Add new event to be able to track progress of extraction of individual entry when extracting an archive. This allows for showing or logging progress of the extraction process, especially useful for large files that might take a long time to extract.

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 @@ namespace SharpCompress.Readers
 
         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 @@ namespace SharpCompress.Readers
 
             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 @@ namespace SharpCompress.Readers
             }
         }
 
+        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 @@ namespace SharpCompress.Readers
     {
         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 @@ namespace SharpCompress.Readers
         //        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 @@ namespace SharpCompress
             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;
         }