@Test
public void testDiff() throws UnknownHostException {
ContextState left;
ContextState right;
CounterColumn leftCol;
CounterColumn rightCol;
// timestamp
leftCol = new CounterColumn(ByteBufferUtil.bytes("x"), 0, 1L);
rightCol = new CounterColumn(ByteBufferUtil.bytes("x"), 0, 2L);
assert rightCol == leftCol.diff(rightCol);
assert null == rightCol.diff(leftCol);
// timestampOfLastDelete
leftCol = new CounterColumn(ByteBufferUtil.bytes("x"), 0, 1L, 1L);
rightCol = new CounterColumn(ByteBufferUtil.bytes("x"), 0, 1L, 2L);
assert rightCol == leftCol.diff(rightCol);
assert null == rightCol.diff(leftCol);
// equality: equal nodes, all counts same
left = ContextState.allocate(3, 0);
left.writeElement(NodeId.fromInt(3), 3L, 0L);
left.writeElement(NodeId.fromInt(6), 2L, 0L);
left.writeElement(NodeId.fromInt(9), 1L, 0L);
right = new ContextState(ByteBufferUtil.clone(left.context), 2);
leftCol = new CounterColumn(ByteBufferUtil.bytes("x"), left.context, 1L);
rightCol = new CounterColumn(ByteBufferUtil.bytes("x"), right.context, 1L);
assert null == leftCol.diff(rightCol);
// greater than: left has superset of nodes (counts equal)
left = ContextState.allocate(4, 0);
left.writeElement(NodeId.fromInt(3), 3L, 0L);
left.writeElement(NodeId.fromInt(6), 2L, 0L);
left.writeElement(NodeId.fromInt(9), 1L, 0L);
left.writeElement(NodeId.fromInt(12), 0L, 0L);
right = ContextState.allocate(3, 0);
right.writeElement(NodeId.fromInt(3), 3L, 0L);
right.writeElement(NodeId.fromInt(6), 2L, 0L);
right.writeElement(NodeId.fromInt(9), 1L, 0L);
leftCol = new CounterColumn(ByteBufferUtil.bytes("x"), left.context, 1L);
rightCol = new CounterColumn(ByteBufferUtil.bytes("x"), right.context, 1L);
assert null == leftCol.diff(rightCol);
// less than: right has subset of nodes (counts equal)
assert leftCol == rightCol.diff(leftCol);
// disjoint: right and left have disjoint node sets
left = ContextState.allocate(3, 0);
left.writeElement(NodeId.fromInt(3), 1L, 0L);
left.writeElement(NodeId.fromInt(4), 1L, 0L);
left.writeElement(NodeId.fromInt(9), 1L, 0L);
right = ContextState.allocate(3, 0);
right.writeElement(NodeId.fromInt(3), 1L, 0L);
right.writeElement(NodeId.fromInt(6), 1L, 0L);
right.writeElement(NodeId.fromInt(9), 1L, 0L);
leftCol = new CounterColumn(ByteBufferUtil.bytes("x"), left.context, 1L);
rightCol = new CounterColumn(ByteBufferUtil.bytes("x"), right.context, 1L);
assert rightCol == leftCol.diff(rightCol);
assert leftCol == rightCol.diff(leftCol);
}
/** Creates a counter context with a single global, 2.1+ shard (a result of increment). */
public ByteBuffer createGlobal(CounterId id, long clock, long count) {
ContextState state = ContextState.allocate(1, 0, 0);
state.writeGlobal(id, clock, count);
return state.context;
}
/**
* Creates a counter context with a single remote shard. For use by tests of compatibility with
* pre-2.1 counters only.
*/
public ByteBuffer createRemote(CounterId id, long clock, long count) {
ContextState state = ContextState.allocate(0, 0, 1);
state.writeRemote(id, clock, count);
return state.context;
}
/**
* Return a context w/ an aggregated count for each counter id.
*
* @param left counter context.
* @param right counter context.
*/
public ByteBuffer merge(ByteBuffer left, ByteBuffer right) {
boolean leftIsSuperSet = true;
boolean rightIsSuperSet = true;
int globalCount = 0;
int localCount = 0;
int remoteCount = 0;
ContextState leftState = ContextState.wrap(left);
ContextState rightState = ContextState.wrap(right);
while (leftState.hasRemaining() && rightState.hasRemaining()) {
int cmp = leftState.compareIdTo(rightState);
if (cmp == 0) {
Relationship rel = compare(leftState, rightState);
if (rel == Relationship.GREATER_THAN) rightIsSuperSet = false;
else if (rel == Relationship.LESS_THAN) leftIsSuperSet = false;
else if (rel == Relationship.DISJOINT) leftIsSuperSet = rightIsSuperSet = false;
if (leftState.isGlobal() || rightState.isGlobal()) globalCount += 1;
else if (leftState.isLocal() || rightState.isLocal()) localCount += 1;
else remoteCount += 1;
leftState.moveToNext();
rightState.moveToNext();
} else if (cmp > 0) {
leftIsSuperSet = false;
if (rightState.isGlobal()) globalCount += 1;
else if (rightState.isLocal()) localCount += 1;
else remoteCount += 1;
rightState.moveToNext();
} else // cmp < 0
{
rightIsSuperSet = false;
if (leftState.isGlobal()) globalCount += 1;
else if (leftState.isLocal()) localCount += 1;
else remoteCount += 1;
leftState.moveToNext();
}
}
if (leftState.hasRemaining()) rightIsSuperSet = false;
else if (rightState.hasRemaining()) leftIsSuperSet = false;
// if one of the contexts is a superset, return it early.
if (leftIsSuperSet) return left;
else if (rightIsSuperSet) return right;
while (leftState.hasRemaining()) {
if (leftState.isGlobal()) globalCount += 1;
else if (leftState.isLocal()) localCount += 1;
else remoteCount += 1;
leftState.moveToNext();
}
while (rightState.hasRemaining()) {
if (rightState.isGlobal()) globalCount += 1;
else if (rightState.isLocal()) localCount += 1;
else remoteCount += 1;
rightState.moveToNext();
}
leftState.reset();
rightState.reset();
return merge(
ContextState.allocate(globalCount, localCount, remoteCount), leftState, rightState);
}
/**
* Creates a counter context with a single local shard. For use by tests of compatibility with
* pre-2.1 counters only.
*/
public ByteBuffer createLocal(long count) {
ContextState state = ContextState.allocate(0, 1, 0);
state.writeLocal(CounterId.getLocalId(), 1L, count);
return state.context;
}
