code review 91750044: net: avoid array copy when shuffling SRV records

net: avoid array copy when shuffling SRV records

We don't need to shift array elements to shuffle them.
We just have to swap a selected element with 0th element.

[ruiu, 2014-06-11 03:21:24]

Hello golang-codereviews@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/go

[ruiu, 2014-06-16 23:02:39]

Ping.

[bradfitz, 2014-06-16 23:52:22]

LGTM

https://codereview.appspot.com/91750044/diff/60001/src/pkg/net/dnsclient.go
File src/pkg/net/dnsclient.go (right):

https://codereview.appspot.com/91750044/diff/60001/src/pkg/net/dnsclient.go#n...
src/pkg/net/dnsclient.go:192: for sum > 0 && len(addrs) > 1 {
should this be sum > 1? seems like sum == 0 wouldn't do anything except
eventually cut down addrs to length 1.

[ruiu, 2014-06-17 00:34:39]

https://codereview.appspot.com/91750044/diff/60001/src/pkg/net/dnsclient.go
File src/pkg/net/dnsclient.go (right):

https://codereview.appspot.com/91750044/diff/60001/src/pkg/net/dnsclient.go#n...
src/pkg/net/dnsclient.go:192: for sum > 0 && len(addrs) > 1 {
If sum == 0 this for loop is skipped. If sum == 1 this for loop needs to be
executed to move weight=1 SRVs to the head of the list. So I think the answer is
no.

[bradfitz, 2014-06-17 00:40:22]

https://codereview.appspot.com/91750044/diff/60001/src/pkg/net/dnsclient.go
File src/pkg/net/dnsclient.go (right):

https://codereview.appspot.com/91750044/diff/60001/src/pkg/net/dnsclient.go#n...
src/pkg/net/dnsclient.go:192: for sum > 0 && len(addrs) > 1 {
On 2014/06/17 00:34:39, ruiu wrote:
> If sum == 0 this for loop is skipped. If sum == 1 this for loop needs to be
> executed to move weight=1 SRVs to the head of the list. So I think the answer
is
> no.

Ah, right.

[ruiu, 2014-06-17 01:00:30]

*** Submitted as https://code.google.com/p/go/source/detail?r=6a85be121cae ***

net: avoid array copy when shuffling SRV records

We don't need to shift array elements to shuffle them.
We just have to swap a selected element with 0th element.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://codereview.appspot.com/91750044