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Diffstat (limited to 'zlib/contrib/dotzlib/DotZLib/ChecksumImpl.cs')
| -rw-r--r-- | zlib/contrib/dotzlib/DotZLib/ChecksumImpl.cs | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/zlib/contrib/dotzlib/DotZLib/ChecksumImpl.cs b/zlib/contrib/dotzlib/DotZLib/ChecksumImpl.cs new file mode 100644 index 0000000..788b2fc --- /dev/null +++ b/zlib/contrib/dotzlib/DotZLib/ChecksumImpl.cs @@ -0,0 +1,202 @@ +//
+// © Copyright Henrik Ravn 2004
+//
+// Use, modification and distribution are subject to the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+using System;
+using System.Runtime.InteropServices;
+using System.Text;
+
+
+namespace DotZLib
+{
+ #region ChecksumGeneratorBase
+ /// <summary>
+ /// Implements the common functionality needed for all <see cref="ChecksumGenerator"/>s
+ /// </summary>
+ /// <example></example>
+ public abstract class ChecksumGeneratorBase : ChecksumGenerator
+ {
+ /// <summary>
+ /// The value of the current checksum
+ /// </summary>
+ protected uint _current;
+
+ /// <summary>
+ /// Initializes a new instance of the checksum generator base - the current checksum is
+ /// set to zero
+ /// </summary>
+ public ChecksumGeneratorBase()
+ {
+ _current = 0;
+ }
+
+ /// <summary>
+ /// Initializes a new instance of the checksum generator basewith a specified value
+ /// </summary>
+ /// <param name="initialValue">The value to set the current checksum to</param>
+ public ChecksumGeneratorBase(uint initialValue)
+ {
+ _current = initialValue;
+ }
+
+ /// <summary>
+ /// Resets the current checksum to zero
+ /// </summary>
+ public void Reset() { _current = 0; }
+
+ /// <summary>
+ /// Gets the current checksum value
+ /// </summary>
+ public uint Value { get { return _current; } }
+
+ /// <summary>
+ /// Updates the current checksum with part of an array of bytes
+ /// </summary>
+ /// <param name="data">The data to update the checksum with</param>
+ /// <param name="offset">Where in <c>data</c> to start updating</param>
+ /// <param name="count">The number of bytes from <c>data</c> to use</param>
+ /// <exception cref="ArgumentException">The sum of offset and count is larger than the length of <c>data</c></exception>
+ /// <exception cref="NullReferenceException"><c>data</c> is a null reference</exception>
+ /// <exception cref="ArgumentOutOfRangeException">Offset or count is negative.</exception>
+ /// <remarks>All the other <c>Update</c> methods are implmeneted in terms of this one.
+ /// This is therefore the only method a derived class has to implement</remarks>
+ public abstract void Update(byte[] data, int offset, int count);
+
+ /// <summary>
+ /// Updates the current checksum with an array of bytes.
+ /// </summary>
+ /// <param name="data">The data to update the checksum with</param>
+ public void Update(byte[] data)
+ {
+ Update(data, 0, data.Length);
+ }
+
+ /// <summary>
+ /// Updates the current checksum with the data from a string
+ /// </summary>
+ /// <param name="data">The string to update the checksum with</param>
+ /// <remarks>The characters in the string are converted by the UTF-8 encoding</remarks>
+ public void Update(string data)
+ {
+ Update(Encoding.UTF8.GetBytes(data));
+ }
+
+ /// <summary>
+ /// Updates the current checksum with the data from a string, using a specific encoding
+ /// </summary>
+ /// <param name="data">The string to update the checksum with</param>
+ /// <param name="encoding">The encoding to use</param>
+ public void Update(string data, Encoding encoding)
+ {
+ Update(encoding.GetBytes(data));
+ }
+
+ }
+ #endregion
+
+ #region CRC32
+ /// <summary>
+ /// Implements a CRC32 checksum generator
+ /// </summary>
+ public sealed class CRC32Checksum : ChecksumGeneratorBase
+ {
+ #region DLL imports
+
+ [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+ private static extern uint crc32(uint crc, int data, uint length);
+
+ #endregion
+
+ /// <summary>
+ /// Initializes a new instance of the CRC32 checksum generator
+ /// </summary>
+ public CRC32Checksum() : base() {}
+
+ /// <summary>
+ /// Initializes a new instance of the CRC32 checksum generator with a specified value
+ /// </summary>
+ /// <param name="initialValue">The value to set the current checksum to</param>
+ public CRC32Checksum(uint initialValue) : base(initialValue) {}
+
+ /// <summary>
+ /// Updates the current checksum with part of an array of bytes
+ /// </summary>
+ /// <param name="data">The data to update the checksum with</param>
+ /// <param name="offset">Where in <c>data</c> to start updating</param>
+ /// <param name="count">The number of bytes from <c>data</c> to use</param>
+ /// <exception cref="ArgumentException">The sum of offset and count is larger than the length of <c>data</c></exception>
+ /// <exception cref="NullReferenceException"><c>data</c> is a null reference</exception>
+ /// <exception cref="ArgumentOutOfRangeException">Offset or count is negative.</exception>
+ public override void Update(byte[] data, int offset, int count)
+ {
+ if (offset < 0 || count < 0) throw new ArgumentOutOfRangeException();
+ if ((offset+count) > data.Length) throw new ArgumentException();
+ GCHandle hData = GCHandle.Alloc(data, GCHandleType.Pinned);
+ try
+ {
+ _current = crc32(_current, hData.AddrOfPinnedObject().ToInt32()+offset, (uint)count);
+ }
+ finally
+ {
+ hData.Free();
+ }
+ }
+
+ }
+ #endregion
+
+ #region Adler
+ /// <summary>
+ /// Implements a checksum generator that computes the Adler checksum on data
+ /// </summary>
+ public sealed class AdlerChecksum : ChecksumGeneratorBase
+ {
+ #region DLL imports
+
+ [DllImport("ZLIB1.dll", CallingConvention=CallingConvention.Cdecl)]
+ private static extern uint adler32(uint adler, int data, uint length);
+
+ #endregion
+
+ /// <summary>
+ /// Initializes a new instance of the Adler checksum generator
+ /// </summary>
+ public AdlerChecksum() : base() {}
+
+ /// <summary>
+ /// Initializes a new instance of the Adler checksum generator with a specified value
+ /// </summary>
+ /// <param name="initialValue">The value to set the current checksum to</param>
+ public AdlerChecksum(uint initialValue) : base(initialValue) {}
+
+ /// <summary>
+ /// Updates the current checksum with part of an array of bytes
+ /// </summary>
+ /// <param name="data">The data to update the checksum with</param>
+ /// <param name="offset">Where in <c>data</c> to start updating</param>
+ /// <param name="count">The number of bytes from <c>data</c> to use</param>
+ /// <exception cref="ArgumentException">The sum of offset and count is larger than the length of <c>data</c></exception>
+ /// <exception cref="NullReferenceException"><c>data</c> is a null reference</exception>
+ /// <exception cref="ArgumentOutOfRangeException">Offset or count is negative.</exception>
+ public override void Update(byte[] data, int offset, int count)
+ {
+ if (offset < 0 || count < 0) throw new ArgumentOutOfRangeException();
+ if ((offset+count) > data.Length) throw new ArgumentException();
+ GCHandle hData = GCHandle.Alloc(data, GCHandleType.Pinned);
+ try
+ {
+ _current = adler32(_current, hData.AddrOfPinnedObject().ToInt32()+offset, (uint)count);
+ }
+ finally
+ {
+ hData.Free();
+ }
+ }
+
+ }
+ #endregion
+
+}
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