Code Review Request: 7168172: (fs) Files.isReadable slow on Windows

[Alan Bateman]

On 23/08/2012 00:33, Ulf Zibis wrote:
> Am 22.08.2012 20:38, schrieb Kurchi Hazra:
>> However, it is faster to simply open the file being checked and close 
>> it. In the case of a directory then, a DirectoryStream can be opened 
>> and closed to check the same.
>
> I would rename checkReadAccess(WindowsPath file) to 
> tryReadAccess(WindowsPath file)
The API that the provider defines is checkAccess so I think it's okay to 
have this private specialized method for read be named checkReadAccess.


> :
>
>
> At least the boolean one could be saved easily and (modes.length == 0) 
> is superfluous:
>
>     public void checkAccess(Path obj, AccessMode... modes) throws 
> IOException {
>         AccessMode r = null;
>         AccessMode w = null;
>         AccessMode x = null;
>         for (AccessMode mode: modes) {
>             switch (mode) {
>                 case READ : r = READ; break;
>                 case WRITE : w = WRITE; break;
>                 case EXECUTE : x = EXECUTE; break;
>                 default: throw new AssertionError("Should not get here");
>             }
>         }
>
>         WindowsPath file = WindowsPath.toWindowsPath(obj);
>
>         // special-case read access to avoid needing to determine 
> effective
>         // access to file
>         if (w == null && x == null) {
>             tryReadAccess(file);
>             return;
>         }
You're right that the modes.length == 0 check could be skipped and then 
it becomes "if (!w && !x) { ... }". I'll leave it to Kurchi as to 
whether she wants to change this. I'm okay either way.

-Alan