From 036938d9d9f0368e9d71008311e97a8abf41f053 Mon Sep 17 00:00:00 2001
From: John <jjenko@volian.com>
Date: Thu, 8 Jun 2017 17:12:52 +0000
Subject: [PATCH] B2016-115 the comparison of the contents of RO.FST files
 would also be seen as different (and loading into memory) even when user
 created a new RO.fst without making any RO changes. We needed to skip past
 the RO.FST header information in the file which contains the date/time the
 FST was created. Also needed to do a garbage collection.

---
 .../Extension/DocVersionExt.cs                | 40 ++-----------------
 .../Extension/ROFSTExt.cs                     | 35 ++++++++++++++++
 2 files changed, 39 insertions(+), 36 deletions(-)

diff --git a/PROMS/VEPROMS.CSLA.Library/Extension/DocVersionExt.cs b/PROMS/VEPROMS.CSLA.Library/Extension/DocVersionExt.cs
index aa032e30..f829701c 100644
--- a/PROMS/VEPROMS.CSLA.Library/Extension/DocVersionExt.cs
+++ b/PROMS/VEPROMS.CSLA.Library/Extension/DocVersionExt.cs
@@ -61,23 +61,8 @@ namespace VEPROMS.CSLA.Library
 				if (fiRofst.Length != roFstInfo.ROLookup.Length) return fiRofst.LastWriteTimeUtc > roFstInfo.DTS;
 
 				// if we can't tell by the DTS or size, compare the contents.  Get all of the rodb's
-				// rofsts of the size of the file & compare bytes. If 
-				ROFstInfoList fstList = ROFstInfoList.GetBySize(rdi.RODbID, (int)fiRofst.Length);
-				if (fstList.Count > 0)
-				{
-					FileStream fsIn = new FileStream(rofstPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
-					// Create an instance of StreamReader that can read characters from the FileStream.
-					BinaryReader r = new BinaryReader(fsIn);
-					byte[] ab = r.ReadBytes((int)fsIn.Length);
-					fsIn.Close();
-					foreach (ROFstInfo irofst in fstList)
-					{
-						// compare contents by comparing each byte.
-						for (int i = 0; i < fiRofst.Length; i++)
-							if (ab[i] != irofst.ROLookup[i]) return true;
-					}
-				}
-				return false;
+				// rofsts of the size of the file & compare bytes.
+				return  ROFstInfoList.ROFstDiffBySize(rofstPath, rdi.RODbID, (int)fiRofst.Length);
 			}
 		}
 		#region VersionType
@@ -244,25 +229,8 @@ namespace VEPROMS.CSLA.Library
 				if (fiRofst.Length != roFstInfo.ROLookup.Length) return AddToRoFstLookup(key,fiRofst.LastWriteTimeUtc > roFstInfo.DTS);
 
 				// if we can't tell by the DTS or size, compare the contents.  Get all of the rodb's
-				// rofsts of the size of the file & compare bytes. If 
-				ROFstInfoList fstList = ROFstInfoList.GetBySize(rdi.RODbID, (int)fiRofst.Length);
-				if (fstList.Count > 0)
-				{
-					// B2017-078  WCN users with Read only access to the RO FST file where not able to open the file for reading when
-					//            another user was accessing the file. Changed FileShare from Read to ReadWrite
-					FileStream fsIn = new FileStream(rofstPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
-					// Create an instance of StreamReader that can read characters from the FileStream.
-					BinaryReader r = new BinaryReader(fsIn);
-					byte[] ab = r.ReadBytes((int)fsIn.Length);
-					fsIn.Close();
-					foreach (ROFstInfo irofst in fstList)
-					{
-						// compare contents by comparing each byte.
-						for (int i = 0; i < fiRofst.Length; i++)
-							if (ab[i] != irofst.ROLookup[i]) return AddToRoFstLookup(key,true);
-					}
-				}
-				return AddToRoFstLookup(key,false);
+				// rofsts of the size of the file & compare bytes.
+				return AddToRoFstLookup(key, ROFstInfoList.ROFstDiffBySize(rofstPath, rdi.RODbID, (int)fiRofst.Length));
 			}
 		}
 
diff --git a/PROMS/VEPROMS.CSLA.Library/Extension/ROFSTExt.cs b/PROMS/VEPROMS.CSLA.Library/Extension/ROFSTExt.cs
index e5214689..b366dfa1 100644
--- a/PROMS/VEPROMS.CSLA.Library/Extension/ROFSTExt.cs
+++ b/PROMS/VEPROMS.CSLA.Library/Extension/ROFSTExt.cs
@@ -1079,6 +1079,41 @@ namespace VEPROMS.CSLA.Library
 				throw new DbCslaException("Error on RoFstInfoList.GetBySize", ex);
 			}
 		}
+		public static bool ROFstDiffBySize(string rofstPath, int roDbID, int len)
+		{
+			try
+			{
+				bool isDifferent = false;
+				using (ROFstInfoList tmp = GetBySize(roDbID, len))
+				{
+					if (tmp.Count > 0)
+					{
+						// B2017-078  WCN users with Read only access to the RO FST file where not able to open the file for reading when
+						//            another user was accessing the file. Changed FileShare from Read to ReadWrite
+						FileStream fsIn = new FileStream(rofstPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
+						// Create an instance of StreamReader that can read characters from the FileStream.
+						BinaryReader r = new BinaryReader(fsIn);
+						byte[] ab = r.ReadBytes((int)fsIn.Length);
+						r.Close();
+						fsIn.Close();
+						foreach (ROFstInfo irofst in tmp)
+						{
+							// compare contents by comparing each byte.
+							for (int i = 20; i < len; i++) // this skips past RO.FST header which has the FST creation date/time
+								if (ab[i] != irofst.ROLookup[i]) isDifferent = true;
+							irofst.Dispose();
+							if (isDifferent) break;
+						}
+					}
+				}
+				GC.Collect();
+				return isDifferent;
+			}
+			catch (Exception ex)
+			{
+				throw new DbCslaException("Error on RoFstInfoList.ROFstDiffBySize", ex);
+			}
+		}
 		private void DataPortal_Fetch(RoFstSizeCriteria criteria)
 		{
 			this.RaiseListChangedEvents = false;