First of all I want to mention that my library is not finished yet. I am at the end of implementing planned features for the first release, but some additional effort is needed. I have no plans to add support for the all features that MS implementation provides in the first release, but want to develop library in evolutionary way. Also I plan add some features in next releases that are not supported by MS implementation: storage compacting and defragmentation. I found on the Internet that users need them.
Sounds good.
More generally, does your library support the properties of the MS compound storage implementation as described here:
http://msdn.microsoft.com/en- us/library/windows/desktop/aa378871(v=vs.85).aspx ?
Here is that list with my comments.
[Incremental access.] Implemented and tested.
[Multiple use.] Not implemented, but I think often about that. The main problem: I can not decide use C++11 threading model or switch to some cross-platform library(Boost.Thread may be?) For now supported one thread per one compound files. Also, threading implementation and testing will require lot of effort. And I not plan to include multithreading support in the first release.
I don't think the library has to care about what type of threading model is used. I imagine the problem of making the files accessible concurrently is even wider as you have to enable multiple processes to read/write concurrently. The MS implementation achieves this using the transactional mechanisms, which moves the responsibility for making it concurrency safe into user land. Essentially every write creates a new subtree (stream), which then is made current by a single atomic write operation, invalidating the previous version of the data.
[Transaction processing.] Not supported. Planned in next releases.
Good, that's one of the main advantages of this model, in my book.
[Low-memory saves.] Yes. I designed the library to be memory efficient. All needed memory is allocated on stream opening. I plan to test memory issues by emulating std::bad_alloc in various places.
Thanks! Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu