9f3124081171957316d70e5a67caf0f5064bac45
1 #
2 # Copyright (c) 2001 Bizar Software Pty Ltd (http://www.bizarsoftware.com.au/)
3 # This module is free software, and you may redistribute it and/or modify
4 # under the same terms as Python, so long as this copyright message and
5 # disclaimer are retained in their original form.
6 #
7 # IN NO EVENT SHALL BIZAR SOFTWARE PTY LTD BE LIABLE TO ANY PARTY FOR
8 # DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING
9 # OUT OF THE USE OF THIS CODE, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE
10 # POSSIBILITY OF SUCH DAMAGE.
11 #
12 # BIZAR SOFTWARE PTY LTD SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
13 # BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
14 # FOR A PARTICULAR PURPOSE. THE CODE PROVIDED HEREUNDER IS ON AN "AS IS"
15 # BASIS, AND THERE IS NO OBLIGATION WHATSOEVER TO PROVIDE MAINTENANCE,
16 # SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
17 #
18 #$Id: back_anydbm.py,v 1.8 2001-09-29 13:27:00 richard Exp $
20 import anydbm, os, marshal
21 from roundup import hyperdb, date
23 #
24 # Now the database
25 #
26 class Database(hyperdb.Database):
27 """A database for storing records containing flexible data types."""
29 def __init__(self, storagelocator, journaltag=None):
30 """Open a hyperdatabase given a specifier to some storage.
32 The meaning of 'storagelocator' depends on the particular
33 implementation of the hyperdatabase. It could be a file name,
34 a directory path, a socket descriptor for a connection to a
35 database over the network, etc.
37 The 'journaltag' is a token that will be attached to the journal
38 entries for any edits done on the database. If 'journaltag' is
39 None, the database is opened in read-only mode: the Class.create(),
40 Class.set(), and Class.retire() methods are disabled.
41 """
42 self.dir, self.journaltag = storagelocator, journaltag
43 self.classes = {}
44 self.transactions = []
46 #
47 # Classes
48 #
49 def __getattr__(self, classname):
50 """A convenient way of calling self.getclass(classname)."""
51 return self.classes[classname]
53 def addclass(self, cl):
54 cn = cl.classname
55 if self.classes.has_key(cn):
56 raise ValueError, cn
57 self.classes[cn] = cl
59 def getclasses(self):
60 """Return a list of the names of all existing classes."""
61 l = self.classes.keys()
62 l.sort()
63 return l
65 def getclass(self, classname):
66 """Get the Class object representing a particular class.
68 If 'classname' is not a valid class name, a KeyError is raised.
69 """
70 return self.classes[classname]
72 #
73 # Class DBs
74 #
75 def clear(self):
76 for cn in self.classes.keys():
77 db = os.path.join(self.dir, 'nodes.%s'%cn)
78 anydbm.open(db, 'n')
79 db = os.path.join(self.dir, 'journals.%s'%cn)
80 anydbm.open(db, 'n')
82 def getclassdb(self, classname, mode='r'):
83 ''' grab a connection to the class db that will be used for
84 multiple actions
85 '''
86 path = os.path.join(os.getcwd(), self.dir, 'nodes.%s'%classname)
87 if os.path.exists(path):
88 return anydbm.open(path, mode)
89 else:
90 return anydbm.open(path, 'n')
92 #
93 # Nodes
94 #
95 def addnode(self, classname, nodeid, node):
96 ''' add the specified node to its class's db
97 '''
98 db = self.getclassdb(classname, 'c')
100 # convert the instance data to builtin types
101 properties = self.classes[classname].properties
102 for key in properties.keys():
103 if isinstance(properties[key], hyperdb.Date):
104 node[key] = node[key].get_tuple()
105 elif isinstance(properties[key], hyperdb.Interval):
106 node[key] = node[key].get_tuple()
108 # now save the marshalled data
109 db[nodeid] = marshal.dumps(node)
110 db.close()
111 setnode = addnode
113 def getnode(self, classname, nodeid, cldb=None):
114 ''' add the specified node to its class's db
115 '''
116 db = cldb or self.getclassdb(classname)
117 if not db.has_key(nodeid):
118 raise IndexError, nodeid
119 res = marshal.loads(db[nodeid])
121 # convert the marshalled data to instances
122 properties = self.classes[classname].properties
123 for key in properties.keys():
124 if key == self.RETIRED_FLAG: continue
125 if isinstance(properties[key], hyperdb.Date):
126 res[key] = date.Date(res[key])
127 elif isinstance(properties[key], hyperdb.Interval):
128 res[key] = date.Interval(res[key])
130 if not cldb: db.close()
131 return res
133 def hasnode(self, classname, nodeid, cldb=None):
134 ''' add the specified node to its class's db
135 '''
136 db = cldb or self.getclassdb(classname)
137 res = db.has_key(nodeid)
138 if not cldb: db.close()
139 return res
141 def countnodes(self, classname, cldb=None):
142 db = cldb or self.getclassdb(classname)
143 return len(db.keys())
144 if not cldb: db.close()
145 return res
147 def getnodeids(self, classname, cldb=None):
148 db = cldb or self.getclassdb(classname)
149 res = db.keys()
150 if not cldb: db.close()
151 return res
153 #
154 # Journal
155 #
156 def addjournal(self, classname, nodeid, action, params):
157 ''' Journal the Action
158 'action' may be:
160 'create' or 'set' -- 'params' is a dictionary of property values
161 'link' or 'unlink' -- 'params' is (classname, nodeid, propname)
162 'retire' -- 'params' is None
163 '''
164 entry = (nodeid, date.Date().get_tuple(), self.journaltag, action,
165 params)
166 db = anydbm.open(os.path.join(self.dir, 'journals.%s'%classname), 'c')
167 if db.has_key(nodeid):
168 s = db[nodeid]
169 l = marshal.loads(db[nodeid])
170 l.append(entry)
171 else:
172 l = [entry]
173 db[nodeid] = marshal.dumps(l)
174 db.close()
176 def getjournal(self, classname, nodeid):
177 ''' get the journal for id
178 '''
179 # attempt to open the journal - in some rare cases, the journal may
180 # not exist
181 try:
182 db = anydbm.open(os.path.join(self.dir, 'journals.%s'%classname),
183 'r')
184 except anydbm.open, error:
185 if error.args[0] != 2: raise
186 return []
187 journal = marshal.loads(db[nodeid])
188 res = []
189 for entry in journal:
190 (nodeid, date_stamp, self.journaltag, action, params) = entry
191 date_obj = date.Date(date_stamp)
192 res.append((nodeid, date_obj, self.journaltag, action, params))
193 db.close()
194 return res
196 def close(self):
197 ''' Close the Database - we must release the circular refs so that
198 we can be del'ed and the underlying anydbm connections closed
199 cleanly.
200 '''
201 self.classes = None
204 #
205 # Basic transaction support
206 #
207 def commit(self):
208 ''' Commit the current transactions.
209 '''
210 # lock the DB
211 for action, classname, entry in self.transactions:
212 # write the node, figure what's changed for the journal.
213 pass
214 # unlock the DB
216 def rollback(self):
217 ''' Reverse all actions from the current transaction.
218 '''
219 self.transactions = []
221 #
222 #$Log: not supported by cvs2svn $
223 #Revision 1.7 2001/08/12 06:32:36 richard
224 #using isinstance(blah, Foo) now instead of isFooType
225 #
226 #Revision 1.6 2001/08/07 00:24:42 richard
227 #stupid typo
228 #
229 #Revision 1.5 2001/08/07 00:15:51 richard
230 #Added the copyright/license notice to (nearly) all files at request of
231 #Bizar Software.
232 #
233 #Revision 1.4 2001/07/30 01:41:36 richard
234 #Makes schema changes mucho easier.
235 #
236 #Revision 1.3 2001/07/25 01:23:07 richard
237 #Added the Roundup spec to the new documentation directory.
238 #
239 #Revision 1.2 2001/07/23 08:20:44 richard
240 #Moved over to using marshal in the bsddb and anydbm backends.
241 #roundup-admin now has a "freshen" command that'll load/save all nodes (not
242 # retired - mod hyperdb.Class.list() so it lists retired nodes)
243 #
244 #