1 files changed, 144 insertions, 0 deletions
diff --git a/Mailman/database/dbcontext.py b/Mailman/database/dbcontext.py
new file mode 100644
index 000000000..b812c9b77
--- /dev/null
+++ b/Mailman/database/dbcontext.py
@@ -0,0 +1,144 @@
+# Copyright (C) 2006 by the Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+# USA.
+
+import weakref
+
+from sqlalchemy import *
+from string import Template
+
+from Mailman import Version
+from Mailman.configuration import config
+from Mailman.database import address
+from Mailman.database import listdata
+from Mailman.database import version
+from Mailman.database.txnsupport import txn
+
+
+
+class MlistRef(weakref.ref):
+    def __init__(self, mlist, callback):
+        super(MlistRef, self).__init__(mlist, callback)
+        self.fqdn_listname = mlist.fqdn_listname
+
+
+
+class DBContext(object):
+    def __init__(self):
+        self.tables = {}
+        self.metadata = None
+        self.session = None
+        # Special transaction used only for MailList.Lock() .Save() and
+        # .Unlock() interface.
+        self._mlist_txns = {}
+
+    def connect(self):
+        # Calculate the engine url
+        url = Template(config.SQLALCHEMY_ENGINE_URL).safe_substitute(
+            config.paths)
+        self.metadata = BoundMetaData(url)
+        self.metadata.engine.echo = config.SQLALCHEMY_ECHO
+        # Create all the table objects, and then let SA conditionally create
+        # them if they don't yet exist.
+        version_table = None
+        for module in (address, listdata, version):
+            table = module.make_table(self.metadata)
+            self.tables[table.name] = table
+            if module is version:
+                version_table = table
+        self.metadata.create_all()
+        # Validate schema version, updating if necessary (XXX)
+        from Mailman.interact import interact
+        r = version_table.select(version_table.c.component=='schema').execute()
+        row = r.fetchone()
+        if row is None:
+            # Database has not yet been initialized
+            version_table.insert().execute(
+                component='schema',
+                version=Version.DATABASE_SCHEMA_VERSION)
+        elif row.version <> Version.DATABASE_SCHEMA_VERSION:
+            # XXX Update schema
+            raise SchemaVersionMismatchError(row.version)
+        self.session = create_session()
+
+    # Cooperative method for use with @txn decorator
+    def _withtxn(self, meth, *args, **kws):
+        try:
+            txn = self.session.create_transaction()
+            rtn = meth(*args, **kws)
+        except:
+            txn.rollback()
+            raise
+        else:
+            txn.commit()
+            return rtn
+
+    def _unlock_mref(self, mref):
+        txn = self._mlist_txns.pop(mref.fqdn_listname, None)
+        if txn is not None:
+            txn.rollback()
+
+    # Higher level interface
+    def api_lock(self, mlist):
+        # Don't try to re-lock a list
+        if mlist.fqdn_listname in self._mlist_txns:
+            return
+        txn = self.session.create_transaction()
+        mref = MlistRef(mlist, self._unlock_mref)
+        self._mlist_txns[mlist.fqdn_listname] = txn
+
+    def api_unlock(self, mlist):
+        txn = self._mlist_txns.pop(mlist.fqdn_listname, None)
+        if txn is not None:
+            txn.rollback()
+
+    def api_save(self, mlist):
+        # When dealing with MailLists, .Save() will always be followed by
+        # .Unlock().  However lists can also be unlocked without saving.  But
+        # if it's been locked it will always be unlocked.  So the rollback in
+        # unlock will essentially be no-op'd if we've already saved the list.
+        txn = self._mlist_txns.pop(mlist.fqdn_listname, None)
+        if txn is not None:
+            txn.commit()
+
+    @txn
+    def api_add_list(self, mlist):
+        self.session.save(mlist)
+
+    @txn
+    def api_remove_list(self, mlist):
+        self.session.delete(mlist)
+
+    @txn
+    def api_find_list(self, listname, hostname):
+        from Mailman.MailList import MailList
+        q = self.session.query(MailList)
+        mlists = q.select_by(list_name=listname, host_name=hostname)
+        assert len(mlists) <= 1, 'Duplicate mailing lists!'
+        if mlists:
+            return mlists[0]
+        return None
+
+    @txn
+    def api_get_list_names(self):
+        table = self.tables['Listdata']
+        results = table.select().execute()
+        return [(row[table.c.list_name], row[table.c.host_name])
+                for row in results.fetchall()]
+
+
+
+dbcontext = DBContext()