Hi all,
I'm using Avro as a serialization format and assume I have a generated specific
class FOO that I use as a Mapper output format:
class FOO {
int a;
List<BAR> barList;
}
where BAR is another generated specific Java class.
When I iterate over "Iterable<FOO> values" in the Reducer it is clear that the
same object of class FOO is reused, i.e.
FOO foo1 = values.iterator.next();
FOO foo2 = values.iterator.next();
assertThat(foo1 == foo2, is (true));
So I have the following questions:
1) Is the list barList reused over the next() calls?
2) If yes, can the objects that are in the barList be reused? For example, if
the first time next() is called, the list contains two BAR objects, the next
time next() is called the barList contains 3 objects and 2 of them are equal by
reference to the two from the list of the first next() call. In other words,
does Hadoop maintain some sort of "object pool"?
3) Why do not AvroTools generate clone() methods since it would be quite
straightforward and more importantly useful given that objects are reused?
Thanks a lot in advance!
Vyacheslav
