def pns_to_xml_utf8(model, xml_types={}, xml_type=xml_dom.Element):
# try to decode the PNS/XML element
try:
attr, first, children, follow = netstring.validate(model[2], 4)
except:
if model[0] != model[3]:
attr = {'pns': model[0]}
else:
attr = None
e = xml_types.get(model[1],
xml_type)(model[1]
or 'http://allegra/ pns-xml-error', attr)
e.xml_first = model[2]
return e, None
# decode the attributes and set the pns attribute
if attr:
attr = dict(
(tuple(netstring.decode(item)) for item in netstring.decode(attr)))
if model[0] != model[3]:
attr['pns'] = model[0]
elif model[0] != model[3]:
attr = {'pns': model[0]}
else:
attr = None
e = xml_types.get(model[1], xml_type)(model[1], attr)
if first:
e.xml_first = first
else:
e.xml_first = ''
if follow:
e.xml_follow = follow
return e, children
def pns_to_xml_unicode (self, resolved, model):
self.xml_parsed, children = pns_to_xml_unicode (
model, self.pns_dom.xml_types, self.pns_dom.xml_type
)
if children:
self.xml_parsed.xml_children = children = list (
netstring.decode (children)
)
for child in children:
subject, name = tuple (
netstring.decode (child)
)
if subject:
context = model[0]
else:
context = subject = model[0]
joined = PNS_XML_continuation (
self.pns_dom, child
)
joined.pns_context = model[3]
self.pns_dom.pns_statement (
(subject, name, ''), context,
joined.pns_to_xml_unicode
)
joined.finalization = self
def statement_unicode (model, prefixes, encoding='ASCII'):
e, children = pns_to_xml_unicode (model)
if children:
e.xml_children = []
for child in netstring.decode (children):
subject, name = netstring.decode (child)
if subject:
e.xml_children.append ('<%s pns="%s"/>' % (
''.join (xml_unicode.xml_prefix_FQN (
unicode (name, 'utf-8'),
prefixes, encoding
)),
xml_unicode.xml_attr (
unicode (subject, 'utf-8'),
encoding
)
))
else:
e.xml_children.append (
'<%s%s'
' />' % xml_unicode.xml_prefix_FQN (
unicode (name, 'utf-8'),
prefixes, encoding
)
)
return xml_unicode.xml_prefixed (
e, prefixes,
' context="%s"' % xml_unicode.xml_attr (
unicode (model[3], 'utf-8'), encoding
), encoding
)
def pns_to_xml_utf8 (self, resolved, model):
if model[4][0] in ('.', '?'):
return False
self.xml_parsed, children = pns_to_xml_utf8 (
model, self.pns_dom.xml_types, self.pns_dom.xml_type
)
# decode the children's name and subject,
if children:
self.xml_parsed.xml_children = children = list (
netstring.decode (children)
)
for child in children:
subject, name = tuple (
netstring.decode (child)
)
if subject:
context = model[0]
else:
context = subject = model[0]
joined = PNS_XML_continuation (
self.pns_dom, child
)
self.pns_dom.pns_statement (
(subject, name, ''), context,
joined.pns_to_xml_unicode
)
joined.finalization = self
return False
def statements_unicode(model, prefixes, contexts, encoding='ASCII'):
for co in netstring.decode(model[2]):
c, o = netstring.decode(co)
if c not in contexts:
continue
for more in statement_unicode((model[0], model[1], o, c, '_'),
prefixes, encoding):
yield more
def statements_unicode (model, prefixes, contexts, encoding='ASCII'):
for co in netstring.decode (model[2]):
c, o = netstring.decode (co)
if c not in contexts:
continue
for more in statement_unicode (
(model[0], model[1], o, c, '_'), prefixes, encoding
):
yield more
def pns_to_xml_unicode_a(self, resolved, model):
if model[4] != ('_') or model[2] == '':
return False
self.pns_contexts = {}
question = resolved[:2]
for co in netstring.decode(model[2]):
c, o = netstring.decode(co) # TODO? fix this
self.pns_to_xml_unicode(resolved, question + (o, c, '_'))
self.pns_contexts[c] = self.xml_parsed
self.xml_parsed = None
return False
def pns_to_xml_unicode (model, xml_types={}, xml_type=xml_dom.Element):
name = unicode (model[1], 'utf-8')
# try to decode the PNS/XML element
try:
attr, first, children, follow = netstring.validate (
model[2], 4
)
except:
# if no PNS/XML element is encoded in the statement object,
# consider the predicate as the element name, the object as
# first CDATA and the subject as only attribute if it is
# distinct from the statement's context. in effect, translate
# *any* PNS statement to an XML element:
#
# <predicate pns="subject">object</predicate>
#
if model[0] != model[3]:
attr = {u'pns': unicode (model[0], 'utf-8')}
else:
attr = None
e = xml_types.get (name, xml_type) (
name or u'http://allegra/ pns-xml-error', attr
)
if model[2]:
e.xml_first = unicode (model[2], 'utf-8')
else:
e.xml_first = u''
return e, None
# decode the attributes and set the pns attribute
if attr:
attr = dict ((
tuple ((
unicode (s, 'utf-8')
for s in netstring.decode (item)
))
for item in netstring.decode (attr)
))
if model[0] != model[3]:
attr[u'pns'] = unicode (model[0], 'utf-8')
elif model[0] != model[3]:
attr = {u'pns': unicode (model[0], 'utf-8')}
else:
attr = None
# decode the name and instanciate an XML element
e = xml_types.get (name, xml_type) (name, attr)
if first:
e.xml_first = unicode (first, 'utf-8')
else:
e.xml_first = u''
if follow:
e.xml_follow = unicode (follow, 'utf-8')
return e, children
def pns_to_xml_unicode_a (self, resolved, model):
if model[4] != ('_') or model[2] == '':
return False
self.pns_contexts = {}
question = resolved[:2]
for co in netstring.decode (model[2]):
c, o = netstring.decode (co) # TODO? fix this
self.pns_to_xml_unicode (
resolved, question+(o, c, '_')
)
self.pns_contexts[c] = self.xml_parsed
self.xml_parsed = None
return False
def pns_timeout (self, sp): if sp == self.PNS_SP: # protocol self.pns_tcp_continue (( self.pns_name, '', '', self.pns_name ), '_') if self.pns_statements.has_key (sp): # timed-out o = self.pns_statements.pop (sp) if o == '': if self.pns_right and self.pns_left: # quitted defered until joined self.pns_quit () else: # quitting self.pns_quitted () else: pass # joining return if self.pns_buffer.has_key (sp): # delete timeouted out buffered subject and predicate o = self.pns_buffer[sp] del self.pns_buffer[sp] else: o = '' # echo the non-protocol timeouts to all subscribers model = list (netstring.decode (sp)) model.append (o) model.append (self.pns_name) self.pns_tcp_continue (model, '_') # quit if timeouts on a statement if self.pns_statements.has_key (sp): self.pns_quit ()
def statement_utf8(model, prefixes):
e, children = pns_to_xml_utf8(model)
if children:
e.xml_children = []
for child in netstring.decode(children):
subject, name = netstring.decode(child)
if subject:
e.xml_children.append(
'<%s pns="%s"/>' %
(''.join(xml_utf8.xml_prefix_FQN(
name, prefixes)), xml_utf8.xml_attr(subject)))
else:
e.xml_children.append('<%s />' %
xml_utf8.xml_prefix_FQN(name, prefixes))
return xml_utf8.xml_prefixed(e, prefixes,
' context="%s"' % xml_utf8.xml_attr(model[3]))
def name_utf8(name, tag='public'):
names = tuple(netstring.decode(name)) or (name, )
if len(names) > 1:
return '<%s names="%s">%s</%s>' % (tag, xml_utf8.xml_attr(
name), ''.join([name_utf8(n, tag) for n in names]), tag)
return '<%s>%s</%s>' % (tag, xml_tf8.xml_cdata(name), tag)
def pns_articulate (self):
try:
encoded = self.pns_pipe.next ()
except StopIteration:
# no more statements to handle, close
self.async_net_push (('0:,0:,0:,0:,',))
# self.close_when_done ()
return
model = list (netstring.decode (encoded))
if '' == model[0]:
if '' == model[1] == model[2]:
self.pns_quit (model[3])
else:
self.pns_command (tuple (model[:3]))
elif '' == model[1] and model[0] == model[3]:
if model[2]:
self.pns_join (model[3], model[2])
else:
self.pns_subscribe (model[3])
else:
self.pns_statement (
tuple (model[:3]), model[3]
)
def name_unicode(name, tag='public', encoding='ASCII'):
names = tuple(netstring.decode(name)) or (name, )
if len(names) > 1:
return '<%s names="%s">%s</%s>' % (
tag, xml_unicode.xml_attr(unicode(name, 'UTF-8')), ''.join(
[name_unicode(n, tag, encoding) for n in names]), tag)
return '<%s>%s</%s>' % (tag, xml_unicode.xml_cdata(unicode(name,
'UTF-8')), tag)
# Note about this implementation
#
# it may be possible to get rid of the last level of PNS/XML articulation
# and make articulation sparser, by allowing un-named child element to
# be completely encoded in their parent. Yet this practically makes encoding
# from XML to PNS also more complex to support sensible trunking.
#
# Most XML leaf elements do not require a PNS/XML statement but the
# presence of one too large in their midst suppose a more elaborated
# algorithm for sparse articulation, counting every bytes in the parent's
# PNS/XML statement to decide which elements to "inline" as:
#
# :subject,:name,::attributes,:first,:follow,,
#
# and which to reference only:
#
# :subject,:name,:,
#
# it just might not be worth the trouble.
#
# TODO: add a depth limit to PNS_XML, avoid the possible infinite loop
# when there is a circular PNS/XML statement in the metabase for
# the articulated XML element tree.
def pns_to_xml_unicode(model, xml_types={}, xml_type=xml_dom.Element):
name = unicode(model[1], 'utf-8')
# try to decode the PNS/XML element
try:
attr, first, children, follow = netstring.validate(model[2], 4)
except:
# if no PNS/XML element is encoded in the statement object,
# consider the predicate as the element name, the object as
# first CDATA and the subject as only attribute if it is
# distinct from the statement's context. in effect, translate
# *any* PNS statement to an XML element:
#
# <predicate pns="subject">object</predicate>
#
if model[0] != model[3]:
attr = {u'pns': unicode(model[0], 'utf-8')}
else:
attr = None
e = xml_types.get(name,
xml_type)(name or u'http://allegra/ pns-xml-error',
attr)
if model[2]:
e.xml_first = unicode(model[2], 'utf-8')
else:
e.xml_first = u''
return e, None
# decode the attributes and set the pns attribute
if attr:
attr = dict((tuple((unicode(s, 'utf-8')
for s in netstring.decode(item)))
for item in netstring.decode(attr)))
if model[0] != model[3]:
attr[u'pns'] = unicode(model[0], 'utf-8')
elif model[0] != model[3]:
attr = {u'pns': unicode(model[0], 'utf-8')}
else:
attr = None
# decode the name and instanciate an XML element
e = xml_types.get(name, xml_type)(name, attr)
if first:
e.xml_first = unicode(first, 'utf-8')
else:
e.xml_first = u''
if follow:
e.xml_follow = unicode(follow, 'utf-8')
return e, children
def async_net_continue(self, encoded):
"handle the following PNS/TCP peer statement"
# Note that there is no validation of the PNS statements
# because they are trusted to be valid. A client *may*
# validate, the peer *must* anyway.
#
self.pns_received += 1
model = list(netstring.decode(encoded))
if len(model) != 5:
assert None == self.log(encoded, 'invalid-peer-statement')
self.handle_close()
return
self.pns_multiplex(model)
resolved = tuple(model[:3])
if '' == model[0]:
# close, index, context and route
handlers = self.pns_commands.get(resolved)
if handlers == None:
assert None == self.log(encoded,
'unsollicited-command-response')
self.handle_close()
return
self.pns_commands[resolved] = [
h for h in handlers if h(resolved, model)
]
if len(self.pns_commands[resolved]) == 0:
del self.pns_commands[resolved]
elif '' == model[1] and model[0] == model[3]:
# TODO: protocol response to join/subscribe
pass
else:
# statements
statements = self.pns_contexts.setdefault(model[3], {})
handlers = statements.get(resolved)
if handlers == None:
# test for a question's answer handler
resolved = (model[0], model[1], '')
handlers = statements.get(resolved)
if handlers == None:
# irrelevant statement
self.pns_noise(model)
return
# relevant statements, handle and refresh the handlers list
statements[resolved] = [h for h in handlers if h(resolved, model)]
# then clean up ...
if len(statements[resolved]) == 0:
del statements[resolved]
if len(statements) == 0:
del self.pns_contexts[model[3]]
if (self.pns_close_when_done and len(self.pns_commands) == 0
and len(self.pns_contexts) == 0
and len(self.pns_subscribed) == 0):
assert None == self.log('done', 'debug')
self.handle_close()
def pns_quatuor (encoded, contexts, max=1024):
# a valid quatuor must have subject, predicate, object and context
#
assert type (max) == int and max % 2 == 0
model = list (netstring.decode (encoded))
if len (model) != 4:
return None, '1 not a quatuor'
if model[3]:
# Validate the context as a public name, but allways check
# the supplied cache of valid PNS names first!
#
if public_names.valid_in_utf8 (model[3], contexts) != None:
return None, '2 invalid context'
if model[0]:
# the predicate length and subject length are limited to
# or 512 bytes minus the ten needed to encode them
#
sp_len = len (model[0]) + len (model[1]) + len (
'%d%d' % (len (model[0]), len (model[1]))
)
if sp_len > max/2:
return None, '3 invalid statement length'
# validate the statement subject as a public name
if model[0] != model[3] and public_names.valid_in_utf8 (
subject, contexts
) == None:
return None, '4 invalid subject'
if model[2]:
# non-empty objects are trunked to fit the 1024 bytes
# PNS/UDP answer datagram. Sorry guys, but there is
# no way to fit more and rationning the number of
# statement per user *does* limit potential abuses.
#
model[2] = model[2][:(
max - sp_len - len ('%d' % (max - sp_len))
)]
#
# this is not an error condition, its a welcome
# feature of any PNS peer, the only "optional"
# error handling that allows use agent to be sloppy
# in their validation of PNS statements. simplistic
# clients should be tolerated ;-)
elif model[1]:
if public_names.valid_in_utf8 (command, contexts) == None:
return None, '5 invalid command predicate'
elif model[2] and public_names.valid_in_utf8 (
model[2], contexts
) == None:
return None, '6 invalid command object'
return model, ''
def pns_to_xml_unicode(self, resolved, model):
self.xml_parsed, children = pns_to_xml_unicode(model,
self.pns_dom.xml_types,
self.pns_dom.xml_type)
if children:
self.xml_parsed.xml_children = children = list(
netstring.decode(children))
for child in children:
subject, name = tuple(netstring.decode(child))
if subject:
context = model[0]
else:
context = subject = model[0]
joined = PNS_XML_continuation(self.pns_dom, child)
joined.pns_context = model[3]
self.pns_dom.pns_statement((subject, name, ''), context,
joined.pns_to_xml_unicode)
joined.finalization = self
def name_utf8 (name, tag='public'):
names = tuple (netstring.decode (name)) or (name,)
if len (names) > 1:
return '<%s names="%s">%s</%s>' % (
tag,
xml_utf8.xml_attr (name),
''.join ([name_utf8 (n, tag) for n in names]),
tag
)
return '<%s>%s</%s>' % (tag, xml_tf8.xml_cdata (name), tag)
def pns_quatuor(encoded, pns_names, PNS_LENGTH=1024):
# a valid quatuor must have subject, predicate, object and context
#
model = list(netstring.decode(encoded))
if len(model) != 4:
return None, '1 not a quatuor'
if model[3]:
# Validate the context as a public name, but allways check
# the supplied cache of valid PNS names first!
#
if not (model[3] in pns_names
or model[3] == pns_name(model[3], set())):
return None, '2 invalid context'
if model[0]:
# the predicate length and subject length are limited to
# or 512 bytes minus the ten needed to encode them
#
sp_len = len(model[0]) + len(model[1]) + len(
'%d%d' % (len(model[0]), len(model[1])))
if sp_len > PNS_LENGTH / 2:
return None, '3 invalid statement length'
# validate the statement subject as a public name
if model[0] != model[3] and not (model[0] in pns_names or model[0]
== pns_name(model[0], set())):
return None, '4 invalid subject'
if model[2]:
# non-empty objects are trunked to fit the 1024 bytes
# PNS/UDP answer datagram. Sorry guys, but there is
# no way to fit more and rationning the number of
# statement per user *does* limit potential abuses.
#
model[2] = model[2][:(PNS_LENGTH - sp_len -
len('%d' % (PNS_LENGTH - sp_len)))]
#
# this is not an error condition, its a welcome
# feature of any PNS peer, the only "optional"
# error handling that allows use agent to be sloppy
# in their validation of PNS statements. simplistic
# clients should be tolerated ;-)
elif model[1]:
if not (model[1] in pns_names
or model[1] == pns_name(model[1], set())):
return None, '5 invalid command predicate'
elif model[2] and not (model[2] in pns_names
or model[2] == pns_name(model[2], set())):
return None, '6 invalid command object'
return model, ''
def statement_unicode(model, prefixes, encoding='ASCII'):
e, children = pns_to_xml_unicode(model)
if children:
e.xml_children = []
for child in netstring.decode(children):
subject, name = netstring.decode(child)
if subject:
e.xml_children.append(
'<%s pns="%s"/>' %
(''.join(
xml_unicode.xml_prefix_FQN(unicode(name, 'utf-8'),
prefixes, encoding)),
xml_unicode.xml_attr(unicode(subject, 'utf-8'),
encoding)))
else:
e.xml_children.append(
'<%s%s'
' />' % xml_unicode.xml_prefix_FQN(unicode(name, 'utf-8'),
prefixes, encoding))
return xml_unicode.xml_prefixed(
e, prefixes, ' context="%s"' %
xml_unicode.xml_attr(unicode(model[3], 'utf-8'), encoding), encoding)
def pns_to_xml_utf8(self, resolved, model):
if model[4][0] in ('.', '?'):
return False
self.xml_parsed, children = pns_to_xml_utf8(model,
self.pns_dom.xml_types,
self.pns_dom.xml_type)
# decode the children's name and subject,
if children:
self.xml_parsed.xml_children = children = list(
netstring.decode(children))
for child in children:
subject, name = tuple(netstring.decode(child))
if subject:
context = model[0]
else:
context = subject = model[0]
joined = PNS_XML_continuation(self.pns_dom, child)
self.pns_dom.pns_statement((subject, name, ''), context,
joined.pns_to_xml_unicode)
joined.finalization = self
return False
def statement_utf8 (model, prefixes):
e, children = pns_to_xml_utf8 (model)
if children:
e.xml_children = []
for child in netstring.decode (children):
subject, name = netstring.decode (child)
if subject:
e.xml_children.append ('<%s pns="%s"/>' % (
''.join (xml_utf8.xml_prefix_FQN (
name, prefixes
)),
xml_utf8.xml_attr (subject)
))
else:
e.xml_children.append (
'<%s />' % xml_utf8.xml_prefix_FQN (
name, prefixes
)
)
return xml_utf8.xml_prefixed (
e, prefixes,
' context="%s"' % xml_utf8.xml_attr (model[3])
)
def pns_to_xml_utf8 (model, xml_types={}, xml_type=xml_dom.Element):
# try to decode the PNS/XML element
try:
attr, first, children, follow = netstring.validate (
model[2], 4
)
except:
if model[0] != model[3]:
attr = {'pns': model[0]}
else:
attr = None
e = xml_types.get (model[1], xml_type) (
model[1] or 'http://allegra/ pns-xml-error', attr
)
e.xml_first = model[2]
return e, None
# decode the attributes and set the pns attribute
if attr:
attr = dict ((
tuple (netstring.decode (item))
for item in netstring.decode (attr)
))
if model[0] != model[3]:
attr['pns'] = model[0]
elif model[0] != model[3]:
attr = {'pns': model[0]}
else:
attr = None
e = xml_types.get (model[1], xml_type) (model[1], attr)
if first:
e.xml_first = first
else:
e.xml_first = ''
if follow:
e.xml_follow = follow
return e, children
def handle_read (self):
datagram, peer = self.recvfrom (pns_datagram_size)
if peer == None:
assert None == self.log ('nop', 'debug')
return
if self.pns_joined.has_key (peer):
# in circle question ...
self.pns_joined[peer].pns_question (datagram, peer)
return
if self.pns_accepted.has_key (peer[0]):
# question from a new peer accepted at right
self.pns_accepted[peer[0]].pns_question (
datagram, peer
)
return
# out of circle
model = list (netstring.decode (datagram))
if (
len (model) != 2 or # TODO: ? 3 instead ?
model[0] == '' or
not public_names.valid_utf8 (model[0])
):
# log and drop invalid out-of-circle question ...
self.log (
'invalid-peer ip="%s"' % peer[0], 'error'
)
return
# if subscribed, joined ...
if self.pns_peer.pns_subscribed.has_key (model[0]):
self.pns_peer.pns_subscribed[
model[0]
].pns_joined (peer)
return
# not subscribed, resolve a PIRP answer >>>
if not self.pns_peers.has_key (peer):
self.pns_peer.pns_resolution.pns_udp_pirp (
model[0], peer
)
def pns_resolve_context (self, resolved, model):
if model != None:
# context(s) found
self.pns_walk_out (resolved[1], model[1])
return # stop walking.
# no context known
for name in tuple (netstring.decode (resolved[1])):
if name in self.pns_walked:
continue
if len (self.pns_walked) >= self.PNS_HORIZON:
break # beyond the horizon, stop walking.
# new and below the horizon
self.pns_walked.add (name)
self.pns_articulator.pns_command (
('', '', name),
self.pns_resolve_index
) # walk up the indexes ...
def pns_resolve_index (self, resolved, model):
if model != None:
# known name
name = model[0]
if (
len (self.pns_walked) > self.PNS_HORIZON or
name in self.pns_walked
):
return
# new and below the horizon
self.pns_walked.add (name)
self.pns_articulator.pns_command (
('', name, ''),
self.pns_resolve_context
) # walk the contexts ...
# unknown name
names = tuple (netstring.decode (resolved[2]))
if len (names) == 0:
# inarticulated
self.pns_articulator.pns_command (
('', name, ''),
self.pns_resolve_context
) # walk the contexts ...
return
# for each name articulated
for name in names:
if name in self.pns_walked:
continue
if len (self.pns_walked) > self.PNS_HORIZON:
break
# new and below the horizon
self.pns_walked.add (name)
self.pns_articulator.pns_command (
('', name, ''),
self.pns_resolve_context
) # walk the contexts ...
def name_unicode (name, tag='public', encoding='ASCII'):
names = tuple (netstring.decode (name)) or (name,)
if len (names) > 1:
return '<%s names="%s">%s</%s>' % (
tag,
xml_unicode.xml_attr (unicode (name, 'UTF-8')),
''.join ([name_unicode (
n, tag, encoding
) for n in names]),
tag
)
return '<%s>%s</%s>' % (
tag, xml_unicode.xml_cdata (unicode (name, 'UTF-8')), tag
)
# Note about this implementation
#
# it may be possible to get rid of the last level of PNS/XML articulation
# and make articulation sparser, by allowing un-named child element to
# be completely encoded in their parent. Yet this practically makes encoding
# from XML to PNS also more complex to support sensible trunking.
#
# Most XML leaf elements do not require a PNS/XML statement but the
# presence of one too large in their midst suppose a more elaborated
# algorithm for sparse articulation, counting every bytes in the parent's
# PNS/XML statement to decide which elements to "inline" as:
#
# :subject,:name,::attributes,:first,:follow,,
#
# and which to reference only:
#
# :subject,:name,:,
#
# it just might not be worth the trouble.
#
# TODO: add a depth limit to PNS_XML, avoid the possible infinite loop
# when there is a circular PNS/XML statement in the metabase for
# the articulated XML element tree.
def pns_articulate(self):
try:
encoded = self.pns_pipe.next()
except StopIteration:
# no more statements to handle, close
self.async_net_push(('0:,0:,0:,0:,', ))
# self.close_when_done ()
return
model = list(netstring.decode(encoded))
if '' == model[0]:
if '' == model[1] == model[2]:
self.pns_quit(model[3])
else:
self.pns_command(tuple(model[:3]))
elif '' == model[1] and model[0] == model[3]:
if model[2]:
self.pns_join(model[3], model[2])
else:
self.pns_subscribe(model[3])
else:
self.pns_statement(tuple(model[:3]), model[3])
def pns_name(encoded, horizon, HORIZON=126):
# Recursively validate a Public Name, returns the empty string if
# the name encoded is invalid or inside the horizon. This function
# does more than just assert that the encoded 8-bit byte string is
# a valid public name: it transform it to a valid public name.
#
# try to decode the articulated public names
names = [n for n in netstring.decode(encoded) if n]
if not names:
if encoded not in horizon and pns_name_clean(encoded):
# clean name new in this horizon
horizon.add(encoded)
return encoded
# unsafe 8-bit byte string or Public Name in the in horizon
return ''
# articulated Public Names
valid = []
for name in names:
# recursively validate each articulated name in this horizon
name = pns_name(name, horizon, HORIZON)
if name:
valid.append(name)
if len(horizon) >= HORIZON:
break # but only under this HORIZON
if len(valid) > 1:
# sort Public Names and encode
valid.sort()
return netstring.encode(valid)
if len(valid) > 0:
# return a "singleton"
return valid[0]
return '' # nothing valid to articulate in this horizon
def pns_name (encoded, horizon, HORIZON=126):
# Recursively validate a Public Name, returns the empty string if
# the name encoded is invalid or inside the horizon. This function
# does more than just assert that the encoded 8-bit byte string is
# a valid public name: it transform it to a valid public name.
#
# try to decode the articulated public names
names = [n for n in netstring.decode (encoded) if n]
if not names:
if encoded not in horizon and pns_name_clean (encoded):
# clean name new in this horizon
horizon.add (encoded)
return encoded
# unsafe 8-bit byte string or Public Name in the in horizon
return ''
# articulated Public Names
valid = []
for name in names:
# recursively validate each articulated name in this horizon
name = pns_name (name, horizon, HORIZON)
if name:
valid.append (name)
if len (horizon) >= HORIZON:
break # but only under this HORIZON
if len (valid) > 1:
# sort Public Names and encode
valid.sort ()
return netstring.encode (valid)
if len (valid) > 0:
# return a "singleton"
return valid[0]
return '' # nothing valid to articulate in this horizon
def pns_question (self, datagram, peer):
# handle in-circle question
if datagram.startswith ('0:,'):
# command: quit right
model = list (netstring.decode (datagram))
if len (model) == 2 and ip_peer.is_ip (model[1]):
self.pns_quit_right (model[1])
return
assert None == self.log (
datagram, 'invalid-protocol-command'
)
self.pns_quitted ()
return
if datagram.startswith (self.PNS_SP):
# protocol question for this circle
if self.pns_right:
# in-circle, forward quit and then close
self.sendto (self.PNS_SP, (
self.pns_left, 3534
))
self.pns_quitted ()
elif self.pns_left:
# ? joining
pass
else:
# ? accept
pass
return
# validate question
model = list (netstring.decode (datagram))
if (len (model) != 2 or not public_names.valid_utf8 (
model[0], self.pns_horizon
)):
assert None == self.log (
datagram, 'invalid-question'
)
# TODO: ban IP addresses that send invalid datagrams!
self.pns_quit ()
return
sp = netstring.encode (model)
if (
self.pns_buffer.get (sp) == '' and
not self.pns_statements.has_key (sp)
):
# buffered not stated, drop
assert None == self.log (datagram, 'drop')
return
# echo the statement to the PNS/TCP subscribers
model.append ('')
model.append (self.pns_name)
self.pns_tcp_continue (model, '?')
if self.pns_statements.get (sp) == '':
# question circled, clear the statement, do not relay
del self.pns_statements[sp]
assert None == self.log (datagram, 'circle')
return
# relay left
self.sendto (sp, (self.pns_left, 3534))
if (
model[1] == '' and
self.pns_peer.pns_subscribed.has_key (model[0])
):
# protocol question for a subscribed circle, bounce
# this peer's IP address as the answer.
left = self.pns_peer.pns_udp.addr[0]
self.pns_sendto_right (
'%s%d:%s' % (sp, len(left), left),
self.pns_right
)
return
# resolve ...
self.pns_peer.pns_resolution.pns_udp_question (model)
def pns_answer (self, datagram, peer):
# handle in-circle and out-of-circle answers
if datagram.startswith ('0:,'):
if not self.pns_right:
# out-of-circle
model = list (netstring.decode (datagram))
if (
len (model) == 3 and
model[1] == '' and
ip_peer.is_ip (model[2])
):
# bounce to join left or right of L
self.pns_join (model[2])
return
assert None == self.log (
datagram, 'invalid-command-answer'
)
self.pns_quit ()
return
if datagram.startswith (self.PNS_SP):
# handle protocol statement
model = list (netstring.decode (datagram))
if not (len (model) == 3 and (
model[2] == '' or ip_peer.is_ip (model[2])
)):
assert None == self.log (
datagram, 'invalid-protocol-answer'
)
self.pns_quit ()
return
if self.pns_right:
# in-circle, quitted at left!
return
# out-of-circle
if model[2]:
# accept questions from R
self.pns_peer.pns_udp.pns_accepted[
model[2]
] = self
else:
# root join
self.pns_in_circle (peer)
return
# validate answer
model = list (netstring.decode (datagram))
if (
(len (model[0]) + len (model[1]) + len (
'%d%d' % (len (model[0]), len (model[1]))
)) > 512
or not public_names.valid_utf8 (
model[0], self.pns_horizon
)
):
assert None == self.log (
datagram, 'invalid-question'
)
self.pns_quit ()
return
sp = netstring.encode (model[:2])
if (
self.pns_buffer.has_key (sp) and
not self.pns_statements.has_key (sp)
):
# buffered not stated, drop
assert None == self.log (datagram, 'drop')
return
# echo to all subscribers
model.append (self.pns_name)
self.pns_tcp_continue (model, '!')
if self.pns_statements.get (sp) == model[2]:
# answer circled, clear the statement, do not relay
del self.pns_statements [sp]
assert None == self.log (datagram, 'circle')
return
# relay right
self.pns_sendto_right (
netstring.encode (model), self.pns_right
)
if (
model[1] == '' and
self.pns_peer.pns_subscribed.has_key (model[0])
):
# protocol answer, let the named circle handle it
if self.pns_peer.self.pns_peer.pns_subscribed[
model[0]
].pns_protocol_answer (model[2]):
return
# resolve ...
self.pns_peer.pns_resolution.pns_udp_answer (model)
def async_net_continue (self, encoded):
"handle the following PNS/TCP peer statement"
# Note that there is no validation of the PNS statements
# because they are trusted to be valid. A client *may*
# validate, the peer *must* anyway.
#
self.pns_received += 1
model = list (netstring.decode (encoded))
if len (model) != 5:
assert None == self.log (
encoded, 'invalid-peer-statement'
)
self.handle_close ()
return
self.pns_multiplex (model)
resolved = tuple (model[:3])
if '' == model[0]:
# close, index, context and route
handlers = self.pns_commands.get (resolved)
if handlers == None:
assert None == self.log (
encoded,
'unsollicited-command-response'
)
self.handle_close ()
return
self.pns_commands[resolved] = [
h for h in handlers if h (resolved, model)
]
if len (self.pns_commands[resolved]) == 0:
del self.pns_commands[resolved]
elif '' == model[1] and model[0] == model[3]:
# TODO: protocol response to join/subscribe
pass
else:
# statements
statements = self.pns_contexts.setdefault (
model[3], {}
)
handlers = statements.get (resolved)
if handlers == None:
# test for a question's answer handler
resolved = (model[0], model[1], '')
handlers = statements.get (resolved)
if handlers == None:
# irrelevant statement
self.pns_noise (model)
return
# relevant statements, handle and refresh the handlers list
statements[resolved] = [
h for h in handlers if h (resolved, model)
]
# then clean up ...
if len (statements[resolved]) == 0:
del statements[resolved]
if len (statements) == 0:
del self.pns_contexts[model[3]]
if (
self.pns_close_when_done and
len (self.pns_commands) == 0 and
len (self.pns_contexts) == 0 and
len (self.pns_subscribed) == 0
):
assert None == self.log ('done', 'debug')
self.handle_close ()
