Add new event handler to allow tracking of progress of extraction progress for individual entry

src/SharpCompress/Common/ReaderExtractionEventArgs.cs

@@ -4,11 +4,13 @@ namespace SharpCompress.Common
 {
     public class ReaderExtractionEventArgs<T> : EventArgs
     {
-        internal ReaderExtractionEventArgs(T entry)
+        internal ReaderExtractionEventArgs(T entry, params object[] paramList)
         {
             Item = entry;
+            ParamList = paramList;
         }
 
         public T Item { get; private set; }
+        public object[] ParamList { get; private set; }
     }
 }

src/SharpCompress/Readers/AbstractReader.cs

@@ -19,6 +19,7 @@ public abstract class AbstractReader<TEntry, TVolume> : IReader, IReaderExtracti
 
         public event EventHandler<ReaderExtractionEventArgs<IEntry>> EntryExtractionBegin;
         public event EventHandler<ReaderExtractionEventArgs<IEntry>> EntryExtractionEnd;
+        public event EventHandler<ReaderExtractionEventArgs<IEntry>> EntryExtractionProgress;
 
         public event EventHandler<CompressedBytesReadEventArgs> CompressedBytesRead;
         public event EventHandler<FilePartExtractionBeginEventArgs> FilePartExtractionBegin;
@@ -181,16 +182,16 @@ public void WriteEntryTo(Stream writableStream)
 
             var streamListener = this as IReaderExtractionListener;
             streamListener.FireEntryExtractionBegin(Entry);
-            Write(writableStream);
+            Write(writableStream, streamListener);
             streamListener.FireEntryExtractionEnd(Entry);
             wroteCurrentEntry = true;
         }
 
-        internal void Write(Stream writeStream)
+        internal void Write(Stream writeStream, IReaderExtractionListener streamListener)
         {
             using (Stream s = OpenEntryStream())
             {
-                s.TransferTo(writeStream);
+                s.TransferTo(writeStream, (sizeTransferred, iterations) => streamListener.FireEntryExtractionProgress(Entry, sizeTransferred, iterations));
             }
         }
 
@@ -255,6 +256,14 @@ void IReaderExtractionListener.FireEntryExtractionBegin(Entry entry)
             }
         }
 
+        void IReaderExtractionListener.FireEntryExtractionProgress(Entry entry, long bytesTransferred, int iterations)
+        {
+            if (EntryExtractionProgress != null)
+            {
+                EntryExtractionProgress(this, new ReaderExtractionEventArgs<IEntry>(entry, new ReaderProgress(entry, bytesTransferred, iterations)));
+            }
+        }
+
         void IReaderExtractionListener.FireEntryExtractionEnd(Entry entry)
         {
             if (EntryExtractionEnd != null)

src/SharpCompress/Readers/IReader.cs

@@ -8,6 +8,7 @@ public interface IReader : IDisposable
     {
         event EventHandler<ReaderExtractionEventArgs<IEntry>> EntryExtractionBegin;
         event EventHandler<ReaderExtractionEventArgs<IEntry>> EntryExtractionEnd;
+        event EventHandler<ReaderExtractionEventArgs<IEntry>> EntryExtractionProgress;
 
         event EventHandler<CompressedBytesReadEventArgs> CompressedBytesRead;
         event EventHandler<FilePartExtractionBeginEventArgs> FilePartExtractionBegin;

src/SharpCompress/Readers/IReaderExtractionListener.cs

@@ -7,5 +7,6 @@ internal interface IReaderExtractionListener : IExtractionListener
         //        void EnsureEntriesLoaded();
         void FireEntryExtractionBegin(Entry entry);
         void FireEntryExtractionEnd(Entry entry);
+        void FireEntryExtractionProgress(Entry entry, long sizeTransferred, int iterations);
     }
 }

src/SharpCompress/Readers/ReaderProgress.cs

@@ -0,0 +1,24 @@
+
+
+using System;
+using SharpCompress.Common;
+
+namespace SharpCompress.Readers
+{
+    public class ReaderProgress
+    {
+        private readonly IEntry _entry;
+        public long BytesTransferred { get; private set; }
+        public int Iterations { get; private set; }
+
+        public int PercentageRead => (int)Math.Round(PercentageReadExact);
+        public double PercentageReadExact => (float)BytesTransferred / _entry.Size * 100;
+
+        public ReaderProgress(IEntry entry, long bytesTransferred, int iterations)
+        {
+            _entry = entry;
+            BytesTransferred = bytesTransferred;
+            Iterations = iterations;
+        }
+    }
+}

src/SharpCompress/Utility.cs

@@ -229,15 +229,18 @@ public static DateTime DosDateToDateTime(Int32 iTime)
             return DosDateToDateTime((UInt32)iTime);
         }
 
-        public static long TransferTo(this Stream source, Stream destination)
+        public static long TransferTo(this Stream source, Stream destination, Action<long, int> action = null)
         {
             byte[] array = new byte[81920];
             int count;
+            var iterations = 0;
             long total = 0;
             while ((count = source.Read(array, 0, array.Length)) != 0)
             {
                 total += count;
                 destination.Write(array, 0, count);
+                iterations++;
+                action?.Invoke(total, iterations);
             }
             return total;
         }