[OpenJDK 2D-Dev] [9] Review-request for 6353518: Creation of a WritableRaster with a custom DataBuffer causes erroneous Exception
Jim Graham
james.graham at oracle.com
Tue Mar 29 21:37:18 UTC 2016
Raster.java, line 742: This branch of the switch statement instantiates
a SWR which doesn't have a specific buffer type. It could be replaced
with just "break;" and let the code after the switch create the raster
(it can't be deleted from the switch statement because the default would
throw an exception, but it could just "break;" on that dataType). At a
minimum, though, it didn't need the instanceof or cast that was added
since it will just fall through to exactly the same code anyway.
Raster.java, line 894: Why was the test for dataType removed from this
if statement?
Raster.java: line 980: Something to file as a potential bug for future
work. The test for getSampleSize(0) in this method is much more
permissive than the test for bitsPerPixel in createPackedRaster just
above this method. Both determine whether to return a BytePackedRaster
so they should probably agree.
Raster.java, line 986: Something to file as a potential bug for future
work since the fix would have to be verified that it doesn't disrupt the
other parts of this method, but... The set of if statements in this
method never checked for a BandedSampleModel to try to create a
BandedRaster as in createBandedRaster. On the other hand, no developer
has complained so far (that I know of, but maybe we have an old bug
filed on it that I'm not aware of).
Raster.java: the same comments for createRaster above apply for
createWritableRaster at line 1033.
The following 2 comments are identical for all of the raster types
{
ByteBandedRaster.java, line 76: This code will throw a
ClassCastException
now instead of the RasterFormatException that used to be thrown.
Do we care? It would be easy enough to add a test to just this
method (and the similar versions in other files).
ByteBandedRaster.java, line 668: Extra credit: This cast could be
avoided
if we make SunWritableRaster employ generics for a strongly
typed DataBuffer.
}
ShortInterleavedRaster - I think the import of DataBuffer can be
eliminated now?
...jim
On 3/28/16 3:18 AM, Ajit Ghaisas wrote:
> Hi,
>
> Thanks Jim for thorough review.
>
> Here is the updated webrev :
> http://cr.openjdk.java.net/~arapte/ajit/6353518/webrev.04/
>
> In this update :
> 1) I have corrected missing space after casting
> 2) I have modified code to adapt suggested indentation for blocks having conditionals & method declaration split on multiple lines.
>
> Please note that, I have done indentation change only if it is related to the code changes done as part of this fix.
> The files in this review already have indentation issues and fixing all of them will result in multiple changes masking the actual code changes that fixes the reported issue.
>
> Request you to review the updated webrev.
>
> Regards,
> Ajit
>
> -----Original Message-----
> From: Jim Graham
> Sent: Thursday, March 24, 2016 5:59 AM
> To: Phil Race
> Cc: 2d-dev
> Subject: Re: [OpenJDK 2D-Dev] [9] Review-request for 6353518: Creation of a WritableRaster with a custom DataBuffer causes erroneous Exception
>
> I should point out that this form I demonstrate below is only used when there are continuation lines on the prefix to the code block (conditionals, method declarations, loop controls, etc.), so:
>
> if (some simple condition) {
> ...
> }
>
> and:
>
> if (some complex condition &&
> some additional condition)
> {
> ...
> }
>
> but, not:
>
> if (some single line condition)
> {
> // blech
> ...
> }
>
> The reason for this is that the standard indentation would recommend:
>
> if (some complex condition &&
> some additional condition) {
> // code block
> }
> or
> void foomethod(int sx, int sy,
> int dx, int dy) {
> // code block
> }
>
> which may be more compact, but the lack of a breaking line means you have to vary the indentation of the declarations/conditionals and as a result they don't line up nicely which makes them harder to scan if they are all related (and frequently in graphics code you end up with a series of very similar arguments or conditionals that are more readable if they line up nicely), and the only indication of when the multiple lines of continued declaration/conditionals end and the body of the method begins is the number of spaces - noting that frequently the indentation on lines in practice is just wrong so this form makes it hard to distinguish between "that line is a continuation line" and "someone indented that line wrong"...
>
> ...jim
>
> On 3/23/16 5:14 PM, Jim Graham wrote:
>> For the record, in many places in the 2D code we also adopt a slight
>> extension of the indentation rules such that the below might be written as:
>>
>> public ByteBandedRaster(SampleModel sampleModel,
>> DataBufferByte dataBuffer,
>> Point origin)
>> {
>> // body lines of the method...
>> }
>>
>> with the open curly brace on the following line so that it more visually
>> points out the beginning of the body block of the method and it's easy
>> to find the start/end of the block by sighting down the left margin. The
>> official policy is for the "{" to be at the end of the previous line
>> after "Point origin) {" and as more new engineers work on the code and
>> follow the official rules, the above form becomes less common. (Sad
>> face since I particularly like the above form...)
>>
>> ...jim
>>
>> On 3/22/16 4:10 PM, Phil Race wrote:
>>> Ajit,
>>>
>>> There is also some odd indentation in ByteBandedRaster.java which is not
>>> yours but
>>>
>>> 98 public ByteBandedRaster(SampleModel sampleModel,
>>> 99 DataBufferByte dataBuffer,
>>> 100 Point origin) {
>>>
>>>
>>> This appears to be the result of someone using tabs a long time ago.
>>>
>>> Since you are touching the method signature lines anyway may be
>>> better fixed so we have these aligned
>>>
>>> public ByteBandedRaster(SampleModel sampleModel,
>>> DataBufferByte dataBuffer,
>>> Point origin) {
>>>
>>> [not sure if that will make it through mail as intended].
>>>
>>> Here in Raster.java, the first condition now seems to be redundant ..
>>> 890 if (dataType == DataBuffer.TYPE_BYTE &&
>>> 891 dataBuffer instanceof DataBufferByte &&
>>>
>>>
>>>
>>> -phil.
>>>
>>>
>>> On 03/22/2016 03:28 PM, Jim Graham wrote:
>>>> Hi Ajit,
>>>>
>>>> Most of your if statements are spaced wrong. There should be a space
>>>> between "if" and the parentheses. I'll review more later, but I
>>>> noticed that issue in the first couple of files I looked at...
>>>>
>>>> ...jim
>>>>
>>>> On 3/15/16 7:05 AM, Ajit Ghaisas wrote:
>>>>> Hi,
>>>>>
>>>>> Thanks Sergey and Jim for suggestions.
>>>>>
>>>>> I have made the data specific Raster constructors type safe
>>>>> now. Also, I have modified all Raster creations in Raster.java to
>>>>> support custom DataBuffer classes.
>>>>>
>>>>> Please review the changes present in updated webrev :
>>>>> http://cr.openjdk.java.net/~arapte/ajit/6353518/webrev.02/
>>>>>
>>>>> Regards,
>>>>> Ajit
>>>>>
>>>>> -----Original Message-----
>>>>> From: Jim Graham
>>>>> Sent: Friday, March 11, 2016 2:40 AM
>>>>> To: Sergey Bylokhov; Ajit Ghaisas; 2d-dev
>>>>> Subject: Re: [OpenJDK 2D-Dev] [9] Review-request for 6353518:
>>>>> Creation of a WritableRaster with a custom DataBuffer causes
>>>>> erroneous Exception
>>>>>
>>>>> Yes, those constructors should be type-safe. Perhaps that was done
>>>>> to save code in the caller, but that is a small price to pay to avoid
>>>>> errors in the future, and it makes sure there is a backup plan for
>>>>> different kinds of buffers...
>>>>>
>>>>> ...jim
>>>>>
>>>>> On 3/10/16 4:48 AM, Sergey Bylokhov wrote:
>>>>>> Hi, Ajit.
>>>>>> What about other cases in Raster.java, where the DataBuffer is passed
>>>>>> as a parameter? Probably we can simplify the code and find all such
>>>>>> issues if we changes the ByteInterleavedRaster/etc. For example:
>>>>>>
>>>>>> ByteInterleavedRaster(SampleModel sampleModel,DataBuffer
>>>>>> dataBuffer,...) to
>>>>>>
>>>>>> ByteInterleavedRaster(SampleModel sampleModel,DataBufferByte
>>>>>> dataBuffer,...)
>>>>>>
>>>>>> Because we throw an exception in such cases anyway:
>>>>>>
>>>>>> if (!(dataBuffer instanceof DataBufferByte)) {
>>>>>> throw new RasterFormatException("ByteInterleavedRasters must
>>>>>> have "
>>>>>> + "byte DataBuffers");
>>>>>> }
>>>>>>
>>>>>> And the compiler will help us, what everybody think about it?
>>>>>>
>>>>>> On 09.03.16 17:38, Ajit Ghaisas wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> Modified the test and added check for
>>>>>>> MultiPixelPackedSampleModel
>>>>>>> condition.
>>>>>>>
>>>>>>> Please review updated webrev :
>>>>>>> http://cr.openjdk.java.net/~arapte/ajit/6353518/webrev.01/
>>>>>>>
>>>>>>> Regards,
>>>>>>> Ajit
>>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: Sergey Bylokhov
>>>>>>> Sent: Wednesday, March 09, 2016 4:06 PM
>>>>>>> To: Ajit Ghaisas; awt-dev at openjdk.java.net; Semyon Sadetsky; Ambarish
>>>>>>> Rapte; 2d-dev
>>>>>>> Subject: Re: [9] Review-request for 6353518: Creation of a
>>>>>>> WritableRaster with a custom DataBuffer causes erroneous Exception
>>>>>>>
>>>>>>> Changes for 2d area.(cc)
>>>>>>>
>>>>>>>
>>>>>>> On 07.03.16 11:20, Ajit Ghaisas wrote:
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> Bug : https://bugs.openjdk.java.net/browse/JDK-6353518
>>>>>>>>
>>>>>>>> Issue : (Text from bug description)
>>>>>>>>
>>>>>>>> An attempt to create a WritableRaster via
>>>>>>>> Raster.createWritableRaster(SampleModel sm, DataBuffer db, Point
>>>>>>>> location) using a custom DataBuffer causes an erroneous
>>>>>>>> RasterFormatException.
>>>>>>>> Apparently the reason for this bug is that IntegerComponentRaster
>>>>>>>> insists on being passed an instance of DataBufferInt rather than
>>>>>>>> just a DataBuffer with a DataType of TYPE_INT.
>>>>>>>> This is quite annoying since DataBufferInt is declared final and
>>>>>>>> thus cannot be extended.
>>>>>>>>
>>>>>>>> Fix :
>>>>>>>>
>>>>>>>> The last line of Raster.createWritableRaster() method already has a
>>>>>>>> way to handle generic case if the input does not match any of the
>>>>>>>> cases in switch statements in that method.
>>>>>>>>
>>>>>>>> The fact that " *InterleavedRaster() constructors throw exception
>>>>>>>> if DataBuffer passed to them does not match the expected type" was
>>>>>>>> ignored earlier.
>>>>>>>>
>>>>>>>> This fix adds a check of "DataBuffer type" before creating
>>>>>>>> respective
>>>>>>>> *InterleavedRaster() objects.
>>>>>>>>
>>>>>>>> It constructs the SunWritableRaster in case DataBuffer type does not
>>>>>>>> match any data specific DataBuffer classes (DataBufferByte,
>>>>>>>> DataBufferUShort, DataBufferInt)
>>>>>>>>
>>>>>>>> Request to review webrev containing this fix :
>>>>>>>>
>>>>>>>> http://cr.openjdk.java.net/~arapte/ajit/6353518/webrev.00/
>>>>>>>>
>>>>>>>> Regards,
>>>>>>>>
>>>>>>>> Ajit
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Best regards, Sergey.
>>>>>>>
>>>>>>
>>>>>>
>>>
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