/// <summary>
/// encodes an entry (bytes+(contexts)+(payload)+weight) to the provided writer
/// </summary>
protected internal virtual void Encode(OfflineSorter.ByteSequencesWriter writer, ByteArrayDataOutput output, sbyte[] buffer, BytesRef spare, BytesRef payload, HashSet <BytesRef> contexts, long weight)
{
int requiredLength = spare.Length + 8 + ((hasPayloads) ? 2 + payload.Length : 0);
if (hasContexts)
{
foreach (BytesRef ctx in contexts)
{
requiredLength += 2 + ctx.Length;
}
requiredLength += 2; // for length of contexts
}
if (requiredLength >= buffer.Length)
{
buffer = ArrayUtil.Grow(buffer, requiredLength);
}
output.Reset(buffer);
output.WriteBytes(spare.Bytes, spare.Offset, spare.Length);
if (hasContexts)
{
foreach (BytesRef ctx in contexts)
{
output.WriteBytes(ctx.Bytes, ctx.Offset, ctx.Length);
output.WriteShort((short)ctx.Length);
}
output.WriteShort((short)contexts.Count);
}
if (hasPayloads)
{
output.WriteBytes(payload.Bytes, payload.Offset, payload.Length);
output.WriteShort((short)payload.Length);
}
output.WriteLong(weight);
writer.Write(buffer, 0, output.Position);
}
protected internal override void Encode(OfflineSorter.ByteSequencesWriter writer, ByteArrayDataOutput output, byte[] buffer, BytesRef spare, BytesRef payload, ICollection <BytesRef> contexts, long weight)
{
if (spare.Length + 4 >= buffer.Length)
{
buffer = ArrayUtil.Grow(buffer, spare.Length + 4);
}
output.Reset(buffer);
output.WriteBytes(spare.Bytes, spare.Offset, spare.Length);
output.WriteInt32(EncodeWeight(weight));
writer.Write(buffer, 0, output.Position);
}
/// <summary>
/// encodes an entry (bytes+weight) to the provided writer
/// </summary>
protected internal virtual void Encode(OfflineSorter.ByteSequencesWriter writer, ByteArrayDataOutput output, sbyte[] buffer, BytesRef spare, long weight)
{
if (spare.Length + 8 >= buffer.Length)
{
buffer = ArrayUtil.Grow(buffer, spare.Length + 8);
}
output.Reset(buffer);
output.WriteBytes(spare.Bytes, spare.Offset, spare.Length);
output.WriteLong(weight);
writer.Write(buffer, 0, output.Position);
}
public override void Build(IInputEnumerator enumerator)
{
if (enumerator.HasContexts)
{
throw new ArgumentException("this suggester doesn't support contexts");
}
string prefix = this.GetType().Name;
var directory = OfflineSorter.DefaultTempDir();
var tempInput = FileSupport.CreateTempFile(prefix, ".input", directory);
var tempSorted = FileSupport.CreateTempFile(prefix, ".sorted", directory);
hasPayloads = enumerator.HasPayloads;
var writer = new OfflineSorter.ByteSequencesWriter(tempInput);
OfflineSorter.ByteSequencesReader reader = null;
var scratch = new BytesRef();
TokenStreamToAutomaton ts2a = GetTokenStreamToAutomaton();
bool success = false;
count = 0;
byte[] buffer = new byte[8];
try
{
var output = new ByteArrayDataOutput(buffer);
BytesRef surfaceForm;
while (enumerator.MoveNext())
{
surfaceForm = enumerator.Current;
ISet <Int32sRef> paths = ToFiniteStrings(surfaceForm, ts2a);
maxAnalyzedPathsForOneInput = Math.Max(maxAnalyzedPathsForOneInput, paths.Count);
foreach (Int32sRef path in paths)
{
Util.Fst.Util.ToBytesRef(path, scratch);
// length of the analyzed text (FST input)
if (scratch.Length > ushort.MaxValue - 2)
{
throw new ArgumentException("cannot handle analyzed forms > " + (ushort.MaxValue - 2) +
" in length (got " + scratch.Length + ")");
}
ushort analyzedLength = (ushort)scratch.Length;
// compute the required length:
// analyzed sequence + weight (4) + surface + analyzedLength (short)
int requiredLength = analyzedLength + 4 + surfaceForm.Length + 2;
BytesRef payload;
if (hasPayloads)
{
if (surfaceForm.Length > (ushort.MaxValue - 2))
{
throw new ArgumentException("cannot handle surface form > " + (ushort.MaxValue - 2) +
" in length (got " + surfaceForm.Length + ")");
}
payload = enumerator.Payload;
// payload + surfaceLength (short)
requiredLength += payload.Length + 2;
}
else
{
payload = null;
}
buffer = ArrayUtil.Grow(buffer, requiredLength);
output.Reset(buffer);
output.WriteInt16((short)analyzedLength);
output.WriteBytes(scratch.Bytes, scratch.Offset, scratch.Length);
output.WriteInt32(EncodeWeight(enumerator.Weight));
if (hasPayloads)
{
for (int i = 0; i < surfaceForm.Length; i++)
{
if (surfaceForm.Bytes[i] == PAYLOAD_SEP)
{
throw new ArgumentException(
"surface form cannot contain unit separator character U+001F; this character is reserved");
}
}
output.WriteInt16((short)surfaceForm.Length);
output.WriteBytes(surfaceForm.Bytes, surfaceForm.Offset, surfaceForm.Length);
output.WriteBytes(payload.Bytes, payload.Offset, payload.Length);
}
else
{
output.WriteBytes(surfaceForm.Bytes, surfaceForm.Offset, surfaceForm.Length);
}
if (Debugging.AssertsEnabled)
{
Debugging.Assert(output.Position == requiredLength, () => output.Position + " vs " + requiredLength);
}
writer.Write(buffer, 0, output.Position);
}
count++;
}
writer.Dispose();
// Sort all input/output pairs (required by FST.Builder):
(new OfflineSorter(new AnalyzingComparer(hasPayloads))).Sort(tempInput, tempSorted);
// Free disk space:
tempInput.Delete();
reader = new OfflineSorter.ByteSequencesReader(tempSorted);
var outputs = new PairOutputs <long?, BytesRef>(PositiveInt32Outputs.Singleton,
ByteSequenceOutputs.Singleton);
var builder = new Builder <PairOutputs <long?, BytesRef> .Pair>(FST.INPUT_TYPE.BYTE1, outputs);
// Build FST:
BytesRef previousAnalyzed = null;
BytesRef analyzed = new BytesRef();
BytesRef surface = new BytesRef();
Int32sRef scratchInts = new Int32sRef();
var input = new ByteArrayDataInput();
// Used to remove duplicate surface forms (but we
// still index the hightest-weight one). We clear
// this when we see a new analyzed form, so it cannot
// grow unbounded (at most 256 entries):
var seenSurfaceForms = new JCG.HashSet <BytesRef>();
var dedup = 0;
while (reader.Read(scratch))
{
input.Reset(scratch.Bytes, scratch.Offset, scratch.Length);
ushort analyzedLength = (ushort)input.ReadInt16();
analyzed.Grow(analyzedLength + 2);
input.ReadBytes(analyzed.Bytes, 0, analyzedLength);
analyzed.Length = analyzedLength;
long cost = input.ReadInt32();
surface.Bytes = scratch.Bytes;
if (hasPayloads)
{
surface.Length = (ushort)input.ReadInt16();
surface.Offset = input.Position;
}
else
{
surface.Offset = input.Position;
surface.Length = scratch.Length - surface.Offset;
}
if (previousAnalyzed == null)
{
previousAnalyzed = new BytesRef();
previousAnalyzed.CopyBytes(analyzed);
seenSurfaceForms.Add(BytesRef.DeepCopyOf(surface));
}
else if (analyzed.Equals(previousAnalyzed))
{
dedup++;
if (dedup >= maxSurfaceFormsPerAnalyzedForm)
{
// More than maxSurfaceFormsPerAnalyzedForm
// dups: skip the rest:
continue;
}
if (seenSurfaceForms.Contains(surface))
{
continue;
}
seenSurfaceForms.Add(BytesRef.DeepCopyOf(surface));
}
else
{
dedup = 0;
previousAnalyzed.CopyBytes(analyzed);
seenSurfaceForms.Clear();
seenSurfaceForms.Add(BytesRef.DeepCopyOf(surface));
}
// TODO: I think we can avoid the extra 2 bytes when
// there is no dup (dedup==0), but we'd have to fix
// the exactFirst logic ... which would be sort of
// hairy because we'd need to special case the two
// (dup/not dup)...
// NOTE: must be byte 0 so we sort before whatever
// is next
analyzed.Bytes[analyzed.Offset + analyzed.Length] = 0;
analyzed.Bytes[analyzed.Offset + analyzed.Length + 1] = (byte)dedup;
analyzed.Length += 2;
Util.Fst.Util.ToInt32sRef(analyzed, scratchInts);
//System.out.println("ADD: " + scratchInts + " -> " + cost + ": " + surface.utf8ToString());
if (!hasPayloads)
{
builder.Add(scratchInts, outputs.NewPair(cost, BytesRef.DeepCopyOf(surface)));
}
else
{
int payloadOffset = input.Position + surface.Length;
int payloadLength = scratch.Length - payloadOffset;
BytesRef br = new BytesRef(surface.Length + 1 + payloadLength);
Array.Copy(surface.Bytes, surface.Offset, br.Bytes, 0, surface.Length);
br.Bytes[surface.Length] = PAYLOAD_SEP;
Array.Copy(scratch.Bytes, payloadOffset, br.Bytes, surface.Length + 1, payloadLength);
br.Length = br.Bytes.Length;
builder.Add(scratchInts, outputs.NewPair(cost, br));
}
}
fst = builder.Finish();
//Util.dotToFile(fst, "/tmp/suggest.dot");
success = true;
}
finally
{
if (success)
{
IOUtils.Dispose(reader, writer);
}
else
{
IOUtils.DisposeWhileHandlingException(reader, writer);
}
tempInput.Delete();
tempSorted.Delete();
}
}
public override void Build(IInputIterator iterator)
{
if (iterator.HasPayloads)
{
throw new System.ArgumentException("this suggester doesn't support payloads");
}
if (iterator.HasContexts)
{
throw new System.ArgumentException("this suggester doesn't support contexts");
}
FileInfo tempInput = FileSupport.CreateTempFile(typeof(FSTCompletionLookup).Name, ".input", OfflineSorter.DefaultTempDir());
FileInfo tempSorted = FileSupport.CreateTempFile(typeof(FSTCompletionLookup).Name, ".sorted", OfflineSorter.DefaultTempDir());
OfflineSorter.ByteSequencesWriter writer = new OfflineSorter.ByteSequencesWriter(tempInput);
OfflineSorter.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.
bool success = false;
count = 0;
try
{
byte[] buffer = new byte[0];
ByteArrayDataOutput output = new ByteArrayDataOutput(buffer);
BytesRef spare;
while ((spare = iterator.Next()) != null)
{
if (spare.Length + 4 >= buffer.Length)
{
buffer = ArrayUtil.Grow(buffer, spare.Length + 4);
}
output.Reset(buffer);
output.WriteInt32(EncodeWeight(iterator.Weight));
output.WriteBytes(spare.Bytes, spare.Offset, spare.Length);
writer.Write(buffer, 0, output.Position);
}
writer.Dispose();
// We don't know the distribution of scores and we need to bucket them, so we'll sort
// and divide into equal buckets.
OfflineSorter.SortInfo info = (new OfflineSorter()).Sort(tempInput, tempSorted);
tempInput.Delete();
FSTCompletionBuilder builder = new FSTCompletionBuilder(buckets, sorter = new ExternalRefSorter(new OfflineSorter()), sharedTailLength);
int inputLines = info.Lines;
reader = new OfflineSorter.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.ReadInt32();
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.Position;
tmp2.Length = tmp1.Length - input.Position;
builder.Add(tmp2, bucket);
line++;
count++;
}
// The two FSTCompletions share the same automaton.
this.higherWeightsCompletion = builder.Build();
this.normalCompletion = new FSTCompletion(higherWeightsCompletion.FST, false, exactMatchFirst);
success = true;
}
finally
{
if (success)
{
IOUtils.Close(reader, writer, sorter);
}
else
{
IOUtils.CloseWhileHandlingException(reader, writer, sorter);
}
tempInput.Delete();
tempSorted.Delete();
}
}
