Commit bf0d57d0 authored by Chrysostomos Nanakos's avatar Chrysostomos Nanakos
Browse files

pithos: Make blocker use selectable storage backend

parent 8cd49d45
......@@ -31,17 +31,7 @@
# interpreted as representing official policies, either expressed
# or implied, of GRNET S.A.
from fileblocker import FileBlocker
def intersect(a, b):
""" return the intersection of two lists """
return list(set(a) & set(b))
def union(a, b):
""" return the union of two lists """
return list(set(a) | set(b))
from store_helpers import get_blocker
class Blocker(object):
......@@ -51,47 +41,49 @@ class Blocker(object):
"""
def __init__(self, **params):
self.rblocker = None
try:
if params['blockpool']:
from radosblocker import RadosBlocker
self.rblocker = RadosBlocker(**params)
except KeyError:
pass
self.fblocker = FileBlocker(**params)
self.hashlen = self.fblocker.hashlen
self.blocksize = params['blocksize']
fblocker, rblocker, hashlen, blocksize = \
get_blocker(params['backend_storage'], **params)
self.fblocker = fblocker
self.rblocker = rblocker
self.hashlen = hashlen
self.blocksize = blocksize
def block_hash(self, data):
"""Hash a block of data"""
return self.fblocker.block_hash(data)
"""Hash a block of data."""
if self.fblocker:
return self.fblocker.block_hash(data)
elif self.rblocker:
return self.rblocker.block_hash(data)
def block_ping(self, hashes):
"""Check hashes for existence and
return those missing from block storage.
"""
r = []
if self.rblocker:
r = self.rblocker.block_ping(hashes)
f = self.fblocker.block_ping(hashes)
return union(r, f)
return self.rblocker.block_ping(hashes)
elif self.fblocker:
return self.fblocker.block_ping(hashes)
def block_retr(self, hashes):
"""Retrieve blocks from storage by their hashes."""
return self.fblocker.block_retr(hashes)
if self.rblocker:
return self.rblocker.block_retr(hashes)
elif self.fblocker:
return self.fblocker.block_retr(hashes)
def block_stor(self, blocklist):
"""Store a bunch of blocks and return (hashes, missing).
Hashes is a list of the hashes of the blocks,
missing is a list of indices in that list indicating
which blocks were missing from the store.
"""
r_missing = []
(hashes, f_missing) = self.fblocker.block_stor(blocklist)
if self.rblocker:
(_, r_missing) = self.rblocker.block_stor(blocklist)
return (hashes, union(r_missing, f_missing))
if self.fblocker:
(hashes, missing) = self.fblocker.block_stor(blocklist)
elif self.rblocker:
(hashes, missing) = self.rblocker.block_stor(blocklist)
return (hashes, missing)
def block_delta(self, blkhash, offset, data):
"""Construct and store a new block from a given block
......@@ -99,15 +91,25 @@ class Blocker(object):
(the hash of the new block, if the block already existed)
"""
blocksize = self.blocksize
r_hash = None
r_existed = True
(f_hash, f_existed) = self.fblocker.block_delta(blkhash, offset, data)
if self.rblocker:
(r_hash, r_existed) = self.rblocker.block_delta(blkhash, offset,
data)
if not r_hash and not f_hash:
if self.fblocker:
(bhash, existed) = self.fblocker.block_delta(blkhash, offset, data)
elif self.rblocker:
(bhash, existed) = self.rblocker.block_delta(blkhash, offset,
data)
if not bhash:
return None, None
if self.rblocker and not r_hash:
if self.rblocker and not bhash:
block = self.rblocker.block_retr((blkhash,))
if not block:
return None, None
block = block[0]
newblock = block[:offset] + data
if len(newblock) > blocksize:
newblock = newblock[:blocksize]
elif len(newblock) < blocksize:
newblock += block[len(newblock):]
bhash, existed = self.rblocker.block_stor((newblock,))
elif self.fblocker and not bhash:
block = self.fblocker.block_retr((blkhash,))
if not block:
return None, None
......@@ -117,6 +119,6 @@ class Blocker(object):
newblock = newblock[:blocksize]
elif len(newblock) < blocksize:
newblock += block[len(newblock):]
r_hash, r_existed = self.rblocker.block_stor((newblock,))
bhash, existed = self.fblocker.block_stor((newblock,))
return f_hash, 1 if r_existed and f_existed else 0
return bhash, 1 if existed else 0
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