On Wed, 18 Jun 2025 16:57:22 GMT, Brian Burkhalter <b...@openjdk.org> wrote:
>> src/java.base/share/classes/java/io/Reader.java line 455: >> >>> 453: List<String> lines = new ArrayList<String>(); >>> 454: >>> 455: StringBuilder sb = new StringBuilder(82); >> >> Is there a reason for this pre-allocation? If the whole content is smaller >> than 8192 in size, this allocation would be redundant because we are going >> through the string constructor path. > >> Is there a reason for this pre-allocation? > > What would you suggest? Start with a smaller allocation and increase it if > needed? There is no possibility of knowing the length of the stream. As this PR explicitly targets performance and as the aim of this method is to keep **all** content in-memory anyways, I wonder if it would be acceptable and even faster to pre-allocate `new StringBuilder(TRANSFER_BUFFER_SIZE)`? In the end, this allocation is just temporary. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/25863#discussion_r2156717996
