def dowaitchanged(self, uri, etag, user, pswd, label=""):
for _ignore in range(self.manager.server_info.waitcount):
req = request(self.manager)
req.method = "HEAD"
req.ruris.append(uri)
req.ruri = uri
if user:
req.user = user
if pswd:
req.pswd = pswd
result, _ignore_resulttxt, response, _ignore_respdata = self.dorequest(req, False, False, label="%s | %s" % (label, "WAITCHANGED"))
if result and (response is not None):
if response.status / 100 == 2:
hdrs = response.msg.getheaders("Etag")
if hdrs:
newetag = hdrs[0].encode("utf-8")
if newetag != etag:
break
else:
return False
delay = self.manager.server_info.waitdelay
starttime = time.time()
while (time.time() < starttime + delay):
pass
else:
return False
return True
def dowaitchanged(self, original_request, uri, etag, user, pswd, label=""):
for _ignore in range(self.manager.server_info.waitcount):
req = request(self.manager)
req.method = "HEAD"
req.host = original_request.host
req.port = original_request.port
req.ruris.append(uri)
req.ruri = uri
if user:
req.user = user
if pswd:
req.pswd = pswd
result, _ignore_resulttxt, response, _ignore_respdata = self.dorequest(req, False, False, label="%s | %s" % (label, "WAITCHANGED"))
if result and (response is not None):
if response.status / 100 == 2:
hdrs = response.msg.getheaders("Etag")
if hdrs:
newetag = hdrs[0].encode("utf-8")
if newetag != etag:
break
else:
return False
delay = self.manager.server_info.waitdelay
starttime = time.time()
while (time.time() < starttime + delay):
pass
else:
return False
return True
def dowaitcount(self, original_request, collection, count, label=""):
hrefs = []
for _ignore in range(self.manager.server_info.waitcount):
req = request(self.manager)
req.method = "PROPFIND"
req.host = original_request.host
req.port = original_request.port
req.ruris.append(collection[0])
req.ruri = collection[0]
req.headers["Depth"] = "1"
if len(collection[1]):
req.user = collection[1]
if len(collection[2]):
req.pswd = collection[2]
req.data = data(self.manager)
req.data.value = """<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:">
<D:prop>
<D:getetag/>
</D:prop>
</D:propfind>
"""
req.data.content_type = "text/xml"
result, _ignore_resulttxt, response, respdata = self.dorequest(req, False, False, label="%s | %s %d" % (label, "WAITCOUNT", count))
hrefs = []
if result and (response is not None) and (response.status == 207) and (respdata is not None):
tree = ElementTree(file=StringIO(respdata))
for response in tree.findall("{DAV:}response"):
href = response.findall("{DAV:}href")[0]
if href.text.rstrip("/") != collection[0].rstrip("/"):
hrefs.append(href.text)
if len(hrefs) == count:
return True, None
delay = self.manager.server_info.waitdelay
starttime = time.time()
while (time.time() < starttime + delay):
pass
if self.manager.debug and hrefs:
# Get the content of each resource
rdata = ""
for href in hrefs:
result, respdata = self.doget(req, (href, collection[1], collection[2],), label)
test = "unknown"
if respdata.startswith("BEGIN:VCALENDAR"):
uid = respdata.find("UID:")
if uid != -1:
uid = respdata[uid + 4:uid + respdata[uid:].find("\r\n")]
test = self.uidmaps.get(uid, "unknown")
rdata += "\n\nhref: {h}\ntest: {t}\n\n{r}\n".format(h=href, t=test, r=respdata)
return False, rdata
else:
return False, len(hrefs)
def dowaitcount(self, original_request, collection, count, label=""):
hrefs = []
for _ignore in range(self.manager.server_info.waitcount):
req = request(self.manager)
req.method = "PROPFIND"
req.host = original_request.host
req.port = original_request.port
req.ruris.append(collection[0])
req.ruri = collection[0]
req.headers["Depth"] = "1"
if len(collection[1]):
req.user = collection[1]
if len(collection[2]):
req.pswd = collection[2]
req.data = data(self.manager)
req.data.value = """<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:">
<D:prop>
<D:getetag/>
</D:prop>
</D:propfind>
"""
req.data.content_type = "text/xml"
result, _ignore_resulttxt, response, respdata = self.dorequest(req, False, False, label="%s | %s %d" % (label, "WAITCOUNT", count))
hrefs = []
if result and (response is not None) and (response.status == 207) and (respdata is not None):
tree = ElementTree(file=StringIO(respdata))
for response in tree.findall("{DAV:}response"):
href = response.findall("{DAV:}href")[0]
if href.text.rstrip("/") != collection[0].rstrip("/"):
hrefs.append(href.text)
if len(hrefs) == count:
return True, None
delay = self.manager.server_info.waitdelay
starttime = time.time()
while (time.time() < starttime + delay):
pass
if self.manager.debug and hrefs:
# Get the content of each resource
rdata = ""
for href in hrefs:
result, respdata = self.doget(req, (href, collection[1], collection[2],), label)
test = "unknown"
if respdata.startswith("BEGIN:VCALENDAR"):
uid = respdata.find("UID:")
if uid != -1:
uid = respdata[uid + 4:uid + respdata[uid:].find("\r\n")]
test = self.uidmaps.get(uid, "unknown")
rdata += "\n\nhref: {h}\ntest: {t}\n\n{r}\n".format(h=href, t=test, r=respdata)
return False, rdata
else:
return False, len(hrefs)
def getResponse(data):
try:
rqst = request.request(data)
uri = rqst.getURI()
uidx = urlMapper[uri]
if uidx != None:
return uidx.getFun()(rqst, uidx.getTemplate())
except ValueError, e:
print e
return None
def dodeleteall(self, deletes, label=""):
if len(deletes) == 0:
return True
for deleter in deletes:
req = request(self.manager)
req.method = "DELETE"
req.ruris.append(deleter[0])
req.ruri = deleter[0]
if len(deleter[1]):
req.user = deleter[1]
if len(deleter[2]):
req.pswd = deleter[2]
self.dorequest(req, False, False, label=label)
def doget(self, resource, label=""):
req = request(self.manager)
req.method = "GET"
req.ruris.append(resource[0])
req.ruri = resource[0]
if len(resource[1]):
req.user = resource[1]
if len(resource[2]):
req.pswd = resource[2]
_ignore_result, _ignore_resulttxt, response, respdata = self.dorequest(req, False, False, label=label)
if response.status / 100 != 2:
return False, None
return True, respdata
def doenddelete(self, description, label=""):
if len(self.end_deletes) == 0:
return True
self.manager.message("trace", "Start: " + description)
for deleter in self.end_deletes:
req = request(self.manager)
req.method = "DELETE"
req.ruris.append(deleter[0])
req.ruri = deleter[0]
if len(deleter[1]):
req.user = deleter[1]
if len(deleter[2]):
req.pswd = deleter[2]
self.dorequest(req, False, False, label=label)
self.manager.message("trace", "{name:<60}{value:>10}".format(name="End: " + description, value="[DONE]"))
def dofindcontains(self, original_request, collection, match, label=""):
hresult = ""
uri = collection[0]
req = request(self.manager)
req.method = "PROPFIND"
req.host = original_request.host
req.port = original_request.port
req.ruris.append(uri)
req.ruri = uri
req.headers["Depth"] = "1"
if len(collection[1]):
req.user = collection[1]
if len(collection[2]):
req.pswd = collection[2]
req.data = data(self.manager)
req.data.value = """<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:">
<D:prop>
<D:getetag/>
</D:prop>
</D:propfind>
"""
req.data.content_type = "text/xml"
result, _ignore_resulttxt, response, respdata = self.dorequest(req, False, False, label="%s | %s" % (label, "FINDNEW"))
if result and (response is not None) and (response.status == 207) and (respdata is not None):
try:
tree = ElementTree(file=StringIO(respdata))
except Exception:
return hresult
request_uri = req.getURI(self.manager.server_info)
for response in tree.findall("{DAV:}response"):
# Get href for this response
href = response.findall("{DAV:}href")
if len(href) != 1:
return False, " Wrong number of DAV:href elements\n"
href = href[0].text
if href != request_uri:
_ignore_result, respdata = self.doget(req, (href, collection[1], collection[2],), label)
if respdata.find(match) != -1:
break
else:
href = None
return href
def dofindcontains(self, original_request, collection, match, label=""):
hresult = ""
uri = collection[0]
req = request(self.manager)
req.method = "PROPFIND"
req.host = original_request.host
req.port = original_request.port
req.ruris.append(uri)
req.ruri = uri
req.headers["Depth"] = "1"
if len(collection[1]):
req.user = collection[1]
if len(collection[2]):
req.pswd = collection[2]
req.data = data(self.manager)
req.data.value = """<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:">
<D:prop>
<D:getetag/>
</D:prop>
</D:propfind>
"""
req.data.content_type = "text/xml"
result, _ignore_resulttxt, response, respdata = self.dorequest(req, False, False, label="%s | %s" % (label, "FINDNEW"))
if result and (response is not None) and (response.status == 207) and (respdata is not None):
try:
tree = ElementTree(file=StringIO(respdata))
except Exception:
return hresult
request_uri = req.getURI(self.manager.server_info)
for response in tree.findall("{DAV:}response"):
# Get href for this response
href = response.findall("{DAV:}href")
if len(href) != 1:
return False, " Wrong number of DAV:href elements\n"
href = href[0].text
if href != request_uri:
_ignore_result, respdata = self.doget(req, (href, collection[1], collection[2],), label)
if respdata.find(match) != -1:
break
else:
href = None
return href
def doenddelete(self, description, label=""):
if len(self.end_deletes) == 0:
return True
self.manager.message("trace", "Start: " + description)
for uri, delete_request in self.end_deletes:
req = request(self.manager)
req.method = "DELETE"
req.host = delete_request.host
req.port = delete_request.port
req.ruris.append(uri)
req.ruri = uri
req.user = delete_request.user
req.pswd = delete_request.pswd
req.cert = delete_request.cert
self.dorequest(req, False, False, label=label)
self.manager.message("trace", "{name:<60}{value:>10}".format(name="End: " + description, value="[DONE]"))
def doenddelete(self, description, label=""):
if len(self.end_deletes) == 0:
return True
description += " " * max(1, STATUSTXT_WIDTH - len(description))
self.manager.log(manager.LOG_HIGH, description, before=1, after=0)
for deleter in self.end_deletes:
req = request(self.manager)
req.method = "DELETE"
req.ruris.append(deleter[0])
req.ruri = deleter[0]
if len(deleter[1]):
req.user = deleter[1]
if len(deleter[2]):
req.pswd = deleter[2]
self.dorequest(req, False, False, label=label)
self.manager.log(manager.LOG_HIGH, "[DONE]")
def doenddelete(self, description, label=""):
if len(self.end_deletes) == 0:
return True
self.manager.message("trace", "Start: " + description)
for uri, delete_request in self.end_deletes:
req = request(self.manager)
req.method = "DELETE"
req.host = delete_request.host
req.port = delete_request.port
req.ruris.append(uri)
req.ruri = uri
req.user = delete_request.user
req.pswd = delete_request.pswd
req.cert = delete_request.cert
self.dorequest(req, False, False, label=label)
self.manager.message("trace", "{name:<60}{value:>10}".format(name="End: " + description, value="[DONE]"))
def doget(self, original_request, resource, label=""):
req = request(self.manager)
req.method = "GET"
req.host = original_request.host
req.port = original_request.port
req.ruris.append(resource[0])
req.ruri = resource[0]
if len(resource[1]):
req.user = resource[1]
if len(resource[2]):
req.pswd = resource[2]
_ignore_result, _ignore_resulttxt, response, respdata = self.dorequest(req, False, False, label=label)
if response.status / 100 != 2:
return False, None
return True, respdata
def dodeleteall(self, deletes, label=""):
if len(deletes) == 0:
return True
for deleter in deletes:
req = request(self.manager)
req.method = "DELETE"
req.ruris.append(deleter[0])
req.ruri = deleter[0]
if len(deleter[1]):
req.user = deleter[1]
if len(deleter[2]):
req.pswd = deleter[2]
_ignore_result, _ignore_resulttxt, response, _ignore_respdata = self.dorequest(req, False, False, label=label)
if response.status / 100 != 2:
return False
return True
def dofindall( self, collection):
hrefs = []
req = request(self.manager)
req.method = "PROPFIND"
req.ruris.append(collection[0])
req.ruri = collection[0]
req.headers["Depth"] = "1"
if len(collection[1]):
req.user = collection[1]
if len(collection[2]):
req.pswd = collection[2]
req.data = data()
req.data.value = """<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:">
<D:prop>
<D:getetag/>
</D:prop>
</D:propfind>
"""
req.data.content_type = "text/xml"
result, _ignore_resulttxt, response, respdata = self.dorequest( req, False, False )
if result and (response is not None) and (response.status == 207) and (respdata is not None):
doc = xml.dom.minidom.parseString( respdata )
def ElementsByName(parent, nsURI, localName):
rc = NodeList()
for node in parent.childNodes:
if node.nodeType == Node.ELEMENT_NODE:
if ((localName == "*" or node.localName == localName) and
(nsURI == "*" or node.namespaceURI == nsURI)):
rc.append(node)
return rc
for response in doc.getElementsByTagNameNS( "DAV:", "response" ):
# Get href for this response
href = ElementsByName(response, "DAV:", "href")
if len(href) != 1:
return False, " Wrong number of DAV:href elements\n"
if href[0].firstChild is not None:
href = href[0].firstChild.data
if href != req.ruri:
hrefs.append((href, collection[1], collection[2]) )
return hrefs
def dodeleteall(self, original_request, deletes, label=""):
if len(deletes) == 0:
return True
for deleter in deletes:
req = request(self.manager)
req.method = "DELETE"
req.host = original_request.host
req.port = original_request.port
req.ruris.append(deleter[0])
req.ruri = deleter[0]
if len(deleter[1]):
req.user = deleter[1]
if len(deleter[2]):
req.pswd = deleter[2]
_ignore_result, _ignore_resulttxt, response, _ignore_respdata = self.dorequest(req, False, False, label=label)
if response.status / 100 != 2:
return False
return True
def dowaitcount(self, collection, count, label=""):
for _ignore in range(self.manager.server_info.waitcount):
req = request(self.manager)
req.method = "PROPFIND"
req.ruris.append(collection[0])
req.ruri = collection[0]
req.headers["Depth"] = "1"
if len(collection[1]):
req.user = collection[1]
if len(collection[2]):
req.pswd = collection[2]
req.data = data()
req.data.value = """<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:">
<D:prop>
<D:getetag/>
</D:prop>
</D:propfind>
"""
req.data.content_type = "text/xml"
result, _ignore_resulttxt, response, respdata = self.dorequest(req, False, False, label="%s | %s %d" % (label, "WAITCOUNT", count))
ctr = 0
if result and (response is not None) and (response.status == 207) and (respdata is not None):
tree = ElementTree(file=StringIO(respdata))
for response in tree.findall("{DAV:}response"):
ctr += 1
if ctr - 1 == count:
return None
delay = self.manager.server_info.waitdelay
starttime = time.time()
while (time.time() < starttime + delay):
pass
else:
return ctr - 1
def dofindnew( self, collection, label = "" ):
hresult = ""
req = request(self.manager)
req.method = "PROPFIND"
req.ruris.append(collection[0])
req.ruri = collection[0]
req.headers["Depth"] = "1"
if len(collection[1]):
req.user = collection[1]
if len(collection[2]):
req.pswd = collection[2]
req.data = data()
req.data.value = """<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:">
<D:prop>
<D:getetag/>
<D:getlastmodified/>
</D:prop>
</D:propfind>
"""
req.data.content_type = "text/xml"
result, _ignore_resulttxt, response, respdata = self.dorequest( req, False, False, label="%s | %s" % (label, "FINDNEW") )
if result and (response is not None) and (response.status == 207) and (respdata is not None):
try:
tree = ElementTree(file=StringIO(respdata))
except Exception:
return hresult
latest = 0
request_uri = req.getURI( self.manager.server_info )
same = []
for response in tree.findall("{DAV:}response" ):
# Get href for this response
href = response.findall("{DAV:}href")
if len(href) != 1:
return False, " Wrong number of DAV:href elements\n"
href = href[0].text
if href != request_uri:
# Get all property status
propstatus = response.findall("{DAV:}propstat")
for props in propstatus:
# Determine status for this propstat
status = props.findall("{DAV:}status")
if len(status) == 1:
statustxt = status[0].text
status = False
if statustxt.startswith("HTTP/1.1 ") and (len(statustxt) >= 10):
status = (statustxt[9] == "2")
else:
status = False
# Get properties for this propstat
prop = props.findall("{DAV:}prop")
for el in prop:
# Get properties for this propstat
glm = el.findall("{DAV:}getlastmodified")
if len(glm) != 1:
continue
value = glm[0].text
value = rfc822.parsedate(value)
value = time.mktime(value)
if value > latest:
hresult = href
latest = value
same = []
elif value == latest:
if len(same) == 0:
same.append(hresult)
same.append(value)
if same:
high_index = -1
for href in same:
try:
index = self.foundnew.index(href)
except ValueError:
hresult = href
break
if index > high_index:
hresult = href
high_index = index
if hresult:
self.foundnew.append(hresult)
return hresult
def dofindnew(self, collection, label="", other=False):
hresult = ""
uri = collection[0]
if other:
uri = self.manager.server_info.extrasubs(uri)
skip = uri
uri = "/".join(uri.split("/")[:-1]) + "/"
else:
skip = None
possible_matches = set()
req = request(self.manager)
req.method = "PROPFIND"
req.ruris.append(uri)
req.ruri = uri
req.headers["Depth"] = "1"
if len(collection[1]):
req.user = collection[1]
if len(collection[2]):
req.pswd = collection[2]
req.data = data(self.manager)
req.data.value = """<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:">
<D:prop>
<D:getetag/>
<D:getlastmodified/>
</D:prop>
</D:propfind>
"""
req.data.content_type = "text/xml"
result, _ignore_resulttxt, response, respdata = self.dorequest(req, False, False, label="%s | %s" % (label, "FINDNEW"))
if result and (response is not None) and (response.status == 207) and (respdata is not None):
try:
tree = ElementTree(file=StringIO(respdata))
except Exception:
return hresult
latest = 0
request_uri = req.getURI(self.manager.server_info)
for response in tree.findall("{DAV:}response"):
# Get href for this response
href = response.findall("{DAV:}href")
if len(href) != 1:
return False, " Wrong number of DAV:href elements\n"
href = href[0].text
if href != request_uri and (not other or href != skip):
# Get all property status
propstatus = response.findall("{DAV:}propstat")
for props in propstatus:
# Determine status for this propstat
status = props.findall("{DAV:}status")
if len(status) == 1:
statustxt = status[0].text
status = False
if statustxt.startswith("HTTP/1.1 ") and (len(statustxt) >= 10):
status = (statustxt[9] == "2")
else:
status = False
if status:
# Get properties for this propstat
prop = props.findall("{DAV:}prop")
for el in prop:
# Get properties for this propstat
glm = el.findall("{DAV:}getlastmodified")
if len(glm) != 1:
continue
value = glm[0].text
value = rfc822.parsedate(value)
value = time.mktime(value)
if value > latest:
possible_matches.clear()
possible_matches.add(href)
latest = value
elif value == latest:
possible_matches.add(href)
elif not hresult:
possible_matches.add(href)
if len(possible_matches) == 1:
hresult = possible_matches.pop()
elif len(possible_matches) > 1:
not_seen_before = possible_matches - self.previously_found
if len(not_seen_before) == 1:
hresult = not_seen_before.pop()
if hresult:
self.previously_found.add(hresult)
return hresult
def dofindnew( self, collection):
hresult = ""
req = request(self.manager)
req.method = "PROPFIND"
req.ruris.append(collection[0])
req.ruri = collection[0]
req.headers["Depth"] = "1"
if len(collection[1]):
req.user = collection[1]
if len(collection[2]):
req.pswd = collection[2]
req.data = data()
req.data.value = """<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:">
<D:prop>
<D:getetag/>
<D:getlastmodified/>
</D:prop>
</D:propfind>
"""
req.data.content_type = "text/xml"
result, _ignore_resulttxt, response, respdata = self.dorequest( req, False, False )
if result and (response is not None) and (response.status == 207) and (respdata is not None):
doc = xml.dom.minidom.parseString( respdata )
def ElementsByName(parent, nsURI, localName):
rc = NodeList()
for node in parent.childNodes:
if node.nodeType == Node.ELEMENT_NODE:
if ((localName == "*" or node.localName == localName) and
(nsURI == "*" or node.namespaceURI == nsURI)):
rc.append(node)
return rc
latest = 0
for response in doc.getElementsByTagNameNS( "DAV:", "response" ):
# Get href for this response
href = ElementsByName(response, "DAV:", "href")
if len(href) != 1:
return False, " Wrong number of DAV:href elements\n"
if href[0].firstChild is not None:
href = href[0].firstChild.data
if href != req.ruri:
# Get all property status
propstatus = ElementsByName(response, "DAV:", "propstat")
for props in propstatus:
# Determine status for this propstat
status = ElementsByName(props, "DAV:", "status")
if len(status) == 1:
statustxt = status[0].firstChild.data
status = False
if statustxt.startswith("HTTP/1.1 ") and (len(statustxt) >= 10):
status = (statustxt[9] == "2")
else:
status = False
# Get properties for this propstat
prop = ElementsByName(props, "DAV:", "prop")
for el in prop:
# Get properties for this propstat
glm = ElementsByName(el, "DAV:", "getlastmodified")
if len(glm) != 1:
continue
if glm[0].firstChild is not None:
value = glm[0].firstChild.data
value = rfc822.parsedate(value)
value = time.mktime(value)
if value > latest:
hresult = href
latest = value
return hresult
def dofindnew(self, original_request, collection, label="", other=False):
hresult = ""
uri = collection[0]
if other:
uri = self.manager.server_info.extrasubs(uri)
skip = uri
uri = "/".join(uri.split("/")[:-1]) + "/"
else:
skip = None
possible_matches = set()
req = request(self.manager)
req.method = "PROPFIND"
req.host = original_request.host
req.port = original_request.port
req.ruris.append(uri)
req.ruri = uri
req.headers["Depth"] = "1"
if len(collection[1]):
req.user = collection[1]
if len(collection[2]):
req.pswd = collection[2]
req.data = data(self.manager)
req.data.value = """<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:">
<D:prop>
<D:getetag/>
<D:getlastmodified/>
</D:prop>
</D:propfind>
"""
req.data.content_type = "text/xml"
result, _ignore_resulttxt, response, respdata = self.dorequest(req, False, False, label="%s | %s" % (label, "FINDNEW"))
if result and (response is not None) and (response.status == 207) and (respdata is not None):
try:
tree = ElementTree(file=StringIO(respdata))
except Exception:
return hresult
latest = 0
request_uri = req.getURI(self.manager.server_info)
for response in tree.findall("{DAV:}response"):
# Get href for this response
href = response.findall("{DAV:}href")
if len(href) != 1:
return False, " Wrong number of DAV:href elements\n"
href = href[0].text
if href != request_uri and (not other or href != skip):
# Get all property status
propstatus = response.findall("{DAV:}propstat")
for props in propstatus:
# Determine status for this propstat
status = props.findall("{DAV:}status")
if len(status) == 1:
statustxt = status[0].text
status = False
if statustxt.startswith("HTTP/1.1 ") and (len(statustxt) >= 10):
status = (statustxt[9] == "2")
else:
status = False
if status:
# Get properties for this propstat
prop = props.findall("{DAV:}prop")
for el in prop:
# Get properties for this propstat
glm = el.findall("{DAV:}getlastmodified")
if len(glm) != 1:
continue
value = glm[0].text
value = rfc822.parsedate(value)
value = time.mktime(value)
if value > latest:
possible_matches.clear()
possible_matches.add(href)
latest = value
elif value == latest:
possible_matches.add(href)
elif not hresult:
possible_matches.add(href)
if len(possible_matches) == 1:
hresult = possible_matches.pop()
elif len(possible_matches) > 1:
not_seen_before = possible_matches - self.previously_found
if len(not_seen_before) == 1:
hresult = not_seen_before.pop()
if hresult:
self.previously_found.add(hresult)
return hresult