1 files changed, 157 insertions, 0 deletions

diff --git a/src/dtf/WixToolset.Dtf.Compression.Zip/ConcatStream.cs b/src/dtf/WixToolset.Dtf.Compression.Zip/ConcatStream.cs
new file mode 100644
index 00000000..20d675d9
--- /dev/null
+++ b/src/dtf/WixToolset.Dtf.Compression.Zip/ConcatStream.cs
@@ -0,0 +1,157 @@
+// 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.Zip
+{
+    using System;
+    using System.IO;
+
+    /// <summary>
+    /// Used to trick a DeflateStream into reading from or writing to
+    /// a series of (chunked) streams instead of a single steream.
+    /// </summary>
+    internal class ConcatStream : Stream
+    {
+        private Stream source;
+        private long position;
+        private long length;
+        private Action<ConcatStream> nextStreamHandler;
+
+        public ConcatStream(Action<ConcatStream> nextStreamHandler)
+        {
+            if (nextStreamHandler == null)
+            {
+                throw new ArgumentNullException("nextStreamHandler");
+            }
+
+            this.nextStreamHandler = nextStreamHandler;
+            this.length = Int64.MaxValue;
+        }
+
+        public Stream Source
+        {
+            get { return this.source; }
+            set { this.source = value; }
+        }
+
+        public override bool CanRead
+        {
+            get { return true; }
+        }
+
+        public override bool CanWrite
+        {
+            get { return true; }
+        }
+
+        public override bool CanSeek
+        {
+            get { return false; }
+        }
+
+        public override long Length
+        {
+            get
+            {
+                return this.length;
+            }
+        }
+
+        public override long Position
+        {
+            get { return this.position; }
+            set { throw new NotSupportedException(); }
+        }
+
+        public override int Read(byte[] buffer, int offset, int count)
+        {
+            if (this.source == null)
+            {
+                this.nextStreamHandler(this);
+            }
+
+            count = (int) Math.Min(count, this.length - this.position);
+
+            int bytesRemaining = count;
+            while (bytesRemaining > 0)
+            {
+                if (this.source == null)
+                {
+                    throw new InvalidOperationException();
+                }
+
+                int partialCount = (int) Math.Min(bytesRemaining,
+                    this.source.Length - this.source.Position);
+
+                if (partialCount == 0)
+                {
+                    this.nextStreamHandler(this);
+                    continue;
+                }
+
+                partialCount = this.source.Read(
+                    buffer, offset + count - bytesRemaining, partialCount);
+                bytesRemaining -= partialCount;
+                this.position += partialCount;
+            }
+
+            return count;
+        }
+
+        public override void Write(byte[] buffer, int offset, int count)
+        {
+            if (this.source == null)
+            {
+                this.nextStreamHandler(this);
+            }
+
+            int bytesRemaining = count;
+            while (bytesRemaining > 0)
+            {
+                if (this.source == null)
+                {
+                    throw new InvalidOperationException();
+                }
+
+                int partialCount = (int) Math.Min(bytesRemaining,
+                    Math.Max(0, this.length - this.source.Position));
+
+                if (partialCount == 0)
+                {
+                    this.nextStreamHandler(this);
+                    continue;
+                }
+
+                this.source.Write(
+                    buffer, offset + count - bytesRemaining, partialCount);
+                bytesRemaining -= partialCount;
+                this.position += partialCount;
+            }
+        }
+
+        public override void Flush()
+        {
+            if (this.source != null)
+            {
+                this.source.Flush();
+            }
+        }
+
+        public override long Seek(long offset, SeekOrigin origin)
+        {
+            throw new NotSupportedException();
+        }
+
+        public override void SetLength(long value)
+        {
+            this.length = value;
+        }
+
+        public override void Close()
+        {
+            if (this.source != null)
+            {
+                this.source.Close();
+            }
+        }
+    }
+}