code review 58240043: net/http: read as much as possible (including EOF) duri...

net/http: read as much as possible (including EOF) during chunked reads

This is the chunked half of https://codereview.appspot.com/49570044 .

We want full reads to return EOF as early as possible, when we
know we're at the end, so http.Transport client connections are eagerly
re-used in the common case, even if no Read or Close follows.

To do this, make the chunkedReader.Read fill up its argument p []byte
buffer as much as possible, as long as that doesn't involve doing
any more blocking reads to read chunk headers. That means if we
have a chunk EOF ("0\r\n") sitting in the incoming bufio.Reader,
we see it and set EOF on our final Read.

[bradfitz, 2014-01-29 11:16:05]

Hello adg@golang.org (cc: golang-codereviews@googlegroups.com),

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

[adg, 2014-01-29 12:10:11]

LGTM

https://codereview.appspot.com/58240043/diff/40001/src/pkg/net/http/chunked.go
File src/pkg/net/http/chunked.go (right):

https://codereview.appspot.com/58240043/diff/40001/src/pkg/net/http/chunked.g...
src/pkg/net/http/chunked.go:71: if cr.err != nil {
you can delete this now

https://codereview.appspot.com/58240043/diff/40001/src/pkg/net/http/chunked.g...
src/pkg/net/http/chunked.go:98: if _, cr.err = io.ReadFull(cr.r, cr.buf[:2]);
cr.err == nil {
man, this is really getting subtle.
add a couple of comments?

https://codereview.appspot.com/58240043/diff/40001/src/pkg/net/http/chunked_t...
File src/pkg/net/http/chunked_test.go (right):

https://codereview.appspot.com/58240043/diff/40001/src/pkg/net/http/chunked_t...
src/pkg/net/http/chunked_test.go:46: // Bunch of small chunks, all read
together.
if these tests are all independent why not make them separate functions

[bradfitz, 2014-01-29 12:44:26]

*** Submitted as https://code.google.com/p/go/source/detail?r=08918ee18957 ***

net/http: read as much as possible (including EOF) during chunked reads

This is the chunked half of https://codereview.appspot.com/49570044 .

We want full reads to return EOF as early as possible, when we
know we're at the end, so http.Transport client connections are eagerly
re-used in the common case, even if no Read or Close follows.

To do this, make the chunkedReader.Read fill up its argument p []byte
buffer as much as possible, as long as that doesn't involve doing
any more blocking reads to read chunk headers. That means if we
have a chunk EOF ("0\r\n") sitting in the incoming bufio.Reader,
we see it and set EOF on our final Read.

LGTM=adg
R=adg
CC=golang-codereviews
https://codereview.appspot.com/58240043