]> git.decadent.org.uk Git - dak.git/blobdiff - daklib/dbconn.py
Merge branch 'master' into contents
[dak.git] / daklib / dbconn.py
index 24f8fb17d9620f99570db40e203ac21381ec142c..d4caf01c9176d60980c13933090950efa477aab9 100755 (executable)
@@ -59,8 +59,10 @@ import sqlalchemy
 from sqlalchemy import create_engine, Table, MetaData, Column, Integer, desc, \
     Text, ForeignKey
 from sqlalchemy.orm import sessionmaker, mapper, relation, object_session, \
-    backref, MapperExtension, EXT_CONTINUE, object_mapper
+    backref, MapperExtension, EXT_CONTINUE, object_mapper, clear_mappers
 from sqlalchemy import types as sqltypes
+from sqlalchemy.orm.collections import attribute_mapped_collection
+from sqlalchemy.ext.associationproxy import association_proxy
 
 # Don't remove this, we re-export the exceptions to scripts which import us
 from sqlalchemy.exc import *
@@ -77,9 +79,6 @@ import warnings
 warnings.filterwarnings('ignore', \
     "The SQLAlchemy PostgreSQL dialect has been renamed from 'postgres' to 'postgresql'.*", \
     SADeprecationWarning)
-# TODO: sqlalchemy needs some extra configuration to correctly reflect
-# the ind_deb_contents_* indexes - we ignore the warnings at the moment
-warnings.filterwarnings("ignore", 'Predicate of partial index', SAWarning)
 
 
 ################################################################################
@@ -205,7 +204,9 @@ class ORMObject(object):
                     # list
                     value = len(value)
                 elif hasattr(value, 'count'):
-                    # query
+                    # query (but not during validation)
+                    if self.in_validation:
+                        continue
                     value = value.count()
                 else:
                     raise KeyError('Do not understand property %s.' % property)
@@ -259,6 +260,8 @@ class ORMObject(object):
     validation_message = \
         "Validation failed because property '%s' must not be empty in object\n%s"
 
+    in_validation = False
+
     def validate(self):
         '''
         This function validates the not NULL constraints as returned by
@@ -273,8 +276,11 @@ class ORMObject(object):
                 getattr(self, property + '_id') is not None:
                 continue
             if not hasattr(self, property) or getattr(self, property) is None:
-                raise DBUpdateError(self.validation_message % \
-                    (property, str(self)))
+                # str() might lead to races due to a 2nd flush
+                self.in_validation = True
+                message = self.validation_message % (property, str(self))
+                self.in_validation = False
+                raise DBUpdateError(message)
 
     @classmethod
     @session_wrapper
@@ -493,37 +499,73 @@ class DBBinary(ORMObject):
         self.poolfile = poolfile
         self.binarytype = binarytype
 
+    @property
+    def pkid(self):
+        return self.binary_id
+
     def properties(self):
         return ['package', 'version', 'maintainer', 'source', 'architecture', \
             'poolfile', 'binarytype', 'fingerprint', 'install_date', \
-            'suites_count', 'binary_id', 'contents_count']
+            'suites_count', 'binary_id', 'contents_count', 'extra_sources']
 
     def not_null_constraints(self):
         return ['package', 'version', 'maintainer', 'source',  'poolfile', \
             'binarytype']
 
+    metadata = association_proxy('key', 'value')
+
     def get_component_name(self):
         return self.poolfile.location.component.component_name
 
     def scan_contents(self):
         '''
         Yields the contents of the package. Only regular files are yielded and
-        the path names are normalized after converting them from either utf-8 or
-        iso8859-1 encoding.
+        the path names are normalized after converting them from either utf-8
+        or iso8859-1 encoding. It yields the string ' <EMPTY PACKAGE>' if the
+        package does not contain any regular file.
         '''
         fullpath = self.poolfile.fullpath
-        debdata = Popen(['dpkg-deb', '--fsys-tarfile', fullpath],
-            stdout = PIPE).stdout
-        tar = TarFile.open(fileobj = debdata, mode = 'r|')
+        dpkg = Popen(['dpkg-deb', '--fsys-tarfile', fullpath], stdout = PIPE)
+        tar = TarFile.open(fileobj = dpkg.stdout, mode = 'r|')
         for member in tar.getmembers():
-            if member.isfile():
+            if not member.isdir():
+                name = normpath(member.name)
+                # enforce proper utf-8 encoding
                 try:
-                    name = member.name.decode('utf-8')
+                    name.decode('utf-8')
                 except UnicodeDecodeError:
-                    name = member.name.decode('iso8859-1')
-                yield normpath(name)
+                    name = name.decode('iso8859-1').encode('utf-8')
+                yield name
         tar.close()
-        debdata.close()
+        dpkg.stdout.close()
+        dpkg.wait()
+
+    def read_control(self):
+        '''
+        Reads the control information from a binary.
+
+        @rtype: text
+        @return: stanza text of the control section.
+        '''
+        import apt_inst
+        fullpath = self.poolfile.fullpath
+        deb_file = open(fullpath, 'r')
+        stanza = apt_inst.debExtractControl(deb_file)
+        deb_file.close()
+
+        return stanza
+
+    def read_control_fields(self):
+        '''
+        Reads the control information from a binary and return
+        as a dictionary.
+
+        @rtype: dict
+        @return: fields of the control section as a dictionary.
+        '''
+        import apt_pkg
+        stanza = self.read_control()
+        return apt_pkg.TagSection(stanza)
 
 __all__.append('DBBinary')
 
@@ -1945,111 +1987,6 @@ __all__.append('get_override_type')
 
 ################################################################################
 
-class DebContents(object):
-    def __init__(self, *args, **kwargs):
-        pass
-
-    def __repr__(self):
-        return '<DebConetnts %s: %s>' % (self.package.package,self.file)
-
-__all__.append('DebContents')
-
-
-class UdebContents(object):
-    def __init__(self, *args, **kwargs):
-        pass
-
-    def __repr__(self):
-        return '<UdebConetnts %s: %s>' % (self.package.package,self.file)
-
-__all__.append('UdebContents')
-
-class PendingBinContents(object):
-    def __init__(self, *args, **kwargs):
-        pass
-
-    def __repr__(self):
-        return '<PendingBinContents %s>' % self.contents_id
-
-__all__.append('PendingBinContents')
-
-def insert_pending_content_paths(package,
-                                 is_udeb,
-                                 fullpaths,
-                                 session=None):
-    """
-    Make sure given paths are temporarily associated with given
-    package
-
-    @type package: dict
-    @param package: the package to associate with should have been read in from the binary control file
-    @type fullpaths: list
-    @param fullpaths: the list of paths of the file being associated with the binary
-    @type session: SQLAlchemy session
-    @param session: Optional SQLAlchemy session.  If this is passed, the caller
-    is responsible for ensuring a transaction has begun and committing the
-    results or rolling back based on the result code.  If not passed, a commit
-    will be performed at the end of the function
-
-    @return: True upon success, False if there is a problem
-    """
-
-    privatetrans = False
-
-    if session is None:
-        session = DBConn().session()
-        privatetrans = True
-
-    try:
-        arch = get_architecture(package['Architecture'], session)
-        arch_id = arch.arch_id
-
-        # Remove any already existing recorded files for this package
-        q = session.query(PendingBinContents)
-        q = q.filter_by(package=package['Package'])
-        q = q.filter_by(version=package['Version'])
-        q = q.filter_by(architecture=arch_id)
-        q.delete()
-
-        for fullpath in fullpaths:
-
-            if fullpath.startswith( "./" ):
-                fullpath = fullpath[2:]
-
-            pca = PendingBinContents()
-            pca.package = package['Package']
-            pca.version = package['Version']
-            pca.file = fullpath
-            pca.architecture = arch_id
-
-            if isudeb:
-                pca.type = 8 # gross
-            else:
-                pca.type = 7 # also gross
-            session.add(pca)
-
-        # Only commit if we set up the session ourself
-        if privatetrans:
-            session.commit()
-            session.close()
-        else:
-            session.flush()
-
-        return True
-    except Exception, e:
-        traceback.print_exc()
-
-        # Only rollback if we set up the session ourself
-        if privatetrans:
-            session.rollback()
-            session.close()
-
-        return False
-
-__all__.append('insert_pending_content_paths')
-
-################################################################################
-
 class PolicyQueue(object):
     def __init__(self, *args, **kwargs):
         pass
@@ -2258,6 +2195,72 @@ __all__.append('get_sections')
 
 ################################################################################
 
+class SrcContents(ORMObject):
+    def __init__(self, file = None, source = None):
+        self.file = file
+        self.source = source
+
+    def properties(self):
+        return ['file', 'source']
+
+__all__.append('SrcContents')
+
+################################################################################
+
+from debian.debfile import Deb822
+
+# Temporary Deb822 subclass to fix bugs with : handling; see #597249
+class Dak822(Deb822):
+    def _internal_parser(self, sequence, fields=None):
+        # The key is non-whitespace, non-colon characters before any colon.
+        key_part = r"^(?P<key>[^: \t\n\r\f\v]+)\s*:\s*"
+        single = re.compile(key_part + r"(?P<data>\S.*?)\s*$")
+        multi = re.compile(key_part + r"$")
+        multidata = re.compile(r"^\s(?P<data>.+?)\s*$")
+
+        wanted_field = lambda f: fields is None or f in fields
+
+        if isinstance(sequence, basestring):
+            sequence = sequence.splitlines()
+
+        curkey = None
+        content = ""
+        for line in self.gpg_stripped_paragraph(sequence):
+            m = single.match(line)
+            if m:
+                if curkey:
+                    self[curkey] = content
+
+                if not wanted_field(m.group('key')):
+                    curkey = None
+                    continue
+
+                curkey = m.group('key')
+                content = m.group('data')
+                continue
+
+            m = multi.match(line)
+            if m:
+                if curkey:
+                    self[curkey] = content
+
+                if not wanted_field(m.group('key')):
+                    curkey = None
+                    continue
+
+                curkey = m.group('key')
+                content = ""
+                continue
+
+            m = multidata.match(line)
+            if m:
+                content += '\n' + line # XXX not m.group('data')?
+                continue
+
+        if curkey:
+            self[curkey] = content
+
+
 class DBSource(ORMObject):
     def __init__(self, source = None, version = None, maintainer = None, \
         changedby = None, poolfile = None, install_date = None):
@@ -2268,6 +2271,10 @@ class DBSource(ORMObject):
         self.poolfile = poolfile
         self.install_date = install_date
 
+    @property
+    def pkid(self):
+        return self.source_id
+
     def properties(self):
         return ['source', 'source_id', 'maintainer', 'changedby', \
             'fingerprint', 'poolfile', 'version', 'suites_count', \
@@ -2277,6 +2284,38 @@ class DBSource(ORMObject):
         return ['source', 'version', 'install_date', 'maintainer', \
             'changedby', 'poolfile', 'install_date']
 
+    def read_control_fields(self):
+        '''
+        Reads the control information from a dsc
+
+        @rtype: tuple
+        @return: fields is the dsc information in a dictionary form
+        '''
+        fullpath = self.poolfile.fullpath
+        fields = Dak822(open(self.poolfile.fullpath, 'r'))
+        return fields
+
+    metadata = association_proxy('key', 'value')
+
+    def scan_contents(self):
+        '''
+        Returns a set of names for non directories. The path names are
+        normalized after converting them from either utf-8 or iso8859-1
+        encoding.
+        '''
+        fullpath = self.poolfile.fullpath
+        from daklib.contents import UnpackedSource
+        unpacked = UnpackedSource(fullpath)
+        fileset = set()
+        for name in unpacked.get_all_filenames():
+            # enforce proper utf-8 encoding
+            try:
+                name.decode('utf-8')
+            except UnicodeDecodeError:
+                name = name.decode('iso8859-1').encode('utf-8')
+            fileset.add(name)
+        return fileset
+
 __all__.append('DBSource')
 
 @session_wrapper
@@ -2420,6 +2459,34 @@ def get_source_in_suite(source, suite, session=None):
 
 __all__.append('get_source_in_suite')
 
+@session_wrapper
+def import_metadata_into_db(obj, session=None):
+    """
+    This routine works on either DBBinary or DBSource objects and imports
+    their metadata into the database
+    """
+    fields = obj.read_control_fields()
+    for k in fields.keys():
+        try:
+            # Try raw ASCII
+            val = str(fields[k])
+        except UnicodeEncodeError:
+            # Fall back to UTF-8
+            try:
+                val = fields[k].encode('utf-8')
+            except UnicodeEncodeError:
+                # Finally try iso8859-1
+                val = fields[k].encode('iso8859-1')
+                # Otherwise we allow the exception to percolate up and we cause
+                # a reject as someone is playing silly buggers
+
+        obj.metadata[get_or_set_metadatakey(k, session)] = val
+
+    session.commit_or_flush()
+
+__all__.append('import_metadata_into_db')
+
+
 ################################################################################
 
 @session_wrapper
@@ -2570,6 +2637,16 @@ def add_deb_to_db(u, filename, session=None):
 
     bin.source_id = bin_sources[0].source_id
 
+    if entry.has_key("built-using"):
+        for srcname, version in entry["built-using"]:
+            exsources = get_sources_from_name(srcname, version, session=session)
+            if len(exsources) != 1:
+                raise NoSourceFieldError, "Unable to find source package (%s = %s) in Built-Using for %s (%s), %s, file %s, type %s, signed by %s" % \
+                                          (srcname, version, bin.package, bin.version, entry["architecture"],
+                                           filename, bin.binarytype, u.pkg.changes["fingerprint"])
+
+            bin.extra_sources.append(exsources[0])
+
     # Add and flush object so it has an ID
     session.add(bin)
 
@@ -2586,7 +2663,7 @@ def add_deb_to_db(u, filename, session=None):
     #    session.rollback()
     #    raise MissingContents, "No contents stored for package %s, and couldn't determine contents of %s" % (bin.package, filename)
 
-    return poolfile
+    return bin, poolfile
 
 __all__.append('add_deb_to_db')
 
@@ -2653,7 +2730,7 @@ class Suite(ORMObject):
             'overrides_count']
 
     def not_null_constraints(self):
-        return ['suite_name', 'version']
+        return ['suite_name']
 
     def __eq__(self, val):
         if isinstance(val, str):
@@ -2897,6 +2974,84 @@ __all__.append('UploadBlock')
 
 ################################################################################
 
+class MetadataKey(ORMObject):
+    def __init__(self, key = None):
+        self.key = key
+
+    def properties(self):
+        return ['key']
+
+    def not_null_constraints(self):
+        return ['key']
+
+__all__.append('MetadataKey')
+
+@session_wrapper
+def get_or_set_metadatakey(keyname, session=None):
+    """
+    Returns MetadataKey object for given uidname.
+
+    If no matching keyname is found, a row is inserted.
+
+    @type uidname: string
+    @param uidname: The keyname to add
+
+    @type session: SQLAlchemy
+    @param session: Optional SQL session object (a temporary one will be
+    generated if not supplied).  If not passed, a commit will be performed at
+    the end of the function, otherwise the caller is responsible for commiting.
+
+    @rtype: MetadataKey
+    @return: the metadatakey object for the given keyname
+    """
+
+    q = session.query(MetadataKey).filter_by(key=keyname)
+
+    try:
+        ret = q.one()
+    except NoResultFound:
+        ret = MetadataKey(keyname)
+        session.add(ret)
+        session.commit_or_flush()
+
+    return ret
+
+__all__.append('get_or_set_metadatakey')
+
+################################################################################
+
+class BinaryMetadata(ORMObject):
+    def __init__(self, key = None, value = None, binary = None):
+        self.key = key
+        self.value = value
+        self.binary = binary
+
+    def properties(self):
+        return ['binary', 'key', 'value']
+
+    def not_null_constraints(self):
+        return ['value']
+
+__all__.append('BinaryMetadata')
+
+################################################################################
+
+class SourceMetadata(ORMObject):
+    def __init__(self, key = None, value = None, source = None):
+        self.key = key
+        self.value = value
+        self.source = source
+
+    def properties(self):
+        return ['source', 'key', 'value']
+
+    def not_null_constraints(self):
+        return ['value']
+
+__all__.append('SourceMetadata')
+
+################################################################################
+
 class DBConn(object):
     """
     database module init.
@@ -2912,11 +3067,13 @@ class DBConn(object):
             self.__createconn()
 
     def __setuptables(self):
-        tables_with_primary = (
+        tables = (
             'architecture',
             'archive',
             'bin_associations',
+            'bin_contents',
             'binaries',
+            'binaries_metadata',
             'binary_acl',
             'binary_acl_map',
             'build_queue',
@@ -2928,40 +3085,38 @@ class DBConn(object):
             'changes_pending_binaries',
             'changes_pending_files',
             'changes_pending_source',
+            'changes_pending_files_map',
+            'changes_pending_source_files',
+            'changes_pool_files',
             'dsc_files',
+            'extra_src_references',
             'files',
             'fingerprint',
             'keyrings',
             'keyring_acl_map',
             'location',
             'maintainer',
+            'metadata_keys',
             'new_comments',
+            # TODO: the maintainer column in table override should be removed.
+            'override',
             'override_type',
-            'pending_bin_contents',
             'policy_queue',
             'priority',
             'section',
             'source',
             'source_acl',
+            'source_metadata',
             'src_associations',
+            'src_contents',
             'src_format',
             'src_uploaders',
             'suite',
-            'uid',
-            'upload_blocks',
-        )
-
-        tables_no_primary = (
-            'changes_pending_files_map',
-            'changes_pending_source_files',
-            'changes_pool_files',
-            'deb_contents',
-            # TODO: the maintainer column in table override should be removed.
-            'override',
             'suite_architectures',
-            'suite_src_formats',
             'suite_build_queue_copy',
-            'udeb_contents',
+            'suite_src_formats',
+            'uid',
+            'upload_blocks',
         )
 
         views = (
@@ -2988,27 +3143,11 @@ class DBConn(object):
             'suite_arch_by_name',
         )
 
-        # Sqlalchemy version 0.5 fails to reflect the SERIAL type
-        # correctly and that is why we have to use a workaround. It can
-        # be removed as soon as we switch to version 0.6.
-        for table_name in tables_with_primary:
+        for table_name in tables:
             table = Table(table_name, self.db_meta, \
-                Column('id', Integer, primary_key = True), \
                 autoload=True, useexisting=True)
             setattr(self, 'tbl_%s' % table_name, table)
 
-        for table_name in tables_no_primary:
-            table = Table(table_name, self.db_meta, autoload=True)
-            setattr(self, 'tbl_%s' % table_name, table)
-
-        # bin_contents needs special attention until update #41 has been
-        # applied
-        self.tbl_bin_contents = Table('bin_contents', self.db_meta, \
-            Column('file', Text, primary_key = True),
-            Column('binary_id', Integer, ForeignKey('binaries.id'), \
-                primary_key = True),
-            autoload=True, useexisting=True)
-
         for view_name in views:
             view = Table(view_name, self.db_meta, autoload=True)
             setattr(self, 'view_%s' % view_name, view)
@@ -3025,30 +3164,6 @@ class DBConn(object):
                properties = dict(archive_id = self.tbl_archive.c.id,
                                  archive_name = self.tbl_archive.c.name))
 
-        mapper(PendingBinContents, self.tbl_pending_bin_contents,
-               properties = dict(contents_id =self.tbl_pending_bin_contents.c.id,
-                                 filename = self.tbl_pending_bin_contents.c.filename,
-                                 package = self.tbl_pending_bin_contents.c.package,
-                                 version = self.tbl_pending_bin_contents.c.version,
-                                 arch = self.tbl_pending_bin_contents.c.arch,
-                                 otype = self.tbl_pending_bin_contents.c.type))
-
-        mapper(DebContents, self.tbl_deb_contents,
-               properties = dict(binary_id=self.tbl_deb_contents.c.binary_id,
-                                 package=self.tbl_deb_contents.c.package,
-                                 suite=self.tbl_deb_contents.c.suite,
-                                 arch=self.tbl_deb_contents.c.arch,
-                                 section=self.tbl_deb_contents.c.section,
-                                 filename=self.tbl_deb_contents.c.filename))
-
-        mapper(UdebContents, self.tbl_udeb_contents,
-               properties = dict(binary_id=self.tbl_udeb_contents.c.binary_id,
-                                 package=self.tbl_udeb_contents.c.package,
-                                 suite=self.tbl_udeb_contents.c.suite,
-                                 arch=self.tbl_udeb_contents.c.arch,
-                                 section=self.tbl_udeb_contents.c.section,
-                                 filename=self.tbl_udeb_contents.c.filename))
-
         mapper(BuildQueue, self.tbl_build_queue,
                properties = dict(queue_id = self.tbl_build_queue.c.id))
 
@@ -3073,7 +3188,11 @@ class DBConn(object):
                                  fingerprint = relation(Fingerprint),
                                  install_date = self.tbl_binaries.c.install_date,
                                  suites = relation(Suite, secondary=self.tbl_bin_associations,
-                                     backref=backref('binaries', lazy='dynamic'))),
+                                     backref=backref('binaries', lazy='dynamic')),
+                                 extra_sources = relation(DBSource, secondary=self.tbl_extra_src_references,
+                                     backref=backref('extra_binary_references', lazy='dynamic')),
+                                 key = relation(BinaryMetadata, cascade='all',
+                                     collection_class=attribute_mapped_collection('key'))),
                 extension = validator)
 
         mapper(BinaryACL, self.tbl_binary_acl,
@@ -3243,7 +3362,9 @@ class DBConn(object):
                                                      primaryjoin=(self.tbl_source.c.id==self.tbl_dsc_files.c.source)),
                                  suites = relation(Suite, secondary=self.tbl_src_associations,
                                      backref=backref('sources', lazy='dynamic')),
-                                 srcuploaders = relation(SrcUploader)),
+                                 srcuploaders = relation(SrcUploader),
+                                 key = relation(SourceMetadata, cascade='all',
+                                     collection_class=attribute_mapped_collection('key'))),
                extension = validator)
 
         mapper(SourceACL, self.tbl_source_acl,
@@ -3288,26 +3409,78 @@ class DBConn(object):
         mapper(BinContents, self.tbl_bin_contents,
             properties = dict(
                 binary = relation(DBBinary,
-                    backref=backref('contents', lazy='dynamic')),
+                    backref=backref('contents', lazy='dynamic', cascade='all')),
                 file = self.tbl_bin_contents.c.file))
 
+        mapper(SrcContents, self.tbl_src_contents,
+            properties = dict(
+                source = relation(DBSource,
+                    backref=backref('contents', lazy='dynamic', cascade='all')),
+                file = self.tbl_src_contents.c.file))
+
+        mapper(MetadataKey, self.tbl_metadata_keys,
+            properties = dict(
+                key_id = self.tbl_metadata_keys.c.key_id,
+                key = self.tbl_metadata_keys.c.key))
+
+        mapper(BinaryMetadata, self.tbl_binaries_metadata,
+            properties = dict(
+                binary_id = self.tbl_binaries_metadata.c.bin_id,
+                binary = relation(DBBinary),
+                key_id = self.tbl_binaries_metadata.c.key_id,
+                key = relation(MetadataKey),
+                value = self.tbl_binaries_metadata.c.value))
+
+        mapper(SourceMetadata, self.tbl_source_metadata,
+            properties = dict(
+                source_id = self.tbl_source_metadata.c.src_id,
+                source = relation(DBSource),
+                key_id = self.tbl_source_metadata.c.key_id,
+                key = relation(MetadataKey),
+                value = self.tbl_source_metadata.c.value))
+
     ## Connection functions
     def __createconn(self):
         from config import Config
         cnf = Config()
-        if cnf["DB::Host"]:
+        if cnf.has_key("DB::Service"):
+            connstr = "postgresql://service=%s" % cnf["DB::Service"]
+        elif cnf.has_key("DB::Host"):
             # TCP/IP
-            connstr = "postgres://%s" % cnf["DB::Host"]
-            if cnf["DB::Port"] and cnf["DB::Port"] != "-1":
+            connstr = "postgresql://%s" % cnf["DB::Host"]
+            if cnf.has_key("DB::Port") and cnf["DB::Port"] != "-1":
                 connstr += ":%s" % cnf["DB::Port"]
             connstr += "/%s" % cnf["DB::Name"]
         else:
             # Unix Socket
-            connstr = "postgres:///%s" % cnf["DB::Name"]
-            if cnf["DB::Port"] and cnf["DB::Port"] != "-1":
+            connstr = "postgresql:///%s" % cnf["DB::Name"]
+            if cnf.has_key("DB::Port") and cnf["DB::Port"] != "-1":
                 connstr += "?port=%s" % cnf["DB::Port"]
 
-        self.db_pg   = create_engine(connstr, echo=self.debug)
+        engine_args = { 'echo': self.debug }
+        if cnf.has_key('DB::PoolSize'):
+            engine_args['pool_size'] = int(cnf['DB::PoolSize'])
+        if cnf.has_key('DB::MaxOverflow'):
+            engine_args['max_overflow'] = int(cnf['DB::MaxOverflow'])
+        if sa_major_version == '0.6' and cnf.has_key('DB::Unicode') and \
+            cnf['DB::Unicode'] == 'false':
+            engine_args['use_native_unicode'] = False
+
+        # Monkey patch a new dialect in in order to support service= syntax
+        import sqlalchemy.dialects.postgresql
+        from sqlalchemy.dialects.postgresql.psycopg2 import PGDialect_psycopg2
+        class PGDialect_psycopg2_dak(PGDialect_psycopg2):
+            def create_connect_args(self, url):
+                if str(url).startswith('postgresql://service='):
+                    # Eww
+                    servicename = str(url)[21:]
+                    return (['service=%s' % servicename], {})
+                else:
+                    return PGDialect_psycopg2.create_connect_args(self, url)
+
+        sqlalchemy.dialects.postgresql.base.dialect = PGDialect_psycopg2_dak
+
+        self.db_pg   = create_engine(connstr, **engine_args)
         self.db_meta = MetaData()
         self.db_meta.bind = self.db_pg
         self.db_smaker = sessionmaker(bind=self.db_pg,
@@ -3316,8 +3489,13 @@ class DBConn(object):
 
         self.__setuptables()
         self.__setupmappers()
+        self.pid = os.getpid()
 
     def session(self):
+        # reinitialize DBConn in new processes
+        if self.pid != os.getpid():
+            clear_mappers()
+            self.__createconn()
         return self.db_smaker()
 
 __all__.append('DBConn')