add DelayingStream class

Test/DelayingStream.cs

@@ -0,0 +1,142 @@
+using System;
+using System.IO;
+
+namespace Test {
+  /// <summary>Stream that can return fewer bytes than
+  /// requested.</summary>
+  public sealed class DelayingStream : Stream
+  {
+    private readonly Stream ms;
+
+    /// <summary>Initializes a new instance of the
+    /// <see cref='DelayingStream'/> class.</summary>
+    /// <param name='ms'/>
+    /// <exception cref='ArgumentNullException'>The parameter <paramref
+    /// name='ms'/> is null.</exception>
+    public DelayingStream(Stream ms) {
+      this.ms = ms ?? throw new ArgumentNullException(nameof(ms));
+    }
+
+    /// <summary>Initializes a new instance of the
+    /// <see cref='DelayingStream'/> class.</summary>
+    /// <param name='bytes'/>
+    public DelayingStream(byte[] bytes) : this(new MemoryStream(bytes)) {
+    }
+
+    /// <summary>Initializes a new instance of the
+    /// <see cref='DelayingStream'/> class.</summary>
+    public DelayingStream() : this(new MemoryStream()) {
+    }
+
+    /// <summary>Initializes a new instance of the
+    /// <see cref='DelayingStream'/> class.</summary>
+    /// <param name='size'/>
+    public DelayingStream(int size) : this(new MemoryStream(size)) {
+    }
+
+    public new void Dispose() {
+      this.ms.Dispose();
+    }
+
+    /// <inheritdoc/>
+    public override long Length => this.ms.Length;
+
+    /// <inheritdoc/>
+    /// <returns/>
+    /// <param name='pos'>Not documented yet.</param>
+    /// <param name='origin'>Not documented yet.</param>
+    public override long Seek(long pos, SeekOrigin origin) {
+      return this.ms.Seek(pos, origin);
+    }
+
+    /// <inheritdoc/>
+    /// <param name='len'>Not documented yet.</param>
+    public override void SetLength(long len) {
+      this.ms.SetLength(len);
+    }
+
+    /// <inheritdoc/>
+    public override long Position
+    {
+      get => this.ms.Position;
+
+      set => this.ms.Position = value;
+    }
+
+    public byte[] ToArray() {
+      var ms = this.ms as MemoryStream;
+      return ms != null ? ms.ToArray() : throw new NotSupportedException();
+    }
+
+    /// <inheritdoc/>
+    public override bool CanRead => this.ms.CanRead;
+
+    /// <inheritdoc/>
+    public override bool CanSeek => this.ms.CanSeek;
+
+    /// <inheritdoc/>
+    public override bool CanWrite => this.ms.CanWrite;
+
+    /// <inheritdoc/>
+    /// <returns/>
+    /// <param name='bytes'>Not documented yet.</param>
+    /// <param name='offset'>Not documented yet.</param>
+    /// <param name='count'>Not documented yet.</param>
+    /// <exception cref='ArgumentNullException'>The parameter <paramref
+    /// name='bytes'/> is null.</exception>
+    public override int Read(byte[] bytes, int offset, int count) {
+      if (bytes == null) {
+        throw new ArgumentNullException(nameof(bytes));
+      }
+      if (offset < 0) {
+        throw new ArgumentException("\"offset\" (" + offset + ") is not" +
+"\u0020greater or equal to 0");
+      }
+      if (offset > bytes.Length) {
+        throw new ArgumentException("\"offset\" (" + offset + ") is not less" +
+"\u0020or equal to " + bytes.Length);
+      }
+      if (count < 0) {
+        throw new ArgumentException(" (" + count + ") is not greater or" +
+"\u0020equal to 0");
+      }
+      if (count > bytes.Length) {
+        throw new ArgumentException(" (" + count + ") is not less or equal" +
+"\u0020to " + bytes.Length);
+      }
+      if (bytes.Length - offset < count) {
+        throw new ArgumentException("\"bytes\" + \"'s length minus \" +" +
+"\u0020offset (" + (bytes.Length - offset) + ") is not greater or equal to " +
+count);
+      }
+      if (count == 0) {
+        return 0;
+      }
+      int b = this.ms.ReadByte();
+      if (b < 0) {
+        return 0;
+      }
+      bytes[offset] = (byte)b;
+      return 1;
+    }
+
+    /// <inheritdoc/>
+    public override void Flush() {
+      this.ms.Flush();
+    }
+
+    /// <inheritdoc/>
+    /// <param name='bytes'>Not documented yet.</param>
+    /// <param name='offset'>Not documented yet.</param>
+    /// <param name='count'>Not documented yet.</param>
+    public override void Write(byte[] bytes, int offset, int count) {
+      this.ms.Write(bytes, offset, count);
+    }
+
+    /// <inheritdoc/>
+    /// <param name='c'>Not documented yet.</param>
+    public override void WriteByte(byte c) {
+      this.ms.WriteByte(c);
+    }
+  }
+}