Cart
[Home] [By Thread] [By Date] [Recent Entries]
Bob Wyman wrote: > Another thing to consider is the potential cost in converting > data to address things like "endian" concerns. If you have to flip the > bits in every number you get and you have many numbers, this can get > expensive. Hmmm... nowhere near as expensive as parsing those numbers from base 10 ASCII :-) A 32-bit endian swap in x86 assembly is not many instructions - can't remember how many offhand, but not many. And it will execute in constant time, whereas a base 10 decoder will take time linearly dependant on the number of digits in the number :-) > Similarly, converting from a "standard" floating point > representation to some different representation supported by your > machine or language might be expensive. That has more scope for expense but, again, I can't see it ever being worse than converting from a base 10 ASCII encoding of the same number. > Also, if it turns out that > your application is primarily concerned with large strings, then a > binary format can deliver very disappointing results. Yep, if we enclosed this entire email in <e> and </e> to make it into XML, then the PER equivelant would be something like a 2-byte variable-length integer encoding the message length followed by the text of the message - a meager saving of 5 bytes out of a couple of K. > > bob wyman > ABS
|
