Another attack of [1]. But yeah, why not do some [2]. Trees to the rescue [3].
$ racket --version Welcome to Racket v8.0 [cs]. $ racket countwords-bogdan2.rkt <kjvbible.txt |tail -1 cpu time: 135 real time: 135 gc time: 8 $ racket countwords-dzoe2.rkt <kjvbible.txt | tail -1 cpu time: 69 real time: 69 gc time: 3 I just changed (countwords) to (time (countwords)) in Bogdan's code to measure the running time. The difference is that I am positively defining which letters form words (a-z, A-Z) and that all others are treated as word separators. The buffer size is the same - and honestly, the speedup between 1024 and 1024^2 bytes buffer is barely measurable. The only option for further speedup I can immediately think of is to allocate a huge vector of wtnodes and change chld field to be a starting index into this big vector (should reduce allocations). Btw, making it unsafe does not speed it up at all (probably CS recognizes the vectors and all those refs are inlined anyway). Cheers, Dominik [1] https://xkcd.com/386/ [2] http://phdcomics.com/comics/archive.php?comicid=1735 [3] https://gist.github.com/dzoep/0e081d0544afac539a4829179c601e0e On 19. 03. 21 11:18, Bogdan Popa wrote: > I updated the gist with some cleanups and additional improvements that > get the runtime down to a little over 1s (vs ~350ms for the optimized C > and Rust code) on my maxed-out 2019 MBP and ~600ms on my M1 Mac Mini. > > Pawel Mosakowski writes: > >> Hi Bogdan, >> >> This is a brilliant solution and also completely over my head. It finishes >> in ~3.75s on my PC and is faster than the Python version which basically >> delegates all the work to C. I will need to spend some time on >> understanding it but I am looking forward to learning something new. >> >> Many thanks, >> Pawel >> >> On Thursday, March 18, 2021 at 7:22:10 PM UTC bogdan wrote: >> >>> I managed to get it about as fast as Python by making it really >>> imperative and rolling my own hash: >>> >>> https://gist.github.com/Bogdanp/fb39d202037cdaadd55dae3d45737571 >>> >>> Sam Tobin-Hochstadt writes: >>> >>>> Here are several variants of the code: >>>> https://gist.github.com/d6fbe3757c462d5b4d1d9393b72f9ab9 >>>> >>>> The enabled version is about the fastest I can get without using >>>> `unsafe` (which the rules said not to do). It's possible to optimize a >>>> tiny bit more by avoiding sorting, but only a few milliseconds -- it >>>> would be more significant if there were more different words. >>>> >>>> Switching to bytes works correctly for the given task, but wouldn't >>>> always work in the case of general UTF8 input. But those versions >>>> appeared not be faster for me. Also, writing my own string-downcase >>>> didn't help. And using a big buffer and doing my own newline splitting >>>> didn't help either. >>>> >>>> The version using just a regexp matching on a port (suggested by >>>> Robby) turned out not to be faster either, so my suspicion is that the >>>> original slowness is just using regexps for splitting words. >>>> >>>> Sam >>>> >>>> On Thu, Mar 18, 2021 at 11:28 AM Sam Tobin-Hochstadt >>>> <sa...@cs.indiana.edu> wrote: >>>>> >>>>> Here's a somewhat-optimized version of the code: >>>>> >>>>> #lang racket/base >>>>> (require racket/string racket/vector racket/port) >>>>> >>>>> (define h (make-hash)) >>>>> >>>>> (time >>>>> (for* ([l (in-lines)] >>>>> [w (in-list (string-split l))] >>>>> [w* (in-value (string-downcase w))]) >>>>> (hash-update! h w* add1 0))) >>>>> >>>>> (define v >>>>> (time >>>>> (for/vector #:length (hash-count h) >>>>> ([(k v) (in-hash h)]) >>>>> (cons k v)))) >>>>> (time (vector-sort! v > #:key cdr)) >>>>> (define p (current-output-port) #;(open-output-nowhere)) >>>>> (time >>>>> (for ([pair (in-vector v)]) >>>>> (write-string (car pair) p) >>>>> (write-string (number->string (cdr pair)) p) >>>>> (newline p))) >>>>> >>>>> It's much more imperative, but also pretty nice and compact. The >>>>> `printf` optimization is significant for that portion of the program, >>>>> but that isn't much of the running time. The overall running time for >>>>> 10 copies of the KJV is about 9 seconds on my laptop. >>>>> >>>>> I think the remaining difference between Racket and other languages is >>>>> likely the `string-split` and `string-downcase` functions, plus the >>>>> relatively-inefficient string representation that Racket uses. >>>>> >>>>> Sam >>>>> >>>>> >>>>> On Thu, Mar 18, 2021 at 10:28 AM Pawel Mosakowski <pa...@mosakowski.net> >>> wrote: >>>>>> >>>>>> Hi David, >>>>>> >>>>>> Yes, the 21 seconds includes the interpreter startup time. I have >>> done a simple test to see how long it takes: >>>>>> >>>>>> $ time racket -e '(displayln "Hello, world")' >>>>>> Hello, world >>>>>> >>>>>> real 0m0.479s >>>>>> user 0m0.449s >>>>>> sys 0m0.030s >>>>>> >>>>>> I have also put my code inside a main function and profiled it: >>>>>> >>>>>> Profiling results >>>>>> ----------------- >>>>>> Total cpu time observed: 20910ms (out of 20970ms) >>>>>> Number of samples taken: 382 (once every 55ms) >>>>>> (Hiding functions with self<1.0% and local<2.0%: 1 of 12 hidden) >>>>>> >>>>>> ============================================================== >>>>>> Caller >>>>>> Idx Total Self Name+src Local% >>>>>> ms(pct) ms(pct) Callee >>>>>> ============================================================== >>>>>> [1] 20910(100.0%) 0(0.0%) [running body] >>> ...word-occurences-profile.rkt":##f >>>>>> profile-thunk [2] 100.0% >>>>>> -------------------------------------------------------------- >>>>>> [running body] [1] 100.0% >>>>>> [2] 20910(100.0%) 0(0.0%) profile-thunk >>> ...ket/pkgs/profile-lib/main.rkt:9:0 >>>>>> run [3] 100.0% >>>>>> -------------------------------------------------------------- >>>>>> profile-thunk [2] 100.0% >>>>>> [3] 20910(100.0%) 0(0.0%) run >>> ...share/racket/pkgs/profile-lib/main.rkt:39:2 >>>>>> main [4] 100.0% >>>>>> -------------------------------------------------------------- >>>>>> run [3] 100.0% >>>>>> [4] 20910(100.0%) 50(0.2%) main >>> ...cket/count-word-occurences-profile.rkt:5:0 >>>>>> read-from-stdin-it [5] 98.5% >>>>>> ??? [6] 0.2% >>>>>> -------------------------------------------------------------- >>>>>> main [4] 100.0% >>>>>> [5] 20606(98.5%) 11796(56.4%) read-from-stdin-it >>> ...-occurences-profile.rkt:19:6 >>>>>> internal-split [7] 42.8% >>>>>> -------------------------------------------------------------- >>>>>> main [4] 100.0% >>>>>> [6] 51(0.2%) 0(0.0%) ??? >>> ...cket/collects/racket/private/sort.rkt:369:3 >>>>>> generic-sort/key [8] 100.0% >>>>>> -------------------------------------------------------------- >>>>>> read-from-stdin-it [5]100.0% >>>>>> [7] 8810(42.1%) 3528(16.9%) internal-split >>> ...collects/racket/string.rkt:117:0 >>>>>> regexp-split [9] 59.9% >>>>>> -------------------------------------------------------------- >>>>>> ??? [6] 100.0% >>>>>> [8] 51(0.2%) 0(0.0%) generic-sort/key >>> .../racket/private/sort.rkt:156:2 >>>>>> copying-mergesort [10]100.0% >>>>>> -------------------------------------------------------------- >>>>>> internal-split [7] 100.0% >>>>>> [9] 5282(25.3%) 2810(13.4%) regexp-split >>> ...ts/racket/private/string.rkt:338:2 >>>>>> loop [11] 46.8% >>>>>> -------------------------------------------------------------- >>>>>> generic-sort/key [8] 10.0% >>>>>> copying-mergesort [10] 90.0% >>>>>> [10] 51(0.2%) 51(0.2%) copying-mergesort >>> ...racket/private/sort.rkt:129:8 >>>>>> copying-mergesort [10] 90.0% >>>>>> -------------------------------------------------------------- >>>>>> regexp-split [9] 100.0% >>>>>> [11] 2471(11.8%) 2471(11.8%) loop >>> ...t/collects/racket/private/string.rkt:169:7 >>>>>> -------------------------------------------------------------- >>>>>> >>>>>> Kind regards, >>>>>> Pawel >>>>>> >>>>>> >>>>>> On Thursday, March 18, 2021 at 2:09:35 PM UTC david....@gmail.com >>> wrote: >>>>>>> >>>>>>> Hi Pawel, >>>>>>> >>>>>>> I'll take a look at the code later, but did that 21 seconds include >>> startup time for the interpreter? >>>>>>> >>>>>>> On Thu, Mar 18, 2021, 9:24 AM Pawel Mosakowski <pa...@mosakowski.net> >>> wrote: >>>>>>>> >>>>>>>> Hello, >>>>>>>> >>>>>>>> I am a Racket beginner and I have come across this article: >>>>>>>> >>>>>>>> https://benhoyt.com/writings/count-words/ >>>>>>>> >>>>>>>> This is my attempt at solving the challenge: >>>>>>>> >>>>>>>> https://pastebin.com/kL16w5Hc >>>>>>>> >>>>>>>> However when I have benchmarked it, it takes ~21 seconds to run >>> compared to the Python and Ruby versions which take around 3-4 seconds. >>>>>>>> >>>>>>>> I understand that both Ruby and Python probably have the string >>> operations and hash tables implemented in optimized C but is there anything >>> I can do to improve performance of my program? >>>>>>>> >>>>>>>> Many thanks for all help and suggestions. >>>>>>>> >>>>>>>> -- >>>>>>>> You received this message because you are subscribed to the Google >>> Groups "Racket Users" group. >>>>>>>> To unsubscribe from this group and stop receiving emails from it, >>> send an email to racket-users...@googlegroups.com. >>>>>>>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/racket-users/118c1340-66d1-421d-92a4-6b66c56cb88fn%40googlegroups.com >>> . >>>>>> >>>>>> -- >>>>>> You received this message because you are subscribed to the Google >>> Groups "Racket Users" group. >>>>>> To unsubscribe from this group and stop receiving emails from it, >>> send an email to racket-users...@googlegroups.com. >>>>>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/racket-users/09c58a34-bd2d-49e7-bfbd-d3253c1e6dd1n%40googlegroups.com >>> . >>> > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. 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