code review 5623053: In json.NewDecoder: if the paramter is also a io.ByteRe...

In json.NewDecoder: if the paramter is also a io.ByteReader, then only read
one byte each time to avoid "over-feeding".

Added a test case to test if the Decoder will over feeding. (Nearly a
verbatim copy from jdnurmi@qwe.cc, the reporter of issue 1955)

Fixes issue 1955

[Nan Deng, 2012-02-03 06:57:34]

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

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

[rsc, 2012-02-06 17:26:21]

I am worried that this wrapping will hurt the performance of json decoding.
It might be necessary to have two different input loops, one using
Read and one using ReadByte.

Russ

[Nan Deng, 2012-02-07 01:19:15]

Russ Cox wrote, On 02/06/2012 12:26 PM:
> I am worried that this wrapping will hurt the performance of json decoding.
> It might be necessary to have two different input loops, one using
> Read and one using ReadByte.

I see. Performance definitely deserves a concern.

I will try several possible solutions then run the benchmark on each of 
them. And submit another CL with the best solution.

Thanks!

-Nan
>
> Russ
>