Neal D. Becker wrote:
Thanks. Actually, though, what I'm talking about is a different archive type, not a data structure. Right now binary data is saved/restored using read/write. mmap is potentially much more efficient for large data structures. OTOH, there is one big problem for it, which is that mmap can only be applied to one contiguous memory region. I believe you would have to serialize one object to one file, and if you want more objects you would need multiple files to map them to. Still, might be interesting.
Hmmm - wouldn't be better to implement a new derivation of std::;basic_streambuf for memory mapped i/o. This would be useful for a lot more than serialization. Of course, all the archive already provided are implemented in terms of streams so they would automatically inherit all the features of memory mapped i/o. The whole topic of custom stream_buf versions or better yet, composable stream_buf adaptors has been under appreciated in my view. I know there was some discussion and work done. I don't know what happened. I suspect it turned out to be "too big" to finish to boost standards in the amount of time that the developer could allocate. I do much appreciate feedback on the serialization library on this list. It is very helpful and encouraging. Note that others have made significant efforts well. These are people that have been experimenting with the library in their own projects. They have been very patient and helpful. Among others I would mention Pavel Vozenilek, Vladimir Prus, David Tonge, and Jeff Finn. Robert Ramey