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

[Ulf Zibis]

Am 23.08.2012 01:50, schrieb Zhong Yu:
>>      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");
>>              }
>>          }
> That'll leave r==null if `modes` is empty. But an empty `modes` is
> supposed to be equivalent to [READ].

Yes, but in that case w and x are also null, so the "special-case read access" will be invoked 
anyway, and the null-ness of r wouldn't matter.

>>          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;
>>          }
>>
>>          ...
>>      }
>>
>> -Ulf
>>