public void testDisjunctionVariable() {
PrologEngine engine = setupDisjunction();
Variable variableY = new Variable("Y");
Result result3 = engine.askQuestion(new Predicate("hello", 1, variableY));
assertTrue(result3.hasAnswer());
assertEquals(new Constant("world"), variableY.getBinding());
result3.next();
assertTrue(result3.hasAnswer());
assertEquals(new Constant("mars"), variableY.getBinding());
result3.next();
assertTrue(result3.hasAnswer());
assertEquals(new Constant("venus"), variableY.getBinding());
}
/** Writes the debug dump of the table into logs. Not thread-safe. */
public void debugDumpTable() {
StringBuilder dump = new StringBuilder(keysAssigned + " keys\n");
TreeMap<Long, Integer> byteIntervals = new TreeMap<Long, Integer>();
int examined = 0;
for (int slot = 0; slot < refs.length; ++slot) {
long ref = refs[slot];
if (ref == 0) {
continue;
}
++examined;
long recOffset = getFirstRecordLengthsOffset(ref, null);
long tailOffset = Ref.getOffset(ref);
writeBuffers.setReadPoint(recOffset);
int valueLength = (int) writeBuffers.readVLong(), keyLength = (int) writeBuffers.readVLong();
long ptrOffset = writeBuffers.getReadPoint();
if (Ref.hasList(ref)) {
byteIntervals.put(recOffset, (int) (ptrOffset + 5 - recOffset));
}
long keyOffset = tailOffset - valueLength - keyLength;
byte[] key = new byte[keyLength];
WriteBuffers.ByteSegmentRef fakeRef = new WriteBuffers.ByteSegmentRef(keyOffset, keyLength);
byteIntervals.put(keyOffset - 4, keyLength + 4);
writeBuffers.populateValue(fakeRef);
System.arraycopy(fakeRef.getBytes(), (int) fakeRef.getOffset(), key, 0, keyLength);
dump.append(Utils.toStringBinary(key, 0, key.length))
.append(" ref [")
.append(dumpRef(ref))
.append("]: ");
Result hashMapResult = new Result();
getValueResult(key, 0, key.length, hashMapResult);
List<WriteBuffers.ByteSegmentRef> results = new ArrayList<WriteBuffers.ByteSegmentRef>();
WriteBuffers.ByteSegmentRef byteSegmentRef = hashMapResult.first();
while (byteSegmentRef != null) {
results.add(hashMapResult.byteSegmentRef);
byteSegmentRef = hashMapResult.next();
}
dump.append(results.size()).append(" rows\n");
for (int i = 0; i < results.size(); ++i) {
WriteBuffers.ByteSegmentRef segment = results.get(i);
byteIntervals.put(
segment.getOffset(),
segment.getLength() + ((i == 0) ? 1 : 0)); // state byte in the first record
}
}
if (examined != keysAssigned) {
dump.append("Found " + examined + " keys!\n");
}
// Report suspicious gaps in writeBuffers
long currentOffset = 0;
for (Map.Entry<Long, Integer> e : byteIntervals.entrySet()) {
long start = e.getKey(), len = e.getValue();
if (start - currentOffset > 4) {
dump.append("Gap! [" + currentOffset + ", " + start + ")\n");
}
currentOffset = start + len;
}
LOG.info("Hashtable dump:\n " + dump.toString());
}
public void testConjunctionBacktrackingVariable() {
PrologEngine engine = setupConjunctionBacktracking();
Variable variableX = new Variable("X");
Predicate question = new Predicate("suitable", 1, variableX);
Result answer = engine.askQuestion(question);
assertTrue(answer.hasAnswer());
assertEquals(new Constant("Eric"), variableX.getBinding());
answer.next();
assertFalse("Only one answer expected", answer.hasAnswer());
}
public void testConjunctionVariable() {
PrologEngine engine = setupConjunction();
Variable variableX = new Variable("X");
Variable variableY = new Variable("Y");
Variable variableZ = new Variable("Z");
Predicate question = new Predicate("three", 3, variableX, variableY, variableZ);
Result answer = engine.askQuestion(question);
assertTrue(answer.hasAnswer());
assertEquals(new Constant("one"), variableX.getBinding());
assertEquals(new Constant("two"), variableY.getBinding());
assertEquals(new Constant("two"), variableZ.getBinding());
answer.next();
assertFalse(answer.hasAnswer());
}