Use `#:authentic`, and `unsafe-vector*-{ref,set!}` saved about 50 more
ms on my machine.

Then getting rid of `set!` and just re-binding the relevant variables
produced another 50 ms speedup.

https://gist.github.com/7fc52e7bdc327fb59c8858a42258c26a

Sam

On Fri, Mar 19, 2021 at 7:21 AM Sam Tobin-Hochstadt
<[email protected]> wrote:
>
> One minor additional suggestion: if you use #:authentic for the struct, it 
> will generate slightly better code for the accessors.
>
> Sam
>
> On Fri, Mar 19, 2021, 6:18 AM Bogdan Popa <[email protected]> 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
>> >> > <[email protected]> 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 
>> >> >> <[email protected]>
>> >> 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 [email protected]
>> >> 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 
>> >> >> >> <[email protected]>
>> >> 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.
>> >> >> >>>
>> >> >> >>> --
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>> >> Groups "Racket Users" group.
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>> >> send an email to [email protected].
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>> >> https://groups.google.com/d/msgid/racket-users/118c1340-66d1-421d-92a4-6b66c56cb88fn%40googlegroups.com
>> >> .
>> >> >> >
>> >> >> > --
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>> >>
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