bsddb3 implementation.

For now, it's the bsddb implementation with a "3" added in crayon.

Author: Anthony Baxter

roundup/backends/back_bsddb3.py

@@ -0,0 +1,228 @@
+#$Id: back_bsddb3.py,v 1.1 2001-07-24 04:26:03 anthonybaxter Exp $
+
+import bsddb3, os, marshal
+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)
+            bsddb3.btopen(db, 'n')
+            db = os.path.join(self.dir, 'journals.%s'%cn)
+            bsddb3.btopen(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 bsddb3.btopen(path, mode)
+
+    #
+    # Nodes
+    #
+    def addnode(self, classname, nodeid, node):
+        ''' add the specified node to its class's db
+        '''
+        db = self.getclassdb(classname, 'c')
+
+        # convert the instance data to builtin types
+        properties = self.classes[classname].properties
+        for key in properties.keys():
+            if properties[key].isDateType:
+                node[key] = node[key].get_tuple()
+            elif properties[key].isIntervalType:
+                node[key] = node[key].get_tuple()
+
+        # now save the marshalled data
+        db[nodeid] = marshal.dumps(node)
+        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 = marshal.loads(db[nodeid])
+
+        # convert the marshalled data to instances
+        properties = self.classes[classname].properties
+        for key in res.keys():
+            if properties[key].isDateType:
+                res[key] = date.Date(res[key])
+            elif properties[key].isIntervalType:
+                res[key] = date.Interval(res[key])
+
+        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().get_tuple(), self.journaltag, action,
+            params)
+        db = bsddb3.btopen(os.path.join(self.dir, 'journals.%s'%classname), 'c')
+        if db.has_key(nodeid):
+            s = db[nodeid]
+            l = marshal.loads(db[nodeid])
+            l.append(entry)
+        else:
+            l = [entry]
+        db[nodeid] = marshal.dumps(l)
+        db.close()
+
+    def getjournal(self, classname, nodeid):
+        ''' get the journal for id
+        '''
+        # attempt to open the journal - in some rare cases, the journal may
+        # not exist
+        try:
+            db = bsddb3.btopen(os.path.join(self.dir, 'journals.%s'%classname),
+                'r')
+        except bsddb3.error, error:
+            if error.args[0] != 2: raise
+            return []
+        # mor handling of bad journals
+        if not db.has_key(nodeid): return []
+        journal = marshal.loads(db[nodeid])
+        res = []
+        for entry in journal:
+            (nodeid, date_stamp, self.journaltag, action, params) = entry
+            date_obj = date.Date(date_stamp)
+            res.append((nodeid, date_obj, self.journaltag, action, params))
+        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 bsddb 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 1.4  2001/07/23 08:25:33  richard
+#more handling of bad journals
+#
+#Revision 1.3  2001/07/23 08:20:44  richard
+#Moved over to using marshal in the bsddb and anydbm backends.
+#roundup-admin now has a "freshen" command that'll load/save all nodes (not
+# retired - mod hyperdb.Class.list() so it lists retired nodes)
+#
+#Revision 1.2  2001/07/23 07:56:05  richard
+#Storing only marshallable data in the db - no nasty pickled class references.
+#
+#Revision 1.1  2001/07/23 07:22:13  richard
+#*sigh* some databases have _foo.so as their underlying implementation.
+#This time for sure, Rocky.
+#
+#Revision 1.1  2001/07/23 07:15:57  richard
+#Moved the backends into the backends package. Anydbm hasn't been tested at all.
+#
+#Revision 1.1  2001/07/23 06:23:41  richard
+#moved hyper_bsddb.py to the new backends package as bsddb.py
+#
+#Revision 1.2  2001/07/22 12:09:32  richard
+#Final commit of Grande Splite
+#
+#Revision 1.1  2001/07/22 11:58:35  richard
+#More Grande Splite
+#