Mercurial > p > roundup > code
diff roundup/backends/back_anydbm.py @ 46:3c5920433866
*sigh* some databases have _foo.so as their underlying implementation.
This time for sure, Rocky.
| author | Richard Jones <richard@users.sourceforge.net> |
|---|---|
| date | Mon, 23 Jul 2001 07:22:13 +0000 |
| parents | |
| children | 671203878652 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/roundup/backends/back_anydbm.py Mon Jul 23 07:22:13 2001 +0000 @@ -0,0 +1,168 @@ +#$Id: back_anydbm.py,v 1.1 2001-07-23 07:22:13 richard Exp $ + +import anydbm, os, cPickle +from roundup import hyperdb, date + +# +# Now the database +# +class Database(hyperdb.Database): + """A database for storing records containing flexible data types.""" + + def __init__(self, storagelocator, journaltag=None): + """Open a hyperdatabase given a specifier to some storage. + + The meaning of 'storagelocator' depends on the particular + implementation of the hyperdatabase. It could be a file name, + a directory path, a socket descriptor for a connection to a + database over the network, etc. + + The 'journaltag' is a token that will be attached to the journal + entries for any edits done on the database. If 'journaltag' is + None, the database is opened in read-only mode: the Class.create(), + Class.set(), and Class.retire() methods are disabled. + """ + self.dir, self.journaltag = storagelocator, journaltag + self.classes = {} + + # + # Classes + # + def __getattr__(self, classname): + """A convenient way of calling self.getclass(classname).""" + return self.classes[classname] + + def addclass(self, cl): + cn = cl.classname + if self.classes.has_key(cn): + raise ValueError, cn + self.classes[cn] = cl + + def getclasses(self): + """Return a list of the names of all existing classes.""" + l = self.classes.keys() + l.sort() + return l + + def getclass(self, classname): + """Get the Class object representing a particular class. + + If 'classname' is not a valid class name, a KeyError is raised. + """ + return self.classes[classname] + + # + # Class DBs + # + def clear(self): + for cn in self.classes.keys(): + db = os.path.join(self.dir, 'nodes.%s'%cn) + anydbm.open(db, 'n') + db = os.path.join(self.dir, 'journals.%s'%cn) + anydbm.open(db, 'n') + + def getclassdb(self, classname, mode='r'): + ''' grab a connection to the class db that will be used for + multiple actions + ''' + path = os.path.join(os.getcwd(), self.dir, 'nodes.%s'%classname) + return anydbm.open(path, mode) + + def addnode(self, classname, nodeid, node): + ''' add the specified node to its class's db + ''' + db = self.getclassdb(classname, 'c') + db[nodeid] = cPickle.dumps(node, 1) + db.close() + setnode = addnode + + def getnode(self, classname, nodeid, cldb=None): + ''' add the specified node to its class's db + ''' + db = cldb or self.getclassdb(classname) + if not db.has_key(nodeid): + raise IndexError, nodeid + res = cPickle.loads(db[nodeid]) + if not cldb: db.close() + return res + + def hasnode(self, classname, nodeid, cldb=None): + ''' add the specified node to its class's db + ''' + db = cldb or self.getclassdb(classname) + res = db.has_key(nodeid) + if not cldb: db.close() + return res + + def countnodes(self, classname, cldb=None): + db = cldb or self.getclassdb(classname) + return len(db.keys()) + if not cldb: db.close() + return res + + def getnodeids(self, classname, cldb=None): + db = cldb or self.getclassdb(classname) + res = db.keys() + if not cldb: db.close() + return res + + # + # Journal + # + def addjournal(self, classname, nodeid, action, params): + ''' Journal the Action + 'action' may be: + + 'create' or 'set' -- 'params' is a dictionary of property values + 'link' or 'unlink' -- 'params' is (classname, nodeid, propname) + 'retire' -- 'params' is None + ''' + entry = (nodeid, date.Date(), self.journaltag, action, params) + db = anydbm.open(os.path.join(self.dir, 'journals.%s'%classname), 'c') + if db.has_key(nodeid): + s = db[nodeid] + l = cPickle.loads(db[nodeid]) + l.append(entry) + else: + l = [entry] + db[nodeid] = cPickle.dumps(l) + db.close() + + def getjournal(self, classname, nodeid): + ''' get the journal for id + ''' + db = anydbm.open(os.path.join(self.dir, 'journals.%s'%classname), 'r') + res = cPickle.loads(db[nodeid]) + db.close() + return res + + def close(self): + ''' Close the Database - we must release the circular refs so that + we can be del'ed and the underlying anydbm connections closed + cleanly. + ''' + self.classes = None + + + # + # Basic transaction support + # + # TODO: well, write these methods (and then use them in other code) + def register_action(self): + ''' Register an action to the transaction undo log + ''' + + def commit(self): + ''' Commit the current transaction, start a new one + ''' + + def rollback(self): + ''' Reverse all actions from the current transaction + ''' + +# +#$Log: not supported by cvs2svn $ +#Revision 1.1 2001/07/23 07:15:57 richard +#Moved the backends into the backends package. Anydbm hasn't been tested at all. +# +#
