| // Lucene version compatibility level 4.8.1 |
| |
| namespace Lucene.Net.Facet.Taxonomy |
| { |
| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| using ArrayUtil = Lucene.Net.Util.ArrayUtil; |
| using AtomicReaderContext = Lucene.Net.Index.AtomicReaderContext; |
| using BinaryDocValues = Lucene.Net.Index.BinaryDocValues; |
| using BytesRef = Lucene.Net.Util.BytesRef; |
| using DocValues = Lucene.Net.Index.DocValues; |
| using Int32sRef = Lucene.Net.Util.Int32sRef; |
| |
| /// <summary> |
| /// Decodes ordinals previously indexed into a <see cref="BinaryDocValues"/> field |
| /// </summary> |
| public class DocValuesOrdinalsReader : OrdinalsReader |
| { |
| private readonly string field; |
| |
| /// <summary> |
| /// Default constructor. |
| /// </summary> |
| public DocValuesOrdinalsReader() |
| : this(FacetsConfig.DEFAULT_INDEX_FIELD_NAME) |
| { |
| } |
| |
| /// <summary> |
| /// Create this, with the specified indexed field name. |
| /// </summary> |
| public DocValuesOrdinalsReader(string field) |
| { |
| this.field = field; |
| } |
| |
| public override OrdinalsSegmentReader GetReader(AtomicReaderContext context) |
| { |
| BinaryDocValues values0 = context.AtomicReader.GetBinaryDocValues(field); |
| if (values0 == null) |
| { |
| values0 = DocValues.EMPTY_BINARY; |
| } |
| |
| BinaryDocValues values = values0; |
| |
| return new OrdinalsSegmentReaderAnonymousInnerClassHelper(this, values); |
| } |
| |
| private class OrdinalsSegmentReaderAnonymousInnerClassHelper : OrdinalsSegmentReader |
| { |
| private readonly DocValuesOrdinalsReader outerInstance; |
| |
| private readonly BinaryDocValues values; |
| |
| public OrdinalsSegmentReaderAnonymousInnerClassHelper(DocValuesOrdinalsReader outerInstance, BinaryDocValues values) |
| { |
| this.outerInstance = outerInstance; |
| this.values = values; |
| } |
| |
| public override void Get(int docID, Int32sRef ordinals) |
| { |
| BytesRef bytes = new BytesRef(); |
| values.Get(docID, bytes); |
| outerInstance.Decode(bytes, ordinals); |
| } |
| } |
| |
| public override string IndexFieldName => field; |
| |
| /// <summary> |
| /// Subclass & override if you change the encoding. |
| /// </summary> |
| protected virtual void Decode(BytesRef buf, Int32sRef ordinals) |
| { |
| // grow the buffer up front, even if by a large number of values (buf.length) |
| // that saves the need to check inside the loop for every decoded value if |
| // the buffer needs to grow. |
| if (ordinals.Int32s.Length < buf.Length) |
| { |
| ordinals.Int32s = ArrayUtil.Grow(ordinals.Int32s, buf.Length); |
| } |
| |
| ordinals.Offset = 0; |
| ordinals.Length = 0; |
| |
| // it is better if the decoding is inlined like so, and not e.g. |
| // in a utility method |
| int upto = buf.Offset + buf.Length; |
| int value = 0; |
| int offset = buf.Offset; |
| int prev = 0; |
| while (offset < upto) |
| { |
| byte b = buf.Bytes[offset++]; |
| if ((sbyte)b >= 0) |
| { |
| ordinals.Int32s[ordinals.Length] = ((value << 7) | b) + prev; |
| value = 0; |
| prev = ordinals.Int32s[ordinals.Length]; |
| ordinals.Length++; |
| } |
| else |
| { |
| value = (value << 7) | (b & 0x7F); |
| } |
| } |
| } |
| } |
| } |