--- /dev/null
+//\r
+// © Copyright Henrik Ravn 2004\r
+//\r
+// Use, modification and distribution are subject to the Boost Software License, Version 1.0.\r
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)\r
+//\r
+\r
+using System;\r
+using System.Runtime.InteropServices;\r
+\r
+namespace DotZLib\r
+{\r
+ /// <summary>\r
+ /// Implements the common functionality needed for all <see cref="Codec"/>s\r
+ /// </summary>\r
+ public abstract class CodecBase : Codec, IDisposable\r
+ {\r
+\r
+ #region Data members\r
+\r
+ /// <summary>\r
+ /// Instance of the internal zlib buffer structure that is\r
+ /// passed to all functions in the zlib dll\r
+ /// </summary>\r
+ internal ZStream _ztream = new ZStream();\r
+\r
+ /// <summary>\r
+ /// True if the object instance has been disposed, false otherwise\r
+ /// </summary>\r
+ protected bool _isDisposed = false;\r
+\r
+ /// <summary>\r
+ /// The size of the internal buffers\r
+ /// </summary>\r
+ protected const int kBufferSize = 16384;\r
+\r
+ private byte[] _outBuffer = new byte[kBufferSize];\r
+ private byte[] _inBuffer = new byte[kBufferSize];\r
+\r
+ private GCHandle _hInput;\r
+ private GCHandle _hOutput;\r
+\r
+ private uint _checksum = 0;\r
+\r
+ #endregion\r
+\r
+ /// <summary>\r
+ /// Initializes a new instance of the <c>CodeBase</c> class.\r
+ /// </summary>\r
+ public CodecBase()\r
+ {\r
+ try\r
+ {\r
+ _hInput = GCHandle.Alloc(_inBuffer, GCHandleType.Pinned);\r
+ _hOutput = GCHandle.Alloc(_outBuffer, GCHandleType.Pinned);\r
+ }\r
+ catch (Exception)\r
+ {\r
+ CleanUp(false);\r
+ throw;\r
+ }\r
+ }\r
+\r
+\r
+ #region Codec Members\r
+\r
+ /// <summary>\r
+ /// Occurs when more processed data are available.\r
+ /// </summary>\r
+ public event DataAvailableHandler DataAvailable;\r
+\r
+ /// <summary>\r
+ /// Fires the <see cref="DataAvailable"/> event\r
+ /// </summary>\r
+ protected void OnDataAvailable()\r
+ {\r
+ if (_ztream.total_out > 0)\r
+ {\r
+ if (DataAvailable != null)\r
+ DataAvailable( _outBuffer, 0, (int)_ztream.total_out);\r
+ resetOutput();\r
+ }\r
+ }\r
+\r
+ /// <summary>\r
+ /// Adds more data to the codec to be processed.\r
+ /// </summary>\r
+ /// <param name="data">Byte array containing the data to be added to the codec</param>\r
+ /// <remarks>Adding data may, or may not, raise the <c>DataAvailable</c> event</remarks>\r
+ public void Add(byte[] data)\r
+ {\r
+ Add(data,0,data.Length);\r
+ }\r
+\r
+ /// <summary>\r
+ /// Adds more data to the codec to be processed.\r
+ /// </summary>\r
+ /// <param name="data">Byte array containing the data to be added to the codec</param>\r
+ /// <param name="offset">The index of the first byte to add from <c>data</c></param>\r
+ /// <param name="count">The number of bytes to add</param>\r
+ /// <remarks>Adding data may, or may not, raise the <c>DataAvailable</c> event</remarks>\r
+ /// <remarks>This must be implemented by a derived class</remarks>\r
+ public abstract void Add(byte[] data, int offset, int count);\r
+\r
+ /// <summary>\r
+ /// Finishes up any pending data that needs to be processed and handled.\r
+ /// </summary>\r
+ /// <remarks>This must be implemented by a derived class</remarks>\r
+ public abstract void Finish();\r
+\r
+ /// <summary>\r
+ /// Gets the checksum of the data that has been added so far\r
+ /// </summary>\r
+ public uint Checksum { get { return _checksum; } }\r
+\r
+ #endregion\r
+\r
+ #region Destructor & IDisposable stuff\r
+\r
+ /// <summary>\r
+ /// Destroys this instance\r
+ /// </summary>\r
+ ~CodecBase()\r
+ {\r
+ CleanUp(false);\r
+ }\r
+\r
+ /// <summary>\r
+ /// Releases any unmanaged resources and calls the <see cref="CleanUp()"/> method of the derived class\r
+ /// </summary>\r
+ public void Dispose()\r
+ {\r
+ CleanUp(true);\r
+ }\r
+\r
+ /// <summary>\r
+ /// Performs any codec specific cleanup\r
+ /// </summary>\r
+ /// <remarks>This must be implemented by a derived class</remarks>\r
+ protected abstract void CleanUp();\r
+\r
+ // performs the release of the handles and calls the dereived CleanUp()\r
+ private void CleanUp(bool isDisposing)\r
+ {\r
+ if (!_isDisposed)\r
+ {\r
+ CleanUp();\r
+ if (_hInput.IsAllocated)\r
+ _hInput.Free();\r
+ if (_hOutput.IsAllocated)\r
+ _hOutput.Free();\r
+\r
+ _isDisposed = true;\r
+ }\r
+ }\r
+\r
+\r
+ #endregion\r
+\r
+ #region Helper methods\r
+\r
+ /// <summary>\r
+ /// Copies a number of bytes to the internal codec buffer - ready for proccesing\r
+ /// </summary>\r
+ /// <param name="data">The byte array that contains the data to copy</param>\r
+ /// <param name="startIndex">The index of the first byte to copy</param>\r
+ /// <param name="count">The number of bytes to copy from <c>data</c></param>\r
+ protected void copyInput(byte[] data, int startIndex, int count)\r
+ {\r
+ Array.Copy(data, startIndex, _inBuffer,0, count);\r
+ _ztream.next_in = _hInput.AddrOfPinnedObject();\r
+ _ztream.total_in = 0;\r
+ _ztream.avail_in = (uint)count;\r
+\r
+ }\r
+\r
+ /// <summary>\r
+ /// Resets the internal output buffers to a known state - ready for processing\r
+ /// </summary>\r
+ protected void resetOutput()\r
+ {\r
+ _ztream.total_out = 0;\r
+ _ztream.avail_out = kBufferSize;\r
+ _ztream.next_out = _hOutput.AddrOfPinnedObject();\r
+ }\r
+\r
+ /// <summary>\r
+ /// Updates the running checksum property\r
+ /// </summary>\r
+ /// <param name="newSum">The new checksum value</param>\r
+ protected void setChecksum(uint newSum)\r
+ {\r
+ _checksum = newSum;\r
+ }\r
+ #endregion\r
+\r
+ }\r
+}\r
projects / ossec-hids.git / blobdiff