[pdftex] Patch for better performance of map file reading

[The Thanh Han]

On Wed, Jul 31, 2002 at 01:44:03AM +0200, Heiko Oberdiek wrote:
> Hello,
> 
> in the mailing list TEX-D-L someone has compared
> old teTeX with TeX Live 7, 10 runs:
>   7s vs. 48s.
> The main reason is the increased map file:
>   800 vs 3000 lines
> 
> Because the difference of performance is very high,
> I have looked at the sources and detected the problem:
> pdfTeX parses the map file and compares the current
> entry with all previous entries to detect duplicate
> entries. But the complexity is then N(N-1)/2 = O(N^2).
> 
> Therefore I have written a patch, that uses a
> hashtable to increase the performance.

excellent work! Many thanks for it. 

Regards,
Thanh