On 2011-05-19 20:07, Beman Dawes wrote:
Yes, agreed. But the assumption is that it is very, very, fast compared to an implementation that must translate between different external and internal representations.
I always assumed that file-access is orders of magnitude slower than DMA. Especially when the file isn't local. Another case might be convincing here: Keys that don't require translation, Mapped that requires it.
2) using a "path" argument to having a file open presumes a real underlying file. Although this is fine, maybe I would like to use an fstream?
What would a real-world use case be?
See below.
3) It would be nice if it would work with an asynchronous file-like services, like, e.g., Asio's RandomAccessHandleService, see http://www.boost.org/doc/libs/1_46_0/doc/html/boost_asio/reference/RandomAcc...
I'd need stronger motivation that "it would be nice"! What would the benefit be?
There's an increased availability of network-based storage mechanisms, like, e.g., Amazon's S3. The combination of (such a) storage backend with a B-tree container delivers a NoSQL-stack, which I think is a considerable benefit. To name a concrete example, using a distributed object store like Ceph's underlying RADOS, see http://ceph.newdream.net/wiki/Librados , as a storage-backend. Operations at this level don't require "expensive" file-system semantics. Cheers, Rutger