def get_repeatable(self, key):
resolver = self.resolver(self.mc)
while 1:
old = new = status_name = None
try:
old, new, status_name = self.mc.gets(self.main_table, key)
#print "get: old=", get_by_table_and_key(self.mc,old), " new=", get_by_table_and_key(self.mc, new), " status_name=", get_by_table_and_key(self.mc, status_name)
except TypeError:
#print "typeerror"
return None # read committed!!
if status_name == self.transaction_status: # I already got
#print 'cache hit'
return self.cache[key]
else:
status_table, status_key = serializer.deserialize(status_name)
state = self.mc.gets(status_table, status_key)
try:
committed_value, to_delete = read_repeatable(old, new, state)
except TypeError:
resolver(status_name)
continue
if self.mc.cas(self.main_table, key, [committed_value,
committed_value,
self.transaction_status]):
if state != 'active' and new != old:
delete_table, delete_key = serializer.deserialize(to_delete)
self.mc.delete(delete_table, delete_key)
target_table, target_key = serializer.deserialize(committed_value)
result = self.mc.gets(target_table, target_key)
self.cache[key] = result
return result
def set(self, key, value):
resolver = self.resolver(self.mc)
while 1:
old = new = status_name = None
try:
old, new, status_name = self.mc.gets(self.main_table, key)
#print "set: old=", get_by_table_and_key(self.mc,old), " new=", get_by_table_and_key(self.mc, new), " status_name=", get_by_table_and_key(self.mc, status_name)
except TypeError:
new_key = self.add_random(value)
if self.mc.add(self.main_table, key, [None, new_key, self.transaction_status]):
break
continue
if status_name == self.transaction_status:
self.cache[key] = value
if old == new:
new_key = self.add_random(value)
if self.mc.cas(self.main_table, key, [old, new_key, self.transaction_status]):
break
else:
del_table, del_key = separate_table_and_key(new_key)
self.mc.delete(del_table, del_key)
else:
target_table, target_key = serializer.deserialize(new)
if not self.mc.replace(target_table, target_key, value):
raise AbortException
break
else:
status_table, status_key = serializer.deserialize(status_name)
state = self.mc.gets(status_table, status_key)
next_old, to_delete = None, None
try:
next_old, to_delete = read_repeatable(old, new, state)
except TypeError:
resolver(status_name)
continue
new_key = self.add_random(value)
result = self.mc.cas(self.main_table, key, [next_old, new_key, self.transaction_status])
if result:
self.cache[key] = value
if to_delete != None and to_delete != next_old:
target_table, target_key = serializer.deserialize(to_delete)
self.mc.delete(target_table, target_key)
#print "setting cache:",self.cache
break
def __call__(self, other_status):
status_table, status_key = serializer.deserialize(other_status)
while True:
sleep(0.001 * randint(0, 1 << self.count))
status = self.mc.gets(status_table, status_key)
if status != 'active':
return
if self.count <= 6:
self.count += 1
else:
self.count = 0
if self.mc.cas(status_table, status_key, 'abort'):
print "robbed!"
return
def get_committed(self, key):
while 1:
old = new = status_name = None
try:
#print "get:",self.mc.gets(key)
old, new, status_name = self.mc.gets(self.main_table, key)
except TypeError:
#print "typeerror"
return None # read committed!!
if status_name == self.transaction_status:
return self.cache[key]
#return self.mc.get(new)
else:
status_table, status_key = serializer.deserialize(status_name)
state = self.mc.gets(status_name)
committed_value, to_delete = read_committed(old,new,state)
if state != 'active':
delete_table, delete_key = serializer.deserialize(to_delete)
self.mc.delete(delete_table, delete_key)
value_table, value_key = serializer.deserialize(committed_value)
result = self.mc.get(value_table, value_key)
self.cache[key] = result
return result
def commit(self): status_table, status_key = serializer.deserialize(self.transaction_status) status = self.mc.gets(status_table, status_key) if status != 'active': raise AbortException return self.mc.cas(status_table, status_key, 'committed')
def separate_table_and_key(org): if org == None: return None table, key = serializer.deserialize(org) return (table,key)
