From 8faebc78d0f22d2b63122dbfd6da698a628820b8 Mon Sep 17 00:00:00 2001
From: Paul Newman <pnewman@aurora-solutions.net>
Date: Wed, 15 Jul 2015 18:13:46 +0100
Subject: [PATCH] Cancel moved from EntryStream to Reader

Relates to previous commit. Following discussion with Adam, moved the Cancel() to the reader.

Example:

while (reader.MoveToNextEntry())
{
  using (var data = new StreamReader(reader.OpenEntryStream()))
  {
    try
    {
      DoSomething(data.ReadLine());
    }
    catch
    {
      reader.Cancel();
      throw;
    }
  }
}
---
 SharpCompress/Common/EntryStream.cs    | 23 +++++---------------
 SharpCompress/Reader/AbstractReader.cs | 30 ++++++++++++++++++--------
 SharpCompress/Reader/IReader.cs        |  3 +++
 3 files changed, 29 insertions(+), 27 deletions(-)

diff --git a/SharpCompress/Common/EntryStream.cs b/SharpCompress/Common/EntryStream.cs
index a14bbbbb..86e50978 100644
--- a/SharpCompress/Common/EntryStream.cs
+++ b/SharpCompress/Common/EntryStream.cs
@@ -1,16 +1,19 @@
 using System;
 using System.IO;
+using SharpCompress.Reader;
 
 namespace SharpCompress.Common
 {
     public class EntryStream : Stream
     {
+        public IReader Reader { get; private set; }
         private Stream stream;
         private bool completed;
         private bool isDisposed;
 
-        internal EntryStream(Stream stream)
+        internal EntryStream(IReader reader, Stream stream)
         {
+            this.Reader = reader;
             this.stream = stream;
         }
 
@@ -26,25 +29,9 @@ namespace SharpCompress.Common
             completed = true;
         }
 
-        public bool Cancelled { get; private set; }
-
-        /// <summary>
-        /// Indicates that the remainder of the stream is not required.
-        /// On dispose, the entry will not be skipped, so it helps with efficiency.
-        /// The downside is that subsequent entries are not usable, as the compressed stream is not positioned at an entry boundary.
-        /// </summary>
-        public void Cancel()
-        {
-          if (!completed)
-          {
-            Cancelled = true;
-            stream.Close();
-          }
-        }
-
         protected override void Dispose(bool disposing)
         {
-            if (!(completed || Cancelled))
+            if (!(completed || Reader.Cancelled))
             {
                 SkipEntry();
             }
diff --git a/SharpCompress/Reader/AbstractReader.cs b/SharpCompress/Reader/AbstractReader.cs
index bd940ce8..699770a3 100644
--- a/SharpCompress/Reader/AbstractReader.cs
+++ b/SharpCompress/Reader/AbstractReader.cs
@@ -67,22 +67,36 @@ namespace SharpCompress.Reader
 
         #endregion
 
+
+        public bool Cancelled { get; private set; }
+
+        /// <summary>
+        /// Indicates that the remaining entries are not required.
+        /// On dispose of an EntryStream, the stream will not skip to the end of the entry.
+        /// An attempt to move to the next entry will throw an exception, as the compressed stream is not positioned at an entry boundary.
+        /// </summary>
+        public void Cancel()
+        {
+          if (!completed)
+          {
+            Cancelled = true;
+          }
+        }
+
         public bool MoveToNextEntry()
         {
             if (completed)
             {
                 return false;
             }
+            if (Cancelled)
+            {
+                throw new InvalidOperationException("Reader has been cancelled.");
+            }
             if (entriesForCurrentReadStream == null)
             {
                 return LoadStreamForReading(RequestInitialStream());
             }
-
-            if (currentEntryStream != null && currentEntryStream.Cancelled)
-            {
-              throw new InvalidOperationException("EntryStream has not been fully consumed.  Read the entire stream or use SkipEntry.");
-            }
-
             if (!wroteCurrentEntry)
             {
                 SkipEntry();
@@ -203,14 +217,12 @@ namespace SharpCompress.Reader
             return stream;
         }
 
-        private EntryStream currentEntryStream;
-
         /// <summary>
         /// Retains a reference to the entry stream, so we can check whether it completed later.
         /// </summary>
         protected EntryStream CreateEntryStream(Stream decompressed)
         {
-          return currentEntryStream = new EntryStream(decompressed);
+          return new EntryStream(this, decompressed);
         }
 
         protected virtual EntryStream GetEntryStream()
diff --git a/SharpCompress/Reader/IReader.cs b/SharpCompress/Reader/IReader.cs
index 769c1741..cf26ea16 100644
--- a/SharpCompress/Reader/IReader.cs
+++ b/SharpCompress/Reader/IReader.cs
@@ -22,6 +22,9 @@ namespace SharpCompress.Reader
         /// <param name="writableStream"></param>
         void WriteEntryTo(Stream writableStream);
 
+        bool Cancelled { get; }
+        void Cancel();
+
         /// <summary>
         /// Moves to the next entry by reading more data from the underlying stream.  This skips if data has not been read.
         /// </summary>