Add reverse dns lookup as a method on InternetAddress.

Add reverse dns lookup as a method on InternetAddress.

BUG=
R=sgjesse@google.com

Committed: https://code.google.com/p/dart/source/detail?r=24393

[Søren Gjesse, 2013-06-25 10:26:16]

lgtm, with comments

https://codereview.chromium.org/17640008/diff/1/runtime/bin/socket.cc
File runtime/bin/socket.cc (right):

https://codereview.chromium.org/17640008/diff/1/runtime/bin/socket.cc#newcode497
runtime/bin/socket.cc:497: OSError* os_error = NULL;
How about this:

char host[MAX_HOST_LEN];  // NI_MAXHOST not avaialable here.
bool ok = Socket::ReverseLookup(addr, host, &os_error);
if (ok) {
  ...

Then you avoid "delete host" both here and in all platform implementations when
there is an error.

You could of cause pass MAX_HOST_LEN

bool ok = Socket::ReverseLookup(addr, host, MAX_HOST_LEN, &os_error);

And then assert it is at least NI_MAXHOST in the platform code.

[Anders Johnsen, 2013-06-25 11:27:35]

https://codereview.chromium.org/17640008/diff/1/runtime/bin/socket.cc
File runtime/bin/socket.cc (right):

https://codereview.chromium.org/17640008/diff/1/runtime/bin/socket.cc#newcode497
runtime/bin/socket.cc:497: OSError* os_error = NULL;
On 2013/06/25 10:26:16, Søren Gjesse wrote:
> How about this:
> 
> char host[MAX_HOST_LEN];  // NI_MAXHOST not avaialable here.
> bool ok = Socket::ReverseLookup(addr, host, &os_error);
> if (ok) {
>   ...
> 
> Then you avoid "delete host" both here and in all platform implementations
when
> there is an error.
> 
> You could of cause pass MAX_HOST_LEN
> 
> bool ok = Socket::ReverseLookup(addr, host, MAX_HOST_LEN, &os_error);
> 
> And then assert it is at least NI_MAXHOST in the platform code.

Done.

[Anders Johnsen, 2013-06-25 11:28:04]

Committed patchset #3 manually as r24393 (presubmit successful).