code = binascii.crc32(key.encode('ascii'))

if code < 0:

code = ~code

def set_servers(self, servers):

"""Set the pool of servers used by this client.

@param servers: an array of servers.

Servers can be passed in two forms:

1. Strings of the form C{"host:port"}, which implies a

default weight of 1.

2. Tuples of the form C{("host:port", weight)}, where

C{weight} is an integer weight value.

"""

#self.servers = []

###add by tzh start

_virtualNodes = {}

_max_vitual_nodes = 250

_virtualNodeArray = range(_max_vitual_nodes)

self.buckets = []

_servers = []

for s in servers:

_host = memcache._Host(s, self.debug, dead_retry=self.dead_retry,

socket_timeout=self.socket_timeout,

flush_on_reconnect=self.flush_on_reconnect)

address = ''

if isinstance(s,tuple):

address = s[0]

else:

address = s

for i in _virtualNodeArray:

key = '%s-node%d' % (address, i)

node_code = newmemcache_hash(key)

if _virtualNodes.has_key(node_code):

raise Exception('has same server!')

_virtualNodes[node_code] = _host

self.buckets.append(node_code)

self.buckets.sort()

_servers.append(_host)

self._virtualNodes = _virtualNodes

self.servers = _servers

###add by tzh end

#self._init_buckets()

def _get_server(self, key):

if isinstance(key, tuple):

serverhash, key = key

else:

#serverhash = serverHashFunction(key)

###update by tzh

serverhash = newmemcache_hash(key)

if not self.buckets:

return None, None

for i in range(memcache.Client._SERVER_RETRIES):

#server = self.buckets[serverhash % len(self.buckets)]

### update by tzh

bucketIndex = bisect.bisect_right(self.buckets, serverhash)

if bucketIndex >= len(self.buckets):

bucketIndex = 0

server = self._virtualNodes[self.buckets[bucketIndex]]

if server.connect():

print("(using server %s)" % server,)

return server, key

serverhash = serverHashFunction(str(serverhash) + str(i))