| /* |
| * 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 |
| * |
| * https://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 System.IO; |
| using System.IO.Compression; |
| using Zstandard.Net; |
| |
| namespace Avro.File.Zstandard |
| { |
| /// <summary> |
| /// Zstandard Compression level |
| /// </summary> |
| public enum ZstandardLevel |
| { |
| Level1 = 1, |
| Level2 = 2, |
| Level3 = 3, |
| Level4 = 4, |
| Level5 = 5, |
| Level6 = 6, |
| Level7 = 7, |
| Level8 = 8, |
| Level9 = 9, |
| Level10 = 10, |
| Level11 = 11, |
| Level12 = 12, |
| Level13 = 13, |
| Level14 = 14, |
| Level15 = 15, |
| Level16 = 16, |
| Level17 = 17, |
| Level18 = 18, |
| Level19 = 19, |
| Default = Level3, |
| Minimum = Level1, |
| Maximum = Level19 |
| } |
| |
| /// <summary> |
| /// Implements Zstandard compression and decompression. |
| /// </summary> |
| public class ZstandardCodec : Codec |
| { |
| public ZstandardLevel Level {get; private set;} |
| |
| public ZstandardCodec() |
| : this(ZstandardLevel.Default) |
| { |
| } |
| |
| public ZstandardCodec(ZstandardLevel level) |
| { |
| Level = level; |
| } |
| |
| /// <inheritdoc/> |
| public override byte[] Compress(byte[] uncompressedData) |
| { |
| using (var outputStream = new MemoryStream()) |
| using (var compressionStream = new ZstandardStream(outputStream, CompressionMode.Compress)) |
| { |
| compressionStream.CompressionLevel = (int)Level; |
| compressionStream.Write(uncompressedData, 0, uncompressedData.Length); |
| compressionStream.Flush(); |
| return outputStream.ToArray(); |
| } |
| } |
| |
| /// <inheritdoc/> |
| public override void Compress(MemoryStream inputStream, MemoryStream outputStream) |
| { |
| inputStream.Position = 0; |
| outputStream.SetLength(0); |
| |
| using (var compressionStream = new ZstandardStream(outputStream, CompressionMode.Compress, true)) |
| { |
| compressionStream.CompressionLevel = (int)Level; |
| inputStream.CopyTo(compressionStream); |
| compressionStream.Flush(); |
| } |
| } |
| |
| /// <inheritdoc/> |
| public override byte[] Decompress(byte[] compressedData, int blockLength) |
| { |
| using (var memoryStream = new MemoryStream(compressedData, 0, blockLength)) |
| using (var outputStream = new MemoryStream()) |
| using (var compressionStream = new ZstandardStream(memoryStream, CompressionMode.Decompress)) |
| { |
| compressionStream.CopyTo(outputStream); |
| compressionStream.Flush(); |
| return outputStream.ToArray(); |
| } |
| } |
| |
| /// <inheritdoc/> |
| public override string GetName() |
| { |
| return DataFileConstants.ZstandardCodec; |
| } |
| |
| /// <inheritdoc/> |
| public override bool Equals(object other) |
| { |
| return this == other || GetType().Name == other.GetType().Name; |
| } |
| |
| /// <inheritdoc/> |
| public override int GetHashCode() |
| { |
| return GetName().GetHashCode(); |
| } |
| |
| /// <inheritdoc/> |
| public override string ToString() |
| { |
| return $"{GetName()}[{(int)Level}]"; |
| } |
| } |
| } |