--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sysperfana/heapanalyser/Libraries/Engine/HeapLib/Cells/Descriptors/Implementations/Ascii/DesAsciiAlgorithmNullTerminatedString.cs	Tue Jun 15 12:47:20 2010 +0300
@@ -0,0 +1,149 @@
+/*
+* 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.Implementations.Ascii
+{
+    internal class DesAsciiAlgorithmNullTerminatedString : DesAsciiAlgorithmBase
+    {
+        #region Constructors & destructor
+        public DesAsciiAlgorithmNullTerminatedString( HeapStatistics aStats )
+            : base( aStats )
+        {
+        }
+        #endregion
+
+        #region From DescriptorAlgorithmBase
+        internal override bool IsDescriptor( HeapCell aCell, out DescriptorInfo aInfo )
+        {
+            // Use this to initialise 'Cell'
+            base.IsDescriptor( aCell, out aInfo );
+
+            bool isDes = ( aCell.Symbol == null && RawItems.Count > 1 );
+            if ( isDes )
+            {
+                isDes = false;
+                int checkedCharCount = 0;
+                int printableCharCount = 0;
+                int letterOrDigitCount = 0;
+                int numberOfHeapAddresses = 0;
+                
+                // Keep reading chars until we hit a NULL
+                bool foundNull = false;
+                foreach ( RawItem item in RawItems )
+                {
+                    if ( Statistics.WithinHeapBounds( item.Data ) )
+                    {
+                        ++numberOfHeapAddresses;
+                    }
+
+                    byte[] data = item.DataArray;
+                    foreach ( byte b in data )
+                    {
+                        if ( b != 0 )
+                        {
+                            ++checkedCharCount;
+
+                            char c = Convert.ToChar( b );
+                            if ( Char.IsLetterOrDigit( c ) )
+                            {
+                                ++letterOrDigitCount;
+                            }
+
+                            bool isPrint = IsPrintableAsciiCharacter( b );
+                            if ( isPrint )
+                            {
+                                ++printableCharCount;
+                            }
+                            else
+                            {
+                                break;
+                            }
+                        }
+                        else
+                        {
+                            foundNull = true;
+                            break;
+                        }
+                    }
+
+                    if ( foundNull )
+                    {
+                        break;
+                    }
+                }
+
+                // All chars must be printable
+                bool allWerePrintable = ( checkedCharCount == printableCharCount && printableCharCount > 0 );
+                if ( foundNull && allWerePrintable && numberOfHeapAddresses == 0 && letterOrDigitCount > 0 )
+                {
+                    // If the size of the cell is very big and the "string" itself is very small, then chances
+                    // are this is not a null terminated string at all. 
+                    int percentageOfStringUsed = AsPercentage( aCell, printableCharCount );
+                    if ( percentageOfStringUsed > KMinimumUtilisationPercentage )
+                    {
+                        aInfo = new DescriptorInfo( aCell );
+                        aInfo.Text = ConvertToText( printableCharCount, 0 );
+                        aInfo.Type = HeapCell.TDescriptorType.ENullTerminatedString;
+                        isDes = true;
+                    }
+                }
+            }
+            //
+            return isDes;
+        }
+        #endregion
+
+        #region Internal constants
+        private const int KMinimumUtilisationPercentage = 10; // Percent
+        #endregion
+
+        #region Internal methods
+        private static int AsPercentage( HeapCell aCell, int aLength )
+        {
+            uint totalLength = aCell.PayloadLength;
+            float ret = ( (float) aLength / (float) totalLength ) * 100.0f;
+            return (int) ret;
+        }
+        #endregion
+    }
+}