Re: [Boost-users] Question about ifstream ranges

From: Pfligersdorffer, Christian (Christian.Pfligersdorffer_at_[hidden])
Date: 2007-03-08 02:32:54

boost-users-bounces_at_[hidden] wrote:
> Pfligersdorffer, Christian wrote:
>> Hello all!
>> 
>> I face the problem of partitioning a file that i read with
> ifstream into portions that are to be processed by some
> clients. I want to ensure that a client only views a specific
> part (window, range) of the stream. So far I store 2
> streamoffsets posStart and posEnd, call seekg on the stream,
> pass it to the client by ref and rely on the client to check
> when it reached posEnd.
>> 
>> However, I certainly cannot copy the whole range into a new
> stream object and pass that one. Efficiency does matter.
>> 
>> Any suggestions? Maybe some iterator-magic can be done?
> 
> How about Boost.Spirit file_iterator?
> That is a read-only RandomAccessIterator for files.
> http://spirit.sourceforge.net/distrib/spirit_1_8_3/libs/spirit
> /doc/file_iterator.html

Hello Shunsuke, 

that's a good idea but unfortunately I cannot use this class in my case. I have some special decoding ifstreams doing decompression and the like. So I'd really need an iterator that takes an i(f)stream object in it's constructor and wraps that.

Thanks anyway!

--
Christian Pfligersdorffer
Dipl.-Ing. Bakk.rer.nat.
Software Engineering
EOS GmbH - Electro Optical Systems
Robert-Stirling-Ring 1
D-82152 Krailling / Munich
Phone [phone]
Fax [phone]
 
christian.pfligersdorffer_at_[hidden]
http://www.eos.info