Merge PR #202, Convert CRC checking to ArraySegment

Convert crc checking to use ArraySegment for parameter validation.
Fixes #183.

Author: piksel

src/ICSharpCode.SharpZipLib/Checksum/Adler32.cs

@@ -117,59 +117,21 @@ public void Update(byte[] buffer)
 				throw new ArgumentNullException(nameof(buffer));
 			}
 
-			Update(buffer, 0, buffer.Length);
+			Update(new ArraySegment<byte>(buffer, 0, buffer.Length));
 		}
 
 		/// <summary>
 		/// Update Adler32 data checksum based on a portion of a block of data
 		/// </summary>
-		/// <param name = "buffer">Contains the data to update the CRC with.</param>
-		/// <param name = "offset">The offset into the buffer where the data starts</param>
-		/// <param name = "count">The number of data bytes to update the CRC with.</param>
-		public void Update(byte[] buffer, int offset, int count)
+		/// <param name = "segment">
+		/// The chunk of data to add
+		/// </param>
+		public void Update(ArraySegment<byte> segment)
 		{
-			if (buffer == null) {
-				throw new ArgumentNullException(nameof(buffer));
-			}
-
-			if (offset < 0) {
-				throw new ArgumentOutOfRangeException(nameof(offset), "cannot be less than zero");
-			}
-
-			if (offset >= buffer.Length) {
-				throw new ArgumentOutOfRangeException(nameof(offset), "not a valid index into buffer");
-			}
-
-			if (count < 0) {
-				throw new ArgumentOutOfRangeException(nameof(count), "cannot be less than zero");
+			foreach (byte b in segment)
+			{
+				Update(b);
 			}
-
-			if (offset + count > buffer.Length) {
-				throw new ArgumentOutOfRangeException(nameof(count), "exceeds buffer size");
-			}
-
-			//(By Per Bothner)
-			uint s1 = checkValue & 0xFFFF;
-			uint s2 = checkValue >> 16;
-
-			while (count > 0) {
-				// We can defer the modulo operation:
-				// s1 maximally grows from 65521 to 65521 + 255 * 3800
-				// s2 maximally grows by 3800 * median(s1) = 2090079800 < 2^31
-				int n = 3800;
-				if (n > count) {
-					n = count;
-				}
-				count -= n;
-				while (--n >= 0) {
-					s1 = s1 + (uint)(buffer[offset++] & 0xff);
-					s2 = s2 + s1;
-				}
-				s1 %= BASE;
-				s2 %= BASE;
-			}
-
-			checkValue = (s2 << 16) | s1;
 		}
 	}
 }

src/ICSharpCode.SharpZipLib/Checksum/BZip2Crc.cs

@@ -161,39 +161,20 @@ public void Update(byte[] buffer)
 				throw new ArgumentNullException(nameof(buffer));
 			}
 
-			Update(buffer, 0, buffer.Length);
+			Update(new ArraySegment<byte>(buffer, 0, buffer.Length));
 		}
 
 		/// <summary>
 		/// Update CRC data checksum based on a portion of a block of data
 		/// </summary>
-		/// <param name = "buffer">Contains the data to update the CRC with.</param>
-		/// <param name = "offset">The offset into the buffer where the data starts</param>
-		/// <param name = "count">The number of data bytes to update the CRC with.</param>
-		public void Update(byte[] buffer, int offset, int count)
+		/// <param name = "segment">
+		/// The chunk of data to add
+		/// </param>
+		public void Update(ArraySegment<byte> segment)
 		{
-			if (buffer == null) {
-				throw new ArgumentNullException(nameof(buffer));
-			}
-
-			if (offset < 0) {
-				throw new ArgumentOutOfRangeException(nameof(offset), "cannot be less than zero");
-			}
-
-			if (offset >= buffer.Length) {
-				throw new ArgumentOutOfRangeException(nameof(offset), "not a valid index into buffer");
-			}
-
-			if (count < 0) {
-				throw new ArgumentOutOfRangeException(nameof(count), "cannot be less than zero");
-			}
-
-			if (offset + count > buffer.Length) {
-				throw new ArgumentOutOfRangeException(nameof(count), "exceeds buffer size");
-			}
-
-			for (int i = 0; i < count; ++i) {
-				Update(buffer[offset++]);
+			foreach (byte b in segment)
+			{
+				Update(b);
 			}
 		}
 	}

src/ICSharpCode.SharpZipLib/Checksum/Crc32.cs

@@ -150,39 +150,19 @@ public void Update(byte[] buffer)
 				throw new ArgumentNullException(nameof(buffer));
 			}
 
-			Update(buffer, 0, buffer.Length);
+			Update(new ArraySegment<byte>(buffer, 0, buffer.Length));
 		}
 
 		/// <summary>
 		/// Update CRC data checksum based on a portion of a block of data
 		/// </summary>
-		/// <param name = "buffer">Contains the data to update the CRC with.</param>
-		/// <param name = "offset">The offset into the buffer where the data starts</param>
-		/// <param name = "count">The number of data bytes to update the CRC with.</param>
-		public void Update(byte[] buffer, int offset, int count)
+		/// <param name = "segment">
+		/// The chunk of data to add
+		/// </param>
+		public void Update(ArraySegment<byte> segment)
 		{
-			if (buffer == null) {
-				throw new ArgumentNullException(nameof(buffer));
-			}
-
-			if (offset < 0) {
-				throw new ArgumentOutOfRangeException(nameof(offset), "cannot be less than zero");
-			}
-
-			if (offset >= buffer.Length) {
-				throw new ArgumentOutOfRangeException(nameof(offset), "not a valid index into buffer");
-			}
-
-			if (count < 0) {
-				throw new ArgumentOutOfRangeException(nameof(count), "cannot be less than zero");
-			}
-
-			if (offset + count > buffer.Length) {
-				throw new ArgumentOutOfRangeException(nameof(count), "exceeds buffer size");
-			}
-
-			for (int i = 0; i < count; ++i) {
-				Update(buffer[offset++]);
+			foreach (byte b in segment) {
+				Update(b);
 			}
 		}
 	}

src/ICSharpCode.SharpZipLib/Checksum/IChecksum.cs

@@ -1,3 +1,5 @@
+using System;
+
 namespace ICSharpCode.SharpZipLib.Checksum
 {
 	/// <summary>
@@ -40,15 +42,9 @@ long Value {
 		/// <summary>
 		/// Adds the byte array to the data checksum.
 		/// </summary>
-		/// <param name = "buffer">
-		/// The buffer which contains the data
-		/// </param>
-		/// <param name = "offset">
-		/// The offset in the buffer where the data starts
-		/// </param>
-		/// <param name = "count">
-		/// the number of data bytes to add.
+		/// <param name = "segment">
+		/// The chunk of data to add
 		/// </param>
-		void Update(byte[] buffer, int offset, int count);
+		void Update(ArraySegment<byte> segment);
 	}
 }

src/ICSharpCode.SharpZipLib/GZip/GzipInputStream.cs

@@ -127,7 +127,7 @@ public override int Read(byte[] buffer, int offset, int count)
 				// Try to read compressed data
 				int bytesRead = base.Read(buffer, offset, count);
 				if (bytesRead > 0) {
-					crc.Update(buffer, offset, bytesRead);
+					crc.Update(new ArraySegment<byte>(buffer, offset, bytesRead));
 				}
 
 				// If this is the end of stream, read the footer

src/ICSharpCode.SharpZipLib/GZip/GzipOutputStream.cs

@@ -123,7 +123,7 @@ public override void Write(byte[] buffer, int offset, int count)
 				throw new InvalidOperationException("Write not permitted in current state");
 			}
 
-			crc.Update(buffer, offset, count);
+			crc.Update(new ArraySegment<byte>(buffer, offset, count));
 			base.Write(buffer, offset, count);
 		}
 

src/ICSharpCode.SharpZipLib/Zip/Compression/DeflaterEngine.cs

@@ -174,7 +174,7 @@ public void SetDictionary(byte[] buffer, int offset, int length)
 				throw new InvalidOperationException("strstart not 1");
 			}
 #endif
-			adler.Update(buffer, offset, length);
+			adler.Update(new ArraySegment<byte>(buffer, offset, length));
 			if (length < DeflaterConstants.MIN_MATCH) {
 				return;
 			}
@@ -336,7 +336,7 @@ public void FillWindow()
 				}
 
 				System.Array.Copy(inputBuf, inputOff, window, strstart + lookahead, more);
-				adler.Update(inputBuf, inputOff, more);
+				adler.Update(new ArraySegment<byte>(inputBuf, inputOff, more));
 
 				inputOff += more;
 				totalIn += more;

src/ICSharpCode.SharpZipLib/Zip/Compression/Inflater.cs

@@ -546,7 +546,7 @@ public void SetDictionary(byte[] buffer, int index, int count)
 				throw new InvalidOperationException("Dictionary is not needed");
 			}
 
-			adler.Update(buffer, index, count);
+			adler.Update(new ArraySegment<byte>(buffer, index, count));
 
 			if ((int)adler.Value != readAdler) {
 				throw new SharpZipBaseException("Wrong adler checksum");
@@ -687,7 +687,7 @@ public int Inflate(byte[] buffer, int offset, int count)
 					*/
 					int more = outputWindow.CopyOutput(buffer, offset, count);
 					if (more > 0) {
-						adler.Update(buffer, offset, more);
+						adler.Update(new ArraySegment<byte>(buffer, offset, more));
 						offset += more;
 						bytesCopied += more;
 						totalOut += (long)more;

src/ICSharpCode.SharpZipLib/Zip/ZipFile.cs

@@ -837,7 +837,7 @@ public bool TestArchive(bool testData, TestStrategy strategy, ZipTestResultHandl
 							long totalBytes = 0;
 							int bytesRead;
 							while ((bytesRead = entryStream.Read(buffer, 0, buffer.Length)) > 0) {
-								crc.Update(buffer, 0, bytesRead);
+								crc.Update(new ArraySegment<byte>(buffer, 0, bytesRead));
 
 								if (resultHandler != null) {
 									totalBytes += bytesRead;
@@ -2069,7 +2069,7 @@ void CopyBytes(ZipUpdate update, Stream destination, Stream source,
 				bytesRead = source.Read(buffer, 0, readSize);
 				if (bytesRead > 0) {
 					if (updateCrc) {
-						crc.Update(buffer, 0, bytesRead);
+						crc.Update(new ArraySegment<byte>(buffer, 0, bytesRead));
 					}
 					destination.Write(buffer, 0, bytesRead);
 					bytesToCopy -= bytesRead;
@@ -2149,7 +2149,7 @@ void CopyEntryDataDirect(ZipUpdate update, Stream stream, bool updateCrc, ref lo
 				bytesRead = stream.Read(buffer, 0, readSize);
 				if (bytesRead > 0) {
 					if (updateCrc) {
-						crc.Update(buffer, 0, bytesRead);
+						crc.Update(new ArraySegment<byte>(buffer, 0, bytesRead));
 					}
 					stream.Position = destinationPosition;
 					stream.Write(buffer, 0, bytesRead);

src/ICSharpCode.SharpZipLib/Zip/ZipInputStream.cs

@@ -585,7 +585,7 @@ int BodyRead(byte[] buffer, int offset, int count)
 			}
 
 			if (count > 0) {
-				crc.Update(buffer, offset, count);
+				crc.Update(new ArraySegment<byte>(buffer, offset, count));
 			}
 
 			if (finished) {