| using Lucene.Net.Support; |
| using System.Runtime.CompilerServices; |
| |
| namespace Lucene.Net.Store |
| { |
| /* |
| * 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. |
| */ |
| |
| /// <summary> |
| /// Wraps another <see cref="IChecksum"/> with an internal buffer |
| /// to speed up checksum calculations. |
| /// </summary> |
| // LUCENENET TODO: This class was public in Lucene. Marking internal, since |
| // a better approach would be to map this to the HashAlgorithm abstract class in .NET |
| // instead of using IChecksum from Java. See LUCENENET-637. |
| // After this conversion is done, this can be made public again. However, it is |
| // now internal so the conversion doesn't introduce a breaking public API change. |
| internal class BufferedChecksum : IChecksum |
| { |
| private readonly IChecksum @in; |
| private readonly byte[] buffer; |
| private int upto; |
| |
| /// <summary> |
| /// Default buffer size: 256 </summary> |
| public const int DEFAULT_BUFFERSIZE = 256; |
| |
| /// <summary> |
| /// Create a new <see cref="BufferedChecksum"/> with <see cref="DEFAULT_BUFFERSIZE"/> </summary> |
| public BufferedChecksum(IChecksum @in) |
| : this(@in, DEFAULT_BUFFERSIZE) |
| { |
| } |
| |
| /// <summary> |
| /// Create a new <see cref="BufferedChecksum"/> with the specified <paramref name="bufferSize"/> </summary> |
| public BufferedChecksum(IChecksum @in, int bufferSize) |
| { |
| this.@in = @in; |
| this.buffer = new byte[bufferSize]; |
| } |
| |
| public virtual void Update(int b) |
| { |
| if (upto == buffer.Length) |
| { |
| Flush(); |
| } |
| buffer[upto++] = (byte)b; |
| } |
| |
| // LUCENENET specific overload for updating a whole byte[] array |
| public virtual void Update(byte[] b) |
| { |
| Update(b, 0, b.Length); |
| } |
| |
| public virtual void Update(byte[] b, int off, int len) |
| { |
| if (len >= buffer.Length) |
| { |
| Flush(); |
| @in.Update(b, off, len); |
| } |
| else |
| { |
| if (upto + len > buffer.Length) |
| { |
| Flush(); |
| } |
| System.Buffer.BlockCopy(b, off, buffer, upto, len); |
| upto += len; |
| } |
| } |
| |
| public virtual long Value |
| { |
| get |
| { |
| Flush(); |
| return @in.Value; |
| } |
| } |
| |
| public virtual void Reset() |
| { |
| upto = 0; |
| @in.Reset(); |
| } |
| |
| [MethodImpl(MethodImplOptions.NoInlining)] |
| private void Flush() |
| { |
| if (upto > 0) |
| { |
| @in.Update(buffer, 0, upto); |
| } |
| upto = 0; |
| } |
| } |
| } |