@Test
public void testRowUniquenessConstraint() throws Exception {
RowUniquenessConstraint<String, String> unique =
new RowUniquenessConstraint<String, String>(
keyspace,
UNIQUE_CF,
"testRowUniquenessConstraint",
UUIDStringSupplier.getInstance())
.withConsistencyLevel(ConsistencyLevel.CL_ONE);
RowUniquenessConstraint<String, String> unique2 =
new RowUniquenessConstraint<String, String>(
keyspace,
UNIQUE_CF,
"testRowUniquenessConstraint",
UUIDStringSupplier.getInstance())
.withConsistencyLevel(ConsistencyLevel.CL_ONE);
try {
unique.withData("abc").acquire();
try {
unique2.acquire();
Assert.fail();
} catch (Exception e) {
LOG.info(e.getMessage());
}
String data = unique.readDataAsString();
Assert.assertNotNull(data);
} catch (Exception e) {
e.printStackTrace();
Assert.fail(e.getMessage());
LOG.error(e.getMessage());
} finally {
unique.release();
}
try {
String data = unique.readDataAsString();
Assert.fail();
} catch (Exception e) {
LOG.info("", e);
}
}
@Override
public void acquireAndApplyMutation(Function<MutationBatch, Boolean> callback)
throws NotUniqueException, Exception {
try {
// Phase 1: Write a unique column
MutationBatch m = keyspace.prepareMutationBatch().setConsistencyLevel(consistencyLevel);
if (data == null) {
m.withRow(columnFamily, key).putEmptyColumn(uniqueColumn, ttl);
} else {
m.withRow(columnFamily, key).putColumn(uniqueColumn, data, ttl);
}
m.execute();
// Phase 2: Read back all columns. There should be only 1
ColumnList<C> result =
keyspace
.prepareQuery(columnFamily)
.setConsistencyLevel(consistencyLevel)
.getKey(key)
.execute()
.getResult();
if (result.size() != 1) {
throw new NotUniqueException(key.toString());
}
// Phase 3: Persist the uniqueness with
m = keyspace.prepareMutationBatch().setConsistencyLevel(consistencyLevel);
if (callback != null) callback.apply(m);
if (data == null) {
m.withRow(columnFamily, key).putEmptyColumn(uniqueColumn, null);
} else {
m.withRow(columnFamily, key).putColumn(uniqueColumn, data, null);
}
m.execute();
} catch (Exception e) {
release();
throw e;
}
}