RFR 8193842: Refactor InputStream-to-OutputStream copy into a utility method (original) (raw)

Remi Forax forax at univ-mlv.fr
Sat Dec 23 23:27:19 UTC 2017

Hi Brian, it's not clear to me that all internal usages should use IOSupport.copy and not InputStream.transferTo, a specific InputStream implementation (like DataInputStream) may come with a more optimized version of transferTo.

It remember me Collections.sort()/List.sort(), at first it was decided that List.sort() should call Collections.sort() but after thinking a little bit more, Collections.sort() was re-written to call List.sort() because it may use faster implementation (like ArrayList.sort()).

cheers, Rémi

----- Mail original -----

De: "Brian Burkhalter" <brian.burkhalter at oracle.com> À: "core-libs-dev" <core-libs-dev at openjdk.java.net> Envoyé: Vendredi 22 Décembre 2017 22:51:17 Objet: RFR 8193842: Refactor InputStream-to-OutputStream copy into a utility method

https://bugs.openjdk.java.net/browse/JDK-8194133 http://cr.openjdk.java.net/~bpb/8194133/webrev.00/

Add jdk.internal.io.IOSupport with copy() methods for InputStream-to-OutputStream copying and modify some classes to use these new methods. One thing that I noticed when looking at this is that in the fix for https://bugs.openjdk.java.net/browse/JDK-8193842, the Files.copy() method had a loop like while ((n = read(…)) > 0) whereas InputStream.transferTo() had while((n = read(…)) >= 0) which is to say that Files.copy() would terminate if there were an empty read() but transferTo() would not. The patch for 8193842 therefore possibly introduced a subtle behavioral change which no one noticed. Thanks, Brian

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