Re: [Boost-users] [iostreams] array_sink full exception

From: Jonathan Turkanis (technews_at_[hidden])
Date: 2005-12-29 23:20:08

Robert Ramey wrote:
> I'm looking at array_sink stream buffer as a possible speed
> enhancement to binary_oarchive in some cases.  My quesion is" What
> happens when the capacity of the array used for the buffer is
> exceeded?  Is an exception thrown or what?

Sorry I didn't respond sooner. I'm way behind on my Boost stuff.

Yes, an exception is thrown. You can see the code at work in
boost/iostreams/detail/streambuf/direct_streambuf.hpp.

> I've looked through the documentation and don't find exceptions
> mentioned.

There are no exceptions mentioned in the docs for array_sink, since it doesn't
throw exceptions. Your right that the behavior should be documented somewhere,
though. I guess I should document stream_buffer::xsputc and
stream_buffer::xsputn to explain what happens when a direct sink is exhausted.

As far as using array_sink in serialization, if you tell me how you want to use
it I may be able to judge whether it is a good idea. It's also possible to
design an array sink that can tell you how full it is (see
boost/iostreams/detail/counted_array.hpp) but it's not as efficient, since it
uses a read/write interface instead of simply delivering a fixed array of
characters to std::streambuf.

> Robert Ramey

-- 
Jonathan Turkanis
www.kangaroologic.com