1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
|
from leap import *
from u1db import errors
from u1db.backends import CommonBackend
from u1db.remote.http_target import HTTPSyncTarget
from swiftclient import client
class OpenStackDatabase(CommonBackend):
"""A U1DB implementation that uses OpenStack as its persistence layer."""
def __init__(self, auth_url, user, auth_key, container):
"""Create a new OpenStack data container."""
self._auth_url = auth_url
self._user = user
self._auth_key = auth_key
self._container = container
self.set_document_factory(LeapDocument)
self._connection = swiftclient.Connection(self._auth_url, self._user,
self._auth_key)
self._get_auth()
#-------------------------------------------------------------------------
# implemented methods from Database
#-------------------------------------------------------------------------
def set_document_factory(self, factory):
self._factory = factory
def set_document_size_limit(self, limit):
raise NotImplementedError(self.set_document_size_limit)
def whats_changed(self, old_generation=0):
raise NotImplementedError(self.whats_changed)
def get_doc(self, doc_id, include_deleted=False):
# TODO: support deleted docs?
headers = self._connection.head_object(self._container, doc_id)
rev = headers['x-object-meta-rev']
response, contents = self._connection.get_object(self._container, doc_id)
return self._factory(doc_id, rev, contents)
def get_all_docs(self, include_deleted=False):
"""Get all documents from the database."""
raise NotImplementedError(self.get_all_docs)
def put_doc(self, doc):
if doc.doc_id is None:
raise errors.InvalidDocId()
self._check_doc_id(doc.doc_id)
self._check_doc_size(doc)
# TODO: check for conflicts?
new_rev = self._allocate_doc_rev(doc.rev)
headers = { 'X-Object-Meta-Rev' : new_rev }
self._connection.put_object(self._container, doc_id, doc.get_json(),
headers=headers)
return new_rev
def delete_doc(self, doc):
raise NotImplementedError(self.delete_doc)
# start of index-related methods: these are not supported by this backend.
def create_index(self, index_name, *index_expressions):
return False
def delete_index(self, index_name):
return False
def list_indexes(self):
return []
def get_from_index(self, index_name, *key_values):
return []
def get_range_from_index(self, index_name, start_value=None,
end_value=None):
return []
def get_index_keys(self, index_name):
return []
# end of index-related methods: these are not supported by this backend.
def get_doc_conflicts(self, doc_id):
return []
def resolve_doc(self, doc, conflicted_doc_revs):
raise NotImplementedError(self.resolve_doc)
def get_sync_target(self):
return OpenStackSyncTarget(self)
def close(self):
raise NotImplementedError(self.close)
def sync(self, url, creds=None, autocreate=True):
raise NotImplementedError(self.close)
def _get_replica_gen_and_trans_id(self, other_replica_uid):
self._update_u1db_data()
return self._sync_log.get_replica_gen_and_trans_id(other_replica_uid)
def _set_replica_gen_and_trans_id(self, other_replica_uid,
other_generation, other_transaction_id):
self._update_u1db_data()
return self._sync_log.set_replica_gen_and_trans_id(other_replica_uid,
other_generation, other_transaction_id)
#-------------------------------------------------------------------------
# implemented methods from CommonBackend
#-------------------------------------------------------------------------
def _get_generation(self):
self._update_u1db_data()
return self._transaction_log.get_generation()
def _get_generation_info(self):
self._update_u1db_data()
return self._transaction_log.get_generation_info()
def _get_doc(self, doc_id, check_for_conflicts=False):
"""Get just the document content, without fancy handling."""
raise NotImplementedError(self._get_doc)
def _has_conflicts(self, doc_id):
raise NotImplementedError(self._has_conflicts)
def _put_and_update_indexes(self, doc_id, old_doc, new_rev, content):
raise NotImplementedError(self._put_and_update_indexes)
def _get_trans_id_for_gen(self, generation):
self._update_u1db_data()
trans_id = self._transaction_log.get_trans_id_for_gen(generation)
if trans_id is None:
raise errors.InvalidGeneration
return trans_id
#-------------------------------------------------------------------------
# OpenStack specific methods
#-------------------------------------------------------------------------
def _is_initialized(self, c):
raise NotImplementedError(self._is_initialized)
def _initialize(self, c):
raise NotImplementedError(self._initialize)
def _get_auth(self):
self._url, self._auth_token = self._connection.get_auth()
return self._url, self.auth_token
def _update_u1db_data(self):
data = self.get_doc('u1db_data').content
self._transaction_log = data['transaction_log']
self._sync_log = data['sync_log']
class OpenStackSyncTarget(HTTPSyncTarget):
def get_sync_info(self, source_replica_uid):
raise NotImplementedError(self.get_sync_info)
def record_sync_info(self, source_replica_uid, source_replica_generation,
source_replica_transaction_id):
raise NotImplementedError(self.record_sync_info)
class SimpleLog(object):
def __init__(self, log=None):
self._log = []
if log:
self._log = log
def append(self, msg):
self._log.append(msg)
def reduce(self, func, initializer=None):
return reduce(func, self._log, initializer)
def map(self, func):
return map(func, self._log)
class TransactionLog(SimpleLog):
"""
A list of (generation, doc_id, transaction_id) tuples.
"""
def get_generation(self):
"""
Return the current generation.
"""
gens = self.map(lambda x: x[0])
if not gens:
return 0
return max(gens)
def get_generation_info(self):
"""
Return the current generation and transaction id.
"""
if not self._log:
return(0, '')
info = self.map(lambda x: (x[0], x[2]))
return reduce(lambda x, y: x if (x[0] > y[0]) else y, info)
def get_trans_id_for_gen(self, gen):
"""
Get the transaction id corresponding to a particular generation.
"""
log = self.reduce(lambda x, y: y if y[0] == gen else x)
if log is None:
return None
return log[2]
class SyncLog(SimpleLog):
"""
A list of (replica_id, generation, transaction_id) tuples.
"""
def find_by_replica_uid(self, replica_uid):
if not self._log:
return ()
return self.reduce(lambda x, y: y if y[0] == replica_uid else x)
def get_replica_gen_and_trans_id(self, other_replica_uid):
"""
Return the last known generation and transaction id for the other db
replica.
"""
info = self.find_by_replica_uid(other_replica_uid)
if not info:
return (0, '')
return (info[1], info[2])
def set_replica_gen_and_trans_id(self, other_replica_uid,
other_generation, other_transaction_id):
"""
Set the last-known generation and transaction id for the other
database replica.
"""
old_log = self._log
self._log = []
for log in old_log:
if log[0] != other_replica_uid:
self.append(log)
self.append((other_replica_uid, other_generation,
other_transaction_id))
|
