RFR(JDK 12/NIO) 8202285: (fs) Add a method to Files for comparing file contents

[Roger Riggs]

Hi Joe,

A few comments about the test.

45: the summary should mention it is testing the Files.mismatch method

I think the @bug line should be empty, this is not a test for a bug.
I don't think you need or use the testng group= functionality; if you 
don't have a need for it omit it.


On the test files, I think I would have used testMismatch DataProvider to
create the files.  It would avoid having to maintain parallel lists of 
matching parameters.
The @beforeSetup might support the dataProvider directly,
but might have to iterate over the array itself, creating the files if 
they do not exist.
And keeping the mapping from name to path in a Map instead of statics.

The code should use Assert.assertEquals(actual, expected, msg) so that 
if there is a difference
it is printed.  (instead of assertTrue ( n==m)...)


The file sizes all seem to be multiples of 1024 or the buffer size.
There might be a  good case for using a more varied sizes.

340: testMismatchNotExists:  can the expected exception be more 
specific:  FileNotFoundException
instead of IOException.

370: This condition for zero made me wonder if there was a test case for 
files that differ at 0.

397: fillArray could probably make good use of System.arraycopy().

Regards, Roger


On 10/17/2018 03:33 PM, Joe Wang wrote:
>
> On 10/17/18, 7:16 AM, Roger Riggs wrote:
>> Hi Joe,
>>
>> Looks good, straightforward and easy to understand.
>
> Glad to hear that,  while it's been back and forth a couple of times, 
> it seems "straightforward and easy" won :-)
>>
>> The spec text in the CSR need to be updated to match. (At least the 
>> paragraph about reflexive and atomic).
>
> CSR: update the text and attachment
> https://bugs.openjdk.java.net/browse/JDK-8202302
>
> Also added coverage to spec case 5 -  reflexive (no new test cases), 
> spec case 6 - symmetric with tests selected from case 3.
> webrevs: http://cr.openjdk.java.net/~joehw/jdk12/8202285/webrev_v05/
>
> Thanks,
> Joe
>
>>
>> Thanks, Roger
>>
>> On 10/16/2018 02:10 PM, Joe Wang wrote:
>>> Hi Daniel,
>>>
>>> @linkplain it is!  Thanks!  And yes, int totalRead was fixed in the 
>>> previous webrevs.
>>>
>>> Current version:
>>> specdiff: 
>>> http://cr.openjdk.java.net/~joehw/jdk12/8202285/specdiff_v04/java/nio/file/Files.html 
>>>
>>> webrevs: http://cr.openjdk.java.net/~joehw/jdk12/8202285/webrev_v04/
>>>
>>> Previous version:
>>> specdiff: 
>>> http://cr.openjdk.java.net/~joehw/jdk12/8202285/specdiff_v03/java/nio/file/Files.html 
>>>
>>> webrevs: http://cr.openjdk.java.net/~joehw/jdk12/8202285/webrev_v03/
>>>
>>> Best regards,
>>> Joe
>>>
>>> On 10/16/18, 2:11 AM, Daniel Fuchs wrote:
>>>> Hi Joe,
>>>>
>>>> There are a few places where {@linkplain } should be used instead
>>>> of {@link }. For instance:
>>>>
>>>> 1545      * <li> The two paths locate the {@link #isSameFile(Path, 
>>>> Path) same file},
>>>>
>>>> This should be {@linkplain } - for the record {@link } will format the
>>>> text as code, {@linkplain } will format it as regular text. Since the
>>>> text of the link is "same file" then it should be formatted as regular
>>>> text - not as code.
>>>>
>>>> The link on the next line should probably be {@linkplain } as well.
>>>>
>>>> Otherwise looks good to me (except for the declaration of
>>>> int totalRead that should be long but Alan already mentioned it).
>>>>
>>>> best regards,
>>>>
>>>> -- daniel
>>>>
>>>>
>>>> On 12/10/2018 20:16, Joe Wang wrote:
>>>>> Here's an update based on all of the great reviews and comments 
>>>>> (thanks all!):
>>>>>
>>>>> JBS: https://bugs.openjdk.java.net/browse/JDK-8202285
>>>>> CSR: https://bugs.openjdk.java.net/browse/JDK-8202302
>>>>>
>>>>> Current version:
>>>>> specdiff: 
>>>>> http://cr.openjdk.java.net/~joehw/jdk12/8202285/specdiff_02/java/nio/file/Files.html 
>>>>>
>>>>> webrevs: http://cr.openjdk.java.net/~joehw/jdk12/8202285/webrev_v02/
>>>>>
>>>>> Previous version:
>>>>> specdiff: 
>>>>> http://cr.openjdk.java.net/~joehw/jdk12/8202285/specdiff_v01/java/nio/file/Files.html 
>>>>>
>>>>> webrevs: http://cr.openjdk.java.net/~joehw/jdk12/8202285/webrev_v01/
>>>>>
>>>>> It's been a while, so here's a summary of what's changed:
>>>>>
>>>>> Spec: Alan's patch to fix inconsistencies in wording/terminology
>>>>> Impl: s/mismatchByAttrs and etc/isSameFile;
>>>>>           Stick with the simple implementation 
>>>>> (InputStream/Buffer) for now. Further improvement may be done if 
>>>>> there's a need;
>>>>>           The impl is smaller than the previous version, merged 
>>>>> the code into Files, removed FilesMismatch.java;
>>>>>
>>>>> Test: more readable variables instead of the array of test files
>>>>>           more comments on the testcases
>>>>>           improved the private methods used for generating the 
>>>>> test files
>>>>>
>>>>> Thanks,
>>>>> Joe
>>>>
>>

-- 
Thanks, Roger