| using Lucene.Net.Analysis.TokenAttributes; |
| using System; |
| using System.Collections.Generic; |
| |
| namespace Lucene.Net.Analysis |
| { |
| /* |
| * 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. |
| */ |
| |
| // TODO: rename to OffsetsXXXTF? ie we only validate |
| // offsets (now anyway...) |
| |
| // TODO: also make a DebuggingTokenFilter, that just prints |
| // all att values that come through it... |
| |
| // TODO: BTSTC should just append this to the chain |
| // instead of checking itself: |
| |
| /// <summary> |
| /// A <see cref="TokenFilter"/> that checks consistency of the tokens (eg |
| /// offsets are consistent with one another). |
| /// </summary> |
| public sealed class ValidatingTokenFilter : TokenFilter |
| { |
| private int pos; |
| private int lastStartOffset; |
| |
| // Maps position to the start/end offset: |
| private readonly IDictionary<int, int> posToStartOffset = new Dictionary<int, int>(); |
| |
| private readonly IDictionary<int, int> posToEndOffset = new Dictionary<int, int>(); |
| |
| private PositionIncrementAttribute posIncAtt; |
| private PositionLengthAttribute posLenAtt; |
| private OffsetAttribute offsetAtt; |
| private CharTermAttribute termAtt; |
| private readonly bool offsetsAreCorrect; |
| |
| private readonly string name; |
| |
| // Returns null if the attr wasn't already added |
| private A GetAttrIfExists<A>() where A : Lucene.Net.Util.Attribute |
| { |
| if (HasAttribute<A>()) |
| { |
| return GetAttribute<A>(); |
| } |
| else |
| { |
| return default; |
| } |
| } |
| |
| /// <summary> |
| /// The <paramref name="name"/> is used to identify this stage when |
| /// throwing exceptions (useful if you have more than one |
| /// instance in your chain). |
| /// </summary> |
| public ValidatingTokenFilter(TokenStream @in, string name, bool offsetsAreCorrect) |
| : base(@in) |
| { |
| posIncAtt = GetAttrIfExists<PositionIncrementAttribute>(); |
| posLenAtt = GetAttrIfExists<PositionLengthAttribute>(); |
| offsetAtt = GetAttrIfExists<OffsetAttribute>(); |
| termAtt = GetAttrIfExists<CharTermAttribute>(); |
| this.name = name; |
| this.offsetsAreCorrect = offsetsAreCorrect; |
| } |
| |
| public override bool IncrementToken() |
| { |
| if (!m_input.IncrementToken()) |
| { |
| return false; |
| } |
| |
| int startOffset = 0; |
| int endOffset = 0; |
| int posLen = 0; |
| |
| if (posIncAtt != null) |
| { |
| pos += posIncAtt.PositionIncrement; |
| if (pos == -1) |
| { |
| throw new Exception("first posInc must be > 0"); |
| } |
| } |
| |
| // System.out.println(" got token=" + termAtt + " pos=" + pos); |
| |
| if (offsetAtt != null) |
| { |
| startOffset = offsetAtt.StartOffset; |
| endOffset = offsetAtt.EndOffset; |
| |
| if (offsetsAreCorrect && offsetAtt.StartOffset < lastStartOffset) |
| { |
| throw new Exception(name + ": offsets must not go backwards startOffset=" + startOffset + " is < lastStartOffset=" + lastStartOffset); |
| } |
| lastStartOffset = offsetAtt.StartOffset; |
| } |
| |
| posLen = posLenAtt == null ? 1 : posLenAtt.PositionLength; |
| |
| if (offsetAtt != null && posIncAtt != null && offsetsAreCorrect) |
| { |
| if (!posToStartOffset.TryGetValue(pos, out int oldStartOffset)) |
| { |
| // First time we've seen a token leaving from this position: |
| posToStartOffset[pos] = startOffset; |
| //System.out.println(" + s " + pos + " -> " + startOffset); |
| } |
| else |
| { |
| // We've seen a token leaving from this position |
| // before; verify the startOffset is the same: |
| //System.out.println(" + vs " + pos + " -> " + startOffset); |
| if (oldStartOffset != startOffset) |
| { |
| throw new Exception(name + ": inconsistent startOffset at pos=" + pos + ": " + oldStartOffset + " vs " + startOffset + "; token=" + termAtt); |
| } |
| } |
| |
| int endPos = pos + posLen; |
| |
| if (!posToEndOffset.TryGetValue(endPos, out int oldEndOffset)) |
| { |
| // First time we've seen a token arriving to this position: |
| posToEndOffset[endPos] = endOffset; |
| //System.out.println(" + e " + endPos + " -> " + endOffset); |
| } |
| else |
| { |
| // We've seen a token arriving to this position |
| // before; verify the endOffset is the same: |
| //System.out.println(" + ve " + endPos + " -> " + endOffset); |
| if (oldEndOffset != endOffset) |
| { |
| throw new Exception(name + ": inconsistent endOffset at pos=" + endPos + ": " + oldEndOffset + " vs " + endOffset + "; token=" + termAtt); |
| } |
| } |
| } |
| |
| return true; |
| } |
| |
| public override void End() |
| { |
| base.End(); |
| |
| // TODO: what else to validate |
| |
| // TODO: check that endOffset is >= max(endOffset) |
| // we've seen |
| } |
| |
| public override void Reset() |
| { |
| base.Reset(); |
| pos = -1; |
| posToStartOffset.Clear(); |
| posToEndOffset.Clear(); |
| lastStartOffset = 0; |
| } |
| } |
| } |