@Override
public synchronized boolean store(OutputStream output) throws IOException {
try {
if (this.normalCompletion == null || normalCompletion.getFST() == null) return false;
normalCompletion.getFST().save(new OutputStreamDataOutput(output));
} finally {
IOUtils.close(output);
}
return true;
}
public void testRequestedCount() throws Exception {
// 'one' is promoted after collecting two higher ranking results.
assertMatchEquals(completion.lookup(stringToCharSequence("one"), 2), "one/0.0", "oneness/1.0");
// 'four' is collected in a bucket and then again as an exact match.
assertMatchEquals(
completion.lookup(stringToCharSequence("four"), 2), "four/0.0", "fourblah/1.0");
// Check reordering of exact matches.
assertMatchEquals(
completion.lookup(stringToCharSequence("four"), 4),
"four/0.0",
"fourblah/1.0",
"fourteen/1.0",
"fourier/0.0");
// 'one' is at the top after collecting all alphabetical results.
assertMatchEquals(
completionAlphabetical.lookup(stringToCharSequence("one"), 2), "one/0.0", "oneness/1.0");
// 'one' is not promoted after collecting two higher ranking results.
FSTCompletion noPromotion = new FSTCompletion(completion.getFST(), true, false);
assertMatchEquals(
noPromotion.lookup(stringToCharSequence("one"), 2), "oneness/1.0", "onerous/1.0");
// 'one' is at the top after collecting all alphabetical results.
assertMatchEquals(
completionAlphabetical.lookup(stringToCharSequence("one"), 2), "one/0.0", "oneness/1.0");
}
public void setUp() throws Exception {
super.setUp();
FSTCompletionBuilder builder = new FSTCompletionBuilder();
for (TermFreq tf : evalKeys()) {
builder.add(tf.term, (int) tf.v);
}
completion = builder.build();
completionAlphabetical = new FSTCompletion(completion.getFST(), false, true);
}
@Override
public synchronized boolean load(InputStream input) throws IOException {
try {
this.higherWeightsCompletion =
new FSTCompletion(
new FST<Object>(new InputStreamDataInput(input), NoOutputs.getSingleton()));
this.normalCompletion =
new FSTCompletion(higherWeightsCompletion.getFST(), false, exactMatchFirst);
} finally {
IOUtils.close(input);
}
return true;
}
@Override
public void build(TermFreqIterator tfit) throws IOException {
if (tfit instanceof TermFreqPayloadIterator) {
throw new IllegalArgumentException("this suggester doesn't support payloads");
}
File tempInput =
File.createTempFile(
FSTCompletionLookup.class.getSimpleName(), ".input", Sort.defaultTempDir());
File tempSorted =
File.createTempFile(
FSTCompletionLookup.class.getSimpleName(), ".sorted", Sort.defaultTempDir());
Sort.ByteSequencesWriter writer = new Sort.ByteSequencesWriter(tempInput);
Sort.ByteSequencesReader reader = null;
ExternalRefSorter sorter = null;
// Push floats up front before sequences to sort them. For now, assume they are non-negative.
// If negative floats are allowed some trickery needs to be done to find their byte order.
boolean success = false;
try {
byte[] buffer = new byte[0];
ByteArrayDataOutput output = new ByteArrayDataOutput(buffer);
BytesRef spare;
while ((spare = tfit.next()) != null) {
if (spare.length + 4 >= buffer.length) {
buffer = ArrayUtil.grow(buffer, spare.length + 4);
}
output.reset(buffer);
output.writeInt(encodeWeight(tfit.weight()));
output.writeBytes(spare.bytes, spare.offset, spare.length);
writer.write(buffer, 0, output.getPosition());
}
writer.close();
// We don't know the distribution of scores and we need to bucket them, so we'll sort
// and divide into equal buckets.
SortInfo info = new Sort().sort(tempInput, tempSorted);
tempInput.delete();
FSTCompletionBuilder builder =
new FSTCompletionBuilder(
buckets, sorter = new ExternalRefSorter(new Sort()), sharedTailLength);
final int inputLines = info.lines;
reader = new Sort.ByteSequencesReader(tempSorted);
long line = 0;
int previousBucket = 0;
int previousScore = 0;
ByteArrayDataInput input = new ByteArrayDataInput();
BytesRef tmp1 = new BytesRef();
BytesRef tmp2 = new BytesRef();
while (reader.read(tmp1)) {
input.reset(tmp1.bytes);
int currentScore = input.readInt();
int bucket;
if (line > 0 && currentScore == previousScore) {
bucket = previousBucket;
} else {
bucket = (int) (line * buckets / inputLines);
}
previousScore = currentScore;
previousBucket = bucket;
// Only append the input, discard the weight.
tmp2.bytes = tmp1.bytes;
tmp2.offset = input.getPosition();
tmp2.length = tmp1.length - input.getPosition();
builder.add(tmp2, bucket);
line++;
}
// The two FSTCompletions share the same automaton.
this.higherWeightsCompletion = builder.build();
this.normalCompletion =
new FSTCompletion(higherWeightsCompletion.getFST(), false, exactMatchFirst);
success = true;
} finally {
if (success) IOUtils.close(reader, writer, sorter);
else IOUtils.closeWhileHandlingException(reader, writer, sorter);
tempInput.delete();
tempSorted.delete();
}
}
/**
* This constructor takes a pre-built automaton.
*
* @param completion An instance of {@link FSTCompletion}.
* @param exactMatchFirst If <code>true</code> exact matches are promoted to the top of the
* suggestions list. Otherwise they appear in the order of discretized weight and alphabetical
* within the bucket.
*/
public FSTCompletionLookup(FSTCompletion completion, boolean exactMatchFirst) {
this(INVALID_BUCKETS_COUNT, exactMatchFirst);
this.normalCompletion = new FSTCompletion(completion.getFST(), false, exactMatchFirst);
this.higherWeightsCompletion = new FSTCompletion(completion.getFST(), true, exactMatchFirst);
}