code review 5440111: crypto: allocate less.

crypto: allocate less.

The code in hash functions themselves could write directly into the
output buffer for a savings of about 50ns. But it's a little ugly so I
wasted a copy.

[agl1, 2011-12-05 22:27:18]

Hello bradfitz@golang.org (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg/

[bradfitz, 2011-12-06 17:21:04]

LGTM

http://codereview.appspot.com/5440111/diff/2013/src/pkg/crypto/hmac/hmac.go
File src/pkg/crypto/hmac/hmac.go (right):

http://codereview.appspot.com/5440111/diff/2013/src/pkg/crypto/hmac/hmac.go#n...
src/pkg/crypto/hmac/hmac.go:52: sum := h.inner.Sum(nil)
you thought it was ugly writing to in[:0] here?

[agl1, 2011-12-06 23:25:26]

*** Submitted as http://code.google.com/p/go/source/detail?r=58a2e71c39b9 ***

crypto: allocate less.

The code in hash functions themselves could write directly into the
output buffer for a savings of about 50ns. But it's a little ugly so I
wasted a copy.

R=bradfitz
CC=golang-dev
http://codereview.appspot.com/5440111

http://codereview.appspot.com/5440111/diff/2013/src/pkg/crypto/hmac/hmac.go
File src/pkg/crypto/hmac/hmac.go (right):

http://codereview.appspot.com/5440111/diff/2013/src/pkg/crypto/hmac/hmac.go#n...
src/pkg/crypto/hmac/hmac.go:52: sum := h.inner.Sum(nil)
On 2011/12/06 17:21:04, bradfitz wrote:
> you thought it was ugly writing to in[:0] here?

Good point, just didn't think about that!