- added testing and fixes for optimistic savepoint support

src/ZODB/Blobs/tests/transaction.txt

@@ -21,6 +21,8 @@ We need a database with a blob supporting storage:
     >>> from ZODB.Blobs.BlobStorage import BlobStorage
     >>> from ZODB.DB import DB
     >>> import transaction
+    >>> import tempfile
+    >>> tempfile.tempdir = "/home/ctheune/blobtemp"
     >>> from tempfile import mkdtemp
     >>> base_storage = MappingStorage("test")
     >>> blob_dir = mkdtemp()
@@ -177,6 +179,14 @@ connections should result in a write conflict error.
         ...
     ConflictError: database conflict error (oid 0x01, class ZODB.Blobs.Blob.Blob)
 
+After the conflict, the winning transaction's result is visible on both
+connections:
+
+    >>> root3['blob1'].open('r').read()
+    'this is blob 1woot!this is from connection 3'
+    >>> root2['blob1'].open('r').read()
+    'this is blob 1woot!this is from connection 3'
+
 BlobStorages implementation of getSize() includes the blob data and adds it to
 the underlying storages result of getSize():
 
@@ -185,6 +195,48 @@ the underlying storages result of getSize():
     >>> blob_size - underlying_size
     91L
 
+
+Savepoints and Blobs
+--------------------
+
+We do support optimistic savepoints :
+
+    >>> connection5 = database.open()
+    >>> root5 = connection5.root()
+    >>> blob = Blob()
+    >>> blob_fh = blob.open("wb")
+    >>> blob_fh.write("I'm a happy blob.")
+    >>> blob_fh.close()
+    >>> root5['blob'] = blob
+    >>> transaction.commit()
+    >>> root5['blob'].open("rb").read()
+    "I'm a happy blob."
+    >>> blob_fh = root5['blob'].open("a")       
+    >>> blob_fh.write(" And I'm singing.")
+    >>> blob_fh.close()
+    >>> root5['blob'].open("rb").read()
+    "I'm a happy blob. And I'm singing."
+    >>> savepoint = transaction.savepoint(optimistic=True)
+    >>> root5['blob'].open("rb").read()
+    "I'm a happy blob. And I'm singing."
+    >>> transaction.get().commit()
+
+We do not support non-optimistic savepoints:
+
+    >>> blob_fh = root5['blob'].open("a")   
+    >>> blob_fh.write(" And the weather is beautiful.")
+    >>> blob_fh.close()
+    >>> root5['blob'].open("rb").read()
+    "I'm a happy blob. And I'm singing. And the weather is beautiful."
+    >>> savepoint = transaction.savepoint()             # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+        ...
+    TypeError: ('Savepoints unsupported', <MultiObjectResourceAdapter for <ZODB.Blobs.Blob.BlobDataManager instance at ...> at ...>)
+
+
+Teardown
+--------
+
 We don't need the storage directory and databases anymore:
 
     >>> import shutil
@@ -192,4 +244,3 @@ We don't need the storage directory and databases anymore:
     >>> tm1.get().abort()
     >>> tm2.get().abort()
     >>> database.close()
-

src/ZODB/Connection.py

@@ -21,6 +21,7 @@ import tempfile
 import threading
 import warnings
 import os
+import shutil
 from time import time
 
 from persistent import PickleCache
@@ -1090,6 +1091,11 @@ class Connection(ExportImport, object):
             else:
                 s = self._storage.storeBlob(oid, serial, data, blobfilename,
                                             self._version, transaction)
+                # we invalidate the object here in order to ensure
+                # that that the next attribute access of its name
+                # unghostify it, which will cause its blob data
+                # to be reattached "cleanly"
+                self.invalidate(s, {oid:True})
             self._handle_serial(s, oid, change=False)
         src.close()
 
@@ -1139,6 +1145,8 @@ BLOB_DIRTY = "store"
 class TmpStore:
     """A storage-like thing to support savepoints."""
 
+    implements(IBlobStorage)
+
     def __init__(self, base_version, storage):
         self._storage = storage
         for method in (
@@ -1149,7 +1157,8 @@ class TmpStore:
 
         self._base_version = base_version
         self._file = tempfile.TemporaryFile()
-        self._blobdir = tempfile.mkdtemp()
+        self._blobdir = tempfile.mkdtemp()      # XXX this needs to go to the 
+                                                # storage dependent blob area
         # position: current file position
         # _tpos: file position at last commit point
         self.position = 0L
@@ -1162,6 +1171,7 @@ class TmpStore:
 
     def close(self):
         self._file.close()
+        shutil.rmtree(self._blobdir)
 
     def load(self, oid, version):
         pos = self.index.get(oid)
@@ -1195,7 +1205,6 @@ class TmpStore:
 
     def storeBlob(self, oid, serial, data, blobfilename, version,
                   transaction):
-        # XXX we need to clean up after ourselves!
         serial = self.store(oid, serial, data, version, transaction)
         assert isinstance(serial, str) # XXX in theory serials could be 
                                        # something else

src/ZODB/tests/testConnectionSavepoint.txt

@@ -193,3 +193,4 @@ However, using a savepoint invalidates any savepoints that come after it:
     InvalidSavepointRollbackError
 
     >>> transaction.abort()
+