Re: [boost] Random Access to Files (RAF) - any interest ?

From: Jonathan Ray (ray.jonathan.w_at_[hidden])
Date: 2006-05-19 09:14:00

Olaf van der Spek <olafvdspek_at_[hidden]> wrote:
>Is it possible to read a range of bytes with a single function call?
>Or would that require one function call per byte?

One function call per byte would be extremely inefficient because of
I/O latency unless the library, the driver, or the drive itself does a
lot caching with some prefetching.    Generally drivers will work
faster when you declare what you want to do in as few calls as
possible rather than splitting it up into many sequential function
calls, because the all-at-once approach gives the driver more latitude
in which to optimize the operation.

I read the Performance section of the RAF paper and it seems they
forgot to declare the units of the table and omitted any discription
of the hardware that they ran the tests on.   Those details are
crucial.

Cheers,
Jonathan Ray