Exemplo n.º 1
0
        /// <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);
        }
Exemplo n.º 2
0
        public override void Build(IInputIterator iterator)
        {
            if (iterator.HasContexts)
            {
                throw new System.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 = iterator.HasPayloads;

            var writer = new OfflineSorter.ByteSequencesWriter(tempInput);

            OfflineSorter.ByteSequencesReader reader = null;
            var scratch = new BytesRef();

            TokenStreamToAutomaton ts2a = TokenStreamToAutomaton;

            bool success = false;

            count = 0;
            byte[] buffer = new byte[8];
            try
            {
                var      output = new ByteArrayDataOutput(buffer);
                BytesRef surfaceForm;

                while ((surfaceForm = iterator.Next()) != null)
                {
                    ISet <IntsRef> paths = ToFiniteStrings(surfaceForm, ts2a);

                    maxAnalyzedPathsForOneInput = Math.Max(maxAnalyzedPathsForOneInput, paths.Count);

                    foreach (IntsRef path in paths)
                    {
                        Util.Fst.Util.ToBytesRef(path, scratch);

                        // length of the analyzed text (FST input)
                        if (scratch.Length > ushort.MaxValue - 2)
                        {
                            throw new System.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 = iterator.Payload;
                            // payload + surfaceLength (short)
                            requiredLength += payload.Length + 2;
                        }
                        else
                        {
                            payload = null;
                        }

                        buffer = ArrayUtil.Grow(buffer, requiredLength);

                        output.Reset(buffer);

                        output.WriteShort((short)analyzedLength);

                        output.WriteBytes(scratch.Bytes, scratch.Offset, scratch.Length);

                        output.WriteInt(EncodeWeight(iterator.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.WriteShort((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);
                        }

                        Debug.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 AnalyzingComparator(hasPayloads))).Sort(tempInput, tempSorted);

                // Free disk space:
                tempInput.Delete();

                reader = new OfflineSorter.ByteSequencesReader(tempSorted);

                var outputs = new PairOutputs <long?, BytesRef>(PositiveIntOutputs.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();
                IntsRef  scratchInts      = new IntsRef();
                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 HashSet <BytesRef>();

                var dedup = 0;
                while (reader.Read(scratch))
                {
                    input.Reset(scratch.Bytes, scratch.Offset, scratch.Length);
                    ushort analyzedLength = (ushort)input.ReadShort();
                    analyzed.Grow(analyzedLength + 2);
                    input.ReadBytes(analyzed.Bytes, 0, analyzedLength);
                    analyzed.Length = analyzedLength;

                    long cost = input.ReadInt();

                    surface.Bytes = scratch.Bytes;
                    if (hasPayloads)
                    {
                        surface.Length = (ushort)input.ReadShort();
                        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.ToIntsRef(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.Close(reader, writer);
                }
                else
                {
                    IOUtils.CloseWhileHandlingException(reader, writer);
                }

                tempInput.Delete();
                tempSorted.Delete();
            }
        }
Exemplo n.º 3
0
        /// <summary>
        /// Parses a specific affix rule putting the result into the provided affix map
        /// </summary>
        /// <param name="affixes"> Map where the result of the parsing will be put </param>
        /// <param name="header"> Header line of the affix rule </param>
        /// <param name="reader"> BufferedReader to read the content of the rule from </param>
        /// <param name="conditionPattern"> <seealso cref="String#format(String, Object...)"/> pattern to be used to generate the condition regex
        ///                         pattern </param>
        /// <param name="seenPatterns"> map from condition -> index of patterns, for deduplication. </param>
        /// <exception cref="IOException"> Can be thrown while reading the rule </exception>
        private void ParseAffix(SortedDictionary <string, IList <char?> > affixes, string header, TextReader reader, string conditionPattern, IDictionary <string, int?> seenPatterns, IDictionary <string, int?> seenStrips)
        {
            BytesRef      scratch = new BytesRef();
            StringBuilder sb      = new StringBuilder();

            string[] args = whitespacePattern.Split(header);

            bool crossProduct = args[2].Equals("Y");

            int numLines = int.Parse(args[3], CultureInfo.InvariantCulture);

            affixData = ArrayUtil.Grow(affixData, (currentAffix << 3) + (numLines << 3));
            ByteArrayDataOutput affixWriter = new ByteArrayDataOutput(affixData, currentAffix << 3, numLines << 3);

            for (int i = 0; i < numLines; i++)
            {
                Debug.Assert(affixWriter.Position == currentAffix << 3);
                string   line     = reader.ReadLine();
                string[] ruleArgs = whitespacePattern.Split(line);

                // from the manpage: PFX flag stripping prefix [condition [morphological_fields...]]
                // condition is optional
                if (ruleArgs.Length < 4)
                {
                    throw new Exception("The affix file contains a rule with less than four elements: " + line /*, reader.LineNumber */);// LUCENENET TODO: LineNumberReader
                }

                char   flag        = flagParsingStrategy.ParseFlag(ruleArgs[1]);
                string strip       = ruleArgs[2].Equals("0") ? "" : ruleArgs[2];
                string affixArg    = ruleArgs[3];
                char[] appendFlags = null;

                int flagSep = affixArg.LastIndexOf('/');
                if (flagSep != -1)
                {
                    string flagPart = affixArg.Substring(flagSep + 1);
                    affixArg = affixArg.Substring(0, flagSep - 0);

                    if (aliasCount > 0)
                    {
                        flagPart = GetAliasValue(int.Parse(flagPart, CultureInfo.InvariantCulture));
                    }

                    appendFlags = flagParsingStrategy.ParseFlags(flagPart);
                    Array.Sort(appendFlags);
                    twoStageAffix = true;
                }

                // TODO: add test and fix zero-affix handling!

                string condition = ruleArgs.Length > 4 ? ruleArgs[4] : ".";
                // at least the gascon affix file has this issue
                if (condition.StartsWith("[", StringComparison.Ordinal) && !condition.EndsWith("]", StringComparison.Ordinal))
                {
                    condition = condition + "]";
                }
                // "dash hasn't got special meaning" (we must escape it)
                if (condition.IndexOf('-') >= 0)
                {
                    condition = condition.Replace("-", "\\-");
                }

                string regex;
                if (".".Equals(condition))
                {
                    regex = ".*"; // Zero condition is indicated by dot
                }
                else if (condition.Equals(strip))
                {
                    regex = ".*"; // TODO: optimize this better:
                                  // if we remove 'strip' from condition, we don't have to append 'strip' to check it...!
                                  // but this is complicated...
                }
                else
                {
                    regex = string.Format(CultureInfo.InvariantCulture, conditionPattern, condition);
                }

                // deduplicate patterns
                int?patternIndex = seenPatterns.ContainsKey(regex) ? seenPatterns[regex] : null;
                if (patternIndex == null)
                {
                    patternIndex = patterns.Count;
                    if (patternIndex > short.MaxValue)
                    {
                        throw new System.NotSupportedException("Too many patterns, please report this to [email protected]");
                    }
                    seenPatterns[regex] = patternIndex;
                    CharacterRunAutomaton pattern = new CharacterRunAutomaton((new RegExp(regex, RegExp.NONE)).ToAutomaton());
                    patterns.Add(pattern);
                }

                int?stripOrd = seenStrips.ContainsKey(strip) ? seenStrips[strip] : null;
                if (stripOrd == null)
                {
                    stripOrd          = seenStrips.Count;
                    seenStrips[strip] = stripOrd;
                    if (stripOrd > char.MaxValue)
                    {
                        throw new System.NotSupportedException("Too many unique strips, please report this to [email protected]");
                    }
                }

                if (appendFlags == null)
                {
                    appendFlags = NOFLAGS;
                }

                EncodeFlags(scratch, appendFlags);
                int appendFlagsOrd = flagLookup.Add(scratch);
                if (appendFlagsOrd < 0)
                {
                    // already exists in our hash
                    appendFlagsOrd = (-appendFlagsOrd) - 1;
                }
                else if (appendFlagsOrd > short.MaxValue)
                {
                    // this limit is probably flexible, but its a good sanity check too
                    throw new System.NotSupportedException("Too many unique append flags, please report this to [email protected]");
                }

                affixWriter.WriteShort((short)flag);
                affixWriter.WriteShort((short)stripOrd);
                // encode crossProduct into patternIndex
                int patternOrd = (int)patternIndex << 1 | (crossProduct ? 1 : 0);
                affixWriter.WriteShort((short)patternOrd);
                affixWriter.WriteShort((short)appendFlagsOrd);

                if (needsInputCleaning)
                {
                    string cleaned = CleanInput(affixArg, sb);
                    affixArg = cleaned.ToString();
                }

                IList <char?> list = affixes.ContainsKey(affixArg) ? affixes[affixArg] : null;
                if (list == null)
                {
                    list = new List <char?>();
                    affixes[affixArg] = list;
                }

                list.Add((char)currentAffix);
                currentAffix++;
            }
        }