[Zodb-checkins] SVN: ZODB/branches/blob-merge-branch/src/ZODB/Blobs/ added tests for Blob.openDetached()

[Wolfgang Schnerring]

Log message for revision 70362:
  added tests for Blob.openDetached()

Changed:
  U   ZODB/branches/blob-merge-branch/src/ZODB/Blobs/Blob.py
  U   ZODB/branches/blob-merge-branch/src/ZODB/Blobs/TODO.txt
  U   ZODB/branches/blob-merge-branch/src/ZODB/Blobs/tests/transaction.txt

-=-
Modified: ZODB/branches/blob-merge-branch/src/ZODB/Blobs/Blob.py
===================================================================
--- ZODB/branches/blob-merge-branch/src/ZODB/Blobs/Blob.py	2006-09-25 09:44:29 UTC (rev 70361)
+++ ZODB/branches/blob-merge-branch/src/ZODB/Blobs/Blob.py	2006-09-25 11:34:08 UTC (rev 70362)
@@ -216,6 +216,7 @@
         if self.blob._p_blob_uncommitted is not None and \
            os.path.exists(self.blob._p_blob_uncommitted):
             os.unlink(self.blob._p_blob_uncommitted)
+            self.blob._p_blob_uncommitted = None
 
     # IDataManager
 

Modified: ZODB/branches/blob-merge-branch/src/ZODB/Blobs/TODO.txt
===================================================================
--- ZODB/branches/blob-merge-branch/src/ZODB/Blobs/TODO.txt	2006-09-25 09:44:29 UTC (rev 70361)
+++ ZODB/branches/blob-merge-branch/src/ZODB/Blobs/TODO.txt	2006-09-25 11:34:08 UTC (rev 70362)
@@ -7,8 +7,6 @@
 
     - Check cache-compatibility with shared network filesystems (mcdonc)
 
-    - tests for openDetached
-
 Far future
 
       More options for blob directory structures (e.g. dirstorages

Modified: ZODB/branches/blob-merge-branch/src/ZODB/Blobs/tests/transaction.txt
===================================================================
--- ZODB/branches/blob-merge-branch/src/ZODB/Blobs/tests/transaction.txt	2006-09-25 09:44:29 UTC (rev 70361)
+++ ZODB/branches/blob-merge-branch/src/ZODB/Blobs/tests/transaction.txt	2006-09-25 11:34:08 UTC (rev 70362)
@@ -232,8 +232,59 @@
     Traceback (most recent call last):
         ...
     TypeError: ('Savepoints unsupported', <ZODB.Blobs.Blob.BlobDataManager instance at 0x...>)
+    >>> transaction.abort()
 
+Reading Blobs outside of a transaction
+--------------------------------------
 
+If you want to read from a Blob outside of transaction boundaries (e.g. to
+stream a file to the browser), you can use the openDetached() method:
+
+    >>> connection6 = database.open()
+    >>> root6 = connection6.root()
+    >>> blob = Blob()
+    >>> blob_fh = blob.open("wb")
+    >>> blob_fh.write("I'm a happy blob.")
+    >>> blob_fh.close()
+    >>> root6['blob'] = blob
+    >>> transaction.commit()
+    >>> blob.openDetached().read()
+    "I'm a happy blob."
+
+Of course, that doesn't work for empty blobs
+
+    >>> blob = Blob()
+    >>> blob.openDetached()
+    Traceback (most recent call last):
+        ...
+    BlobError: Blob does not exist.
+
+nor when the Blob is already opened for writing:
+
+    >>> blob = Blob()
+    >>> blob_fh = blob.open("wb")
+    >>> blob.openDetached()
+    Traceback (most recent call last):
+        ...
+    BlobError: Already opened for writing.
+
+It does work when the transaction was aborted, though:
+
+    >>> blob = Blob()
+    >>> blob_fh = blob.open("wb")
+    >>> blob_fh.write("I'm a happy blob.")
+    >>> blob_fh.close()
+    >>> root6['blob'] = blob
+    >>> transaction.commit()
+
+    >>> blob_fh = blob.open("wb")
+    >>> blob_fh.write("And I'm singing.")
+    >>> blob_fh.close()
+    >>> transaction.abort()
+    >>> blob.openDetached().read()
+    "I'm a happy blob."
+
+
 Teardown
 --------