RFR [9] 8006627: UUID to/from String performance should be improved by reducing object allocations

[Claes Redestad]

Hi,

  was asked offline to add a length check at the start (prevents 
potentially costly scans for huge, invalid input; negligible performance 
impact for normal cases) and realized dash1 < 0 || dash2 < 0 || dash3 < 
0 implies dash4 < 0, so the first three checks are unnecessary and can 
be skipped:

  http://cr.openjdk.java.net/~redestad/8006627/webrev.5

  /Claes

On 2014-07-21 20:32, Claes Redestad wrote:
> Hi,
>
>  new webrev which ensures we always throw some kind of IAE for invalid 
> inputs and adds a few tests to cover this behavior: 
> http://cr.openjdk.java.net/~redestad/8006627/webrev.4
>
> /Claes
>
> On 2014-07-21 20:05, Claes Redestad wrote:
>> Hi,
>>
>>  IIOB is invalid to throw here, so I'll fix that. 
>> NumberFormatException is a IllegalArgumentException, so I think it's 
>> a gray area if the dash4 + 1 < name.length()-check is needed.
>>
>>  I sincerely hope keeping error messages as-is isn't required, though.
>>
>> /Claes
>>
>> On 2014-07-21 18:51, Peter Levart wrote:
>>> Hi Claes,
>>>
>>> Invalid inputs to UUID.fromString() behave a little different than 
>>> before. IllegalArgumentException is not thrown for the following 
>>> inputs:
>>>
>>> For example:
>>>
>>> "0": IllegalArgumentException: Invalid UUID string: 0 (before patch)
>>> "0": IndexOutOfBoundsException (after patch)
>>>
>>> "-0": IllegalArgumentException: Invalid UUID string: -0 (before patch)
>>> "-0": NumberFormatException (after patch)
>>>
>>> "0-0-0-0-": IllegalArgumentException: Invalid UUID string: 0-0-0-0- 
>>> (before patch)
>>> "0-0-0-0-": NumberFormatException (after patch)
>>>
>>> The following input (and similar) do throw NumberFormatException as 
>>> before, but messages are a little different. That's OK, I suppose.
>>>
>>> "0-0-0-x-0": NumberFormatException: For input string: "x" (before 
>>> patch)
>>> "0-0-0-x-0": NumberFormatException: Error at index 1 in: "x" (after 
>>> patch)
>>>
>>> "0-0-0--0": NumberFormatException: For input string: "" (before patch)
>>> "0-0-0--0": NumberFormatException: (after patch)
>>>
>>>
>>> The 1st 3 examples could be fixed by checking that dash1,2,3,4 are 
>>> all > 0 and that dash4 + 1 < name.length()
>>>
>>>
>>> Regards, Peter
>>>
>>>
>>> On 07/21/2014 01:41 PM, Claes Redestad wrote:
>>>> On 07/19/2014 02:59 PM, Ivan Gerasimov wrote:
>>>>> This looks just beautiful!
>>>>
>>>> Thanks!
>>>>
>>>>> But why do you need the digits() function at all?
>>>>> In my opinion, using formatUnsignedLong directly would be no less 
>>>>> clearer.
>>>>
>>>> Sure!
>>>>
>>>> http://cr.openjdk.java.net/~redestad/8006627/webrev.2/
>>>>
>>>> Small improvement with client compiler; no measurable change with 
>>>> tiered.
>>>>
>>>> /Claes
>>>>
>>>>>
>>>>> Sincerely yours,
>>>>> Ivan
>>>>>
>>>>> On 19.07.2014 8:59, Claes Redestad wrote:
>>>>>> Hi,
>>>>>>
>>>>>>  after recent changes, this patch has been revisited and improved 
>>>>>> slightly, primarily simplifying and speeding up the toString 
>>>>>> method slightly more:
>>>>>>
>>>>>> http://cr.openjdk.java.net/~redestad/8006627/webrev.1/
>>>>>>
>>>>>>  /Claes
>>>>>>
>>>>>> On 2014-06-15 00:41, Claes Redestad wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> please review this patch to improve UUID performance, originally 
>>>>>>> proposed by Steven Schlansker, rebased to use the 
>>>>>>> allocation-free methods added in 
>>>>>>> https://bugs.openjdk.java.net/browse/JDK-8041972
>>>>>>>
>>>>>>> Webrev: http://cr.openjdk.java.net/~redestad/8006627/webrev.0/
>>>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8006627
>>>>>>>
>>>>>>> Thanks!
>>>>>>>
>>>>>>> /Claes
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>