Re: [Boost-users] Boost serialization : Stream error exception

From: smith smithson (smith4894_at_[hidden])
Date: 2006-08-25 10:43:05

I figured out what the problem is; I use a buffered
version of iostream/stream_buf to buffer data from my
mmap'd file and pass it out when requested. For some
reason if the very first character in the buffer is
character 255 (an extended ascii character) in any of
the buffers, I get the stream error exception. Any
suggestions why this might happen? Is this reserved in
some way? I see the issue in both text mode and binary
mode.

I'm using boost 1.32.0.

--- Robert Ramey <ramey_at_[hidden]> wrote:

> Its not clear whether your using binary, text or ?
> type
> of archives.  Also it would help to know which
> version
> of boost you're using.  The lastest version of boost
> in the CVS head (1.35?) use an implementation of
> binary archives which bypasses streams in favor of
> direct calls to the stream_buffer.  The is
> measurably
> faster.
> 
> Of course I have to be suspicious of you stream i/o
> re-implementation. Which like all standard library
> implementations is much trickier to get right than
> first meets the eye.
> 
> Other than this I'm not sure what more I can say.
> 
> I'm sure this doesn't help much - and I'm sorry
> about that.
> 
> Robert Ramey
> 
> 
> smith smithson wrote:
> > I'm trying to use boost serialization to
> > serialize/deserialize data to and from a mmap'd
> file.
> > I have my own ostream/istream classes that
> essentially
> > read/write bytes from a mmap'd file. The process
> works
> > fine except on some rare occasions (With different
> > objects/number of objects), in which case boost
> throws
> > a "stream error" exception. Any ideas what could
> > trigger this? A search of the Boost archives
> indicated
> > other people had the same problem, where the
> solution
> > was "use binary mode when you open the file"...
> but
> > I'm not using a file on disk, I'm using a mmap'd
> file.
> > (As a side note, the mmap file is large enough to
> hold
> > all my data and does not need to be expanded or
> > remmap'd etc)
> >
> > The OS i'm using is Linux.
> >
> > Thanks for any suggestions...
> >
> >
> >
> >
> >
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> 
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