def _response_nonfinal(self, status: bytes, phrase: bytes,
res_headers: RawHeaderListType) -> None:
"Got a non-final response."
nfres = HttpResponse(self.add_note)
nfres.process_top_line(self.exchange.res_version, status, phrase)
nfres.process_raw_headers(res_headers)
StatusChecker(nfres, self.request)
self.nonfinal_responses.append(nfres)
def __init__(self, config: SectionProxy) -> None:
thor.events.EventEmitter.__init__(self)
self.config = config
self.notes = [] # type: List[Note]
self.transfer_in = 0
self.transfer_out = 0
self.request = HttpRequest(self.ignore_note) # type: HttpRequest
self.nonfinal_responses = [] # type: List[HttpResponse]
self.response = HttpResponse(self.add_note) # type: HttpResponse
self.exchange = None # type: thor.http.ClientExchange
self.fetch_started = False
self.fetch_done = False
def __init__(self) -> None:
thor.events.EventEmitter.__init__(self)
self.notes = [] # type: List[Note]
self.transfer_in = 0
self.transfer_out = 0
self.request = HttpRequest(self.ignore_note) # type: HttpRequest
self.nonfinal_responses = [] # type: List[HttpResponse]
self.response = HttpResponse(self.add_note) # type: HttpResponse
self.exchange = None # type: thor.http.ClientExchange
self.follow_robots_txt = True # Should we pay attention to robots file?
self.fetch_started = False
self.fetch_done = False
def __init__(self) -> None:
thor.events.EventEmitter.__init__(self)
self.notes = [] # type: List[Note]
self.transfer_in = 0
self.transfer_out = 0
self.request = HttpRequest(self.ignore_note) # type: HttpRequest
self.nonfinal_responses = [] # type: List[HttpResponse]
self.response = HttpResponse(self.add_note) # type: HttpResponse
self.exchange = None # type: thor.http.ClientExchange
self.follow_robots_txt = True # Should we pay attention to robots file?
self.fetch_started = False
self.fetch_done = False
def _response_nonfinal(self, status: bytes, phrase: bytes,
res_headers: RawHeaderListType) -> None:
"Got a non-final response."
nfres = HttpResponse(self.add_note)
nfres.process_top_line(self.exchange.res_version, status, phrase)
nfres.process_raw_headers(res_headers)
StatusChecker(nfres, self.request)
self.nonfinal_responses.append(nfres)
def __init__(self, iri, method="GET", req_hdrs=None, req_body=None,
status_cb=None, body_procs=None, name=None):
RedState.__init__(self, name)
self.request = HttpRequest(self.notes, self.name)
self.request.method = method
self.request.set_iri(iri)
self.request.headers = req_hdrs or []
self.request.payload = req_body
self.response = HttpResponse(self.notes, self.name)
self.response.is_head_response = (method == "HEAD")
self.response.base_uri = self.request.uri
self.response.set_decoded_procs(body_procs or [])
self.exchange = None
self.status_cb = status_cb
self.done_cb = None
self.outstanding_tasks = 0
self._st = [] # FIXME: this is temporary, for debugging thor
class RedFetcher(RedState):
"""
Fetches the given URI (with the provided method, headers and body) and
calls:
- status_cb as it progresses, and
- every function in the body_procs list with each chunk of the body, and
- done_cb when all tasks are done.
If provided, type indicates the type of the request, and is used to
help set notes and status_cb appropriately.
The done() method is called when the response is done, NOT when all
tasks are done. It can add tasks by calling add_task().
"""
client = RedHttpClient()
def __init__(self, iri, method="GET", req_hdrs=None, req_body=None,
status_cb=None, body_procs=None, name=None):
RedState.__init__(self, name)
self.request = HttpRequest(self.notes, self.name)
self.request.method = method
self.request.set_iri(iri)
self.request.headers = req_hdrs or []
self.request.payload = req_body
self.response = HttpResponse(self.notes, self.name)
self.response.is_head_response = (method == "HEAD")
self.response.base_uri = self.request.uri
self.response.set_decoded_procs(body_procs or [])
self.exchange = None
self.status_cb = status_cb
self.done_cb = None
self.outstanding_tasks = 0
self._st = [] # FIXME: this is temporary, for debugging thor
def __getstate__(self):
state = self.__dict__.copy()
del state['exchange']
del state['status_cb']
del state['done_cb']
return state
def add_task(self, task, *args):
"Remeber that we've started a task."
self.outstanding_tasks += 1
self._st.append('add_task(%s)' % str(task))
task(*args, done_cb=self.finish_task)
def finish_task(self):
"Note that we've finished a task, and see if we're done."
self.outstanding_tasks -= 1
self._st.append('finish_task()')
assert self.outstanding_tasks >= 0, self._st
if self.outstanding_tasks == 0:
if self.done_cb:
self.done_cb()
self.done_cb = None
# clean up potentially cyclic references
self.status_cb = None
def done(self):
"Callback for when the response is complete and analysed."
raise NotImplementedError
def preflight(self):
"""
Callback to check to see if we should bother running. Return True
if so; False if not.
"""
return True
def run(self, done_cb=None):
"""
Make an asynchronous HTTP request to uri, calling status_cb as it's
updated and done_cb when it's done. Reason is used to explain what the
request is in the status callback.
"""
self.outstanding_tasks += 1
self._st.append('run(%s)' % str(done_cb))
self.done_cb = done_cb
if not self.preflight() or self.request.uri == None:
# generally a good sign that we're not going much further.
self.finish_task()
return
if 'user-agent' not in [i[0].lower() for i in self.request.headers]:
self.request.headers.append(
(u"User-Agent", u"RED/%s (http://redbot.org/)" % __version__))
self.exchange = self.client.exchange()
self.exchange.on('response_start', self._response_start)
self.exchange.on('response_body', self._response_body)
self.exchange.on('response_done', self._response_done)
self.exchange.on('error', self._response_error)
if self.status_cb and self.name:
self.status_cb("fetching %s (%s)" % (
self.request.uri, self.name
))
req_hdrs = [
(k.encode('ascii', 'replace'), v.encode('latin-1', 'replace')) \
for (k, v) in self.request.headers
]
self.exchange.request_start(
self.request.method, self.request.uri, req_hdrs
)
self.request.start_time = thor.time()
if self.request.payload != None:
self.exchange.request_body(self.request.payload)
self.exchange.request_done([])
def _response_start(self, status, phrase, res_headers):
"Process the response start-line and headers."
self._st.append('_response_start(%s, %s)' % (status, phrase))
self.response.start_time = thor.time()
self.response.version = self.exchange.res_version
self.response.status_code = status.decode('iso-8859-1', 'replace')
self.response.status_phrase = phrase.decode('iso-8859-1', 'replace')
self.response.set_headers(res_headers)
StatusChecker(self.response, self.request)
checkCaching(self.response, self.request)
def _response_body(self, chunk):
"Process a chunk of the response body."
self.response.feed_body(chunk)
def _response_done(self, trailers):
"Finish analysing the response, handling any parse errors."
self._st.append('_response_done()')
self.response.complete_time = thor.time()
self.response.transfer_length = self.exchange.input_transfer_length
self.response.header_length = self.exchange.input_header_length
self.response.body_done(True, trailers)
if self.status_cb and self.name:
self.status_cb("fetched %s (%s)" % (
self.request.uri, self.name
))
self.done()
self.finish_task()
def _response_error(self, error):
"Handle an error encountered while fetching the response."
self._st.append('_response_error(%s)' % (str(error)))
self.response.complete_time = thor.time()
self.response.http_error = error
if isinstance(error, httperr.BodyForbiddenError):
self.add_note('header-none', rs.BODY_NOT_ALLOWED)
# elif isinstance(error, httperr.ExtraDataErr):
# res.payload_len += len(err.get('detail', ''))
elif isinstance(error, httperr.ChunkError):
err_msg = error.detail[:20] or ""
self.add_note('header-transfer-encoding', rs.BAD_CHUNK,
chunk_sample=err_msg.encode('string_escape')
)
self.done()
self.finish_task()
class RedFetcher(thor.events.EventEmitter):
"""
Abstract class for a fetcher.
Fetches the given URI (with the provided method, headers and body) and:
- emits 'status' and 'debug' as it progresses
- emits 'fetch_done' when the fetch is finished.
If provided, 'name' indicates the type of the request, and is used to
help set notes and status events appropriately.
"""
check_name = "undefined"
response_phrase = "undefined"
client = RedHttpClient()
client.idle_timeout = 5
robot_emitter = thor.events.EventEmitter()
def __init__(self, config: SectionProxy) -> None:
thor.events.EventEmitter.__init__(self)
self.config = config
self.notes = [] # type: List[Note]
self.transfer_in = 0
self.transfer_out = 0
self.request = HttpRequest(self.ignore_note) # type: HttpRequest
self.nonfinal_responses = [] # type: List[HttpResponse]
self.response = HttpResponse(self.add_note) # type: HttpResponse
self.exchange = None # type: thor.http.ClientExchange
self.fetch_started = False
self.fetch_done = False
def __getstate__(self) -> Dict[str, Any]:
state = thor.events.EventEmitter.__getstate__(self)
del state["exchange"]
return state
def __repr__(self) -> str:
out = [self.__class__.__name__]
if self.request.uri:
out.append("%s" % self.request.uri)
if self.fetch_started:
out.append("fetch_started")
if self.fetch_done:
out.append("fetch_done")
return "<%s at %#x>" % (", ".join(out), id(self))
def add_note(self, subject: str, note: Type[Note],
**kw: Union[str, int]) -> None:
"Set a note."
if "response" not in kw:
kw["response"] = self.response_phrase
self.notes.append(note(subject, kw))
def ignore_note(self, subject: str, note: Type[Note], **kw: str) -> None:
"Ignore a note (for requests)."
return
def preflight(self) -> bool:
"""
Check to see if we should bother running. Return True
if so; False if not. Can be overridden.
"""
return True
def set_request(
self,
iri: str,
method: str = "GET",
req_hdrs: StrHeaderListType = None,
req_body: bytes = None,
) -> None:
"""
Set the resource's request. All values are strings.
"""
self.request.method = method
self.response.is_head_response = method == "HEAD" # type: ignore
try:
self.request.set_iri(iri)
except httperr.UrlError as why:
self.response.http_error = why
self.response.base_uri = self.request.uri # type: ignore
if req_hdrs:
self.request.set_headers(req_hdrs)
self.request.payload = req_body # type: ignore # FIXME: encoding
self.request.complete = True # cheating a bit
def check(self) -> None:
"""
Make an asynchronous HTTP request to uri, emitting 'status' as it's
updated and 'fetch_done' when it's done. Reason is used to explain what the
request is in the status callback.
"""
if not self.preflight() or self.request.uri is None:
# generally a good sign that we're not going much further.
self._fetch_done()
return
self.run_continue(True)
def run_continue(self, allowed: bool) -> None:
"""
Continue after getting the robots file.
"""
if not allowed:
self.response.http_error = RobotsTxtError()
self._fetch_done()
return
self.fetch_started = True
if "user-agent" not in [i[0].lower() for i in self.request.headers]:
self.request.headers.append(("User-Agent", UA_STRING))
self.exchange = self.client.exchange()
self.exchange.on("response_nonfinal", self._response_nonfinal)
self.exchange.once("response_start", self._response_start)
self.exchange.on("response_body", self._response_body)
self.exchange.once("response_done", self._response_done)
self.exchange.on("error", self._response_error)
self.emit("status",
"fetching %s (%s)" % (self.request.uri, self.check_name))
self.emit("debug",
"fetching %s (%s)" % (self.request.uri, self.check_name))
req_hdrs = [
(k.encode("ascii", "replace"), v.encode("ascii", "replace"))
for (k, v) in self.request.headers
] # FIXME: should complain
self.exchange.request_start(
self.request.method.encode("ascii"),
self.request.uri.encode("ascii"),
req_hdrs,
)
self.request.start_time = thor.time()
if not self.fetch_done: # the request could have immediately failed.
if self.request.payload is not None:
self.exchange.request_body(self.request.payload)
self.transfer_out += len(self.request.payload)
if not self.fetch_done: # the request could have immediately failed.
self.exchange.request_done([])
def _response_nonfinal(self, status: bytes, phrase: bytes,
res_headers: RawHeaderListType) -> None:
"Got a non-final response."
nfres = HttpResponse(self.add_note)
nfres.process_top_line(self.exchange.res_version, status, phrase)
nfres.process_raw_headers(res_headers)
StatusChecker(nfres, self.request)
self.nonfinal_responses.append(nfres)
def _response_start(self, status: bytes, phrase: bytes,
res_headers: RawHeaderListType) -> None:
"Process the response start-line and headers."
self.response.start_time = thor.time()
self.response.process_top_line(self.exchange.res_version, status,
phrase)
self.response.process_raw_headers(res_headers)
StatusChecker(self.response, self.request)
checkCaching(self.response, self.request)
def _response_body(self, chunk: bytes) -> None:
"Process a chunk of the response body."
self.transfer_in += len(chunk)
self.response.feed_body(chunk)
def _response_done(self, trailers: List[Tuple[bytes, bytes]]) -> None:
"Finish analysing the response, handling any parse errors."
self.emit("debug",
"fetched %s (%s)" % (self.request.uri, self.check_name))
self.response.transfer_length = self.exchange.input_transfer_length
self.response.header_length = self.exchange.input_header_length
self.response.body_done(True, trailers)
self._fetch_done()
def _response_error(self, error: httperr.HttpError) -> None:
"Handle an error encountered while fetching the response."
self.emit(
"debug",
"fetch error %s (%s) - %s" %
(self.request.uri, self.check_name, error.desc),
)
err_sample = error.detail[:40] or ""
if isinstance(error, httperr.ExtraDataError):
if self.response.status_code == "304":
self.add_note("body", BODY_NOT_ALLOWED, sample=err_sample)
else:
self.add_note("body", EXTRA_DATA, sample=err_sample)
elif isinstance(error, httperr.ChunkError):
self.add_note("header-transfer-encoding",
BAD_CHUNK,
chunk_sample=err_sample)
elif isinstance(error, httperr.HeaderSpaceError):
subject = "header-%s" % (error.detail.lower().strip())
self.add_note(subject, HEADER_NAME_SPACE, header_name=error.detail)
else:
self.response.http_error = error
self._fetch_done()
def _fetch_done(self) -> None:
if not self.fetch_done:
self.fetch_done = True
self.exchange = None
self.emit("fetch_done")
def checkCaching(response: HttpResponse, request: HttpRequest = None) -> None:
"Examine HTTP caching characteristics."
# get header values
lm_hdr = response.parsed_headers.get("last-modified", None)
date_hdr = response.parsed_headers.get("date", None)
expires_hdr = response.parsed_headers.get("expires", None)
etag_hdr = response.parsed_headers.get("etag", None)
age_hdr = response.parsed_headers.get("age", None)
cc_set = response.parsed_headers.get("cache-control", [])
cc_list = [k for (k, v) in cc_set]
cc_dict = dict(cc_set)
cc_keys = list(cc_dict.keys())
# Last-Modified
if lm_hdr:
serv_date = date_hdr or response.start_time
if lm_hdr > serv_date:
response.add_note("header-last-modified", LM_FUTURE)
else:
response.add_note(
"header-last-modified",
LM_PRESENT,
last_modified_string=relative_time(lm_hdr, serv_date),
)
# known Cache-Control directives that don't allow duplicates
known_cc = [
"max-age",
"no-store",
"s-maxage",
"public",
"private",
"pre-check",
"post-check",
"stale-while-revalidate",
"stale-if-error",
]
# check for mis-capitalised directives /
# assure there aren't any dup directives with different values
for cc in cc_keys:
if cc.lower() in known_cc and cc != cc.lower():
response.add_note("header-cache-control",
CC_MISCAP,
cc_lower=cc.lower(),
cc=cc)
if cc in known_cc and cc_list.count(cc) > 1:
response.add_note("header-cache-control", CC_DUP, cc=cc)
# Who can store this?
if request and request.method not in cacheable_methods:
response.store_shared = response.store_private = False
request.add_note("method", METHOD_UNCACHEABLE, method=request.method)
return # bail; nothing else to see here
if "no-store" in cc_keys:
response.store_shared = response.store_private = False
response.add_note("header-cache-control", NO_STORE)
return # bail; nothing else to see here
if "private" in cc_keys:
response.store_shared = False
response.store_private = True
response.add_note("header-cache-control", PRIVATE_CC)
elif (request
and "authorization" in [k.lower() for k, v in request.headers]
and "public" not in cc_keys):
response.store_shared = False
response.store_private = True
response.add_note("header-cache-control", PRIVATE_AUTH)
else:
response.store_shared = response.store_private = True
response.add_note("header-cache-control", STOREABLE)
# no-cache?
if "no-cache" in cc_keys:
if lm_hdr is None and etag_hdr is None:
response.add_note("header-cache-control", NO_CACHE_NO_VALIDATOR)
else:
response.add_note("header-cache-control", NO_CACHE)
return
# pre-check / post-check
if "pre-check" in cc_keys or "post-check" in cc_keys:
if "pre-check" not in cc_keys or "post-check" not in cc_keys:
response.add_note("header-cache-control", CHECK_SINGLE)
else:
pre_check = post_check = None
try:
pre_check = int(cc_dict["pre-check"])
post_check = int(cc_dict["post-check"])
except ValueError:
response.add_note("header-cache-control", CHECK_NOT_INTEGER)
if pre_check is not None and post_check is not None:
if pre_check == 0 and post_check == 0:
response.add_note("header-cache-control", CHECK_ALL_ZERO)
elif post_check > pre_check:
response.add_note("header-cache-control",
CHECK_POST_BIGGER)
post_check = pre_check
elif post_check == 0:
response.add_note("header-cache-control", CHECK_POST_ZERO)
else:
response.add_note(
"header-cache-control",
CHECK_POST_PRE,
pre_check=pre_check,
post_check=post_check,
)
# vary?
vary = response.parsed_headers.get("vary", set())
if "*" in vary:
response.add_note("header-vary", VARY_ASTERISK)
return # bail; nothing else to see here
if len(vary) > 3:
response.add_note("header-vary",
VARY_COMPLEX,
vary_count=f_num(len(vary)))
else:
if "user-agent" in vary:
response.add_note("header-vary", VARY_USER_AGENT)
if "host" in vary:
response.add_note("header-vary", VARY_HOST)
# calculate age
response.age = age_hdr or 0
age_str = relative_time(response.age, 0, 0)
if date_hdr and date_hdr > 0:
apparent_age = max(0, int(response.start_time - date_hdr))
else:
apparent_age = 0
current_age = max(apparent_age, response.age)
current_age_str = relative_time(current_age, 0, 0)
if response.age >= 1:
response.add_note("header-age header-date", CURRENT_AGE, age=age_str)
# Check for clock skew and dateless origin server.
if not date_hdr:
response.add_note("", DATE_CLOCKLESS)
if expires_hdr or lm_hdr:
response.add_note("header-expires header-last-modified",
DATE_CLOCKLESS_BAD_HDR)
else:
skew = date_hdr - response.start_time + (response.age)
if response.age > max_clock_skew and (current_age -
skew) < max_clock_skew:
response.add_note("header-date header-age", AGE_PENALTY)
elif abs(skew) > max_clock_skew:
response.add_note(
"header-date",
DATE_INCORRECT,
clock_skew_string=relative_time(skew, 0, 2),
)
else:
response.add_note("header-date", DATE_CORRECT)
# calculate freshness
freshness_lifetime = 0
has_explicit_freshness = False
has_cc_freshness = False
freshness_hdrs = ["header-date"]
if "s-maxage" in cc_keys:
freshness_lifetime = cc_dict["s-maxage"]
freshness_hdrs.append("header-cache-control")
has_explicit_freshness = True
has_cc_freshness = True
elif "max-age" in cc_keys:
freshness_lifetime = cc_dict["max-age"]
freshness_hdrs.append("header-cache-control")
has_explicit_freshness = True
has_cc_freshness = True
elif "expires" in response.parsed_headers:
# An invalid Expires header means it's automatically stale
has_explicit_freshness = True
freshness_hdrs.append("header-expires")
freshness_lifetime = (expires_hdr or 0) - (date_hdr
or int(response.start_time))
freshness_left = freshness_lifetime - current_age
freshness_left_str = relative_time(abs(int(freshness_left)), 0, 0)
freshness_lifetime_str = relative_time(int(freshness_lifetime), 0, 0)
response.freshness_lifetime = freshness_lifetime
fresh = freshness_left > 0
if has_explicit_freshness:
if fresh:
response.add_note(
" ".join(freshness_hdrs),
FRESHNESS_FRESH,
freshness_lifetime=freshness_lifetime_str,
freshness_left=freshness_left_str,
current_age=current_age_str,
)
elif has_cc_freshness and response.age > freshness_lifetime:
response.add_note(
" ".join(freshness_hdrs),
FRESHNESS_STALE_CACHE,
freshness_lifetime=freshness_lifetime_str,
freshness_left=freshness_left_str,
current_age=current_age_str,
)
else:
response.add_note(
" ".join(freshness_hdrs),
FRESHNESS_STALE_ALREADY,
freshness_lifetime=freshness_lifetime_str,
freshness_left=freshness_left_str,
current_age=current_age_str,
)
# can heuristic freshness be used?
elif response.status_code in heuristic_cacheable_status:
response.add_note("header-last-modified", FRESHNESS_HEURISTIC)
else:
response.add_note("", FRESHNESS_NONE)
# can stale responses be served?
if "must-revalidate" in cc_keys:
if fresh:
response.add_note("header-cache-control", FRESH_MUST_REVALIDATE)
elif has_explicit_freshness:
response.add_note("header-cache-control", STALE_MUST_REVALIDATE)
elif "proxy-revalidate" in cc_keys or "s-maxage" in cc_keys:
if fresh:
response.add_note("header-cache-control", FRESH_PROXY_REVALIDATE)
elif has_explicit_freshness:
response.add_note("header-cache-control", STALE_PROXY_REVALIDATE)
else:
if fresh:
response.add_note("header-cache-control", FRESH_SERVABLE)
elif has_explicit_freshness:
response.add_note("header-cache-control", STALE_SERVABLE)
# public?
if "public" in cc_keys: # TODO: check for authentication in request
response.add_note("header-cache-control", PUBLIC)
class RedFetcher(RedState):
"""
Abstract class for a fetcher.
Fetches the given URI (with the provided method, headers and body) and
calls:
- status_cb as it progresses, and
- every function in the body_procs list with each chunk of the body, and
- done_cb when all tasks are done.
If provided, type indicates the type of the request, and is used to
help set notes and status_cb appropriately.
The done() method is called when the response is done, NOT when all
tasks are done. It can add tasks by calling add_task().
"""
client = RedHttpClient()
robot_files = {} # cache of robots.txt
robot_cache_dir = None
robot_lookups = {}
def __init__(self, iri, method="GET", req_hdrs=None, req_body=None,
status_cb=None, body_procs=None, name=None):
RedState.__init__(self, name)
self.request = HttpRequest(self.notes, self.name)
self.request.method = method
self.request.set_iri(iri)
self.request.headers = req_hdrs or []
self.request.payload = req_body
self.response = HttpResponse(self.notes, self.name)
self.response.is_head_response = (method == "HEAD")
self.response.base_uri = self.request.uri
self.response.set_decoded_procs(body_procs or [])
self.exchange = None
self.status_cb = status_cb
self.done_cb = None # really should be "all tasks done"
self.outstanding_tasks = 0
self.follow_robots_txt = True # Should we pay attention to robots file?
self._st = [] # FIXME: this is temporary, for debugging thor
def __getstate__(self):
state = self.__dict__.copy()
del state['exchange']
del state['status_cb']
del state['done_cb']
return state
def add_task(self, task, *args):
"Remeber that we've started a task."
self.outstanding_tasks += 1
self._st.append('add_task(%s)' % str(task))
task(*args, done_cb=self.finish_task)
def finish_task(self):
"Note that we've finished a task, and see if we're done."
self.outstanding_tasks -= 1
self._st.append('finish_task()')
assert self.outstanding_tasks >= 0, self._st
if self.outstanding_tasks == 0:
if self.done_cb:
self.done_cb()
self.done_cb = None
# clean up potentially cyclic references
self.status_cb = None
def done(self):
"Callback for when the response is complete and analysed."
raise NotImplementedError
def preflight(self):
"""
Callback to check to see if we should bother running. Return True
if so; False if not.
"""
return True
def fetch_robots_txt(self, url, cb, network=True):
"""
Fetch the robots.txt URL and then feed the response to cb.
If the status code is not 200, send a blank doc back.
If network is False, we won't use the network, will return the result
immediately if cached, and will assume it's OK if we don't have a
cached file.
"""
origin = url_to_origin(self.request.uri)
if origin == None:
cb("")
return ""
origin_hash = hashlib.sha1(origin).hexdigest()
if self.robot_files.has_key(origin):
# FIXME: freshness lifetime
cb(self.robot_files[origin])
return self.robot_files[origin]
if self.robot_cache_dir:
robot_fd = CacheFile(path.join(self.robot_cache_dir, origin_hash))
cached_robots_txt = robot_fd.read()
if cached_robots_txt != None:
cb(cached_robots_txt)
return cached_robots_txt
if not network:
cb("")
return ""
if self.robot_lookups.has_key(origin):
self.robot_lookups[origin].append(cb)
else:
self.robot_lookups[origin] = [cb]
exchange = self.client.exchange()
@thor.on(exchange)
def response_start(status, phrase, headers):
exchange.status = status
exchange.res_body = ""
@thor.on(exchange)
def response_body(chunk):
exchange.res_body += chunk
@thor.on(exchange)
def response_done(trailers):
if not exchange.status.startswith("2"):
robots_txt = ""
else:
robots_txt = exchange.res_body
self.robot_files[origin] = robots_txt
if self.robot_cache_dir:
robot_fd = CacheFile(
path.join(self.robot_cache_dir, origin_hash))
robot_fd.write(robots_txt, 60*30)
for _cb in self.robot_lookups[origin]:
_cb(robots_txt)
del self.robot_lookups[origin]
p_url = urlsplit(url)
robots_url = "%s://%s/robots.txt" % (p_url.scheme, p_url.netloc)
exchange.request_start("GET", robots_url,
[('User-Agent', UA_STRING)])
exchange.request_done([])
def run(self, done_cb=None):
"""
Make an asynchronous HTTP request to uri, calling status_cb as it's
updated and done_cb when it's done. Reason is used to explain what the
request is in the status callback.
"""
self.outstanding_tasks += 1
self._st.append('run(%s)' % str(done_cb))
self.done_cb = done_cb
if not self.preflight() or self.request.uri == None:
# generally a good sign that we're not going much further.
self.finish_task()
return
if self.follow_robots_txt:
self.fetch_robots_txt(self.request.uri, self.run_continue)
else:
self.run_continue("")
def run_continue(self, robots_txt):
"""
Continue after getting the robots file.
TODO: refactor callback style into events.
"""
if robots_txt == "": # empty or non-200
pass
else:
checker = RobotFileParser()
checker.parse(robots_txt.decode('ascii', 'replace').encode('ascii', 'replace').splitlines())
if not checker.can_fetch(UA_STRING, self.request.uri):
self.response.http_error = RobotsTxtError()
self.finish_task()
return # TODO: show error?
if 'user-agent' not in [i[0].lower() for i in self.request.headers]:
self.request.headers.append(
(u"User-Agent", UA_STRING))
self.exchange = self.client.exchange()
self.exchange.on('response_start', self._response_start)
self.exchange.on('response_body', self._response_body)
self.exchange.on('response_done', self._response_done)
self.exchange.on('error', self._response_error)
if self.status_cb and self.name:
self.status_cb("fetching %s (%s)" % (
self.request.uri, self.name
))
req_hdrs = [
(k.encode('ascii', 'replace'), v.encode('latin-1', 'replace')) \
for (k, v) in self.request.headers
]
self.exchange.request_start(
self.request.method, self.request.uri, req_hdrs
)
self.request.start_time = thor.time()
if self.request.payload != None:
self.exchange.request_body(self.request.payload)
self.transfer_out += len(self.request.payload)
self.exchange.request_done([])
def _response_start(self, status, phrase, res_headers):
"Process the response start-line and headers."
self._st.append('_response_start(%s, %s)' % (status, phrase))
self.response.start_time = thor.time()
self.response.version = self.exchange.res_version
self.response.status_code = status.decode('iso-8859-1', 'replace')
self.response.status_phrase = phrase.decode('iso-8859-1', 'replace')
self.response.set_headers(res_headers)
StatusChecker(self.response, self.request)
checkCaching(self.response, self.request)
def _response_body(self, chunk):
"Process a chunk of the response body."
self.transfer_in += len(chunk)
self.response.feed_body(chunk)
def _response_done(self, trailers):
"Finish analysing the response, handling any parse errors."
self._st.append('_response_done()')
self.response.complete_time = thor.time()
self.response.transfer_length = self.exchange.input_transfer_length
self.response.header_length = self.exchange.input_header_length
self.response.body_done(True, trailers)
if self.status_cb and self.name:
self.status_cb("fetched %s (%s)" % (
self.request.uri, self.name
))
self.done()
self.finish_task()
def _response_error(self, error):
"Handle an error encountered while fetching the response."
self._st.append('_response_error(%s)' % (str(error)))
self.response.complete_time = thor.time()
self.response.http_error = error
if isinstance(error, httperr.BodyForbiddenError):
self.add_note('header-none', rs.BODY_NOT_ALLOWED)
# elif isinstance(error, httperr.ExtraDataErr):
# res.payload_len += len(err.get('detail', ''))
elif isinstance(error, httperr.ChunkError):
err_msg = error.detail[:20] or ""
self.add_note('header-transfer-encoding', rs.BAD_CHUNK,
chunk_sample=err_msg.encode('string_escape')
)
self.done()
self.finish_task()
class RedFetcher(thor.events.EventEmitter):
"""
Abstract class for a fetcher.
Fetches the given URI (with the provided method, headers and body) and:
- emits 'status' as it progresses
- emits 'fetch_done' when the fetch is finished.
If provided, 'name' indicates the type of the request, and is used to
help set notes and status events appropriately.
"""
check_name = "undefined"
response_phrase = "undefined"
client = RedHttpClient()
robot_fetcher = RobotFetcher()
def __init__(self) -> None:
thor.events.EventEmitter.__init__(self)
self.notes = [] # type: List[Note]
self.transfer_in = 0
self.transfer_out = 0
self.request = HttpRequest(self.ignore_note) # type: HttpRequest
self.nonfinal_responses = [] # type: List[HttpResponse]
self.response = HttpResponse(self.add_note) # type: HttpResponse
self.exchange = None # type: thor.http.ClientExchange
self.follow_robots_txt = True # Should we pay attention to robots file?
self.fetch_started = False
self.fetch_done = False
def __getstate__(self) -> Dict[str, Any]:
state = thor.events.EventEmitter.__getstate__(self)
del state['exchange']
return state
def __repr__(self) -> str:
out = [self.__class__.__name__]
if self.request.uri:
out.append("%s" % self.request.uri)
if self.fetch_started:
out.append("fetch_started")
if self.fetch_done:
out.append("fetch_done")
return "<%s at %#x>" % (", ".join(out), id(self))
def add_note(self, subject: str, note: Type[Note], **kw: Union[str, int]) -> None:
"Set a note."
if 'response' not in kw:
kw['response'] = self.response_phrase
self.notes.append(note(subject, kw))
def ignore_note(self, subject: str, note: Type[Note], **kw: str) -> None:
"Ignore a note (for requests)."
return
def preflight(self) -> bool:
"""
Check to see if we should bother running. Return True
if so; False if not. Can be overridden.
"""
return True
def set_request(self, iri: str, method: str="GET",
req_hdrs: StrHeaderListType=None, req_body: bytes=None) -> None:
"""
Set the resource's request. All values are strings.
"""
self.request.method = method
self.response.is_head_response = (method == "HEAD") # type: ignore
self.request.set_iri(iri)
self.response.base_uri = self.request.uri # type: ignore
if req_hdrs:
self.request.set_headers(req_hdrs)
self.request.payload = req_body # type: ignore # FIXME: encoding
self.request.complete = True # cheating a bit
def check(self) -> None:
"""
Make an asynchronous HTTP request to uri, emitting 'status' as it's
updated and 'fetch_done' when it's done. Reason is used to explain what the
request is in the status callback.
"""
if not self.preflight() or self.request.uri is None:
# generally a good sign that we're not going much further.
self._fetch_done()
return
if self.follow_robots_txt:
self.robot_fetcher.once("robot-%s" % self.request.uri, self.run_continue)
self.robot_fetcher.check_robots(self.request.uri)
else:
self.run_continue(True)
def run_continue(self, allowed: bool) -> None:
"""
Continue after getting the robots file.
"""
if not allowed:
self.response.http_error = RobotsTxtError()
self._fetch_done()
return
self.fetch_started = True
if 'user-agent' not in [i[0].lower() for i in self.request.headers]:
self.request.headers.append(("User-Agent", UA_STRING))
self.exchange = self.client.exchange()
self.exchange.on('response_nonfinal', self._response_nonfinal)
self.exchange.once('response_start', self._response_start)
self.exchange.on('response_body', self._response_body)
self.exchange.once('response_done', self._response_done)
self.exchange.on('error', self._response_error)
self.emit("status", "fetching %s (%s)" % (self.request.uri, self.check_name))
req_hdrs = [(k.encode('ascii'), v.encode('ascii')) for (k, v) in self.request.headers]
self.exchange.request_start(
self.request.method.encode('ascii'), self.request.uri.encode('ascii'), req_hdrs)
self.request.start_time = thor.time()
if self.request.payload != None:
self.exchange.request_body(self.request.payload)
self.transfer_out += len(self.request.payload)
self.exchange.request_done([])
def _response_nonfinal(self, status: bytes, phrase: bytes,
res_headers: RawHeaderListType) -> None:
"Got a non-final response."
nfres = HttpResponse(self.add_note)
nfres.process_top_line(self.exchange.res_version, status, phrase)
nfres.process_raw_headers(res_headers)
StatusChecker(nfres, self.request)
self.nonfinal_responses.append(nfres)
def _response_start(self, status: bytes, phrase: bytes,
res_headers: RawHeaderListType) -> None:
"Process the response start-line and headers."
self.response.start_time = thor.time()
self.response.process_top_line(self.exchange.res_version, status, phrase)
self.response.process_raw_headers(res_headers)
StatusChecker(self.response, self.request)
checkCaching(self.response, self.request)
def _response_body(self, chunk: bytes) -> None:
"Process a chunk of the response body."
self.transfer_in += len(chunk)
self.response.feed_body(chunk)
def _response_done(self, trailers: List[Tuple[bytes, bytes]]) -> None:
"Finish analysing the response, handling any parse errors."
self.emit("status", "fetched %s (%s)" % (self.request.uri, self.check_name))
self.response.transfer_length = self.exchange.input_transfer_length
self.response.header_length = self.exchange.input_header_length
self.response.body_done(True, trailers)
self._fetch_done()
def _response_error(self, error: httperr.HttpError) -> None:
"Handle an error encountered while fetching the response."
self.emit("status", "fetch error %s (%s) - %s" % (
self.request.uri, self.check_name, error.desc))
err_sample = error.detail[:40] or ""
if error.client_recoverable:
pass # we'll get to this later.
elif isinstance(error, httperr.ExtraDataError):
if self.response.status_code == "304":
self.add_note('body', BODY_NOT_ALLOWED, sample=err_sample)
else:
self.add_note('body', EXTRA_DATA, sample=err_sample)
elif isinstance(error, httperr.ChunkError):
self.add_note('header-transfer-encoding', BAD_CHUNK, chunk_sample=err_sample)
else:
self.response.http_error = error
self._fetch_done()
def _fetch_done(self) -> None:
if not self.fetch_done:
self.fetch_done = True
self.emit("fetch_done")
def checkCaching(response: HttpResponse, request: HttpRequest=None) -> None:
"Examine HTTP caching characteristics."
# get header values
lm_hdr = response.parsed_headers.get('last-modified', None)
date_hdr = response.parsed_headers.get('date', None)
expires_hdr = response.parsed_headers.get('expires', None)
etag_hdr = response.parsed_headers.get('etag', None)
age_hdr = response.parsed_headers.get('age', None)
cc_set = response.parsed_headers.get('cache-control', [])
cc_list = [k for (k, v) in cc_set]
cc_dict = dict(cc_set)
cc_keys = list(cc_dict.keys())
# Last-Modified
if lm_hdr:
serv_date = date_hdr or response.start_time
if lm_hdr > serv_date:
response.add_note('header-last-modified', LM_FUTURE)
else:
response.add_note('header-last-modified', LM_PRESENT,
last_modified_string=relative_time(lm_hdr, serv_date))
# known Cache-Control directives that don't allow duplicates
known_cc = ["max-age", "no-store", "s-maxage", "public",
"private", "pre-check", "post-check",
"stale-while-revalidate", "stale-if-error"]
# check for mis-capitalised directives /
# assure there aren't any dup directives with different values
for cc in cc_keys:
if cc.lower() in known_cc and cc != cc.lower():
response.add_note('header-cache-control', CC_MISCAP,
cc_lower=cc.lower(), cc=cc)
if cc in known_cc and cc_list.count(cc) > 1:
response.add_note('header-cache-control', CC_DUP, cc=cc)
# Who can store this?
if request and request.method not in cacheable_methods:
response.store_shared = response.store_private = False
request.add_note('method', METHOD_UNCACHEABLE, method=request.method)
return # bail; nothing else to see here
elif 'no-store' in cc_keys:
response.store_shared = response.store_private = False
response.add_note('header-cache-control', NO_STORE)
return # bail; nothing else to see here
elif 'private' in cc_keys:
response.store_shared = False
response.store_private = True
response.add_note('header-cache-control', PRIVATE_CC)
elif request and 'authorization' in [k.lower() for k, v in request.headers] \
and 'public' not in cc_keys:
response.store_shared = False
response.store_private = True
response.add_note('header-cache-control', PRIVATE_AUTH)
else:
response.store_shared = response.store_private = True
response.add_note('header-cache-control', STOREABLE)
# no-cache?
if 'no-cache' in cc_keys:
if lm_hdr is None and etag_hdr is None:
response.add_note('header-cache-control', NO_CACHE_NO_VALIDATOR)
else:
response.add_note('header-cache-control', NO_CACHE)
return
# pre-check / post-check
if 'pre-check' in cc_keys or 'post-check' in cc_keys:
if 'pre-check' not in cc_keys or 'post-check' not in cc_keys:
response.add_note('header-cache-control', CHECK_SINGLE)
else:
pre_check = post_check = None
try:
pre_check = int(cc_dict['pre-check'])
post_check = int(cc_dict['post-check'])
except ValueError:
response.add_note('header-cache-control', CHECK_NOT_INTEGER)
if pre_check is not None and post_check is not None:
if pre_check == 0 and post_check == 0:
response.add_note('header-cache-control', CHECK_ALL_ZERO)
elif post_check > pre_check:
response.add_note('header-cache-control', CHECK_POST_BIGGER)
post_check = pre_check
elif post_check == 0:
response.add_note('header-cache-control', CHECK_POST_ZERO)
else:
response.add_note('header-cache-control', CHECK_POST_PRE,
pre_check=pre_check, post_check=post_check)
# vary?
vary = response.parsed_headers.get('vary', set())
if "*" in vary:
response.add_note('header-vary', VARY_ASTERISK)
return # bail; nothing else to see here
elif len(vary) > 3:
response.add_note('header-vary', VARY_COMPLEX, vary_count=f_num(len(vary)))
else:
if "user-agent" in vary:
response.add_note('header-vary', VARY_USER_AGENT)
if "host" in vary:
response.add_note('header-vary', VARY_HOST)
# TODO: enumerate the axes in a message
# calculate age
response.age = age_hdr or 0
age_str = relative_time(response.age, 0, 0)
if date_hdr and date_hdr > 0:
apparent_age = max(0, int(response.start_time - date_hdr))
else:
apparent_age = 0
current_age = max(apparent_age, response.age)
current_age_str = relative_time(current_age, 0, 0)
if response.age >= 1:
response.add_note('header-age header-date', CURRENT_AGE, age=age_str)
# Check for clock skew and dateless origin server.
if not date_hdr:
response.add_note('', DATE_CLOCKLESS)
if expires_hdr or lm_hdr:
response.add_note('header-expires header-last-modified', DATE_CLOCKLESS_BAD_HDR)
else:
skew = date_hdr - response.start_time + (response.age)
if response.age > max_clock_skew and (current_age - skew) < max_clock_skew:
response.add_note('header-date header-age', AGE_PENALTY)
elif abs(skew) > max_clock_skew:
response.add_note('header-date', DATE_INCORRECT,
clock_skew_string=relative_time(skew, 0, 2))
else:
response.add_note('header-date', DATE_CORRECT)
# calculate freshness
freshness_lifetime = 0
has_explicit_freshness = False
has_cc_freshness = False
freshness_hdrs = ['header-date']
if 's-maxage' in cc_keys:
freshness_lifetime = cc_dict['s-maxage']
freshness_hdrs.append('header-cache-control')
has_explicit_freshness = True
has_cc_freshness = True
elif 'max-age' in cc_keys:
freshness_lifetime = cc_dict['max-age']
freshness_hdrs.append('header-cache-control')
has_explicit_freshness = True
has_cc_freshness = True
elif 'expires' in response.parsed_headers:
# An invalid Expires header means it's automatically stale
has_explicit_freshness = True
freshness_hdrs.append('header-expires')
freshness_lifetime = (expires_hdr or 0) - (date_hdr or response.start_time)
freshness_left = freshness_lifetime - current_age
freshness_left_str = relative_time(abs(int(freshness_left)), 0, 0)
freshness_lifetime_str = relative_time(int(freshness_lifetime), 0, 0)
response.freshness_lifetime = freshness_lifetime
fresh = freshness_left > 0
if has_explicit_freshness:
if fresh:
response.add_note(" ".join(freshness_hdrs), FRESHNESS_FRESH,
freshness_lifetime=freshness_lifetime_str,
freshness_left=freshness_left_str,
current_age=current_age_str)
# FIXME: response.age = None
elif has_cc_freshness and response.age > freshness_lifetime:
response.add_note(" ".join(freshness_hdrs), FRESHNESS_STALE_CACHE,
freshness_lifetime=freshness_lifetime_str,
freshness_left=freshness_left_str,
current_age=current_age_str)
else:
response.add_note(" ".join(freshness_hdrs), FRESHNESS_STALE_ALREADY,
freshness_lifetime=freshness_lifetime_str,
freshness_left=freshness_left_str,
current_age=current_age_str)
# can heuristic freshness be used?
elif response.status_code in heuristic_cacheable_status:
response.add_note('header-last-modified', FRESHNESS_HEURISTIC)
else:
response.add_note('', FRESHNESS_NONE)
# can stale responses be served?
if 'must-revalidate' in cc_keys:
if fresh:
response.add_note('header-cache-control', FRESH_MUST_REVALIDATE)
elif has_explicit_freshness:
response.add_note('header-cache-control', STALE_MUST_REVALIDATE)
elif 'proxy-revalidate' in cc_keys or 's-maxage' in cc_keys:
if fresh:
response.add_note('header-cache-control', FRESH_PROXY_REVALIDATE)
elif has_explicit_freshness:
response.add_note('header-cache-control', STALE_PROXY_REVALIDATE)
else:
if fresh:
response.add_note('header-cache-control', FRESH_SERVABLE)
elif has_explicit_freshness:
response.add_note('header-cache-control', STALE_SERVABLE)
# public?
if 'public' in cc_keys: # TODO: check for authentication in request
response.add_note('header-cache-control', PUBLIC)