def encode(self, value):
"Return a bytestring representation of the value"
if isinstance(value, Token):
return b(value.value)
elif isinstance(value, bytes):
return value
elif isinstance(value, (int, long)):
value = b(str(value))
elif isinstance(value, float):
value = b(repr(value))
elif not isinstance(value, basestring):
value = unicode(value)
if isinstance(value, unicode):
value = value.encode(self.encoding, self.encoding_errors)
return value
def acquire(self, blocking=None, blocking_timeout=None):
"""
Use Redis to hold a shared, distributed lock named ``name``.
Returns True once the lock is acquired.
If ``blocking`` is False, always return immediately. If the lock
was acquired, return True, otherwise return False.
``blocking_timeout`` specifies the maximum number of seconds to
wait trying to acquire the lock.
"""
sleep = self.sleep
token = b(uuid.uuid1().hex)
if blocking is None:
blocking = self.blocking
if blocking_timeout is None:
blocking_timeout = self.blocking_timeout
stop_trying_at = None
if blocking_timeout is not None:
stop_trying_at = mod_time.time() + blocking_timeout
while 1:
if self.do_acquire(token):
self.local.token = token
return True
if not blocking:
return False
if stop_trying_at is not None and mod_time.time() > stop_trying_at:
return False
mod_time.sleep(sleep)
def pack_command(self, *args):
'''
Pack a series of arguments into the Redis protocol.
For an optimized special case for PUBLISH messages,
see pack_publish_command.
:return: array of all arguments packed into the Redis
wire protocol.
:rtype: [string]
'''
output = []
# the client might have included 1 or more literal arguments in
# the command name, e.g., 'CONFIG GET'. The Redis server expects these
# arguments to be sent separately, so split the first argument
# manually. All of these arguements get wrapped in the Token class
# to prevent them from being encoded.
command = args[0]
if ' ' in command:
args = tuple([Token(s) for s in command.split(' ')]) + args[1:]
else:
args = (Token(command),) + args[1:]
buff = SYM_EMPTY.join(
(SYM_STAR, b(str(len(args))), SYM_CRLF))
for arg in imap(self.encode, args):
# to avoid large string mallocs, chunk the command into the
# output list if we're sending large values
if len(buff) > 6000 or len(arg) > 6000:
buff = SYM_EMPTY.join(
(buff, SYM_DOLLAR, b(str(len(arg))), SYM_CRLF))
output.append(buff)
output.append(arg)
buff = SYM_CRLF
else:
buff = SYM_EMPTY.join((buff, SYM_DOLLAR, b(str(len(arg))),
SYM_CRLF, arg, SYM_CRLF))
output.append(buff)
return output
