1 # Copyright 2011-2012 GRNET S.A. All rights reserved.
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4 # without modification, are permitted provided that the following
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34 from hashlib import new as newhasher
35 from binascii import hexlify
37 from radosblocker import RadosBlocker
38 from fileblocker import FileBlocker
41 """ return the intersection of two lists """
42 return list(set(a) & set(b))
45 """ return the union of two lists """
46 return list(set(a) | set(b))
49 class Blocker(object):
51 Required constructor parameters: blocksize, blockpath, hashtype,
55 def __init__(self, **params):
56 params['blockpool'] = 'blocks'
57 self.rblocker = RadosBlocker(**params)
58 self.fblocker = FileBlocker(**params)
59 self.hashlen = self.rblocker.hashlen
61 # def _get_rear_block(self, blkhash, create=0):
62 # return self.rblocker._get_rear_block(blkhash, create)
64 # def _check_rear_block(self, blkhash):
65 # return self.rblocker._check_rear_block(blkhash)
66 # return self.rblocker._check_rear_block(blkhash) and
67 # self.fblocker._check_rear_block(blkhash)
69 def block_hash(self, data):
70 """Hash a block of data"""
71 return self.rblocker.block_hash(data)
73 def block_ping(self, hashes):
74 """Check hashes for existence and
75 return those missing from block storage.
77 # return self.rblocker.block_ping(hashes)
78 r = self.rblocker.block_ping(hashes)
79 f = self.fblocker.block_ping(hashes)
82 def block_retr(self, hashes):
83 """Retrieve blocks from storage by their hashes."""
84 return self.fblocker.block_retr(hashes)
86 def block_stor(self, blocklist):
87 """Store a bunch of blocks and return (hashes, missing).
88 Hashes is a list of the hashes of the blocks,
89 missing is a list of indices in that list indicating
90 which blocks were missing from the store.
92 # return self.rblocker.block_stor(blocklist)
93 (hashes, r_missing) = self.rblocker.block_stor(blocklist)
94 (_, f_missing) = self.fblocker.block_stor(blocklist)
95 return (hashes, union(r_missing, f_missing))
98 def block_delta(self, blkhash, offset, data):
99 """Construct and store a new block from a given block
100 and a data 'patch' applied at offset. Return:
101 (the hash of the new block, if the block already existed)
103 # return self.rblocker.block_delta(blkhash, offset, data)
105 (f_hash, f_existed) = self.fblocker.block_delta(blkhash, offset, data)
106 (r_hash, r_existed) = self.rblocker.block_delta(blkhash, offset, data)
107 if not r_hash and not f_hash:
110 block = self.fblocker.block_retr((blkhash,))
114 newblock = block[:offset] + data
115 if len(newblock) > blocksize:
116 newblock = newblock[:blocksize]
117 elif len(newblock) < blocksize:
118 newblock += block[len(newblock):]
119 r_hash, r_existed = self.rblocker.block_stor((newblock,))
121 return f_hash, 1 if r_existed and f_existed else 0