private void GetPathSlotNames(int col, ref VBuffer <DvText> dst)
        {
            var numTrees = _ensemble.NumTrees;

            var totalNodeCount = _totalLeafCount - numTrees;
            var names          = dst.Values;

            if (Utils.Size(names) < totalNodeCount)
            {
                names = new DvText[totalNodeCount];
            }

            int i = 0;
            int t = 0;

            foreach (var tree in _ensemble.GetTrees())
            {
                var numLeaves = tree.NumLeaves;
                for (int l = 0; l < tree.NumLeaves - 1; l++)
                {
                    names[i++] = new DvText(string.Format("Tree{0:000}Node{1:000}", t, l));
                }
                t++;
            }
            _host.Assert(i == totalNodeCount);
            dst = new VBuffer <DvText>(totalNodeCount, names, dst.Indices);
        }
Exemple #2
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            public override void InitializeNextPass(IRow row, RoleMappedSchema schema)
            {
                Host.Assert(!_streaming && PassNum < 2 || PassNum < 1);
                Host.AssertValue(schema.Label);

                var score = schema.GetUniqueColumn(MetadataUtils.Const.ScoreValueKind.Score);

                _labelGetter = RowCursorUtils.GetLabelGetter(row, schema.Label.Index);
                _scoreGetter = row.GetGetter <float>(score.Index);
                Host.AssertValue(_labelGetter);
                Host.AssertValue(_scoreGetter);

                if (IsMainPass())
                {
                    Host.Assert(_topExamples.Count == 0);
                    if (_nameIndex < 0)
                    {
                        int rowCounter = 0;
                        _nameGetter = (ref DvText dst) => dst = new DvText((rowCounter++).ToString());
                    }
                    else
                    {
                        _nameGetter = row.GetGetter <DvText>(_nameIndex);
                    }
                }
            }
Exemple #3
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        private int[][] CompileSlotMap(string slotMapString, int srcSlotCount)
        {
            var parts   = new DvText(slotMapString).Split(new[] { ';' }).ToArray();
            var slotMap = new int[parts.Length][];

            for (int i = 0; i < slotMap.Length; i++)
            {
                var slotIndices = parts[i].Split(new[] { ',' }).ToArray();
                var slots       = new int[slotIndices.Length];
                slotMap[i] = slots;
                for (int j = 0; j < slots.Length; j++)
                {
                    int index;
                    if (!int.TryParse(slotIndices[j].ToString(), out index) || index < 0 || index >= srcSlotCount)
                    {
                        throw Host.Except("Unexpected slot index '{1}' in group {0}. Expected 0 to {2}", i, slotIndices[j], srcSlotCount - 1);
                    }
                    slots[j] = index;
                }

                if (slots.Distinct().Count() < slots.Length)
                {
                    throw Host.Except("Group '{0}' has duplicate slot indices", parts[i]);
                }
            }

            return(slotMap);
        }
Exemple #4
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        private void AddTerms(DvText txt, char[] separators, List <DvText> terms)
        {
            Host.AssertNonEmpty(separators);

            var rest = txt;

            if (separators.Length > 1)
            {
                while (rest.HasChars)
                {
                    DvText term;
                    rest.SplitOne(separators, out term, out rest);
                    term = term.Trim();
                    if (term.HasChars)
                    {
                        terms.Add(term);
                    }
                }
            }
            else
            {
                var separator = separators[0];
                while (rest.HasChars)
                {
                    DvText term;
                    rest.SplitOne(separator, out term, out rest);
                    term = term.Trim();
                    if (term.HasChars)
                    {
                        terms.Add(term);
                    }
                }
            }
        }
Exemple #5
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        private ValueGetter <VBuffer <DvText> > MakeGetterOne(IRow input, int iinfo)
        {
            Host.AssertValue(input);
            Host.Assert(Infos[iinfo].TypeSrc.IsText);

            var getSrc     = GetSrcGetter <DvText>(input, iinfo);
            var src        = default(DvText);
            var terms      = new List <DvText>();
            var separators = _exes[iinfo].Separators;

            return
                ((ref VBuffer <DvText> dst) =>
            {
                getSrc(ref src);
                terms.Clear();

                AddTerms(src, separators, terms);

                var values = dst.Values;
                if (terms.Count > 0)
                {
                    if (Utils.Size(values) < terms.Count)
                    {
                        values = new DvText[terms.Count];
                    }
                    terms.CopyTo(values);
                }

                dst = new VBuffer <DvText>(terms.Count, values, dst.Indices);
            });
        }
        private void ComposeNgramString(uint[] ngram, int count, StringBuilder sb, int keyCount, TermGetter termGetter)
        {
            Host.AssertValue(sb);
            Host.AssertValue(ngram);
            Host.Assert(keyCount > 0);

            sb.Clear();
            DvText term = default(DvText);
            string sep  = "";

            for (int iterm = 0; iterm < count; iterm++)
            {
                sb.Append(sep);
                sep = "|";
                var unigram = ngram[iterm];
                if (unigram <= 0 || unigram > keyCount)
                {
                    sb.Append("*");
                }
                else
                {
                    termGetter((int)unigram - 1, ref term);
                    term.AddToStringBuilder(sb);
                }
            }
        }
 private static uint HashCore(uint seed, ref DvText value, int i, uint mask)
 {
     Contracts.Assert(Utils.IsPowerOfTwo(mask + 1));
     if (!value.HasChars)
     {
         return(0);
     }
     return((value.Trim().Hash(Hashing.MurmurRound(seed, (uint)i)) & mask) + 1);
 }
Exemple #8
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        private void GetSlotNames(int iinfo, ref VBuffer <DvText> dst)
        {
            Host.Assert(0 <= iinfo && iinfo < Infos.Length);

            Host.AssertValue(_exes[iinfo].SlotMap);

            int n      = _exes[iinfo].OutputValueCount;
            var output = dst.Values;

            if (Utils.Size(output) < n)
            {
                output = new DvText[n];
            }

            var              srcColumnName       = Source.Schema.GetColumnName(Infos[iinfo].Source);
            bool             useDefaultSlotNames = !Source.Schema.HasSlotNames(Infos[iinfo].Source, Infos[iinfo].TypeSrc.VectorSize);
            VBuffer <DvText> srcSlotNames        = default(VBuffer <DvText>);

            if (!useDefaultSlotNames)
            {
                Source.Schema.GetMetadata(MetadataUtils.Kinds.SlotNames, Infos[iinfo].Source, ref srcSlotNames);
                useDefaultSlotNames =
                    !srcSlotNames.IsDense ||
                    srcSlotNames.Length != Infos[iinfo].TypeSrc.ValueCount;
            }

            var outputSlotName = new StringBuilder();

            for (int slot = 0; slot < n; slot++)
            {
                var slotList = _exes[iinfo].SlotMap[slot];

                outputSlotName.Clear();

                foreach (var inputSlotIndex in slotList)
                {
                    if (outputSlotName.Length > 0)
                    {
                        outputSlotName.Append("+");
                    }

                    if (useDefaultSlotNames)
                    {
                        outputSlotName.AppendFormat("{0}[{1}]", srcColumnName, inputSlotIndex);
                    }
                    else
                    {
                        outputSlotName.Append(srcSlotNames.Values[inputSlotIndex]);
                    }
                }

                output[slot] = new DvText(outputSlotName.ToString());
            }

            dst = new VBuffer <DvText>(n, output, dst.Indices);
        }
        /// <summary>
        /// Determine the default scorer for a schema bound mapper. This looks for text-valued ScoreColumnKind
        /// metadata on the first column of the mapper. If that text is found and maps to a scorer loadable class,
        /// that component is used. Otherwise, the GenericScorer is used.
        /// </summary>
        /// <param name="mapper">The schema bound mapper to get the default scorer.</param>.
        /// <param name="suffix">An optional suffix to append to the default column names.</param>
        public static TScorerFactory GetScorerComponent(
            ISchemaBoundMapper mapper,
            string suffix = null)
        {
            Contracts.AssertValue(mapper);

            ComponentCatalog.LoadableClassInfo info = null;
            DvText scoreKind = default;

            if (mapper.OutputSchema.ColumnCount > 0 &&
                mapper.OutputSchema.TryGetMetadata(TextType.Instance, MetadataUtils.Kinds.ScoreColumnKind, 0, ref scoreKind) &&
                scoreKind.HasChars)
            {
                var loadName = scoreKind.ToString();
                info = ComponentCatalog.GetLoadableClassInfo <SignatureDataScorer>(loadName);
                if (info == null || !typeof(IDataScorerTransform).IsAssignableFrom(info.Type))
                {
                    info = null;
                }
            }

            Func <IHostEnvironment, IDataView, ISchemaBoundMapper, RoleMappedSchema, IDataScorerTransform> factoryFunc;

            if (info == null)
            {
                factoryFunc = (env, data, innerMapper, trainSchema) =>
                              new GenericScorer(
                    env,
                    new GenericScorer.Arguments()
                {
                    Suffix = suffix
                },
                    data,
                    innerMapper,
                    trainSchema);
            }
            else
            {
                factoryFunc = (env, data, innerMapper, trainSchema) =>
                {
                    object args = info.CreateArguments();
                    if (args is ScorerArgumentsBase scorerArgs)
                    {
                        scorerArgs.Suffix = suffix;
                    }
                    return((IDataScorerTransform)info.CreateInstance(
                               env,
                               args,
                               new object[] { data, innerMapper, trainSchema }));
                };
            }

            return(ComponentFactoryUtils.CreateFromFunction(factoryFunc));
        }
 protected override void GetScoreValueKind(int col, ref DvText dst)
 {
     Contracts.Assert(0 <= col && col < ColumnCount);
     if (col == base.ColumnCount)
     {
         dst = new DvText(MetadataUtils.Const.ScoreValueKind.Probability);
     }
     else
     {
         base.GetScoreValueKind(col, ref dst);
     }
 }
        private ValueGetter <uint> ComposeGetterOneCore(ValueGetter <DvText> getSrc, uint seed, uint mask)
        {
            DvText src = default(DvText);

            return
                ((ref uint dst) =>
            {
                // REVIEW: Should we verify that the key value is within the advertised KeyCount?
                // Values greater than KeyCount should be treated as zeros.
                getSrc(ref src);
                dst = HashCore(seed, ref src, mask);
            });
        }
            public void GetSlotNames(ref VBuffer <DvText> slotNames)
            {
                var values = slotNames.Values;

                if (Utils.Size(values) < UnweightedCounters.TruncationLevel)
                {
                    values = new DvText[UnweightedCounters.TruncationLevel];
                }

                for (int i = 0; i < UnweightedCounters.TruncationLevel; i++)
                {
                    values[i] = new DvText(string.Format("@{0}", i + 1));
                }
                slotNames = new VBuffer <DvText>(UnweightedCounters.TruncationLevel, values);
            }
            public void GetSlotNames(ref VBuffer <DvText> slotNames)
            {
                var values = slotNames.Values;

                if (Utils.Size(values) < _size)
                {
                    values = new DvText[_size];
                }

                for (int i = 0; i < _size; i++)
                {
                    values[i] = new DvText(string.Format("(Label_{0})", i));
                }
                slotNames = new VBuffer <DvText>(_size, values);
            }
 /// <summary>
 /// Returns the set of column ids which match the value of specified metadata kind.
 /// The metadata type should be of type text.
 /// </summary>
 public static IEnumerable <int> GetColumnSet(this ISchema schema, string metadataKind, string value)
 {
     for (int col = 0; col < schema.ColumnCount; col++)
     {
         var columnType = schema.GetMetadataTypeOrNull(metadataKind, col);
         if (columnType != null && columnType.IsText)
         {
             DvText val = default(DvText);
             schema.GetMetadata(metadataKind, col, ref val);
             if (val.EqualsStr(value))
             {
                 yield return(col);
             }
         }
     }
 }
            public bool GetWordVector(ref DvText word, float[] wordVector)
            {
                if (word.IsNA)
                {
                    return(false);
                }
                string  rawWord = word.GetRawUnderlyingBufferInfo(out int ichMin, out int ichLim);
                NormStr str     = _pool.Get(rawWord, ichMin, ichLim);

                if (str != null)
                {
                    _wordVectors.CopyTo(str.Id * Dimension, wordVector, Dimension);
                    return(true);
                }
                return(false);
            }
Exemple #16
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        private DvText Textify(ref StringBuilder sb, ref StringBuilder temp, ref char[] cbuffer, ref Pair[] buffer, HashSet <Pair> pairs)
        {
            Contracts.AssertValueOrNull(sb);
            Contracts.AssertValueOrNull(temp);
            Contracts.AssertValueOrNull(cbuffer);
            Contracts.AssertValueOrNull(buffer);
            Contracts.Assert(Utils.Size(pairs) > 0);
            int count = pairs.Count;

            // Keep things in the same order they were inserted, by sorting on order.
            Utils.EnsureSize(ref buffer, count);
            pairs.CopyTo(buffer);
            pairs.Clear();

            // Optimize the one value case, where we don't have to use the string builder.
            if (count == 1)
            {
                var value = buffer[0].Value;
                _stringifyMapper(ref value, ref temp);
                return(Utils.Size(temp) > 0 ? new DvText(temp.ToString()) : DvText.Empty);
            }

            Array.Sort(buffer, 0, count, Comparer <Pair> .Create((x, y) => x.Order - y.Order));
            if (sb == null)
            {
                sb = new StringBuilder();
            }
            Contracts.Assert(sb.Length == 0);
            // The more general collision case.
            sb.Append('{');
            for (int i = 0; i < count; ++i)
            {
                var pair = buffer[i];
                if (i > 0)
                {
                    sb.Append(',');
                }
                var value = pair.Value;
                _stringifyMapper(ref value, ref temp);
                InvertHashUtils.AppendToEnd(temp, sb, ref cbuffer);
            }
            sb.Append('}');
            var retval = new DvText(sb.ToString());

            sb.Clear();
            return(retval);
        }
 private MetadataUtils.MetadataGetter <VBuffer <DvText> > CreateSlotNamesGetter(string prefix)
 {
     return
         ((int col, ref VBuffer <DvText> dst) =>
     {
         var values = dst.Values;
         if (Utils.Size(values) < _scoreSize)
         {
             values = new DvText[_scoreSize];
         }
         for (int i = 0; i < _scoreSize; i++)
         {
             values[i] = new DvText(string.Format("{0} ({1})", prefix, _quantiles[i]));
         }
         dst = new VBuffer <DvText>(_scoreSize, values);
     });
 }
                private void SlotNamesGetter(int iinfo, ref VBuffer <DvText> dst)
                {
                    Contracts.Assert(0 <= iinfo && iinfo < InfoCount);
                    var values = dst.Values;

                    if (Utils.Size(values) < _truncationLevel)
                    {
                        values = new DvText[_truncationLevel];
                    }
                    for (int i = 0; i < _truncationLevel; i++)
                    {
                        values[i] =
                            new DvText(string.Format("{0}@{1}", iinfo == NdcgCol ? Ndcg : iinfo == DcgCol ? Dcg : MaxDcg,
                                                     i + 1));
                    }
                    dst = new VBuffer <DvText>(_truncationLevel, values);
                }
 // REVIEW: Figure out how to avoid having the column name in each slot name.
 private MetadataUtils.MetadataGetter <VBuffer <DvText> > CreateSlotNamesGetter(int numTopClusters, string suffix)
 {
     return
         ((int col, ref VBuffer <DvText> dst) =>
     {
         var values = dst.Values;
         if (Utils.Size(values) < numTopClusters)
         {
             values = new DvText[numTopClusters];
         }
         for (int i = 1; i <= numTopClusters; i++)
         {
             values[i - 1] = new DvText(string.Format("#{0} {1}", i, suffix));
         }
         dst = new VBuffer <DvText>(numTopClusters, values);
     });
 }
Exemple #20
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        /// <summary>
        /// Gets the mapping from T into a StringBuilder representation, using various heuristics.
        /// This StringBuilder representation will be a component of the composed KeyValues for the
        /// hash outputs.
        /// </summary>
        public static ValueMapper <T, StringBuilder> GetSimpleMapper <T>(ISchema schema, int col)
        {
            Contracts.AssertValue(schema);
            Contracts.Assert(0 <= col && col < schema.ColumnCount);
            var type = schema.GetColumnType(col).ItemType;

            Contracts.Assert(type.RawType == typeof(T));
            var conv = Conversion.Conversions.Instance;

            // First: if not key, then get the standard string converison.
            if (!type.IsKey)
            {
                return(conv.GetStringConversion <T>(type));
            }

            bool identity;

            // Second choice: if key, utilize the KeyValues metadata for that key, if it has one and is text.
            if (schema.HasKeyNames(col, type.KeyCount))
            {
                // REVIEW: Non-textual KeyValues are certainly possible. Should we handle them?
                // Get the key names.
                VBuffer <DvText> keyValues = default(VBuffer <DvText>);
                schema.GetMetadata(MetadataUtils.Kinds.KeyValues, col, ref keyValues);
                DvText value = default(DvText);

                // REVIEW: We could optimize for identity, but it's probably not worthwhile.
                var keyMapper = conv.GetStandardConversion <T, uint>(type, NumberType.U4, out identity);
                return
                    ((ref T src, ref StringBuilder dst) =>
                {
                    ClearDst(ref dst);
                    uint intermediate = 0;
                    keyMapper(ref src, ref intermediate);
                    if (intermediate == 0)
                    {
                        return;
                    }
                    keyValues.GetItemOrDefault((int)(intermediate - 1), ref value);
                    value.AddToStringBuilder(dst);
                });
            }

            // Third choice: just use the key value itself, subject to offsetting by the min.
            return(conv.GetKeyStringConversion <T>(type.AsKey));
        }
 private void UpdateColumnValues(string path, List <string> values)
 {
     // Cache the column values for future Getter calls.
     for (int i = 0; i < _colValues.Length; i++)
     {
         var source = _parent._srcDirIndex[i];
         if (source >= 0 && source < values.Count)
         {
             _colValues[i] = new DvText(values[source]);
         }
         else if (source == FilePathColIndex)
         {
             // Force Unix path for consistency.
             var cleanPath = path.Replace(@"\", @"/");
             _colValues[i] = new DvText(cleanPath);
         }
     }
 }
        private void GetTreeSlotNames(int col, ref VBuffer <DvText> dst)
        {
            var numTrees = _ensemble.NumTrees;

            var names = dst.Values;

            if (Utils.Size(names) < numTrees)
            {
                names = new DvText[numTrees];
            }

            for (int t = 0; t < numTrees; t++)
            {
                names[t] = new DvText(string.Format("Tree{0:000}", t));
            }

            dst = new VBuffer <DvText>(numTrees, names, dst.Indices);
        }
            private void GetSlotNames(int iinfo, ref VBuffer <DvText> dst)
            {
                Contracts.Assert(iinfo == 0);
                Contracts.Assert(Utils.Size(_slotNames) > 0);

                int size   = Utils.Size(_slotNames);
                var values = dst.Values;

                if (Utils.Size(values) < size)
                {
                    values = new DvText[size];
                }
                for (int i = 0; i < _slotNames.Length; i++)
                {
                    values[i] = new DvText(_slotNames[i]);
                }
                dst = new VBuffer <DvText>(size, values, dst.Indices);
            }
            public ValueGetter <VBuffer <DvText> > GetGroupSummarySlotNames(string prefix)
            {
                return
                    ((ref VBuffer <DvText> dst) =>
                {
                    var values = dst.Values;
                    if (Utils.Size(values) < UnweightedCounters.TruncationLevel)
                    {
                        values = new DvText[UnweightedCounters.TruncationLevel];
                    }

                    for (int i = 0; i < UnweightedCounters.TruncationLevel; i++)
                    {
                        values[i] = new DvText(string.Format("{0}@{1}", prefix, i + 1));
                    }
                    dst = new VBuffer <DvText>(UnweightedCounters.TruncationLevel, values);
                });
            }
        private QuantileRegressionPerInstanceEvaluator(IHostEnvironment env, ModelLoadContext ctx, ISchema schema)
            : base(env, ctx, schema)
        {
            CheckInputColumnTypes(schema);

            // *** Binary format **
            // base
            // int: _scoreSize
            // int[]: Ids of the quantile names

            _scoreSize = ctx.Reader.ReadInt32();
            Host.CheckDecode(_scoreSize > 0);
            _quantiles = new DvText[_scoreSize];
            for (int i = 0; i < _scoreSize; i++)
            {
                _quantiles[i] = new DvText(ctx.LoadNonEmptyString());
            }
            _outputType = new VectorType(NumberType.R8, _scoreSize);
        }
Exemple #26
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        private object GetSpecifiedValue <T>(string srcStr, ColumnType dstType, RefPredicate <T> isNA)
        {
            var val = default(T);

            if (!string.IsNullOrEmpty(srcStr))
            {
                // Handles converting input strings to correct types.
                DvText srcTxt = new DvText(srcStr);
                bool   identity;
                var    strToT = Conversions.Instance.GetStandardConversion <DvText, T>(TextType.Instance, dstType.ItemType, out identity);
                strToT(ref srcTxt, ref val);
                // Make sure that the srcTxt can legitimately be converted to dstType, throw error otherwise.
                if (isNA(ref val))
                {
                    throw Contracts.Except("No conversion of '{0}' to '{1}'", srcStr, dstType.ItemType);
                }
            }

            return(val);
        }
        private void GetSlotNames(int iinfo, ref VBuffer <DvText> dst)
        {
            Host.Assert(0 <= iinfo && iinfo < Infos.Length);
            Host.Assert(_slotNamesTypes[iinfo] != null);

            var keyCount = Infos[iinfo].TypeSrc.ItemType.KeyCount;

            Host.Assert(Source.Schema.HasKeyNames(Infos[iinfo].Source, keyCount));

            var unigramNames = new VBuffer <DvText>();

            // Get the key values of the unigrams.
            Source.Schema.GetMetadata(MetadataUtils.Kinds.KeyValues, Infos[iinfo].Source, ref unigramNames);
            Host.Check(unigramNames.Length == keyCount);

            var pool   = _ngramMaps[iinfo];
            var values = dst.Values;

            var ngramCount = pool.Count;

            if (Utils.Size(values) < ngramCount)
            {
                Array.Resize(ref values, ngramCount);
            }

            StringBuilder sb = new StringBuilder();

            uint[] ngram = new uint[_exes[iinfo].NgramLength];
            for (int slot = 0; slot < pool.Count; slot++)
            {
                var n = pool.GetById(slot, ref ngram);
                Host.Assert(n >= 0);

                // Get the unigrams composing the current ngram.
                ComposeNgramString(ngram, n, sb, keyCount,
                                   unigramNames.GetItemOrDefault);
                values[slot] = new DvText(sb.ToString());
            }

            dst = new VBuffer <DvText>(ngramCount, values, dst.Indices);
        }
Exemple #28
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        public VBuffer <DvText> GetMetadata()
        {
            int count = _slotToValueSet.Count;

            Contracts.Assert(count <= _slots);
            StringBuilder sb   = null;
            StringBuilder temp = null;

            Pair[] pairs   = null;
            char[] cbuffer = null;

            bool sparse = count <= _slots / 2;

            if (sparse)
            {
                // Sparse
                var indices = new int[count];
                var values  = new DvText[count];
                int i       = 0;
                foreach (var p in _slotToValueSet)
                {
                    Contracts.Assert(0 <= p.Key && p.Key < _slots);
                    indices[i]  = p.Key;
                    values[i++] = Textify(ref sb, ref temp, ref cbuffer, ref pairs, p.Value);
                }
                Contracts.Assert(i == count);
                Array.Sort(indices, values);
                return(new VBuffer <DvText>((int)_slots, count, values, indices));
            }
            else
            {
                // Dense
                var values = new DvText[_slots];
                foreach (var p in _slotToValueSet)
                {
                    Contracts.Assert(0 <= p.Key && p.Key < _slots);
                    values[p.Key] = Textify(ref sb, ref temp, ref cbuffer, ref pairs, p.Value);
                }
                return(new VBuffer <DvText>(values.Length, values));
            }
        }
 protected ValueGetter <VBuffer <DvText> > GetKeyValueGetter(AggregatorDictionaryBase[] dictionaries)
 {
     if (Utils.Size(dictionaries) == 0)
     {
         return(null);
     }
     return
         ((ref VBuffer <DvText> dst) =>
     {
         var values = dst.Values;
         if (Utils.Size(values) < dictionaries.Length)
         {
             values = new DvText[dictionaries.Length];
         }
         for (int i = 0; i < dictionaries.Length; i++)
         {
             values[i] = new DvText(dictionaries[i].ColName);
         }
         dst = new VBuffer <DvText>(dictionaries.Length, values, dst.Indices);
     });
 }
Exemple #30
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        private ValueGetter <VBuffer <DvText> > MakeGetterVec(IRow input, int iinfo)
        {
            Host.AssertValue(input);
            Host.Assert(Infos[iinfo].TypeSrc.IsVector);
            Host.Assert(Infos[iinfo].TypeSrc.ItemType.IsText);

            int cv = Infos[iinfo].TypeSrc.VectorSize;

            Contracts.Assert(cv >= 0);

            var getSrc     = GetSrcGetter <VBuffer <DvText> >(input, iinfo);
            var src        = default(VBuffer <DvText>);
            var terms      = new List <DvText>();
            var separators = _exes[iinfo].Separators;

            return
                ((ref VBuffer <DvText> dst) =>
            {
                getSrc(ref src);
                terms.Clear();

                for (int i = 0; i < src.Count; i++)
                {
                    AddTerms(src.Values[i], separators, terms);
                }

                var values = dst.Values;
                if (terms.Count > 0)
                {
                    if (Utils.Size(values) < terms.Count)
                    {
                        values = new DvText[terms.Count];
                    }
                    terms.CopyTo(values);
                }

                dst = new VBuffer <DvText>(terms.Count, values, dst.Indices);
            });
        }