World: r3wp
[Core] Discuss core issues
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Maxim 18-May-2010 [16783x2] | for searches its usually ok... since the result is often used only to cycle over and create other data. |
and in any case, you can copy the result of the search, at which point you have a perfect size and as little wasted RAM as possible. | |
Pekr 18-May-2010 [16785] | Max - where do I get the dataset from, if I would try to rewrite your find-fast into a version using 'parse? :-) Do you generate one? |
Maxim 18-May-2010 [16786x2] | look in profiling, there is a full script with verbose printing and everything you need, just replace the loop in one of the funcs :-) |
you can easily compare your results with the current best ... I'll be happy if you can beat the ultimate-find and give the exact same feature... searching on any field of a record and return the whole record. | |
Henrik 18-May-2010 [16788] | overall, about 500MB of RAM where saved by not pre-allocating large buffers <- hmm... I thought the allocation did not necessarily mean usage, only that GC is simpler, or is it different under Unix and Windows?. |
Maxim 18-May-2010 [16789x2] | I use windows task manager to look at ram use... the peak was 900MB and average was 700MB... removing pre-allocation it went down to 350 with peaks of ~ 500 IIRC |
linux usually has more precise RAM reports AFAIK. | |
Henrik 18-May-2010 [16791x2] | ok, let's say you allocate 2 GB, if you can, does Windows start to swap? |
because if Windows only reports allocation and not actual use, then the task manager doesn't report true usage. | |
Maxim 18-May-2010 [16793x5] | the process manager reports a few different values, current, swapped, peak, and some more obscure ones. |
if an application allocates and reserves 2GB I really don't care if its only using 10mb of it... my system is clogged and its not the OS's fault. | |
though I did a special of XP install which forces the OS NEVER to swap... and XP tends to be MUCH smoother because of it. | |
(special install of XP) playing around with some obscure registry keys. | |
though for these tests, no swapping occured. | |
Henrik 18-May-2010 [16798x2] | I recently watched a talk by Poul Henning Kamp, author of Varnish, who talked about how many people misunderstand how memory allocation works in modern OS'es. Since he's a FreeBSD kernel developer, he has some bias, but he made some interesting points in that memory allocation is nearly free in various unixes, but most people ignore that an only allocate, perhaps just enough or below what they need. |
Whether this can be translated directly to REBOL, I don't know. | |
Maxim 18-May-2010 [16800] | problem is when you task switch, or run several RAM intensive apps... they do kill each other, even on unix. |
Henrik 18-May-2010 [16801] | but that's because the RAM is actually used, correct? |
Maxim 18-May-2010 [16802x2] | (based on rendering 3D animations which required 4GB of swap file , just to load a scene ;-) |
yes... but as long as only one application is running the CPU, you can have A LOT of apps in virtual RAM without real system slow down (on unix). | |
Henrik 18-May-2010 [16804x2] | I guess I'm wrong with Windows. allocating a 100 MB string takes time. |
takes even longer under OSX. | |
Tomc 20-May-2010 [16806x3] | while[here: find/skip here key 2][insert tail result second here here: at here 2] |
rebol0 (untried) suspect parse is more efficent | |
ahh party moved to profileing and it has all been done | |
Pekr 20-May-2010 [16809x2] | For more precise system usage under Windows, please use SysInternals tools (now part of MS) |
http://technet.microsoft.com/en-us/sysinternals/default.aspx... look at RAM Map, Process Manager, etc. | |
Terry 20-May-2010 [16811x2] | Q. how to use a word as a string value in path? ie: ["a" 1 "b" 2] n: "b" ie/(n) >> 2 |
nvm | |
Claude 20-May-2010 [16813x2] | very strange a: true logic? a => true |
but a:[true] logic? a/1 => false | |
Sunanda 20-May-2010 [16815] | That's because [true] is a word, not a value. Try this: a: reduce [true] logic? a/1 >> true |
Claude 20-May-2010 [16816] | oki thanks |
Terry 24-May-2010 [16817x2] | What's the advantage of using words in blocks? ie: [a "one b "two] vs ie2: ["a" "one" "b" "two"] |
seeing you run out global word space very quickly? | |
Henrik 24-May-2010 [16819] | dialects and selection |
Terry 24-May-2010 [16820x2] | ie2/("a") >> "one" |
so dialects then? | |
Pekr 24-May-2010 [16822] | yes, and the code readability maybe - ie2/("a") vs ie2/a |
Henrik 24-May-2010 [16823] | using words as table keys is probably not a good idea. |
Pekr 24-May-2010 [16824] | why? because of word limit? or any other consequences? |
Henrik 24-May-2010 [16825] | limit, forbidden chars, etc. |
Ladislav 24-May-2010 [16826x3] | word comparison is faster than string comparison |
(word comparison is O(1), while string comparison is O(n)) | |
moreover, words have context, strings don't | |
Geomol 24-May-2010 [16829] | Is it a benefit, that SWITCH is case insensitive? >> s: "aA" == "aA" >> switch s/1 [#"A" [print "A"] #"a" [print "a"]] A |
Steeve 24-May-2010 [16830] | use strings not chars |
Gregg 24-May-2010 [16831x2] | On words in blocks, if you use strings they may be duplicated as you copy blocks, which words aren't. |
On SWITCH, I think it's consistent with REBOL in general. | |
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