[go-nuts] sync.Map for caching
sync.Map in Go 1.9 is a little low on examples/doc in the wild, so I thought I should ask here. The new type is promoted as a replacement for RWMutex in mostly read use cases with stable keys. I assume that a typical in memory cache would fit that description. With RWMutex, if the cost of creating the cache item is high, I would maybe do something ala: mu.RLock() // Check cache mu.RUnclock() // Return if found // If Not found: mu.Lock() defer mu.Unlock() // Double check cache, return if found // Create item and put in cache I don't see how the above can be written with a sync.Map without adding a mutex. bep -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[go-nuts] Re: sync.Map for caching
Thanks, snmed, I was looking at LoadOrStore, but I was assuming that any func would be executed in any case. A more illustrative running sample of your first example: https://play.golang.org/p/vjlVu1GnUQ Thanks again! bep fredag 1. september 2017 08.24.10 UTC+2 skrev snmed følgende: > > Hi > > Here are two examples how to achieve it: > https://play.golang.org/p/wAtyGMSw6g or > https://play.golang.org/p/EZWZUOpuwb > > First example: In best cases it executes the creator function once and > returns always the stored item, in bad cases it executes the creator > function multiple times but returns always the first > stored item. > > Second example uses a lock to create and store the item. > > If the creator function is expensive, then I would use the latter example > otherwise the first. > > Cheers snmed > > > Am Freitag, 1. September 2017 00:18:35 UTC+2 schrieb bep: >> >> sync.Map in Go 1.9 is a little low on examples/doc in the wild, so I >> thought I should ask here. >> >> The new type is promoted as a replacement for RWMutex in mostly read use >> cases with stable keys. I assume that a typical in memory cache would fit >> that description. >> >> With RWMutex, if the cost of creating the cache item is high, I would >> maybe do something ala: >> >> mu.RLock() >> // Check cache >> mu.RUnclock() >> >> // Return if found >> >> // If Not found: >> mu.Lock() >> defer mu.Unlock() >> // Double check cache, return if found >> // Create item and put in cache >> >> >> >> >> I don't see how the above can be written with a sync.Map without adding a >> mutex. >> >> bep >> > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[go-nuts] Re: Variable scope for text/template
https://github.com/golang/go/issues/10608 bep fredag 6. oktober 2017 07.22.49 UTC+2 skrev Hein Meling følgende: > > Hi all, > > Please see linked example code. I've been trying set a "global" variable > ($LastName in the example) for use inside a named template (phony in the > example), but the scoping rules for the template packages does not follow > common scoping rules typically used in other languages, including Go. And > it is not possible to pass more "arguments/pipelines" to the named > template. Any suggestions on how to accomplish something like this. > > https://play.golang.org/p/VjeNwr6RFe > > All the best, > :) Hein > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[go-nuts] Re: Conditionally set go template variables
No.
See https://github.com/golang/go/issues/10608
In Hugo I built a hackish workaround, see http://gohugo.io/extras/scratch/
bep
onsdag 20. juli 2016 20.56.47 UTC+2 skrev Tong Sun følgende:
>
> How to conditionally set go template variables?
>
> I want the output of the following code
> https://play.golang.org/p/6e14hS2u1r
>
>
> {
> sweaters := Inventory{"", 17}
> tmpl, err := template.New("test").
> Parse(`{{$material := "something"}}{{if .Material}} {{$material :=
> .Material}} {{end}}` +
> "{{.Count}} items are made of {{$material}}.\n")
> check(err)
> err = tmpl.Execute(os.Stdout, sweaters)
> check(err)
> }
> {
> sweaters := Inventory{"wool", 17}
> tmpl, err := template.New("test").
> Parse(`{{$material := "something"}}{{if .Material}} {{$material :=
> .Material}} {{end}}` +
> "{{.Count}} items are made of {{$material}}.\n")
> check(err)
> err = tmpl.Execute(os.Stdout, sweaters)
> check(err)
> }
>
>
>
> to be
>
> 17 items are made of something.
> 17 items are made of wool.
>
>
>
> Using the exact same template. Is that possible?
>
> Thanks
>
>
>
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[go-nuts] [ANN] gitmap: map filenames to last commit-info
I wrote this as part of a feature in Hugo, the static site generator, to use the last updated timestamp from the Git repo as the page modification date. But then I thought it might be interesting to others (and myself), so I pulled the code into its own repo. https://github.com/bep/gitmap A fairly fast way to create a map from all the filenames to info objects for a given revision of a Git repo. This library uses os/exec to talk to Git. There are faster ways to do this by using some Go Git-lib or C bindings, but that adds dependencies I really don't want or need. If some git log kung fu master out there have suggestions for improvements, please open an issue or a PR. bep -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [go-nuts] Go 1.7 is released
Congrats! Good stuff! I wrote the benchmark below to compare two branches in Hugo, but ran a set after 1.7 upgrade: 4 random but fairly big Hugo sites, each built 6 times, rendered to memory: - go1.6.2 0.17-DEV 24.479727984s - All OK - go1.6.2 0.17-MULTILINGUAL 26.49965009s - All OK - go1.7 0.17-DEV 21.830323612s - All OK - go1.7 0.17-MULTILINGUAL 23.164846844s - All OK That should be a great 10%+ speedup, and that in an application I would already consider pretty fast. https://github.com/bep/hugo-benchmark tirsdag 16. august 2016 02.04.08 UTC+2 skrev chai2010 følgende: > > go1.7.windows-amd64.zip missing. > > 2016-08-16 7:28 GMT+08:00 Chris Broadfoot > > : > >> Hello gophers, >> >> We just released Go 1.7. >> >> You can read the announcement blog post here: >> https://blog.golang.org/go1.7 >> >> You can download binary and source distributions from our download page: >> https://golang.org/dl/ >> >> To compile from source using a Git checkout, update to the release with >> "git checkout go1.7" and build as usual. >> >> To find out what has changed, read the release notes: >> https://golang.org/doc/go1.7 >> >> Thanks to everyone who contributed to the release. >> >> Chris >> >> -- >> You received this message because you are subscribed to the Google Groups >> "golang-nuts" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to golang-nuts...@googlegroups.com . >> >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > https://github.com/golang-china/gopl-zh > https://github.com/golang-china > https://github.com/chai2010 > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[go-nuts] Remove vs Delete
I had this discussion with another Gopher about the difference between Delete and Remove. I found this definition which I agree on: *"Delete <http://dictionary.reference.com/browse/delete>* and *remove <http://dictionary.reference.com/browse/remove>* are defined quite similarly, but the main difference between them is that *delete* means *erase* (i.e. rendered nonexistent or nonrecoverable), while *remove* connotes *take away and set aside* (but kept in existence)." Translated to computer terms, remove would be to flag it/hide it, while delete would be to delete it from disk/erease it. But then he mentioned: https://golang.org/pkg/os/#Remove I don't expect the os.Remove* funcs to ever be renamed, but wouldn't it be more precise if they were named os.Delete etc.? bep -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
