Re: ColorSync Profile name length - Take 2
Re: ColorSync Profile name length - Take 2
- Subject: Re: ColorSync Profile name length - Take 2
- From: email@hidden
- Date: Fri, 2 Sep 2005 19:30:32 -0500
On Sep 2, 2005, at 6:29 PM, Marco Ugolini wrote: In a message dated Fri, 2 Sep 2005 10:43:17, Rolf Gierling wrote:
1) Pre-Mac OS 10.2, ColorSync internally used FSSpec-based file I/O. Path-based locations were internally converted into FSSpecs.
2) For slightly better performance on Mac OS 10.2, ColorSync internally uses POSIX-based file I/O. FSSpec-based locations are internally converted into posix paths.
Does everyone else understand this, or am I the only dummy around here going: "Uh?"?
I don't think Rolf Gierling failed horribly in explaining what was going on. The issue is not poor definitions but rather programmer jargon that is difficult to fully explain to those not fully steeped in Mac OS X programming issues. Below is my best attempt at a layman's explanation.
As I stated in a previous post, there are several ways for a programmer to specify a file on Mac OS X. An FSSpec is one way, although it's really a hold-over from the pre-OS X days and it has some limitations such as being set up specifically only for HFS+ volumes and only has space for 63 character file names. For that reason, operating system calls which accept an FSSpec need to convert that FSSpec to some other form which it can then pass on to "lower-level" operating system calls. Hence there is a little bit of conversion overhead each time you use an FSSpec to specify a file.
So what Rolf Gierling is saying is that, before 10.2, ColorSync actually did things backwards by converting a file path to an FSSpec and then using the FSSpec each time it wanted to access the file. After 10.2, they got smart and did the opposite by converting all FSSpec's to file paths immediately. File paths can then be passed directly to "low-level" operating system calls (part of a set of UNIX system calls which are standardized in the POSIX standard) which do not do any further conversion of the file path and hence have less overhead.
Brendan Younger |
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden