class Cache:
"""Class representing D3N."""
# Replacement policies
LRU = "LRU"
LFU = "LFU"
LRU_S = "LRU_S"
FIFO = "FIFO"
RAND = "RAND"
# Write policies
WRITE_BACK = "WB"
WRITE_THROUGH = "WT"
# Layer
L1 = "L1"
L2 = "L2"
consistent = "consistent"
rendezvous = "rendezvous"
rr = "rr"
def __init__(self, layer, size, replace_pol, write_pol, hash_ring,
hash_type, obj_size, full_size, logger):
self._replace_pol = replace_pol # Replacement policy
self._write_pol = write_pol # Write policy
self._layer = layer # Layer info
self._size = size # Cache size
self.spaceLeft = size # Cache size
self._logger = logger
self.hashmap = {} # Mapping
self.hash_ring = hash_ring
self._hash_type = hash_type
self._obj_size = obj_size
if (self._size == 0):
self.zerosize = True
self._size = 1
else:
self.zerosize = False
if (self._replace_pol == Cache.LRU):
self.cache = LRU(self._size)
elif (self._replace_pol == Cache.FIFO):
self.cache = deque()
elif (self._replace_pol == Cache.LRU_S):
self.cache = LRU(self._size)
self.shadow = LRU(full_size)
self.hist = []
for i in range(full_size):
self.hist.append(0)
# Statistics
self._hit_count = 0
self._miss_count = 0
self._backend_bw = 0
self._crossrack_bw = 0
self._intrarack_bw = 0
self.miss_lat = 0
self.lat_count = 0
def _insert1(self, key, size):
# No eviction
if not self.zerosize:
if (self._replace_pol == Cache.LRU_S):
self.shadow[key] = 1
if (int(size) <= self.spaceLeft):
if (self._replace_pol == Cache.LRU):
self.cache[key] = int(size)
elif (self._replace_pol == Cache.LRU_S):
self.cache[key] = int(size)
elif (self._replace_pol == Cache.FIFO):
self.cache.append(key)
self.hashmap[key] = int(size)
self.spaceLeft -= int(size)
else:
while (int(size) > self.spaceLeft):
self._evict()
if (self._replace_pol == Cache.LRU):
self.cache[key] = int(size)
elif (self._replace_pol == Cache.LRU_S):
self.cache[key] = int(size)
elif (self._replace_pol == Cache.FIFO):
self.cache.append(key)
self.hashmap[key] = int(size)
self.spaceLeft -= int(size)
def _insert(self, key, size):
# No eviction
if not self.zerosize:
if (self._replace_pol == Cache.LRU_S):
self.cache[key] = int(size)
self.shadow[key] = int(size)
elif (self._replace_pol == Cache.LRU):
self.cache[key] = int(size)
else:
if (int(size) <= self.spaceLeft):
if (self._replace_pol == Cache.LRU):
self.cache[key] = int(size)
elif (self._replace_pol == Cache.LRU_S):
self.cache[key] = int(size)
elif (self._replace_pol == Cache.FIFO):
self.cache.append(key)
self.hashmap[key] = int(size)
self.spaceLeft -= int(size)
else:
while (int(size) > self.spaceLeft):
self._evict()
if (self._replace_pol == Cache.LRU):
self.cache[key] = int(size)
elif (self._replace_pol == Cache.LRU_S):
self.cache[key] = int(size)
elif (self._replace_pol == Cache.FIFO):
self.cache.append(key)
self.hashmap[key] = int(size)
self.spaceLeft -= int(size)
def read1(self, key, size):
if self._layer == "BE":
return 1
if self.zerosize == True:
return None
"""Read a object from the cache."""
r = None
if (self._replace_pol == Cache.LRU_S):
if self.shadow.has_key(key):
count = 0
for i in self.shadow.keys():
if i == key:
self.hist[count] += 1
break
count += 1
self.shadow[key] = 1
if key in self.hashmap:
if (self._replace_pol == Cache.LRU):
self._update_use(key)
elif (self._replace_pol == Cache.LRU_S):
self._update_use(key)
self._hit_count += 1
r = 1
else:
self._miss_count += 1
return r
def read(self, key, size):
if self._layer == "BE":
return 1
if self.zerosize == True:
return None
"""Read a object from the cache."""
r = None
if (self._replace_pol == Cache.LRU_S):
if self.cache.has_key(key):
self._hit_count += 1
self.cache[key] = self.cache[key]
r = 1
else:
self._miss_count += 1
if self.shadow.has_key(key):
count = 0
for i in self.shadow.keys():
if i == key:
self.hist[count] += 1
break
count += 1
self.shadow[key] = 1
else:
if key in self.hashmap:
if (self._replace_pol == Cache.LRU):
self._update_use(key)
elif (self._replace_pol == Cache.LRU_S):
self._update_use(key)
self._hit_count += 1
r = 1
else:
self._miss_count += 1
return r
def checkKey(self, key):
if self._layer == "BE":
return 1
if self.zerosize == True:
return 0
"""Read a object from the cache."""
r = 0
if (self._replace_pol == Cache.LRU_S) or (self._replace_pol
== Cache.LRU):
if self.cache.has_key(key):
r = 1
else:
r = 0
return r
def _evict(self):
if (self._replace_pol == Cache.LRU):
id = self.cache.peek_last_item()[0]
del self.cache[id]
elif (self._replace_pol == Cache.LRU_S):
id = self.cache.peek_last_item()[0]
del self.cache[id]
elif (self._replace_pol == Cache.FIFO):
id = self.cache.popleft()
self.spaceLeft += int(self.hashmap[id])
del self.hashmap[id]
def _update_use(self, key):
"""Update the use of a cache."""
if (self._replace_pol == Cache.LRU):
self.cache[key] = self.hashmap[key]
if (self._replace_pol == Cache.LRU_S):
self.cache[key] = self.hashmap[key]
def set_cache_size(self, size):
new_size = self.cache.get_size() + int(size)
self.cache.set_size(int(new_size))
def set_backend_bw(self, value):
self._backend_bw += value
def set_crossrack_bw(self, value):
self._crossrack_bw += value
def set_intrarack_bw(self, value):
self._intrarack_bw += value
def get_backend_bw(self):
return self._backend_bw
def get_crossrack_bw(self):
return self._crossrack_bw
def get_intrarack_bw(self):
return self._intrarack_bw
def get_replace_pol(self):
return self._replace_pol
def get_hit_count(self):
return self._hit_count
def get_miss_count(self):
return self._miss_count
def get_available_space(self):
return self.spaceLeft
def get_replace_poll(self):
return self._replace_pol
def reset_shadow_cache():
self.shadow.clear()
def print_cache(self):
print self.cache
def get_l2_address(self, key):
if (self._hash_type == Cache.consistent):
return self.hash_ring.get_node(key)
elif (self._hash_type == Cache.rendezvous):
return self.hash_ring.find_node(key)
elif (self._hash_type == Cache.rr):
val = key.split("_")[1]
res = int(val) % int(self.hash_ring)
return res
