Added new method to load historical object revisions.

src/ZODB/BaseStorage.py

@@ -84,7 +84,7 @@
 ##############################################################################
 """Handy standard storage machinery
 """
-__version__='$Revision: 1.6 $'[11:-2]
+__version__='$Revision: 1.7 $'[11:-2]
 
 import time, bpthread, UndoLogCompatible
 from POSException import UndoError
@@ -218,3 +218,6 @@ class BaseStorage(UndoLogCompatible.UndoLogCompatible):
 
     def pack(self, t, referencesf): pass
 
+    def loadSerial(self, oid, serial):
+        raise POSException.Unsupported, (
+            "Retrieval of historical revisions is not supported")

src/ZODB/Connection.py

@@ -84,8 +84,8 @@
 ##############################################################################
 """Database connection support
 
-$Id: Connection.py,v 1.32 2000/05/09 19:09:16 jim Exp $"""
-__version__='$Revision: 1.32 $'[11:-2]
+$Id: Connection.py,v 1.33 2000/05/20 15:54:28 jim Exp $"""
+__version__='$Revision: 1.33 $'[11:-2]
 
 from cPickleCache import PickleCache
 from POSException import ConflictError, ExportError
@@ -439,6 +439,15 @@ class Connection(ExportImport.ExportImport):
                 error=sys.exc_info())
             raise
 
+    def oldstate(self, object, serial):
+        oid=object._p_oid
+        p = self._storage.loadSerial(oid, serial)
+        file=StringIO(p)
+        unpickler=Unpickler(file)
+        unpickler.persistent_load=self._persistent_load
+        unpickler.load()
+        return  unpickler.load()
+
     def setklassstate(self, object,
                       tt=type(()), ct=type(HelperClass)):
         try:

src/ZODB/FileStorage.py

@@ -184,7 +184,7 @@
 #   may have a back pointer to a version record or to a non-version
 #   record.
 #
-__version__='$Revision: 1.36 $'[11:-2]
+__version__='$Revision: 1.37 $'[11:-2]
 
 import struct, time, os, bpthread, string, base64, sys
 from struct import pack, unpack
@@ -584,6 +584,34 @@ class FileStorage(BaseStorage.BaseStorage):
         try: return self._load(oid, version, self._index, self._file)
         finally: self._lock_release()
 
+    def loadSerial(self, oid, serial):
+        _index=self._index
+        file=self._file
+        seek=file.seek
+        read=file.read
+        pos=_index[oid]
+        while 1:
+            seek(pos)
+            h=read(42)
+            doid,dserial,prev,tloc,vlen,plen = unpack(">8s8s8s8sH8s", h)
+            if doid != oid: raise CorruptedDataError, h
+            if dserial == serial: break # Yeee ha!
+            # Keep looking for serial
+            pos=u64(prev)
+            if not pos: raise KeyError, serial
+            continue
+            
+        if vlen:
+            pnv=read(8) # Read location of non-version data
+            read(8) # skip past version link
+            read(vlen) # skip version
+
+        if plen != z64: return read(u64(plen))
+
+        # We got a backpointer, probably from a commit.
+        pnv=read(8)
+        return _loadBack(file, oid, pnv)[0]
+                    
     def modifiedInVersion(self, oid):
         self._lock_acquire()
         try: