1 files changed, 90 insertions, 0 deletions

diff --git a/src/dtf/WixToolset.Dtf.Compression/BasicUnpackStreamContext.cs b/src/dtf/WixToolset.Dtf.Compression/BasicUnpackStreamContext.cs
new file mode 100644
index 00000000..94d13b9c
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+++ b/src/dtf/WixToolset.Dtf.Compression/BasicUnpackStreamContext.cs
@@ -0,0 +1,90 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Dtf.Compression
+{
+    using System;
+    using System.IO;
+    using System.Diagnostics.CodeAnalysis;
+
+    /// <summary>
+    /// Stream context used to extract a single file from an archive into a memory stream.
+    /// </summary>
+    [SuppressMessage("Microsoft.Design", "CA1001:TypesThatOwnDisposableFieldsShouldBeDisposable")]
+    public class BasicUnpackStreamContext : IUnpackStreamContext
+    {
+        private Stream archiveStream;
+        private Stream fileStream;
+
+        /// <summary>
+        /// Creates a new BasicExtractStreamContext that reads from the specified archive stream.
+        /// </summary>
+        /// <param name="archiveStream">Archive stream to read from.</param>
+        public BasicUnpackStreamContext(Stream archiveStream)
+        {
+            this.archiveStream = archiveStream;
+        }
+
+        /// <summary>
+        /// Gets the stream for the extracted file, or null if no file was extracted.
+        /// </summary>
+        public Stream FileStream
+        {
+            get
+            {
+                return this.fileStream;
+            }
+        }
+
+        /// <summary>
+        /// Opens the archive stream for reading. Returns a DuplicateStream instance,
+        /// so the stream may be virtually opened multiple times.
+        /// </summary>
+        /// <param name="archiveNumber">The archive number to open (ignored; 0 is assumed).</param>
+        /// <param name="archiveName">The name of the archive being opened.</param>
+        /// <param name="compressionEngine">Instance of the compression engine doing the operations.</param>
+        /// <returns>A stream from which archive bytes are read.</returns>
+        public Stream OpenArchiveReadStream(int archiveNumber, string archiveName, CompressionEngine compressionEngine)
+        {
+            return new DuplicateStream(this.archiveStream);
+        }
+
+        /// <summary>
+        /// Does *not* close the stream. The archive stream should be managed by
+        /// the code that invokes the archive extraction.
+        /// </summary>
+        /// <param name="archiveNumber">The archive number of the stream to close.</param>
+        /// <param name="archiveName">The name of the archive being closed.</param>
+        /// <param name="stream">The stream being closed.</param>
+        public void CloseArchiveReadStream(int archiveNumber, string archiveName, Stream stream)
+        {
+            // Do nothing.
+        }
+
+        /// <summary>
+        /// Opens a stream for writing extracted file bytes. The returned stream is a MemoryStream
+        /// instance, so the file is extracted straight into memory.
+        /// </summary>
+        /// <param name="path">Path of the file within the archive.</param>
+        /// <param name="fileSize">The uncompressed size of the file to be extracted.</param>
+        /// <param name="lastWriteTime">The last write time of the file.</param>
+        /// <returns>A stream where extracted file bytes are to be written.</returns>
+        public Stream OpenFileWriteStream(string path, long fileSize, DateTime lastWriteTime)
+        {
+            this.fileStream = new MemoryStream(new byte[fileSize], 0, (int) fileSize, true, true);
+            return this.fileStream;
+        }
+
+        /// <summary>
+        /// Does *not* close the file stream. The file stream is saved in memory so it can
+        /// be read later.
+        /// </summary>
+        /// <param name="path">Path of the file within the archive.</param>
+        /// <param name="stream">The file stream to be closed.</param>
+        /// <param name="attributes">The attributes of the extracted file.</param>
+        /// <param name="lastWriteTime">The last write time of the file.</param>
+        public void CloseFileWriteStream(string path, Stream stream, FileAttributes attributes, DateTime lastWriteTime)
+        {
+            // Do nothing.
+        }
+    }
+}