On 28.06.2011, at 21:37, Charles Srstka wrote: > On Jun 28, 2011, at 12:00 PM, Jens Alfke wrote: > >> Another way (that I often use) is to define a C struct that matches the >> fields and layout of the header, then cast the bytes to a pointer to that >> struct and read the fields. It makes your code look a lot cleaner, but you >> have to be careful to (a) make sure the compiler packs the struct fields >> properly, and (b) you byte-swap all integer/float fields appropriately. > > It’s my understanding that reading/writing a struct directly to/from a file > is considered poor practice, because of the two things you mentioned: endian > issues, and the fact that you don’t know how the compiler will align the > fields — and even if you test that, you don’t know that it’s not going to > change in some future version of clang or gcc, or that Apple’s not going to > switch to a new architecture or something in which the compilers will emit > different output.
- the endian issue you'll have to deal with anyway - regarding struct alignment: the 80ies file format had tons of of serialized struct data which usually better end up in a struct. Well, streamed reading has bad performance, so you'd not want to use it in image (or movie) manipulation code. Streamed reading just to put it back into a struct is another anti-pattern. The "don't" is to use binary structs for new defined protocols for transfer, for the given reasons. Regards, Tom_E _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com