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 207: > 205: target.put(cbuf, 0, n); > 206: nread += n; > 207: remaining -= n; Wouldn't there be a possibility for target.put(cbuf, 0, n) to throw BufferOverflowException ? For example: - there's room (remaining) for TRANSFER_BUFFER_SIZE + 1 characters in target - cbuff is sized to TRANSFER_BUFFER_SIZE - 1st iteration of do loop transfers TRANSFER_BUFFER_SIZE charasters (remaining == 1) - 2nd iteration reads > 1 (up to TRANSFER_BUFFER_SIZE) characters - target.put throws BufferOverflowException You have to limit the amount read in each iteration to be Math.min(remaining, cbuf.length) ------------- PR: https://git.openjdk.java.net/jdk/pull/1915
