On Sep 12, 12:59 am, "Web Specialist" <[EMAIL PROTECTED]> wrote: > I'm using Jorn's Form Validation in a monster form. Using jQuery > 1.2minified version returns all validation in =~ 16 sec. Using > uncompressed > version returns in 6 sec. Comparing with an older version I don't have any > improvement.
That speed difference is almost certainly caused by odd circumstances, not by the compression. A minified jQuery version is semantically identical to an uncompressed version. A MIN'd copy essentially only has whitespaces and comments removed, and those are meaningless for the JS engine, which means they have no effect on execution speed. During the JS compilation phase, only meaningful tokens are converted to bytecode for the JS interpreter, while whitespace and comments are literally stripped out. Now... if you have a really odd JS engine which does not compile the source code to bytecode (or recompiles it on each call) then i could understand a menial speed diff between MIN'd and uncompressed code, but i would be surprised if any commercial JS engine out there does that. A packed version is decompressed at the time the outer-most code is run (when jQuery is first included), after which the compression overhead is gone. This means that PACKing only has an overhead at load- time (which may or may not be less than the time it would take to transfer an unpacked copy). It has no effect on the execution speed of the JS code once the initial expansion is done, however. If your MIN'd code is using YUIMin (as opposed to Doug Crockford's jsmin), then it is functionally similar to the conventional PACK process, in that it will have an initial overhead while the code is unpacked, but afterwards the bytecode engine will have uncompressed code and the decompression will play no role on the execution speed.
