Github user aweisberg commented on a diff in the pull request:
https://github.com/apache/cassandra/pull/271#discussion_r220621697
--- Diff:
src/java/org/apache/cassandra/locator/AbstractReplicaCollection.java ---
@@ -58,45 +63,332 @@
};
}
- protected final List<Replica> list;
- protected final boolean isSnapshot;
- protected AbstractReplicaCollection(List<Replica> list, boolean
isSnapshot)
+ /**
+ * A simple list with no comodification checks and immutability by
default (only append permitted, and only one initial copy)
+ * this permits us to reduce the amount of garbage generated, by not
wrapping iterators or unnecessarily copying
+ * and reduces the amount of indirection necessary, as well as
ensuring monomorphic callsites
+ */
+ protected static class ReplicaList implements Iterable<Replica>
{
- this.list = list;
- this.isSnapshot = isSnapshot;
+ private static final Replica[] EMPTY = new Replica[0];
+ Replica[] contents;
+ int begin, size;
+
+ public ReplicaList() { this(0); }
+ public ReplicaList(int capacity) { contents = capacity == 0 ?
EMPTY : new Replica[capacity]; }
+ public ReplicaList(Replica[] contents, int begin, int size) {
this.contents = contents; this.begin = begin; this.size = size; }
+
+ public boolean isSubList(ReplicaList subList)
+ {
+ return subList.contents == contents;
+ }
+
+ public Replica get(int index)
+ {
+ if (index > size)
+ throw new IndexOutOfBoundsException();
+ return contents[begin + index];
+ }
+
+ public void add(Replica replica)
+ {
+ // can only add to full array - if we have sliced it, we must
be a snapshot
+ assert begin == 0;
--- End diff --
Shouldn't be possible to disable this check.
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