This is the simplest possible ConcurrentHashMap I could come up with
that works and is actually concurrent in the way one would expect.
It's pretty unconventional, being based on a persistent red-black
tree, and not particularly memory-efficient or cache-friendly. I
think this is a good place to start, though, and it should perform
reasonably well for most workloads. Patches for a more efficient
implementation are welcome!
I also implemented AtomicReferenceArray, since I was using it in my
first, naive attempt to implement ConcurrentHashMap.
I had to do a bit of refactoring, including moving some non-standard
stuff from java.util.Collections to avian.Data so I could make it
available to code outside the java.util package, which is why I had to
modify several unrelated files.
This is a very dumb implementation that wastes space and time by
constructing a full-blown ArrayList as backend. However, it is
better to have a dumb implementation than none at all, and we can
always do something about the performance when, and if, that should
become necessary.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Previously, I used a shell script to extract modification date ranges
from the Git history, but that was complicated and unreliable, so now
every file just gets the same year range in its copyright header. If
someone needs to know when a specific file was modified and by whom,
they can look at the Git history themselves; no need to include it
redundantly in the header.
Added to collection:
public boolean containsAll(Collection<?> c);
public boolean removeAll(Collection<?> c);
Added to list:
public boolean addAll(int startIndex, Collection<? extends T> c);
Also where possible for inner classes I made them extend the abstract version instead of just implement the interface. This helps reduce code duplication where possible.
These changes were necessary to support protobuf 2.5.0
