Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

Nice! Arnaud On Tue, 7 Sep 2021, 18:02 Keith Randall, wrote: > Sounds good. CL up for review at > https://go-review.googlesource.com/c/go/+/347917 > > On Mon, Sep 6, 2021 at 7:30 PM Arnaud Delobelle wrote: > >> If the growing function is currently >> >> f(x) = 2x for x < 1024 >> f(x) =

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

Sounds good. CL up for review at https://go-review.googlesource.com/c/go/+/347917 On Mon, Sep 6, 2021 at 7:30 PM Arnaud Delobelle wrote: > If the growing function is currently > > f(x) = 2x for x < 1024 > f(x) = x + x/4 otherwise > > (Which I haven't checked), couldn't a simple way be to

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

If the growing function is currently f(x) = 2x for x < 1024 f(x) = x + x/4 otherwise (Which I haven't checked), couldn't a simple way be to use e.g. f(x) = 2xfor x < 1024 f(x) = x + x/4 + 768 otherwise Then f(1023) = 2046 f(1024) = 2048 So the function is monotonic

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

I don't think this is an important thing to fix, but I agree it is a bit odd. If there's a simple way to restore monotonicity we'll consider it. A similar issue: https://github.com/golang/go/issues/41239 On Sunday, September 5, 2021 at 8:59:01 AM UTC-7 jake...@gmail.com wrote: > You are 100% cor

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

You are 100% correct. I missed that value. oops On Sunday, September 5, 2021 at 10:16:08 AM UTC-4 arn...@gmail.com wrote: > > > On Sun, 5 Sep 2021, 14:59 jake...@gmail.com, wrote: > [...] > >> In the example given (https://play.golang.org/p/RJbEkmFsPKM >>

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

On Sun, Sep 5, 2021 at 3:59 PM jake...@gmail.com wrote: > Like Brian, I think part of he problem is possibly a miscommunication > based on "monotonically increasing". The term means that each point is > greater than, *or equal to*, the previous one. > https://en.wikipedia.org/wiki/Monotonic_funct

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

On Sun, 5 Sep 2021, 14:59 jake...@gmail.com, wrote: [...] > In the example given (https://play.golang.org/p/RJbEkmFsPKM > ), the capacities *are *"monotonically > increasing", as no number in the second column is smaller than the one > before it. > Nitpick

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

Like Brian, I think part of he problem is possibly a miscommunication based on "monotonically increasing". The term means that each point is greater than, *or equal to*, the previous one. https://en.wikipedia.org/wiki/Monotonic_function. In other words, it never decreases. In the example given

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

Ah I see. In particular, if you have a slice whose len and cap are both 1000, the new cap is 2048; but if you have a slice whose len and cap are both 1100, then the new cap is 1408. I don't see that as a problem in any shape or form. All that's required is: (1) New cap is at least as large as

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

On Sun, 2021-09-05 at 03:51 -0700, Brian Candler wrote: > I'm not sure you're clear about what "monotonically increasing" > means. > > Are you saying that there are some cases where append() results in > the allocated size of a slice *shrinking*? If so, please > demonstrate. I think he means that

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

I'm not sure you're clear about what "monotonically increasing" means. Are you saying that there are some cases where append() results in the allocated size of a slice *shrinking*? If so, please demonstrate. -- You received this message because you are subscribed to the Google Groups "golang-

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

On Sunday, September 5, 2021 at 2:26:23 AM UTC-4 axel.wa...@googlemail.com wrote: > On Sun, Sep 5, 2021 at 7:02 AM tapi...@gmail.com > wrote: > >> >> >> On Sunday, September 5, 2021 at 12:52:06 AM UTC-4 Kurtis Rader wrote: >> >>> On Sat, Sep 4, 2021 at 9:38 PM tapi...@gmail.com >>> wrote: >

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

On Sun, Sep 5, 2021 at 7:02 AM tapi...@gmail.com wrote: > > > On Sunday, September 5, 2021 at 12:52:06 AM UTC-4 Kurtis Rader wrote: > >> On Sat, Sep 4, 2021 at 9:38 PM tapi...@gmail.com >> wrote: >> >>> Why? That is an undocumented implementation detail. Furthermore, the length of "x1" and

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

On Sunday, September 5, 2021 at 12:52:06 AM UTC-4 Kurtis Rader wrote: > On Sat, Sep 4, 2021 at 9:38 PM tapi...@gmail.com > wrote: > >> Why? That is an undocumented implementation detail. Furthermore, the >>> length of "x1" and "x2" at the time when they are appended to, in >>> combination wi

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

On Sat, Sep 4, 2021 at 9:38 PM tapi...@gmail.com wrote: > Why? That is an undocumented implementation detail. Furthermore, the >> length of "x1" and "x2" at the time when they are appended to, in >> combination with the value being appended, are reasonable predictors of the >> capacity of the new

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

On Sunday, September 5, 2021 at 12:12:46 AM UTC-4 Kurtis Rader wrote: > On Sat, Sep 4, 2021 at 8:57 PM tapi...@gmail.com > wrote: > >> On Saturday, September 4, 2021 at 11:50:17 PM UTC-4 Kurtis Rader wrote: >> >>> On Sat, Sep 4, 2021 at 8:39 PM tapi...@gmail.com >>> wrote: >>> The probl

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

On Sunday, September 5, 2021 at 12:16:48 AM UTC-4 kortschak wrote: > This is what you're describing, right? > https://play.golang.org/p/RJbEkmFsPKM > > The code that does this is here > > https://github.com/golang/go/blob/9133245be7365c23fcd60e3bb60ebb614970cdab/src/runtime/slice.go#L183-L242

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

This is what you're describing, right? https://play.golang.org/p/RJbEkmFsPKM The code that does this is here https://github.com/golang/go/blob/9133245be7365c23fcd60e3bb60ebb614970cdab/src/runtime/slice.go#L183-L242 . Note that there are cap adjustments to optimise block sizes and alignments. This

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

On Sat, Sep 4, 2021 at 8:57 PM tapi...@gmail.com wrote: > On Saturday, September 4, 2021 at 11:50:17 PM UTC-4 Kurtis Rader wrote: > >> On Sat, Sep 4, 2021 at 8:39 PM tapi...@gmail.com >> wrote: >> >>> The problem of the current algorithm is it is not monotonically >>> increasing: >>> >> >> Pleas

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

On Saturday, September 4, 2021 at 11:50:17 PM UTC-4 Kurtis Rader wrote: > On Sat, Sep 4, 2021 at 8:39 PM tapi...@gmail.com > wrote: > >> The problem of the current algorithm is it is not monotonically >> increasing: >> > > Please explain why that is a problem. Also, I think you are > misusin

Re: [go-nuts] Re: slices grow at 25% after 1024 but why 1024?

On Sat, Sep 4, 2021 at 8:39 PM tapi...@gmail.com wrote: > The problem of the current algorithm is it is not monotonically increasing: > Please explain why that is a problem. Also, I think you are misusing "monotonically increasing". The behavior up to length 1024 is not "monotonically increasing