Hi Revar, your data are really enlightening.
I had a few requests to make our service (www.clipperz.com) compatible with the iPhone, as the users that could try it with an iPhone reported only shameless failure. :-( As our application is very heavy on JavaScript (the crypto code and some BinInt algebra hit the processor very hard, even on desktops) I can see no option to make it work with a system that is basically 100 times slower. Anyway, I would be very interested anyway in your javascript LZW compressor/decompressor code. :-) Giulio Cesare On 8/2/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > I had a bit of a twisted epiphany yesterday... To reduce the size of > my calculator's bookmarklet, I could compress it, then use javascript > inside the data: URI to decompress it. So I coded up an LZW > compressor and a javascript decompressor and tried them out. > > The bookmarklet was reduced to 34% of it's original size, which was a > real win! In my desktop Safari web browser it worked like a charm. > In the iPhone... not so much. Turns out it runs afoul of the 5 > second scripting timeout. I went through the javascript code and did > a ton of optimizations, which sped up the code about 400%, but it's > still timing out. I even redid the algorithm to be faster but > compress less well. (Result was ~65% original size instead of 34%) > Still no go. > > When all is said and done, I can only seem to decompress about 14KB > of compressed data (about 20K uncompressed) before the iPhone will > time it out. > > Sooooooo... I took a comparative look at the speed the code is > running, between my desktop Safari (on a 2.3GHz intel) and the iPhone > (667MHz ARM11). On the desktop I could decode 10000 bytes of > compressed data in 39 milliseconds. On the iPhone, the same > decompress with the same code took 3492 milliseconds. > > Normalizing that data for processor speed (flawed, using MHz, but I > have no other comparative metrics), that's still over 1000x faster on > the desktop, per MHz. Three orders of magnitude. > > ... > > Hmm. I sense room for improvement. > > > - Revar > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "iPhoneWebDev" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/iphonewebdev?hl=en -~----------~----~----~----~------~----~------~--~---
