Hello, I'm looking to better understand how to handle the difference between a cmis:document having no content stream, and a content stream that is empty (0 bytes). This scenario is handled differently by the example CMIS servers, and I'd like to understand which is correct.
The example in-memory server tracks a document's content by maintaining a ContentStream (fContent <https://svn.apache.org/viewvc/chemistry/opencmis/trunk/chemistry-opencmis-server/chemistry-opencmis-server-inmemory/src/main/java/org/apache/chemistry/opencmis/inmemory/storedobj/impl/DocumentImpl.java?view=markup#l39> ) for each Document. If the document has no content stream, then fContent is null. If the document has a content stream, fContent is a ContentStreamDataImpl <https://svn.apache.org/viewvc/chemistry/opencmis/trunk/chemistry-opencmis-server/chemistry-opencmis-server-inmemory/src/main/java/org/apache/chemistry/opencmis/inmemory/storedobj/impl/ContentStreamDataImpl.java?view=markup> object which may have 0 or more bytes of underlying data. Whether fContent is null or is a populated ContentStream object, it is returned by the getContentStream service. The in-memory server handles no content stream differently than an empty content stream. This matches the TCK test testAppendStream <https://svn.apache.org/viewvc/chemistry/opencmis/trunk/chemistry-opencmis-test/chemistry-opencmis-test-tck/src/main/java/org/apache/chemistry/opencmis/tck/tests/crud/SetAndDeleteContentTest.java?view=markup#l220> which starts by creating a document with empty content. The test ensures that a non-null ContentStream is returned after the document is created, and that ContentStream must be empty (0 bytes). The fileshare example server does not differentiate between no content stream and a file having 0 bytes of content. In its getContentStream implementation <https://svn.apache.org/viewvc/chemistry/opencmis/trunk/chemistry-opencmis-server/chemistry-opencmis-server-fileshare/src/main/java/org/apache/chemistry/opencmis/fileshare/FileShareRepository.java?view=markup#l1128>, it throws a CmisConstraintException if the file has 0 bytes (per the specification <http://docs.oasis-open.org/cmis/CMIS/v1.1/errata01/os/CMIS-v1.1-errata01-os-complete.html#x1-26500011>). This causes the testAppendStream to fail, because it expects an empty content stream. If the getContentStream service returned an empty ContentStream instead, this would cause the CreateDocumentWithNoContent <https://svn.apache.org/viewvc/chemistry/opencmis/trunk/chemistry-opencmis-test/chemistry-opencmis-test-tck/src/main/java/org/apache/chemistry/opencmis/tck/tests/crud/CreateDocumentWithoutContent.java?revision=1389521&view=markup#l90> test to fail, because the browser binding will add a filename "content" <https://svn.apache.org/viewvc/chemistry/opencmis/trunk/chemistry-opencmis-server/chemistry-opencmis-server-bindings/src/main/java/org/apache/chemistry/opencmis/server/impl/browser/ObjectService.java?view=markup#l800> if the returned ContentStream has no filename set. So I'm not really sure where the problem lies. If we consider that the in-memory server's functionality is correct, then the fileshare server should have CapabilityContentStreamUpdates.NONE. The fileshare server can't know if a file has 0 bytes or no content stream. If this distinction isn't important, then tests shouldn't enforce this difference. Also, the behavior of the browser binding is different than other bindings, but I don't know if that's an issue. Please let me know what you think. I'd be happy to help with code changes (if needed). Also please let me know if there is a more effective way to communicate this information because this is my first time using the Apache dev mailing lists. Thanks, Jake Karnes ECM Consultant Zia Consulting m: 408.314.7075 5525 Central Avenue, Suite 200 Boulder, CO 80301 www.ziaconsulting.com
