[go-nuts] Re: Data locality in large slices

With times under one nanosecond I'm wondering what you're actually measuring. Aggressive optimization could make this an "empty" loop. Synthetic benchmarks like this can be tricky to interpret. On Wednesday, August 3, 2016 at 7:56:32 AM UTC-4, Ondrej wrote: > > I wanted to see if there was a

[go-nuts] Data locality in large slices

I wanted to see if there was a difference when loading values from a large-ish slice (1 elements) - to see if caches, locality and other things had any meaningful impacts. Whilst individual value loading (just a single element) seemed to be equally fast regardless of element position (see

[go-nuts] Re: Data locality in large slices

Downgrading to 1.6.3, I'm also getting consistent benchmark results. I'll try 1.7 on my Mac at home later today, to see if it's a 1.7 thing or a Windows thing or...? On Wednesday, 3 August 2016 14:55:20 UTC+1, C Banning wrote: > > PS - that's with Go v1.6. > > On Wednesday, August 3, 2016 at

[go-nuts] Re: Will compiler do optimization here?

Have you tried examining the assembler output? go build -gcflags="-S" program.go if I recall correctly. On Wednesday, August 3, 2016 at 11:27:36 AM UTC-4, T L wrote: > > > I know a string value can be used as []byte if the first parameter if the > builtin copy/append function is a []byte

[go-nuts] Re: Will compiler do optimization here?

On Wednesday, August 3, 2016 at 11:59:27 PM UTC+8, Hotei wrote: > > Have you tried examining the assembler output? go build -gcflags="-S" > program.go if I recall correctly. > yes, the output is different, looks like optimization is not made here, but I can't make sure. > > > On

Re: [go-nuts] Is there a function in standard lib to convert []T to a []interface{}?

On Wednesday, August 3, 2016 at 11:46:43 PM UTC+8, Axel Wagner wrote: > > True, but it would still be just the same loop, it wouldn't actually be > significantly faster. And you'd need to put quite some machinery into a > pretty rarely used functionality, which means it also wouldn't be

Re: [go-nuts] Is there a function in standard lib to convert []T to a []interface{}?

On Wed, Aug 3, 2016 at 7:36 AM T L wrote: > Often, I need converting a []T to []interface{} to use the []interface as > a variable length parameter. > But converting a []T for []interface{} in a for loop is neither clean nor > efficient. > If there was a builtin that did

Re: [go-nuts] Is there a function in standard lib to convert []T to a []interface{}?

Don't confuse variadic arguments with slice arguments, by the way. On Wed, Aug 3, 2016 at 8:20 AM T L wrote: > > > On Wednesday, August 3, 2016 at 10:53:34 PM UTC+8, Jessta wrote: > >> On 4 Aug 2016 12:36 a.m., "T L" wrote: >> > >> > Often, I need

[go-nuts] Will compiler do optimization here?

I know a string value can be used as []byte if the first parameter if the builtin copy/append function is a []byte value: > var bs []byte = make([]byte, 10) > copy(bs, "abcde") but if do explicit conversion anyway on the second string value > var bs []byte = make([]byte, 10) > copy(bs,

Re: [go-nuts] protobuf go and pointers

On Wed, Aug 3, 2016 at 8:58 AM, Sankar wrote: > > I have a .proto2 file, like: > > message s { > optional double a = 1; > } > > When I run protoc and generate the .pb.go file, it contains code like: > > type S struct { > A*float64

Re: [go-nuts] protobuf go and pointers

Thanks for the explanation. It does look much better in proto3. I will see if it will be possible to switch to proto3. 2016-08-03 21:37 GMT+05:30 Ian Lance Taylor : > On Wed, Aug 3, 2016 at 8:58 AM, Sankar wrote: >> >> I have a .proto2 file, like: >>

Re: [go-nuts] Is there a function in standard lib to convert []T to a []interface{}?

On 4 Aug 2016 12:36 a.m., "T L" wrote: > > Often, I need converting a []T to []interface{} to use the []interface as a variable length parameter. > But converting a []T for []interface{} in a for loop is neither clean nor efficient. > > So is there a function in standard lib

[go-nuts] protobuf go and pointers

Hi I have a .proto2 file, like: message s { optional double a = 1; } When I run protoc and generate the .pb.go file, it contains code like: type S struct { A*float64 `protobuf:"fixed64,1,opt,name=a" json:"a,omitempty"` XXX_unrecognized []byte `json:"-"` } Why is the A field

[go-nuts] Is there a function in standard lib to convert []T to a []interface{}?

Often, I need converting a []T to []interface{} to use the []interface as a variable length parameter. But converting a []T for []interface{} in a for loop is neither clean nor efficient. So is there a function in standard lib to convert []T to a []interface{}? -- You received this message

Re: [go-nuts] Is there a function in standard lib to convert []T to a []interface{}?

https://github.com/golang/go/issues/15209 On Wednesday, August 3, 2016 at 11:20:01 AM UTC-4, T L wrote: > > > > On Wednesday, August 3, 2016 at 10:53:34 PM UTC+8, Jessta wrote: >> >> On 4 Aug 2016 12:36 a.m., "T L" wrote: >> > >> > Often, I need converting a []T to

Re: [go-nuts] Is there a function in standard lib to convert []T to a []interface{}?

You probably don't want to actually call fmt.Println(s...) with s an []interface{}. Just do fmt.Print(s) instead. On Wed, Aug 3, 2016 at 5:20 PM, T L wrote: > > > On Wednesday, August 3, 2016 at 10:53:34 PM UTC+8, Jessta wrote: >> >> On 4 Aug 2016 12:36 a.m., "T L"

Re: [go-nuts] Is there a function in standard lib to convert []T to a []interface{}?

True, but it would still be just the same loop, it wouldn't actually be significantly faster. And you'd need to put quite some machinery into a pretty rarely used functionality, which means it also wouldn't be cleaner. The thing is, that the memory representation of []T and []J, with J being an

[go-nuts] Why doesn't std lib use the method in this article to make err variables constant?

http://dave.cheney.net/2016/04/07/constant-errors -- 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,

Re: [go-nuts] rsa.GenerateKey does not return on sepcial bits

done. https://github.com/golang/go/issues/16596 On Thursday, August 4, 2016 at 12:01:55 PM UTC+8, bradfitz wrote: > > Please file a bug. > > > On Wed, Aug 3, 2016 at 8:20 PM, steve wang > wrote: > >> https://play.golang.org/p/gYYUDxj6Z5 >> >> Is this an issue? >> >> --

Re: [go-nuts] Is there a function in standard lib to convert []T to a []interface{}?

On Thursday, August 4, 2016 at 12:16:37 AM UTC+8, Ian Lance Taylor wrote: > > On Wed, Aug 3, 2016 at 9:12 AM, T L > wrote: > > > > On Wednesday, August 3, 2016 at 11:46:43 PM UTC+8, Axel Wagner wrote: > >> > >> True, but it would still be just the same loop, it wouldn't

[go-nuts] Re: files, readers, byte arrays (slices?), byte buffers and http.requests

Doh. Thanks. I did the setup but didnt click "execute". Revisiting this because its now a bottleneck since it directly impact user experience (how long a request will take to process) and scalability (requests per second a single instance can handle). It wasn't pre-mature optimization, rather

[go-nuts] Re: Will compiler do optimization here?

I surely will use the first version in practice. I just want to make things clear, :) On Thursday, August 4, 2016 at 3:23:11 AM UTC+8, Hotei wrote: > > If you create the source as a byte array by converting it ([]byte("abcde") > then the compiler can NOT optimize it away. However - I don't

[go-nuts] rsa.GenerateKey does not return on sepcial bits

https://play.golang.org/p/gYYUDxj6Z5 Is this an issue? -- 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

[go-nuts] Re: Why doesn't std lib use the method in this article to make err variables constant?

Because we cannot change symbols covered by the Go 1 contract. On Thursday, 4 August 2016 14:20:18 UTC+10, T L wrote: > > http://dave.cheney.net/2016/04/07/constant-errors > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from

[go-nuts] Re: Will compiler do optimization here?

Looking at the asm it appears that there is a conversion func called in the second version - right before the copy with memmove. Based on this I'd say what happens AFTER the conversion is the same in both version since the destination is the same and the content is the same. The only

Re: [go-nuts] checking for connection error?

Hi Victor, There are no "constant" errors in the sql package if thats what you are looking for. Generally if .Ping() returns an error there is no connection - afaik the error string might give some indication but it is totally up to the driver/database. If you want to sleep and try again later

[go-nuts] Re: How to check that a Go package has not been modified?

I'm a bit uneasy about this. Since checksumming is not collision-resistant, I would be careful just relying on this. The goal was to avoid diffing files but I don't know what is the fastest way. In any case, I guess a checksum is not enough to guarantee file integrity (against malice). Maybe

[go-nuts] Re: How to check that a Go package has not been modified?

What is the purpose of this? For instance, In govendor the hash of the files, file names, and path is computed and recorded. That way if they are modified it is detected. So yeah, md5 or blake2 would work just fine. On Wednesday, August 3, 2016 at 10:14:53 AM UTC-7, atd...@gmail.com wrote: > >

[go-nuts] Re: Will compiler do optimization here?

On Thursday, August 4, 2016 at 12:40:41 AM UTC+8, Hotei wrote: > > Looking at the asm it appears that there is a conversion func called in > the second version - right before the copy with memmove. > > Based on this I'd say what happens AFTER the conversion is the same in > both version since

[go-nuts] Re: How to check that a Go package has not been modified?

Yes, I suppose that clamping the file size, and the requirement that the package must pass compilation, even md5 shall do. Thanks to the avalanche effect. On Wednesday, August 3, 2016 at 9:36:34 PM UTC+2, Hotei wrote: > > The fact that collisions are possible does not make them "easy to create"

[go-nuts] Re: Go test package names

Tests are usually included in the package. Testing a package cannot become easier this way and it is the only way to test internal functions, types, variables or constants. However if you have large test files, it may make sense to keep them in a separate repository because go-getting the

[go-nuts] Re: Data locality in large slices

Tu cast pola s ktorou pracujes mas v L1/ L2 cache. V momente ked pristupujes k inej casti pola ktora je niekolko megabajtov vzdialena tak procesor musi natiahnut tie udaje z ram do cache. Neviem presne cisla ale trva to zhruba tych 300 strojovych cyklov . Vypadok L2 neviem kolko trva, je to v

[go-nuts] Re: How to check that a Go package has not been modified?

The fact that collisions are possible does not make them "easy to create" especially when you add the compileable requirement. If you're uneasy about md5 you could always use more bits - like SHA1 used by "git" or SHA256 (or larger) if you're really paranoid. On Wednesday, August 3, 2016 at

[go-nuts] Re: Will compiler do optimization here?

If you create the source as a byte array by converting it ([]byte("abcde") then the compiler can NOT optimize it away. However - I don't think it will *use* the capacity information in the source since it's not relevant and it's going to copy the data bytes and length in any case. If you're

Re: [go-nuts] Is there a function in standard lib to convert []T to a []interface{}?

On Wednesday, August 3, 2016 at 6:16:37 PM UTC+2, Ian Lance Taylor wrote: > > On Wed, Aug 3, 2016 at 9:12 AM, T L > wrote: > > > > On Wednesday, August 3, 2016 at 11:46:43 PM UTC+8, Axel Wagner wrote: > >> > >> True, but it would still be just the same loop, it wouldn't

[go-nuts] Re: how to apply netutil.LimitListener() to ListenAndServeTLS()'s listener? how to fetch ListenAndServeTLS()'s listener?

I perused your blog entry you mentioned. It's very interesting and will come in handy in the future. Thank you. I can appreciate your point of view about accepting the fact that currently listeners are not part of the Server and just proceed to produce code and get it done ASAP. My

[go-nuts] building an exe that will embed import in the .exe

Hi, i have a program that imports a package from github.com/abc... when i build the .exe how can i have the package/dependency included in the .exe ? thanks, Al -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group

[go-nuts] Re: How to get struct of function

I suggest you also take a look at the Go spec that describes method values: https://golang.org/ref/spec#Method_values It seems to click on what you want to do. Also, take a look at this article from Alex Edwards: http://www.alexedwards.net/blog/organising-database-access more specifically, the

[go-nuts] Re: SWIG: typemap for std::string* arguments in std_string.i?

Please give me your typemap. Thanks! -- 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

[go-nuts] Re: how to apply netutil.LimitListener() to ListenAndServeTLS()'s listener? how to fetch ListenAndServeTLS()'s listener?

Your research revealed the essential lines from ListenAndServeTLS that basically say: 1. create a tls listener 2. have the server serve using that listener The LimitListener example follows this same pattern, just with net.Listener instead of a tls.Listener. A careful reading reveals that

[go-nuts] Re: how to apply netutil.LimitListener() to ListenAndServeTLS()'s listener? how to fetch ListenAndServeTLS()'s listener?

The issue here in essence is that an http.Server doesn't store a new.Listener to expose, it only operates on one provided to the Serve method. Without changing the api, there's no way to expose a listener in an http.Server in a way that doesn't interfere with the other methods. However, I

Re: [go-nuts] building an exe that will embed import in the .exe

Hello, When you compile go program, all your source and source from all imported packages is compiled together in the same binary (.exe). You don't need to worry about it. That's actually one of the go strengths, no dll hell. On 03.08.2016 07:57, ov35...@gmail.com wrote: Hi, i have a

Re: [go-nuts] Re: How to check that a Go package has not been modified?

A few years ago, I uploaded a parallel “find duplicate files in a filesystem” utility to GitHub. It is called “dup” for “find duplicates.” https://github.com/MichaelTJones/dup/blob/master/dup.go In that program, which first groups files by size, then compares the first few bytes, then

[go-nuts] Data locality in large slices

You need to use the values to ensure that compiler does not remove the code. Even if the compiler does not do this, your Intel CPU will, if effectively runs an ssa implementation in hardware and will spot the dead stores and skip the load. -- You received this message because you are

[go-nuts] Re: Data locality in large slices

(I have now recreated it on my Mac, under 1.7rc5, the runtime differences are still there.) I thought the compiler was removing these as you suggest, but then StartEnd and EndStart had wildly different running times, despite using the very same values. So I added dummy assignments to double

Re: [go-nuts] Server TCP

What's the "login package"? On Wed, Aug 3, 2016 at 3:12 PM, wrote: > Anyone know why the tcp server closes its connection after of answer the > login package? > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. >

[go-nuts] Re: Data locality in large slices

Those arguments must live beyond the scope of the enclosing function. -- 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.

[go-nuts] Re: how to apply netutil.LimitListener() to ListenAndServeTLS()'s listener? how to fetch ListenAndServeTLS()'s listener?

I tried just what you mentioned. Unfortunately even my interim solution when it is outside of the net.http package and within mine, there are many services that are not exported meaning I can't use them at all and the variables themselves are inaccessible. I tried copying pasting some

[go-nuts] Server TCP

Anyone know why the tcp server closes its connection after of answer the login package? -- 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