Fixed bug #130459 by providing a well known temporary directory to place

uncommitted data in (ported from 3.8).
--This line, and those below, will be ignored--

M    src/ZODB/tests/blob_packing.txt
M    src/ZODB/tests/blob_tempdir.txt
M    src/ZODB/tests/testblob.py
M    src/ZODB/blob.py

src/ZODB/blob.py

@@ -294,6 +294,7 @@ class FilesystemHelper:
 
     def __init__(self, base_dir):
         self.base_dir = base_dir
+        self.temp_dir = os.path.join(base_dir, 'tmp')
 
     def create(self):
         if not os.path.exists(self.base_dir):
@@ -301,6 +302,11 @@ class FilesystemHelper:
             log("Blob cache directory '%s' does not exist. "
                 "Created new directory." % self.base_dir,
                 level=logging.INFO)
+        if not os.path.exists(self.temp_dir):
+            os.makedirs(self.temp_dir, 0700)
+            log("Blob temporary directory '%s' does not exist. "
+                "Created new directory." % self.temp_dir,
+                level=logging.INFO)
 
     def isSecure(self, path):
         """Ensure that (POSIX) path mode bits are 0700."""
@@ -375,6 +381,17 @@ class FilesystemHelper:
                     oids.append(oid)
         return oids
 
+    def listOIDs(self):
+        """Lists all OIDs and their paths.
+
+        """
+        for candidate in os.listdir(self.base_dir):
+            if candidate == 'tmp':
+                continue
+            oid = utils.repr_to_oid(candidate)
+            yield oid, self.getPathForOID(oid)
+
+
 class BlobStorage(SpecificationDecoratorBase):
     """A storage to support blobs."""
 
@@ -404,8 +421,7 @@ class BlobStorage(SpecificationDecoratorBase):
 
     @non_overridable
     def temporaryDirectory(self):
-        return self.fshelper.base_dir
-
+        return self.fshelper.temp_dir
 
     @non_overridable
     def __repr__(self):
@@ -471,18 +487,8 @@ class BlobStorage(SpecificationDecoratorBase):
         # if they are still needed by attempting to load the revision
         # of that object from the database.  This is maybe the slowest
         # possible way to do this, but it's safe.
-
-        # XXX we should be tolerant of "garbage" directories/files in
-        # the base_directory here.
-
-        # XXX If this method gets refactored we have to watch out for extra
-        # files from uncommitted transactions. The current implementation
-        # doesn't have a problem, but future refactorings likely will.
-
         base_dir = self.fshelper.base_dir
-        for oid_repr in os.listdir(base_dir):
-            oid = utils.repr_to_oid(oid_repr)
-            oid_path = os.path.join(base_dir, oid_repr)
+        for oid, oid_path in self.fshelper.listOIDs():
             files = os.listdir(oid_path)
             files.sort()
 
@@ -501,11 +507,8 @@ class BlobStorage(SpecificationDecoratorBase):
     @non_overridable
     def _packNonUndoing(self, packtime, referencesf):
         base_dir = self.fshelper.base_dir
-        for oid_repr in os.listdir(base_dir):
-            oid = utils.repr_to_oid(oid_repr)
-            oid_path = os.path.join(base_dir, oid_repr)
+        for oid, oid_path in self.fshelper.listOIDs():
             exists = True
-
             try:
                 self.load(oid, None) # no version support
             except (POSKeyError, KeyError):

src/ZODB/tests/blob_packing.txt

@@ -29,18 +29,9 @@ Set up:
     >>> storagefile = mktemp()
     >>> blob_dir = mkdtemp()
 
-A helper method to assure a unique timestamp across multiple platforms.  This
-method also makes sure that after retrieving a timestamp that was *before* a
-transaction was committed, that at least one second passes so the packing time
-actually is before the commit time.
-
-   >>> import time
-   >>> def new_time():
-   ...     now = new_time = time.time()
-   ...     while new_time <= now:
-   ...         new_time = time.time()
-   ...     time.sleep(1)
-   ...     return new_time
+A helper method to assure a unique timestamp across multiple platforms:
+
+    >>> from ZODB.tests.testblob import new_time
 
 UNDOING
 =======

src/ZODB/tests/blob_tempdir.txt

@@ -31,17 +31,18 @@ First, we need a datatabase with blob support::
   >>> from ZODB.blob import BlobStorage
   >>> from ZODB.DB import DB
   >>> from tempfile import mkdtemp
+  >>> import os.path
   >>> base_storage = MappingStorage("test")
   >>> blob_dir = mkdtemp()
   >>> blob_storage = BlobStorage(blob_dir, base_storage)
   >>> database = DB(blob_storage)
 
 Now we create a blob and put it in the database. After that we open it for
-writing and expect the file to be in the blob directory::
+writing and expect the file to be in the blob temporary directory::
 
   >>> blob = Blob()
   >>> connection = database.open()
   >>> connection.add(blob)
   >>> w = blob.open('w')
-  >>> w.name.startswith(blob_dir)
+  >>> w.name.startswith(os.path.join(blob_dir, 'tmp'))
   True

src/ZODB/tests/testblob.py

@@ -13,6 +13,7 @@
 ##############################################################################
 
 import base64, os, shutil, tempfile, unittest
+import time
 from zope.testing import doctest
 import ZODB.tests.util
 
@@ -26,6 +27,22 @@ import transaction
 from ZODB.tests.testConfig import ConfigTestBase
 from ZConfig import ConfigurationSyntaxError
 
+
+def new_time():
+    """Create a _new_ time stamp.
+
+    This method also makes sure that after retrieving a timestamp that was
+    *before* a transaction was committed, that at least one second passes so
+    the packing time actually is before the commit time.
+
+    """
+    now = new_time = time.time()
+    while new_time <= now:
+        new_time = time.time()
+    time.sleep(1)
+    return new_time
+
+
 class BlobConfigTestBase(ConfigTestBase):
 
     def setUp(self):
@@ -292,6 +309,86 @@ Works with savepoints too:
 
     """
 
+
+def packing_with_uncommitted_data_non_undoing():
+    """
+    This covers regression for bug #130459.
+
+    When uncommitted data exists it formerly was written to the root of the
+    blob_directory and confused our packing strategy. We now use a separate
+    temporary directory that is ignored while packing.
+
+    >>> import transaction
+    >>> from ZODB.MappingStorage import MappingStorage
+    >>> from ZODB.blob import BlobStorage
+    >>> from ZODB.DB import DB
+    >>> from ZODB.serialize import referencesf
+    >>> from tempfile import mkdtemp
+
+    >>> base_storage = MappingStorage("test")
+    >>> blob_dir = mkdtemp()
+    >>> blob_storage = BlobStorage(blob_dir, base_storage)
+    >>> database = DB(blob_storage)
+    >>> connection = database.open()
+    >>> root = connection.root()
+    >>> from ZODB.blob import Blob
+    >>> root['blob'] = Blob()
+    >>> connection.add(root['blob'])
+    >>> root['blob'].open('w').write('test')
+
+    >>> blob_storage.pack(new_time(), referencesf)
+
+    Clean up:
+
+    >>> database.close()
+    >>> import shutil
+    >>> shutil.rmtree(blob_dir)
+
+    """
+
+def packing_with_uncommitted_data_undoing():
+    """
+    This covers regression for bug #130459.
+
+    When uncommitted data exists it formerly was written to the root of the
+    blob_directory and confused our packing strategy. We now use a separate
+    temporary directory that is ignored while packing.
+
+    >>> import transaction
+    >>> from ZODB.FileStorage.FileStorage import FileStorage
+    >>> from ZODB.blob import BlobStorage
+    >>> from ZODB.DB import DB
+    >>> from ZODB.serialize import referencesf
+    >>> from tempfile import mkdtemp, mktemp
+
+    >>> storagefile = mktemp()
+    >>> base_storage = FileStorage(storagefile)
+    >>> blob_dir = mkdtemp()
+    >>> blob_storage = BlobStorage(blob_dir, base_storage)
+    >>> database = DB(blob_storage)
+    >>> connection = database.open()
+    >>> root = connection.root()
+    >>> from ZODB.blob import Blob
+    >>> root['blob'] = Blob()
+    >>> connection.add(root['blob'])
+    >>> root['blob'].open('w').write('test')
+
+    >>> blob_storage.pack(new_time(), referencesf)
+
+    Clean up:
+
+    >>> database.close()
+    >>> import shutil
+    >>> shutil.rmtree(blob_dir)
+
+    >>> os.unlink(storagefile)
+    >>> os.unlink(storagefile+".index")
+    >>> os.unlink(storagefile+".tmp")
+
+
+    """
+
+
 def test_suite():
     suite = unittest.TestSuite()
     suite.addTest(unittest.makeSuite(ZODBBlobConfigTest))