RFR: 8278268 - (ch) InputStream returned by Channels.newInputStream should have fast path for FileChannel targets [v21]

[Markus KARG]

On Mon, 20 Mar 2023 21:00:31 GMT, Brian Burkhalter <bpb at openjdk.org> wrote:

>> Markus KARG has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Abstracted testMoreThanTwoGB
>
> test/jdk/java/nio/channels/Channels/TransferToBase.java line 222:
> 
>> 220:                         byte[] rndBytes = createRandomBytes(BYTES_PER_WRITE, 0);
>> 221:                         ByteBuffer src = ByteBuffer.wrap(rndBytes);
>> 222:                         fc.write(src);
> 
> Should this code perhaps allow for a short write, i.e., `FileChannel::write` returning a value less than `rndBytes.length`? For example, something like this:
> 
>                     long pos = initPos;
>                     while (pos < BYTES_WRITTEN) {
>                         int len = Math.toIntExact(BYTES_WRITTEN - pos);
>                         if (len > BYTES_PER_WRITE)
>                             len = BYTES_PER_WRITE;
>                         byte[] rndBytes = createRandomBytes(len, 0);
>                         ByteBuffer src = ByteBuffer.wrap(rndBytes);
>                         pos += fc.write(src);
>                     }

I have incorporated your proposed code change.

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PR Review Comment: https://git.openjdk.org/jdk/pull/6711#discussion_r1144017216