--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hyperdb_bsddb.py	Fri Jul 20 07:35:55 2001 +0000
@@ -0,0 +1,165 @@
+#$Id: hyperdb_bsddb.py,v 1.1 2001-07-20 07:35:55 richard Exp $
+
+import bsddb, os, cPickle
+import date
+
+#
+# Now the database
+#
+class 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)
+            bsddb.btopen(db, 'n')
+            db = os.path.join(self.dir, 'journals.%s'%cn)
+            bsddb.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 bsddb.btopen(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 = bsddb.btopen(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 = bsddb.btopen(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 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 $
+