Replace MS-ZIP implementation (nw)

Author: mnadareski

SabreTools.Compression/Deflate/DeflateStream.cs

@@ -615,6 +615,17 @@ public override void Write(byte[] buffer, int offset, int count)
             if (_disposed) throw new ObjectDisposedException("DeflateStream");
             _baseStream.Write(buffer, offset, count);
         }
+
+        /// <summary>
+        /// Set the dictionary to be used for either Inflation or Deflation.
+        /// </summary>
+        /// <param name="dictionary">The dictionary bytes to use.</param>
+        /// <returns>Z_OK if all goes well.</returns>
+        public int SetDictionary(byte[] dictionary)
+        {
+            return _baseStream.SetDictionary(dictionary);
+        }
+
         #endregion
 
 

SabreTools.Compression/Deflate/ZlibBaseStream.cs

@@ -620,6 +620,16 @@ public static byte[] UncompressBuffer(byte[] compressed, Stream decompressor)
             }
         }
 
+        /// <summary>
+        /// Set the dictionary to be used for either Inflation or Deflation.
+        /// </summary>
+        /// <param name="dictionary">The dictionary bytes to use.</param>
+        /// <returns>Z_OK if all goes well.</returns>
+        public int SetDictionary(byte[] dictionary)
+        {
+            return z.SetDictionary(dictionary);
+        }
+
     }
 
 

SabreTools.Compression/MSZIP/Decompressor.cs

@@ -0,0 +1,101 @@
+using System;
+using System.IO;
+using SabreTools.IO.Extensions;
+
+namespace SabreTools.Compression.MSZIP
+{
+    /// <see href="https://msopenspecs.azureedge.net/files/MS-MCI/%5bMS-MCI%5d.pdf"/>
+    public class Decompressor
+    {
+        /// <summary>
+        /// Source stream for the decompressor
+        /// </summary>
+        private readonly Stream _source;
+
+        #region Constructors
+
+        /// <summary>
+        /// Create a MS-ZIP decompressor
+        /// </summary>
+        private Decompressor(Stream source)
+        {
+            // Validate the inputs
+            if (source.Length == 0)
+                throw new ArgumentOutOfRangeException(nameof(source));
+            if (!source.CanRead)
+                throw new InvalidOperationException(nameof(source));
+
+            _source = source;
+        }
+
+        /// <summary>
+        /// Create a MS-ZIP decompressor
+        /// </summary>
+        public static Decompressor Create(byte[] source)
+            => Create(new MemoryStream(source));
+
+        /// <summary>
+        /// Create a MS-ZIP decompressor
+        /// </summary>
+        public static Decompressor Create(Stream source)
+        {
+            // Create the decompressor
+            var decompressor = new Decompressor(source);
+
+            // Validate the header
+            var header = new Models.Compression.MSZIP.BlockHeader();
+            header.Signature = source.ReadUInt16();
+            if (header.Signature != 0x4B43)
+                throw new InvalidDataException(nameof(source));
+
+            // Return
+            return decompressor;
+        }
+
+        #endregion
+
+        /// <summary>
+        /// Decompress source data to an output stream
+        /// </summary>
+        public bool CopyTo(Stream dest)
+        {
+            // Ignore unwritable streams
+            if (!dest.CanWrite)
+                return false;
+
+            byte[]? history = null;
+            while (true)
+            {
+                byte[] buffer = new byte[32 * 1024];
+                var blockStream = new Deflate.DeflateStream(_source, Deflate.CompressionMode.Decompress);
+                if (history != null)
+                    blockStream.SetDictionary(history);
+
+                int read = blockStream.Read(buffer, 0, buffer.Length);
+                if (read <= 0)
+                    break;
+
+                // Write to output
+                dest.Write(buffer, 0, read);
+
+                // Save the history for rollover
+                history = new byte[read];
+                Array.Copy(buffer, history, read);
+
+                // Handle end of stream
+                if (_source.Position >= _source.Length)
+                    break;
+
+                // Validate the header
+                var header = new Models.Compression.MSZIP.BlockHeader();
+                header.Signature = _source.ReadUInt16();
+                if (header.Signature != 0x4B43)
+                    break;
+            }
+
+            // Flush and return
+            dest.Flush();
+            return true;
+        }
+    }
+}