def expect_handler(self):
"""
Handler for Expect Header.
"""
expect = self.request.headers.get(EXPECT_HEADER)
if self.request.version == "1.1":
if expect.lower() == "100-continue":
self.transport.write(b"HTTP/1.1 100 Continue\r\n\r\n")
else:
self.write_error(
HeaderExpectationFailed(f"Unknown Expect: {expect}"))
async def http1_request_header(self):
"""
Receive and parse request header into self.request.
"""
HEADER_MAX_SIZE = min(8192, self.request_max_size)
# Receive until full header is in buffer
buf = self.recv_buffer
pos = 0
while True:
pos = buf.find(b"\r\n\r\n", pos)
if pos != -1:
break
pos = max(0, len(buf) - 3)
if pos >= HEADER_MAX_SIZE:
break
await self._receive_more()
if pos >= HEADER_MAX_SIZE:
raise PayloadTooLarge("Request header exceeds the size limit")
# Parse header content
try:
head = buf[:pos]
raw_headers = head.decode(errors="surrogateescape")
reqline, *split_headers = raw_headers.split("\r\n")
method, self.url, protocol = reqline.split(" ")
if protocol == "HTTP/1.1":
self.keep_alive = True
elif protocol == "HTTP/1.0":
self.keep_alive = False
else:
raise Exception # Raise a Bad Request on try-except
self.head_only = method.upper() == "HEAD"
request_body = False
headers = []
for name, value in (h.split(":", 1) for h in split_headers):
name, value = h = name.lower(), value.lstrip()
if name in ("content-length", "transfer-encoding"):
request_body = True
elif name == "connection":
self.keep_alive = value.lower() == "keep-alive"
headers.append(h)
except Exception:
raise InvalidUsage("Bad Request")
headers_instance = Header(headers)
self.upgrade_websocket = (headers_instance.get(
"upgrade", "").lower() == "websocket")
# Prepare a Request object
request = self.protocol.request_class(
url_bytes=self.url.encode(),
headers=headers_instance,
head=bytes(head),
version=protocol[5:],
method=method,
transport=self.protocol.transport,
app=self.protocol.app,
)
# Prepare for request body
self.request_bytes_left = self.request_bytes = 0
if request_body:
headers = request.headers
expect = headers.get("expect")
if expect is not None:
if expect.lower() == "100-continue":
self.expecting_continue = True
else:
raise HeaderExpectationFailed(f"Unknown Expect: {expect}")
if headers.get("transfer-encoding") == "chunked":
self.request_body = "chunked"
pos -= 2 # One CRLF stays in buffer
else:
self.request_body = True
self.request_bytes_left = self.request_bytes = int(
headers["content-length"])
# Remove header and its trailing CRLF
del buf[:pos + 4]
self.stage = Stage.HANDLER
self.request, request.stream = request, self
self.protocol.state["requests_count"] += 1