Why is IOCTL_CDROM_READ_TOC so slow?

[Waldeck Schutzer]

I just realized that IOCTL_CDROM_READ_TOC is used almost everywhere in 
mcicda and somewhere else, but on the other hand it is as fast as a 
snail. A 68-track CD took 10 minutes to scan in cdplayer and if you 
press play, another 10 minutes will pass before it even starts playing! 
It appears to be a good idea to cache the TOC somewhere, but where and how?

Best,
Waldeck