@Before
public void setUp() throws IOException {
inputLhs = new Hfs(new SequenceFile(new Fields("a", "b")), getTestRoot() + "/lhs");
inputRhs = new Hfs(new SequenceFile(new Fields("c", "d")), getTestRoot() + "/rhs");
TapHelper.writeToTap(
inputLhs,
new Tuple("1", "A"),
new Tuple("1", "B"),
new Tuple("1", "C"),
new Tuple("2", "D"),
new Tuple("2", "H"),
new Tuple("2", "I"));
TapHelper.writeToTap(inputRhs, new Tuple("1", "E"), new Tuple("2", "F"), new Tuple("2", "G"));
}
@Test
public void checkLimits() throws IOException {
Tap<JobConf, ?, ?> output =
new Hfs(new SequenceFile(new Fields("a", "b", "d")), getTestRoot() + "/output");
Pipe lhs = new Pipe("lhs");
Pipe rhs = new Pipe("rhs");
Pipe joined =
new CoGroup(lhs, new Fields("a"), rhs, new Fields("c"), new LimitJoin(new long[] {2, 1}));
Map<String, Tap> sources = new HashMap<String, Tap>();
sources.put("lhs", inputLhs);
sources.put("rhs", inputRhs);
CascadingUtil.get().getFlowConnector().connect(sources, output, joined).complete();
// These would be the results of an ordinary inner join
Set<Tuple> allowedResults =
new HashSet<Tuple>(
Arrays.asList(
new Tuple("1", "A", "E"),
new Tuple("1", "B", "E"),
new Tuple("1", "C", "E"),
new Tuple("2", "D", "F"),
new Tuple("2", "D", "G"),
new Tuple("2", "H", "F"),
new Tuple("2", "H", "G"),
new Tuple("2", "I", "F"),
new Tuple("2", "I", "G")));
/*
Example good output:
1 A E
1 B E
2 D F
2 H F
*/
// Read the results and make sure we saw two results from allowedResults with 1 as the key, and
// two with 2 as the key
Set<Tuple> results = new HashSet<Tuple>(TapHelper.getAllTuples(output));
Assert.assertEquals(4, results.size());
int key1 = 0;
int key2 = 0;
for (Tuple result : results) {
Assert.assertTrue(allowedResults.contains(result));
String key = result.getString(0);
if (key.equals("1")) {
key1++;
} else if (key.equals("2")) {
key2++;
} else {
throw new IllegalStateException("Key should be 1 or 2");
}
}
Assert.assertEquals(2, key1);
Assert.assertEquals(2, key2);
}