@Override
public List<LookupResult> lookup(CharSequence key, boolean onlyMorePopular, int num) {
assert num > 0;
BytesRef scratch = new BytesRef(key);
int prefixLength = scratch.length;
Arc<Long> arc = new Arc<Long>();
// match the prefix portion exactly
Long prefixOutput = null;
try {
prefixOutput = lookupPrefix(scratch, arc);
} catch (IOException bogus) {
throw new RuntimeException(bogus);
}
if (prefixOutput == null) {
return Collections.<LookupResult>emptyList();
}
List<LookupResult> results = new ArrayList<LookupResult>(num);
CharsRef spare = new CharsRef();
if (exactFirst && arc.isFinal()) {
spare.grow(scratch.length);
UnicodeUtil.UTF8toUTF16(scratch, spare);
results.add(
new LookupResult(spare.toString(), decodeWeight(prefixOutput + arc.nextFinalOutput)));
if (--num == 0) {
return results; // that was quick
}
}
// complete top-N
MinResult<Long> completions[] = null;
try {
completions = Util.shortestPaths(fst, arc, weightComparator, num);
} catch (IOException bogus) {
throw new RuntimeException(bogus);
}
BytesRef suffix = new BytesRef(8);
for (MinResult<Long> completion : completions) {
scratch.length = prefixLength;
// append suffix
Util.toBytesRef(completion.input, suffix);
scratch.append(suffix);
spare.grow(scratch.length);
UnicodeUtil.UTF8toUTF16(scratch, spare);
results.add(
new LookupResult(spare.toString(), decodeWeight(prefixOutput + completion.output)));
}
return results;
}
/** Returns the weight associated with an input string, or null if it does not exist. */
public Object get(CharSequence key) {
Arc<Long> arc = new Arc<Long>();
Long result = null;
try {
result = lookupPrefix(new BytesRef(key), arc);
} catch (IOException bogus) {
throw new RuntimeException(bogus);
}
if (result == null || !arc.isFinal()) {
return null;
} else {
return Integer.valueOf(decodeWeight(result + arc.nextFinalOutput));
}
}