| using System; |
| using System.Runtime.CompilerServices; |
| using Directory = Lucene.Net.Store.Directory; |
| |
| namespace Lucene.Net.Codecs.Compressing |
| { |
| /* |
| * 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 FieldInfos = Lucene.Net.Index.FieldInfos; |
| using IOContext = Lucene.Net.Store.IOContext; |
| using SegmentInfo = Lucene.Net.Index.SegmentInfo; |
| |
| /// <summary> |
| /// A <see cref="TermVectorsFormat"/> that compresses chunks of documents together in |
| /// order to improve the compression ratio. |
| /// <para/> |
| /// @lucene.experimental |
| /// </summary> |
| public class CompressingTermVectorsFormat : TermVectorsFormat |
| { |
| private readonly string formatName; |
| private readonly string segmentSuffix; |
| private readonly CompressionMode compressionMode; |
| private readonly int chunkSize; |
| |
| /// <summary> |
| /// Create a new <see cref="CompressingTermVectorsFormat"/>. |
| /// <para/> |
| /// <paramref name="formatName"/> is the name of the format. this name will be used |
| /// in the file formats to perform |
| /// codec header checks (<see cref="CodecUtil.CheckHeader(Lucene.Net.Store.DataInput, string, int, int)"/>). |
| /// <para/> |
| /// The <paramref name="compressionMode"/> parameter allows you to choose between |
| /// compression algorithms that have various compression and decompression |
| /// speeds so that you can pick the one that best fits your indexing and |
| /// searching throughput. You should never instantiate two |
| /// <see cref="CompressingTermVectorsFormat"/>s that have the same name but |
| /// different <see cref="CompressionMode"/>s. |
| /// <para/> |
| /// <paramref name="chunkSize"/> is the minimum byte size of a chunk of documents. |
| /// Higher values of <paramref name="chunkSize"/> should improve the compression |
| /// ratio but will require more memory at indexing time and might make document |
| /// loading a little slower (depending on the size of your OS cache compared |
| /// to the size of your index). |
| /// </summary> |
| /// <param name="formatName"> The name of the <see cref="StoredFieldsFormat"/>. </param> |
| /// <param name="segmentSuffix"> A suffix to append to files created by this format. </param> |
| /// <param name="compressionMode"> The <see cref="CompressionMode"/> to use. </param> |
| /// <param name="chunkSize"> The minimum number of bytes of a single chunk of stored documents. </param> |
| /// <seealso cref="CompressionMode"/> |
| public CompressingTermVectorsFormat(string formatName, string segmentSuffix, CompressionMode compressionMode, int chunkSize) |
| { |
| this.formatName = formatName; |
| this.segmentSuffix = segmentSuffix; |
| this.compressionMode = compressionMode; |
| if (chunkSize < 1) |
| { |
| throw new ArgumentException("chunkSize must be >= 1"); |
| } |
| this.chunkSize = chunkSize; |
| } |
| |
| [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| public override sealed TermVectorsReader VectorsReader(Directory directory, SegmentInfo segmentInfo, FieldInfos fieldInfos, IOContext context) |
| { |
| return new CompressingTermVectorsReader(directory, segmentInfo, segmentSuffix, fieldInfos, context, formatName, compressionMode); |
| } |
| |
| [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| public override sealed TermVectorsWriter VectorsWriter(Directory directory, SegmentInfo segmentInfo, IOContext context) |
| { |
| return new CompressingTermVectorsWriter(directory, segmentInfo, segmentSuffix, context, formatName, compressionMode, chunkSize); |
| } |
| |
| public override string ToString() |
| { |
| return this.GetType().Name + "(compressionMode=" + compressionMode + ", chunkSize=" + chunkSize + ")"; |
| } |
| } |
| } |