1 # Copyright 2011 GRNET S.A. All rights reserved.
3 # Redistribution and use in source and binary forms, with or
4 # without modification, are permitted provided that the following
7 # 1. Redistributions of source code must retain the above
8 # copyright notice, this list of conditions and the following
11 # 2. Redistributions in binary form must reproduce the above
12 # copyright notice, this list of conditions and the following
13 # disclaimer in the documentation and/or other materials
14 # provided with the distribution.
16 # THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
17 # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 # WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 # PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
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21 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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24 # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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32 # or implied, of GRNET S.A.
34 from os.path import realpath, join, exists, isdir
35 from os import makedirs, unlink
36 from errno import ENOENT
38 from context_file import ContextFile
43 Required contstructor parameters: mappath, namelen.
49 def __init__(self, **params):
51 self.namelen = params['namelen']
52 mappath = realpath(params['mappath'])
53 if not isdir(mappath):
54 if not exists(mappath):
57 raise ValueError("Variable mappath '%s' is not a directory" % (mappath,))
58 self.mappath = mappath
60 def get_rear_map(self, name, create=0):
61 name = join(self.mappath, hex(int(name)))
62 return ContextFile(name, create)
64 def delete_rear_map(self, name):
65 name = join(self.mappath, hex(int(name)))
74 def map_retr(self, name, blkoff=0, nr=100000000000000):
75 """Return as a list, part of the hashes map of an object
76 at the given block offset.
77 By default, return the whole hashes map.
79 namelen = self.namelen
82 with self.get_rear_map(name, 0) as rmap:
84 hashes = list(rmap.sync_read_chunks(namelen, nr, blkoff))
87 def map_stor(self, name, hashes=(), blkoff=0, create=1):
88 """Store hashes in the given hashes map, replacing the old ones."""
89 namelen = self.namelen
90 with self.get_rear_map(name, 1) as rmap:
91 rmap.sync_write_chunks(namelen, blkoff, hashes, None)
93 # def map_copy(self, src, dst):
94 # """Copy a hashes map to another one, replacing it."""
95 # with self.get_rear_map(src, 0) as rmap:
99 def map_remv(self, name):
100 """Remove a hashes map. Returns true if the map was found and removed."""
101 return self.delete_rear_map(name)