# time? In practice there's only one case where this arises (client DONE -> +# MIGHT_SWITCH_PROTOCOL versus DONE -> MUST_CLOSE), and we resolve it by +# explicitly prioritizing the DONE -> MIGHT_SWITCH_PROTOCOL transition. +# +# Implementation +# -------------- +# +# The event-triggered transitions for the server and client machines are all +# stored explicitly in a table. Ditto for the state-triggered transitions that +# involve just the server and client state. +# +# The transitions for the other machines, and the state-triggered transitions +# that involve the other machines, are written out as explicit Python code. +# +# It'd be nice if there were some cleaner way to do all this. This isn't +# *too* terrible, but I feel like it could probably be better. +# +# WARNING +# ------- +# +# The script that generates the state machine diagrams for the docs knows how +# to read out the EVENT_TRIGGERED_TRANSITIONS and STATE_TRIGGERED_TRANSITIONS +# tables. But it can't automatically read the transitions that are written +# directly in Python code. So if you touch those, you need to also update the +# script to keep it in sync! +from typing import cast, Dict, Optional, Set, Tuple, Type, Union + +from ._events import * +from ._util import LocalProtocolError, Sentinel + +# Everything in __all__ gets re-exported as part of the h11 public API. +__all__ = [ + "CLIENT", + "SERVER", + "IDLE", + "SEND_RESPONSE", + "SEND_BODY", + "DONE", + "MUST_CLOSE", + "CLOSED", + "MIGHT_SWITCH_PROTOCOL", + "SWITCHED_PROTOCOL", + "ERROR", +] + + +class CLIENT(Sentinel, metaclass=Sentinel): + pass + + +class SERVER(Sentinel, metaclass=Sentinel): + pass + + +# States +class IDLE(Sentinel, metaclass=Sentinel): + pass + + +class SEND_RESPONSE(Sentinel, metaclass=Sentinel): + pass + + +class SEND_BODY(Sentinel, metaclass=Sentinel): + pass + + +class DONE(Sentinel, metaclass=Sentinel): + pass + + +class MUST_CLOSE(Sentinel, metaclass=Sentinel): + pass + + +class CLOSED(Sentinel, metaclass=Sentinel): + pass + + +class ERROR(Sentinel, metaclass=Sentinel): + pass + + +# Switch types +class MIGHT_SWITCH_PROTOCOL(Sentinel, metaclass=Sentinel): + pass + + +class SWITCHED_PROTOCOL(Sentinel, metaclass=Sentinel): + pass + + +class _SWITCH_UPGRADE(Sentinel, metaclass=Sentinel): + pass + + +class _SWITCH_CONNECT(Sentinel, metaclass=Sentinel): + pass + + +EventTransitionType = Dict[ + Type[Sentinel], + Dict[ + Type[Sentinel], + Dict[Union[Type[Event], Tuple[Type[Event], Type[Sentinel]]], Type[Sentinel]], + ], +] + +EVENT_TRIGGERED_TRANSITIONS: EventTransitionType = { + CLIENT: { + IDLE: {Request: SEND_BODY, ConnectionClosed: CLOSED}, + SEND_BODY: {Data: SEND_BODY, EndOfMessage: DONE}, + DONE: {ConnectionClosed: CLOSED}, + MUST_CLOSE: {ConnectionClosed: CLOSED}, + CLOSED: {ConnectionClosed: CLOSED}, + MIGHT_SWITCH_PROTOCOL: {}, + SWITCHED_PROTOCOL: {}, + ERROR: {}, + }, + SERVER: { + IDLE: { + ConnectionClosed: CLOSED, + Response: SEND_BODY, + # Special case: server sees client Request events, in this form + (Request, CLIENT): SEND_RESPONSE, + }, + SEND_RESPONSE: { + InformationalResponse: SEND_RESPONSE, + Response: SEND_BODY, + (InformationalResponse, _SWITCH_UPGRADE): SWITCHED_PROTOCOL, + (Response, _SWITCH_CONNECT): SWITCHED_PROTOCOL, + }, + SEND_BODY: {Data: SEND_BODY, EndOfMessage: DONE}, + DONE: {ConnectionClosed: CLOSED}, + MUST_CLOSE: {ConnectionClosed: CLOSED}, + CLOSED: {ConnectionClosed: CLOSED}, + SWITCHED_PROTOCOL: {}, + ERROR: {}, + }, +} + +StateTransitionType = Dict[ + Tuple[Type[Sentinel], Type[Sentinel]], Dict[Type[Sentinel], Type[Sentinel]] +] + +# NB: there are also some special-case state-triggered transitions hard-coded +# into _fire_state_triggered_transitions below. +STATE_TRIGGERED_TRANSITIONS: StateTransitionType = { + # (Client state, Server state) -> new states + # Protocol negotiation + (MIGHT_SWITCH_PROTOCOL, SWITCHED_PROTOCOL): {CLIENT: SWITCHED_PROTOCOL}, + # Socket shutdown + (CLOSED, DONE): {SERVER: MUST_CLOSE}, + (CLOSED, IDLE): {SERVER: MUST_CLOSE}, + (ERROR, DONE): {SERVER: MUST_CLOSE}, + (DONE, CLOSED): {CLIENT: MUST_CLOSE}, + (IDLE, CLOSED): {CLIENT: MUST_CLOSE}, + (DONE, ERROR): {CLIENT: MUST_CLOSE}, +} + + +class ConnectionState: + def __init__(self) -> None: + # Extra bits of state that don't quite fit into the state model. + + # If this is False then it enables the automatic DONE -> MUST_CLOSE + # transition. Don't set this directly; call .keep_alive_disabled() + self.keep_alive = True + + # This is a subset of {UPGRADE, CONNECT}, containing the proposals + # made by the client for switching protocols. + self.pending_switch_proposals: Set[Type[Sentinel]] = set() + + self.states: Dict[Type[Sentinel], Type[Sentinel]] = {CLIENT: IDLE, SERVER: IDLE} + + def process_error(self, role: Type[Sentinel]) -> None: + self.states[role] = ERROR + self._fire_state_triggered_transitions() + + def process_keep_alive_disabled(self) -> None: + self.keep_alive = False + self._fire_state_triggered_transitions() + + def process_client_switch_proposal(self, switch_event: Type[Sentinel]) -> None: + self.pending_switch_proposals.add(switch_event) + self._fire_state_triggered_transitions() + + def process_event( + self, + role: Type[Sentinel], + event_type: Type[Event], + server_switch_event: Optional[Type[Sentinel]] = None, + ) -> None: + _event_type: Union[Type[Event], Tuple[Type[Event], Type[Sentinel]]] = event_type + if server_switch_event is not None: + assert role is SERVER + if server_switch_event not in self.pending_switch_proposals: + raise LocalProtocolError( + "Received server _SWITCH_UPGRADE event without a pending proposal" + ) + _event_type = (event_type, server_switch_event) + if server_switch_event is None and _event_type is Response: + self.pending_switch_proposals = set() + self._fire_event_triggered_transitions(role, _event_type) + # Special case: the server state does get to see Request + # events. + if _event_type is Request: + assert role is CLIENT + self._fire_event_triggered_transitions(SERVER, (Request, CLIENT)) + self._fire_state_triggered_transitions() + + def _fire_event_triggered_transitions( + self, + role: Type[Sentinel], + event_type: Union[Type[Event], Tuple[Type[Event], Type[Sentinel]]], + ) -> None: + state = self.states[role] + try: + new_state = EVENT_TRIGGERED_TRANSITIONS[role][state][event_type] + except KeyError: + event_type = cast(Type[Event], event_type) + raise LocalProtocolError( + "can't handle event type {} when role={} and state={}".format( + event_type.__name__, role, self.states[role] + ) + ) from None + self.states[role] = new_state + + def _fire_state_triggered_transitions(self) -> None: + # We apply these rules repeatedly until converging on a fixed point + while True: + start_states = dict(self.states) + + # It could happen that both these special-case transitions are + # enabled at the same time: + # + # DONE -> MIGHT_SWITCH_PROTOCOL + # DONE -> MUST_CLOSE + # + # For example, this will always be true of a HTTP/1.0 client + # requesting CONNECT. If this happens, the protocol switch takes + # priority. From there the client will either go to + # SWITCHED_PROTOCOL, in which case it's none of our business when + # they close the connection, or else the server will deny the + # request, in which case the client will go back to DONE and then + # from there to MUST_CLOSE. + if self.pending_switch_proposals: + if self.states[CLIENT] is DONE: + self.states[CLIENT] = MIGHT_SWITCH_PROTOCOL + + if not self.pending_switch_proposals: + if self.states[CLIENT] is MIGHT_SWITCH_PROTOCOL: + self.states[CLIENT] = DONE + + if not self.keep_alive: + for role in (CLIENT, SERVER): + if self.states[role] is DONE: + self.states[role] = MUST_CLOSE + + # Tabular state-triggered transitions + joint_state = (self.states[CLIENT], self.states[SERVER]) + changes = STATE_TRIGGERED_TRANSITIONS.get(joint_state, {}) + self.states.update(changes) + + if self.states == start_states: + # Fixed point reached + return + + def start_next_cycle(self) -> None: + if self.states != {CLIENT: DONE, SERVER: DONE}: + raise LocalProtocolError( + f"not in a reusable state. self.states={self.states}" + ) + # Can't reach DONE/DONE with any of these active, but still, let's be + # sure. + assert self.keep_alive + assert not self.pending_switch_proposals + self.states = {CLIENT: IDLE, SERVER: IDLE} diff --git a/venv/Lib/site-packages/h11/_util.py b/venv/Lib/site-packages/h11/_util.py new file mode 100644 index 0000000..6718445 --- /dev/null +++ b/venv/Lib/site-packages/h11/_util.py @@ -0,0 +1,135 @@ +from typing import Any, Dict, NoReturn, Pattern, Tuple, Type, TypeVar, Union + +__all__ = [ + "ProtocolError", + "LocalProtocolError", + "RemoteProtocolError", + "validate", + "bytesify", +] + + +class ProtocolError(Exception): + """Exception indicating a violation of the HTTP/1.1 protocol. + + This as an abstract base class, with two concrete base classes: + :exc:`LocalProtocolError`, which indicates that you tried to do something + that HTTP/1.1 says is illegal, and :exc:`RemoteProtocolError`, which + indicates that the remote peer tried to do something that HTTP/1.1 says is + illegal. See :ref:`error-handling` for details. + + In addition to the normal :exc:`Exception` features, it has one attribute: + + .. attribute:: error_status_hint + + This gives a suggestion as to what status code a server might use if + this error occurred as part of a request. + + For a :exc:`RemoteProtocolError`, this is useful as a suggestion for + how you might want to respond to a misbehaving peer, if you're + implementing a server. + + For a :exc:`LocalProtocolError`, this can be taken as a suggestion for + how your peer might have responded to *you* if h11 had allowed you to + continue. + + The default is 400 Bad Request, a generic catch-all for protocol + violations. + + """ + + def __init__(self, msg: str, error_status_hint: int = 400) -> None: + if type(self) is ProtocolError: + raise TypeError("tried to directly instantiate ProtocolError") + Exception.__init__(self, msg) + self.error_status_hint = error_status_hint + + +# Strategy: there are a number of public APIs where a LocalProtocolError can +# be raised (send(), all the different event constructors, ...), and only one +# public API where RemoteProtocolError can be raised +# (receive_data()). Therefore we always raise LocalProtocolError internally, +# and then receive_data will translate this into a RemoteProtocolError. +# +# Internally: +# LocalProtocolError is the generic "ProtocolError". +# Externally: +# LocalProtocolError is for local errors and RemoteProtocolError is for +# remote errors. +class LocalProtocolError(ProtocolError): + def _reraise_as_remote_protocol_error(self) -> NoReturn: + # After catching a LocalProtocolError, use this method to re-raise it + # as a RemoteProtocolError. This method must be called from inside an + # except: block. + # + # An easy way to get an equivalent RemoteProtocolError is just to + # modify 'self' in place. + self.__class__ = RemoteProtocolError # type: ignore + # But the re-raising is somewhat non-trivial -- you might think that + # now that we've modified the in-flight exception object, that just + # doing 'raise' to re-raise it would be enough. But it turns out that + # this doesn't work, because Python tracks the exception type + # (exc_info[0]) separately from the exception object (exc_info[1]), + # and we only modified the latter. So we really do need to re-raise + # the new type explicitly. + # On py3, the traceback is part of the exception object, so our + # in-place modification preserved it and we can just re-raise: + raise self + + +class RemoteProtocolError(ProtocolError): + pass + + +def validate( + regex: Pattern[bytes], data: bytes, msg: str = "malformed data", *format_args: Any +) -> Dict[str, bytes]: + match = regex.fullmatch(data) + if not match: + if format_args: + msg = msg.format(*format_args) + raise LocalProtocolError(msg) + return match.groupdict() + + +# Sentinel values +# +# - Inherit identity-based comparison and hashing from object +# - Have a nice repr +# - Have a *bonus property*: type(sentinel) is sentinel +# +# The bonus property is useful if you want to take the return value from +# next_event() and do some sort of dispatch based on type(event). + +_T_Sentinel = TypeVar("_T_Sentinel", bound="Sentinel") + + +class Sentinel(type): + def __new__( + cls: Type[_T_Sentinel], + name: str, + bases: Tuple[type, ...], + namespace: Dict[str, Any], + **kwds: Any + ) -> _T_Sentinel: + assert bases == (Sentinel,) + v = super().__new__(cls, name, bases, namespace, **kwds) + v.__class__ = v # type: ignore + return v + + def __repr__(self) -> str: + return self.__name__ + + +# Used for methods, request targets, HTTP versions, header names, and header +# values. Accepts ascii-strings, or bytes/bytearray/memoryview/..., and always +# returns bytes. +def bytesify(s: Union[bytes, bytearray, memoryview, int, str]) -> bytes: + # Fast-path: + if type(s) is bytes: + return s + if isinstance(s, str): + s = s.encode("ascii") + if isinstance(s, int): + raise TypeError("expected bytes-like object, not int") + return bytes(s) diff --git a/venv/Lib/site-packages/h11/_version.py b/venv/Lib/site-packages/h11/_version.py new file mode 100644 index 0000000..76e7327 --- /dev/null +++ b/venv/Lib/site-packages/h11/_version.py @@ -0,0 +1,16 @@ +# This file must be kept very simple, because it is consumed from several +# places -- it is imported by h11/__init__.py, execfile'd by setup.py, etc. + +# We use a simple scheme: +# 1.0.0 -> 1.0.0+dev -> 1.1.0 -> 1.1.0+dev +# where the +dev versions are never released into the wild, they're just what +# we stick into the VCS in between releases. +# +# This is compatible with PEP 440: +# http://legacy.python.org/dev/peps/pep-0440/ +# via the use of the "local suffix" "+dev", which is disallowed on index +# servers and causes 1.0.0+dev to sort after plain 1.0.0, which is what we +# want. (Contrast with the special suffix 1.0.0.dev, which sorts *before* +# 1.0.0.) + +__version__ = "0.16.0"