On Sat, 9 Jan 2021 23:06:22 GMT, Philippe Marschall
<github.com+471021+marsch...@openjdk.org> wrote:
>> Implement three optimiztations for Reader.read(CharBuffer)
>>
>> * Add a code path for heap buffers in Reader#read to use the backing array
>> instead of allocating a new one.
>> * Change the code path for direct buffers in Reader#read to limit the
>> intermediate allocation to `TRANSFER_BUFFER_SIZE`.
>> * Implement `InputStreamReader#read(CharBuffer)` and delegate to
>> `StreamDecoder`.
>> * Implement `StreamDecoder#read(CharBuffer)` and avoid buffer allocation.
>
> Philippe Marschall has updated the pull request incrementally with one
> additional commit since the last revision:
>
> Add unit tests
>
> - add unit test for Reader#read(CharBuffer)
> - add unit test for InputStreamReader#reader(CharBuffer)
> - test with both on-heap and off-heap buffers
src/java.base/share/classes/java/io/Reader.java line 198:
> 196: } else {
> 197: int remaining = target.remaining();
> 198: char cbuf[] = new char[Math.min(remaining,
> TRANSFER_BUFFER_SIZE)];
Would there be value in making this a (lazily created) member variable? That
would allow a single instance to be reused. It seems likely that, if one call
is made with a direct CharBuffer, subsequent calls will also be made with
direct instances (probably same instance?).
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PR: https://git.openjdk.java.net/jdk/pull/1915
