«

I'm trying to create a program that will buffer data received in UDP
packets.

I'd like to use an STL object that will allow me to add on new data
like this:

buffer+=newdata;

I don't think I can use a string because I don't think it allows 0
characters.

Any ideas on what to use?

On 2006-10-18, <> wrote:
> I'm trying to create a program that will buffer data received in UDP
> packets.
>
> I'd like to use an STL object that will allow me to add on new data
> like this:
>
> buffer+=newdata;
>
> I don't think I can use a string because I don't think it allows 0
> characters.
>
> Any ideas on what to use?

You could subclass Vector or a List, and then overload the += operator
for that purpose.
Just an idea.

--
Salvatore Iovene
http://www.iovene.com

wrote:
> I'm trying to create a program that will buffer data received in UDP
> packets.
>
> I'd like to use an STL object that will allow me to add on new data
> like this:
>
> buffer+=newdata;
>
> I don't think I can use a string because I don't think it allows 0
> characters.
>
> Any ideas on what to use?
>

1. Yes, std::string allows 0 characters.

2. You should probably use a std::vector<unsigned char>, though, since
you may not receive string data.

3. std::copy(newdata.begin(),
newdata.end(),
std::back_inserter(buffer));

On 18 Oct 2006 11:44:09 -0700 in comp.lang.c++,
wrote,
>I don't think I can use a string because I don't think it allows 0
>characters.

std::string can contain '\0' characters, no problem.

> 2. You should probably use a std::vector<unsigned char>, though, since
> you may not receive string data.

You might want std::deque, since you'll probably want to pop data out
of the buffer too.

Michael

Salvatore Iovene wrote:
> On 2006-10-18, <> wrote:

> > I'm trying to create a program that will buffer data received in UDP
> > packets.
> >
> > I'd like to use an STL object that will allow me to add on new data
> > like this:
> >
> > buffer+=newdata;
> >
> > I don't think I can use a string because I don't think it allows 0
> > characters.
> >
> > Any ideas on what to use?
>
> You could subclass Vector or a List, and then overload the += operator
> for that purpose.
> Just an idea.

subclass == derive from?

can you derive from the std containers?

--
Nick Keighley

Nick Keighley schrieb:

> Salvatore Iovene wrote:
> > On 2006-10-18, <> wrote:
>
> > > I'm trying to create a program that will buffer data received in UDP
> > > packets.
> > >
> > > I'd like to use an STL object that will allow me to add on new data
> > > like this:
> > >
> > > buffer+=newdata;
> > >
> > > I don't think I can use a string because I don't think it allows 0
> > > characters.
> > >
> > > Any ideas on what to use?
> >
> > You could subclass Vector or a List, and then overload the += operator
> > for that purpose.
> > Just an idea.
>
> subclass == derive from?
>
> can you derive from the std containers?

You can. But you don't want to.

ralpe

Salvatore Iovene wrote:

> On 2006-10-18, <> wrote:
>
>>I'm trying to create a program that will buffer data received in UDP
>>packets.
>>
>>I'd like to use an STL object that will allow me to add on new data
>>like this:
>>
>>buffer+=newdata;
>>
>>I don't think I can use a string because I don't think it allows 0
>>characters.
>>
>>Any ideas on what to use?
>
>
> You could subclass Vector or a List, and then overload the += operator
> for that purpose.
> Just an idea.
>

In general, you don't want to use a linked list for receiving
packet data. Way too slow.

--
Thomas Matthews

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wrote:

> I'm trying to create a program that will buffer data received in UDP
> packets.
>
> I'd like to use an STL object that will allow me to add on new data
> like this:
>
> buffer+=newdata;
>
> I don't think I can use a string because I don't think it allows 0
> characters.
>
> Any ideas on what to use?
>

If you use std::vector, pre-allocate the size for the average
packet. You don't want std::vector to reallocate while you
are receiving data.

Also, search the web for "double buffering". A minimum of
two buffers used for send and receiving.

Many embedded systems pre-allocate a space for the data
packets. These are arrays of unsigned chars. The goal
is to haul the data in as fast as possible, then analyze
it. An array has the minimal access times and least
overhead.

--
Thomas Matthews

C++ newsgroup welcome message:
http://www.slack.net/~shiva/welcome.txt
C++ Faq: http://www.parashift.com/c++-faq-lite
C Faq: http://www.eskimo.com/~scs/c-faq/top.html
alt.comp.lang.learn.c-c++ faq:
http://www.comeaucomputing.com/learn/faq/
Other sites:
http://www.josuttis.com -- C++ STL Library book
http://www.sgi.com/tech/stl -- Standard Template Library