Hi again,
please consider to add hash() to interface Map, as an additional performance
opportunity, see:
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6812862
It was rejected with:
implement a wrapper class for the "key" to customize its hash() & equals()
methods
Unfortunately my earlier comment on this appears to be lost by migration to
Jira, so here again:
Instantiating a wrapper object for each key contradicts the purpose of performance tuning and
additionally increases memory footprint.
-Ulf
Am 08.04.2013 20:07, schrieb Mike Duigou:
Hello all;
This is a combined review for the new default methods on the java.util.Map
interface being added for the JSR-335 lambda libraries. The reviews are being
combined because they share a common unit test.
http://cr.openjdk.java.net/~mduigou/JDK-8010122/0/webrev/
8004518: Add in-place operations to Map
forEach()
replaceAll()
8010122: Add atomic operations to Map
getOrDefault()
putIfAbsent() *
remove(K, V)
replace(K, V)
replace(K, V, V)
compute() *
merge() *
computeIfAbsent() *
computeIfPresent() *
The * operations treat null values as being absent. (ie. the same as there
being no mapping for the specified key).
The default implementations provided in Map are overridden in HashMap for
performance purposes, in Hashtable for atomicity and performance purposes and
in Collections for atomicity.
Mike
