On Apr 15 2013, at 13:03 , Steven Schlansker wrote:
On Apr 15, 2013, at 12:21 PM, Martin Buchholz <martinrb@google.com> wrote:
On Mon, Apr 15, 2013 at 11:31 AM, Martin Buchholz <martinrb@google.com>wrote:
OTOH, I'm guessing you are trying to improve the performance of operations like List.toString. More efficient (single copy char[]) would be to collect all the sub-CharSequences in a CharSequence[], pre-compute the final length of the char[], allocate an array of exactly the required length, and create the final string directly from that using the package-private constructor (but in the unlikely event that a subsequence changed in size while concat'ing, be prepared to resize the array).
Proceeding further along this train of thought, I might start with AbstractCollection.toString() (and similar methods) and attempt to make it maximally efficient. Maybe add a method to JavaLangAccess to make a String directly from a perfectly sized array (as needed elsewhere?). Maybe create a StringBuilder-like class that works better for typical use cases?
For what it's worth, a patch that I contributed and Mike (and others) then rewrote contains this functionality already:
http://cr.openjdk.java.net/~mduigou/JDK-8006627/2/webrev/src/share/classes/s...
It's not merged yet though.
It is not forgotten. :-)