--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sysperfana/heapanalyser/Libraries/Engine/HeapLib/Cells/Descriptors/DescriptorAlgorithmBase.cs	Tue Jun 15 12:47:20 2010 +0300
@@ -0,0 +1,152 @@
+/*
+* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+*
+* Redistribution and use in source and binary forms, with or without
+* modification, are permitted provided that the following conditions are met:
+*
+* - Redistributions of source code must retain the above copyright notice,
+*   this list of conditions and the following disclaimer.
+* - Redistributions in binary form must reproduce the above copyright notice,
+*   this list of conditions and the following disclaimer in the documentation
+*   and/or other materials provided with the distribution.
+* - Neither the name of Nokia Corporation nor the names of its contributors
+*   may be used to endorse or promote products derived from this software
+*   without specific prior written permission.
+*
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+* POSSIBILITY OF SUCH DAMAGE.
+* 
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description: 
+*
+*/
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+using SymbianUtils.RawItems;
+using HeapLib.Statistics;
+
+namespace HeapLib.Cells.Descriptors
+{
+    public abstract class DescriptorAlgorithmBase
+    {
+        #region Constructors & destructor
+        protected DescriptorAlgorithmBase( HeapStatistics aStats )
+        {
+            iStats = aStats;
+        }
+        #endregion
+
+        #region Framework API
+        internal virtual bool IsDescriptor( HeapCell aCell, out DescriptorInfo aInfo )
+        {
+            aInfo = null;
+            iCell = aCell;
+            //
+            bool couldBeDescriptor = ( aCell.Symbol == null && RawItems.Count > 1 );
+            if ( couldBeDescriptor )
+            {
+                int payloadLength = PayloadLengthWhenCellIsDescriptor;
+                int possibleDescriptorLength = CalculatedDescriptorLength;
+                //
+                couldBeDescriptor = ( possibleDescriptorLength <= payloadLength );
+                //
+                if ( couldBeDescriptor )
+                {
+                    // Need to make a descriptor info object just to get the type...
+                    DescriptorInfo info = new DescriptorInfo( aCell );
+                    couldBeDescriptor = ( info.Type != HeapCell.TDescriptorType.EUnknown );
+                }
+            }
+            //
+            return couldBeDescriptor;
+        }
+        #endregion
+
+        #region Properties
+        protected HeapCell Cell
+        {
+            get { return iCell; }
+        }
+
+        protected RawItemCollection RawItems
+        {
+            get { return Cell.RawItems; }
+        }
+
+        protected HeapStatistics Statistics
+        {
+            get { return iStats; }
+        }
+
+        protected int PayloadLengthWhenCellIsDescriptor
+        {
+            get
+            {
+                // Layout is:
+                //
+                // First DWORD:
+                //
+                //   < 4 bits> Type
+                //   <28 bits> Length
+                //
+                // Second DWORD:
+                //
+                //   Max Length
+                //
+                // Reduce the size by 4 since we discard the descriptor length
+                int payloadLength = (int) Cell.PayloadLength - 4;
+                return payloadLength;
+            }
+        }
+
+        protected int CalculatedDescriptorLength
+        {
+            get
+            {
+                uint vTable = Cell.PossibleVTableAddress;
+                uint len = vTable & KDescriptorLengthMask;
+                return (int) len;
+            }
+        }
+
+        protected int CalculatedDescriptorMaxLength
+        {
+            get
+            {
+                System.Diagnostics.Debug.Assert( RawItems.Count >= 2 );
+                RawItem maxLenRI = Cell.RawItems[ 1 ];
+                int maxLength = (int) maxLenRI.Data;
+                return maxLength;
+            }
+        }
+        #endregion
+
+        #region Shared constants
+        protected const int KDescriptorRawItemOffsetAfterLengthAndType = 1;
+        protected const int KDescriptorTextMaxLength = 256;
+        protected const byte KDescriptorPaddingMagicCharacterValue = 0xa5;
+        protected const uint KDescriptorLengthMask = 0x00FFFFFF;
+        #endregion
+
+        #region Data members
+        private readonly HeapStatistics iStats;
+        private HeapCell iCell = new HeapCell();
+        #endregion
+    }
+}