Re: Getting the file name from a FILE *

jacob navia wrote:
> Richard Tobin wrote:
>> In article <a4b54$48651e78$541fc2ec$18525@[EMAIL PROTECTED]
>,
>> Serve Lau <nihao@[EMAIL PROTECTED]
> wrote:
>>
>>> Resource heavy software like commercial games do not use malloc, they 
>>> often implement their own memory manager. Adding the filename inside 
>>> FILE now introduces an obligatory malloc that wont be used.
>>
>> And just what problem will this cause in practice?
>>
>> The idea that "resource heavy" games might be significantly affected by
>> a few dozen malloc()ed bytes for each open file seems implausible, to
>> say the least.
>>
>> -- Richard
> 
> That kind of software uses megabytes of memory easily, but they do
> not open a lot of files, just a few configuration files, images
> and such, never more than (say) 100 files opened at the same
> time at most. With an average path length of say 100 we have
> around 10K.
> 
> BIG DEAL!


Really? I'm in a gaming project, a remake of a classic turn-based WW2
strategy game.


Today we load the complete map of a scenario from a single file, BUT
ideas has been put forward, to generate the scenario map from some basic
image building blocks instead.

Also, there are thousands of icons, which are overlayed on the map, each
icon has multiple variants for different orientation, to give player a
sense of dynamics in movement of units.

The icon file has grown to >50 MB and is still growing, we will consider
moving this into a central repository... and splitting it into multiple
files, so that players don't have to download everything, when more
icons are added.

Depending on future design decisions, there might be WAY MORE than 100
files to open... our map database has today around 1000 full-scale maps.

When adding features like _fname(), there will be a cost, the main thing
might not even the extra bloat by mem usage, but that this trigger more
cache misses, worse branch prediction etc. etc.

This is QoI issues, and I'm sure you have a set of benchmarks to detect
such side-effects...

One of the reasons to use C, is for the programmer to decides for 
themselves when bloat is acceptable, and when it is not.

-- 
Tor <bwzcab@[EMAIL PROTECTED]
 | tr i-za-h a-z>