Add support to retrieve raw extension data to ZEO

See https://github.com/zopefoundation/ZODB/pull/183 for context.

src/ZEO/ClientStorage.py

@@ -371,14 +371,20 @@ class ClientStorage(ZODB.ConflictResolution.ConflictResolvingStorage):
 
         self._info.update(info)
 
-        for iface in (
+        ifacev = (
             ZODB.interfaces.IStorageRestoreable,
             ZODB.interfaces.IStorageIteration,
             ZODB.interfaces.IStorageUndoable,
             ZODB.interfaces.IStorageCurrentRecordIteration,
             ZODB.interfaces.IBlobStorage,
             ZODB.interfaces.IExternalGC,
-            ):
+        )
+        # if ZODB is recent enough to have IStorageIterationRaw - use it too
+        IStorageIterationRaw = getattr(ZODB.interfaces, 'IStorageIterationRaw', None)
+        if IStorageIterationRaw is not None:
+            ifacev += (IStorageIterationRaw,)
+
+        for iface in ifacev:
             if (iface.__module__, iface.__name__) in self._info.get(
                 'interfaces', ()):
                 zope.interface.alsoProvides(self, iface)
@@ -978,7 +984,11 @@ class ClientStorage(ZODB.ConflictResolution.ConflictResolvingStorage):
         if self._db is not None:
             self._db.invalidate(tid, oids)
 
-    # IStorageIteration
+    # IStorageIteration + IStorageIterationRaw
+
+    def supportsTransactionInformationRaw(self):
+        """Storage API: return whether iterated transactions are provided with raw metadata"""
+        return self._info.get('supportsTransactionInformationRaw', False)
 
     def iterator(self, start=None, stop=None):
         """Return an IStorageTransactionInformation iterator."""
@@ -1068,18 +1078,13 @@ class TransactionIterator(object):
 
 class ClientStorageTransactionInformation(ZODB.BaseStorage.TransactionRecord):
 
-    def __init__(self, storage, txiter, tid, status, user, description,
-                 extension):
+    def __init__(self, storage, txiter, *args):
         self._storage = storage
         self._txiter = txiter
         self._completed = False
         self._riid = None
 
-        self.tid = tid
-        self.status = status
-        self.user = user
-        self.description = description
-        self.extension = extension
+        super(ClientStorageTransactionInformation, self).__init__(*args)
 
     def __iter__(self):
         riid = self._storage._call('iterator_record_start',

src/ZEO/StorageServer.py

@@ -230,6 +230,10 @@ class ZEOStorage(object):
         supportsUndo = (getattr(storage, 'supportsUndo', lambda : False)()
                         and self.connection.protocol_version[1:] >= b'310')
 
+        supportsTransactionInformationRaw = \
+                getattr(storage, 'supportsTransactionInformationRaw',
+                        lambda : False)()
+
         # Communicate the backend storage interfaces to the client
         storage_provides = zope.interface.providedBy(storage)
         interfaces = []
@@ -240,6 +244,7 @@ class ZEOStorage(object):
                 'size': storage.getSize(),
                 'name': storage.getName(),
                 'supportsUndo': supportsUndo,
+                'supportsTransactionInformationRaw': supportsTransactionInformationRaw,
                 'supports_record_iternext': hasattr(self, 'record_iternext'),
                 'interfaces': tuple(interfaces),
                 }
@@ -571,6 +576,10 @@ class ZEOStorage(object):
                     info.user,
                     info.description,
                     info.extension)
+            # propagate IStorageTransactionInformationRaw if we have its data
+            raw_extension = getattr(info, "raw_extension", None)
+            if raw_extension is not None:
+                item += (raw_extension,)
             # Keep a reference to the last iterator result to allow starting a
             # record iterator off it.
             self._txn_iterators_last[iid] = info

src/ZEO/tests/ZEO4/StorageServer.py

@@ -719,6 +719,10 @@ class ZEOStorage(object):
                     info.user,
                     info.description,
                     info.extension)
+            # propagate IStorageTransactionInformationRaw if we have its data
+            raw_extension = getattr(info, "raw_extension", None)
+            if raw_extension is not None:
+                item += (raw_extension,)
             # Keep a reference to the last iterator result to allow starting a
             # record iterator off it.
             self._txn_iterators_last[iid] = info

src/ZEO/tests/testZEO.py

@@ -173,6 +173,11 @@ class GenericTestBase(
             )
         self._storage.registerDB(DummyDB())
 
+        # here we trust ZEO to properly propagate
+        # supportsTransactionInformationRaw from original storage.
+        self.supportsTransactionInformationRaw = \
+                self._storage.supportsTransactionInformationRaw()
+
     def getZEOConfig(self):
         return forker.ZEOConfig(('127.0.0.1', 0))
 
@@ -320,15 +325,22 @@ class FileStorageTests(FullGenericTests):
         </filestorage>
         """
 
-    _expected_interfaces = (
-        ('ZODB.interfaces', 'IStorageRestoreable'),
-        ('ZODB.interfaces', 'IStorageIteration'),
-        ('ZODB.interfaces', 'IStorageUndoable'),
-        ('ZODB.interfaces', 'IStorageCurrentRecordIteration'),
-        ('ZODB.interfaces', 'IExternalGC'),
-        ('ZODB.interfaces', 'IStorage'),
-        ('zope.interface', 'Interface'),
-        )
+    def setUp(self):
+        super(FileStorageTests, self).setUp()
+
+        self._expected_interfaces = set((
+            ('ZODB.interfaces', 'IStorageRestoreable'),
+            ('ZODB.interfaces', 'IStorageIteration'),
+            ('ZODB.interfaces', 'IStorageUndoable'),
+            ('ZODB.interfaces', 'IStorageCurrentRecordIteration'),
+            ('ZODB.interfaces', 'IExternalGC'),
+            ('ZODB.interfaces', 'IStorage'),
+            ('zope.interface', 'Interface'),
+        ))
+
+        if self.supportsTransactionInformationRaw:
+            self._expected_interfaces.add(
+                ('ZODB.interfaces', 'IStorageIterationRaw'))
 
     def checkInterfaceFromRemoteStorage(self):
         # ClientStorage itself doesn't implement IStorageIteration, but the
@@ -338,9 +350,17 @@ class FileStorageTests(FullGenericTests):
             ZEO.ClientStorage.ClientStorage))
         self.failUnless(ZODB.interfaces.IStorageIteration.providedBy(
             self._storage))
+        # same for IStorageIterationRaw
+        IStorageIterationRaw = getattr(ZODB.interfaces, 'IStorageIterationRaw', None)
+        if IStorageIterationRaw is not None:
+            self.failIf(IStorageIterationRaw.implementedBy(
+                ZEO.ClientStorage.ClientStorage))
+            self.assertEqual(IStorageIterationRaw.providedBy(self._storage),
+                             self.supportsTransactionInformationRaw)
+
         # This is communicated using ClientStorage's _info object:
         self.assertEquals(self._expected_interfaces,
-            self._storage._info['interfaces']
+            set(self._storage._info['interfaces'])
             )
 
 class FileStorageSSLTests(FileStorageTests):
@@ -353,16 +373,12 @@ class FileStorageSSLTests(FileStorageTests):
 
 
 class FileStorageHexTests(FileStorageTests):
-    _expected_interfaces = (
-        ('ZODB.interfaces', 'IStorageRestoreable'),
-        ('ZODB.interfaces', 'IStorageIteration'),
-        ('ZODB.interfaces', 'IStorageUndoable'),
-        ('ZODB.interfaces', 'IStorageCurrentRecordIteration'),
-        ('ZODB.interfaces', 'IExternalGC'),
-        ('ZODB.interfaces', 'IStorage'),
-        ('ZODB.interfaces', 'IStorageWrapper'),
-        ('zope.interface', 'Interface'),
-        )
+
+    def setUp(self):
+        super(FileStorageHexTests, self).setUp()
+
+        self._expected_interfaces.add(
+            ('ZODB.interfaces', 'IStorageWrapper'))
 
     def getConfig(self):
         return """\