"""
Dict client protocol implementation.
@author: U{Pavel Pergamenshchik<mailto:pp64@cornell.edu>}
"""
from twisted.protocols import basic
from twisted.internet import defer, protocol
from twisted.python import log
from StringIO import StringIO
def parseParam(line):
"""Chew one dqstring or atom from beginning of line and return (param, remaningline)"""
if line == '':
return (None, '')
elif line[0] != '"': mode = 1
else: mode = 2
res = ""
io = StringIO(line)
if mode == 2: io.read(1)
while 1:
a = io.read(1)
if a == '"':
if mode == 2:
io.read(1) return (res, io.read())
elif a == '\\':
a = io.read(1)
if a == '':
return (None, line) elif a == '':
if mode == 1:
return (res, io.read())
else:
return (None, line) elif a == ' ':
if mode == 1:
return (res, io.read())
res += a
def makeAtom(line):
"""Munch a string into an 'atom'"""
return filter(lambda x: not (x in map(chr, range(33)+[34, 39, 92])), line)
def makeWord(s):
mustquote = range(33)+[34, 39, 92]
result = []
for c in s:
if ord(c) in mustquote:
result.append("\\")
result.append(c)
s = "".join(result)
return s
def parseText(line):
if len(line) == 1 and line == '.':
return None
else:
if len(line) > 1 and line[0:2] == '..':
line = line[1:]
return line
class Definition:
"""A word definition"""
def __init__(self, name, db, dbdesc, text):
self.name = name
self.db = db
self.dbdesc = dbdesc
self.text = text
class DictClient(basic.LineReceiver):
"""dict (RFC2229) client"""
data = None MAX_LENGTH = 1024
state = None
mode = None
result = None
factory = None
def __init__(self):
self.data = None
self.result = None
def connectionMade(self):
self.state = "conn"
self.mode = "command"
def sendLine(self, line):
"""Throw up if the line is longer than 1022 characters"""
if len(line) > self.MAX_LENGTH - 2:
raise ValueError("DictClient tried to send a too long line")
basic.LineReceiver.sendLine(self, line)
def lineReceived(self, line):
try:
line = line.decode("UTF-8")
except UnicodeError: return
if self.mode == "text": code = "text"
else:
if len(line) < 4:
log.msg("DictClient got invalid line from server -- %s" % line)
self.protocolError("Invalid line from server")
self.transport.LoseConnection()
return
code = int(line[:3])
line = line[4:]
method = getattr(self, 'dictCode_%s_%s' % (code, self.state), self.dictCode_default)
method(line)
def dictCode_default(self, line):
"""Unkown message"""
log.msg("DictClient got unexpected message from server -- %s" % line)
self.protocolError("Unexpected server message")
self.transport.loseConnection()
def dictCode_221_ready(self, line):
"""We are about to get kicked off, do nothing"""
pass
def dictCode_220_conn(self, line):
"""Greeting message"""
self.state = "ready"
self.dictConnected()
def dictCode_530_conn(self):
self.protocolError("Access denied")
self.transport.loseConnection()
def dictCode_420_conn(self):
self.protocolError("Server temporarily unavailable")
self.transport.loseConnection()
def dictCode_421_conn(self):
self.protocolError("Server shutting down at operator request")
self.transport.loseConnection()
def sendDefine(self, database, word):
"""Send a dict DEFINE command"""
assert self.state == "ready", "DictClient.sendDefine called when not in ready state"
self.result = None self.data = None self.state = "define"
command = "DEFINE %s %s" % (makeAtom(database.encode("UTF-8")), makeWord(word.encode("UTF-8")))
self.sendLine(command)
def sendMatch(self, database, strategy, word):
"""Send a dict MATCH command"""
assert self.state == "ready", "DictClient.sendMatch called when not in ready state"
self.result = None
self.data = None
self.state = "match"
command = "MATCH %s %s %s" % (makeAtom(database), makeAtom(strategy), makeAtom(word))
self.sendLine(command.encode("UTF-8"))
def dictCode_550_define(self, line):
"""Invalid database"""
self.mode = "ready"
self.defineFailed("Invalid database")
def dictCode_550_match(self, line):
"""Invalid database"""
self.mode = "ready"
self.matchFailed("Invalid database")
def dictCode_551_match(self, line):
"""Invalid strategy"""
self.mode = "ready"
self.matchFailed("Invalid strategy")
def dictCode_552_define(self, line):
"""No match"""
self.mode = "ready"
self.defineFailed("No match")
def dictCode_552_match(self, line):
"""No match"""
self.mode = "ready"
self.matchFailed("No match")
def dictCode_150_define(self, line):
"""n definitions retrieved"""
self.result = []
def dictCode_151_define(self, line):
"""Definition text follows"""
self.mode = "text"
(word, line) = parseParam(line)
(db, line) = parseParam(line)
(dbdesc, line) = parseParam(line)
if not (word and db and dbdesc):
self.protocolError("Invalid server response")
self.transport.loseConnection()
else:
self.result.append(Definition(word, db, dbdesc, []))
self.data = []
def dictCode_152_match(self, line):
"""n matches found, text follows"""
self.mode = "text"
self.result = []
self.data = []
def dictCode_text_define(self, line):
"""A line of definition text received"""
res = parseText(line)
if res == None:
self.mode = "command"
self.result[-1].text = self.data
self.data = None
else:
self.data.append(line)
def dictCode_text_match(self, line):
"""One line of match text received"""
def l(s):
p1, t = parseParam(s)
p2, t = parseParam(t)
return (p1, p2)
res = parseText(line)
if res == None:
self.mode = "command"
self.result = map(l, self.data)
self.data = None
else:
self.data.append(line)
def dictCode_250_define(self, line):
"""ok"""
t = self.result
self.result = None
self.state = "ready"
self.defineDone(t)
def dictCode_250_match(self, line):
"""ok"""
t = self.result
self.result = None
self.state = "ready"
self.matchDone(t)
def protocolError(self, reason):
"""override to catch unexpected dict protocol conditions"""
pass
def dictConnected(self):
"""override to be notified when the server is ready to accept commands"""
pass
def defineFailed(self, reason):
"""override to catch reasonable failure responses to DEFINE"""
pass
def defineDone(self, result):
"""override to catch succesful DEFINE"""
pass
def matchFailed(self, reason):
"""override to catch resonable failure responses to MATCH"""
pass
def matchDone(self, result):
"""override to catch succesful MATCH"""
pass
class InvalidResponse(Exception):
pass
class DictLookup(DictClient):
"""Utility class for a single dict transaction. To be used with DictLookupFactory"""
def protocolError(self, reason):
if not self.factory.done:
self.factory.d.errback(InvalidResponse(reason))
self.factory.clientDone()
def dictConnected(self):
if self.factory.queryType == "define":
apply(self.sendDefine, self.factory.param)
elif self.factory.queryType == "match":
apply(self.sendMatch, self.factory.param)
def defineFailed(self, reason):
self.factory.d.callback([])
self.factory.clientDone()
self.transport.loseConnection()
def defineDone(self, result):
self.factory.d.callback(result)
self.factory.clientDone()
self.transport.loseConnection()
def matchFailed(self, reason):
self.factory.d.callback([])
self.factory.clientDone()
self.transport.loseConnection()
def matchDone(self, result):
self.factory.d.callback(result)
self.factory.clientDone()
self.transport.loseConnection()
class DictLookupFactory(protocol.ClientFactory):
"""Utility factory for a single dict transaction"""
protocol = DictLookup
done = None
def __init__(self, queryType, param, d):
self.queryType = queryType
self.param = param
self.d = d
self.done = 0
def clientDone(self):
"""Called by client when done."""
self.done = 1
del self.d
def clientConnectionFailed(self, connector, error):
self.d.errback(error)
def clientConnectionLost(self, connector, error):
if not self.done:
self.d.errback(error)
def buildProtocol(self, addr):
p = self.protocol()
p.factory = self
return p
def define(host, port, database, word):
"""Look up a word using a dict server"""
d = defer.Deferred()
factory = DictLookupFactory("define", (database, word), d)
from twisted.internet import reactor
reactor.connectTCP(host, port, factory)
return d
def match(host, port, database, strategy, word):
"""Match a word using a dict server"""
d = defer.Deferred()
factory = DictLookupFactory("match", (database, strategy, word), d)
from twisted.internet import reactor
reactor.connectTCP(host, port, factory)
return d