root / snf-pithos-backend / pithos / backends / lib / hashfiler / radosmapper.py @ 29148653
History | View | Annotate | Download (3.2 kB)
1 |
# Copyright 2011-2012 GRNET S.A. All rights reserved.
|
---|---|
2 |
#
|
3 |
# Redistribution and use in source and binary forms, with or
|
4 |
# without modification, are permitted provided that the following
|
5 |
# conditions are met:
|
6 |
#
|
7 |
# 1. Redistributions of source code must retain the above
|
8 |
# copyright notice, this list of conditions and the following
|
9 |
# disclaimer.
|
10 |
#
|
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.
|
15 |
#
|
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
|
20 |
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
21 |
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
22 |
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
|
23 |
# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
24 |
# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
25 |
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
26 |
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
27 |
# POSSIBILITY OF SUCH DAMAGE.
|
28 |
#
|
29 |
# The views and conclusions contained in the software and
|
30 |
# documentation are those of the authors and should not be
|
31 |
# interpreted as representing official policies, either expressed
|
32 |
# or implied, of GRNET S.A.
|
33 |
|
34 |
from binascii import hexlify |
35 |
|
36 |
from context_object import RadosObject |
37 |
from rados import * |
38 |
|
39 |
CEPH_CONF_FILE = "/etc/ceph/ceph.conf"
|
40 |
|
41 |
|
42 |
class RadosMapper(object): |
43 |
"""Mapper.
|
44 |
Required constructor parameters: mappath, namelen.
|
45 |
"""
|
46 |
|
47 |
mappool = None
|
48 |
namelen = None
|
49 |
|
50 |
def __init__(self, **params): |
51 |
self.params = params
|
52 |
self.namelen = params['namelen'] |
53 |
mappool = params['mappool']
|
54 |
|
55 |
rados = Rados(conffile=CEPH_CONF_FILE) |
56 |
rados.connect() |
57 |
ioctx = rados.open_ioctx(mappool) |
58 |
|
59 |
self.mappool = mappool
|
60 |
self.rados = rados
|
61 |
self.ioctx = ioctx
|
62 |
|
63 |
def _get_rear_map(self, maphash, create=0): |
64 |
name = hexlify(maphash) |
65 |
return RadosObject(name, self.ioctx, create) |
66 |
|
67 |
def _check_rear_map(self, maphash): |
68 |
name = hexlify(maphash) |
69 |
try:
|
70 |
self.ioctx.stat(name)
|
71 |
return True |
72 |
except ObjectNotFound:
|
73 |
return False |
74 |
|
75 |
def map_retr(self, maphash, blkoff=0, nr=100000000000000): |
76 |
"""Return as a list, part of the hashes map of an object
|
77 |
at the given block offset.
|
78 |
By default, return the whole hashes map.
|
79 |
"""
|
80 |
namelen = self.namelen
|
81 |
hashes = () |
82 |
|
83 |
with self._get_rear_map(maphash, 0) as rmap: |
84 |
if rmap:
|
85 |
hashes = list(rmap.sync_read_chunks(namelen, nr, blkoff))
|
86 |
return hashes
|
87 |
|
88 |
def map_stor(self, maphash, hashes=(), blkoff=0, create=1): |
89 |
"""Store hashes in the given hashes map."""
|
90 |
namelen = self.namelen
|
91 |
if self._check_rear_map(maphash): |
92 |
return
|
93 |
with self._get_rear_map(maphash, 1) as rmap: |
94 |
rmap.sync_write_chunks(namelen, blkoff, hashes, None)
|