0023850: TDataStd_ByteArray is too slow on storage on disk

Optimization of a byte-array for XML persistence (binary persistence is ok).
A possible bug is corrected (size of an array is extended a little).
Same improvement for storage of a TDataStd_TreeNode.
Improvement of speed of storage of several Ocaf attributes in XML file format.
Also, format of storage of a double value is extended to keep 17 digits after a decimal point (it was used only 15 digits before).
Several draw-commands are added to manipulate the basic Ocaf attributes:
BooleanArray
BooleanList
IntegerList
RealList
A test-script for OCAF document successfully saved and opened from disk in XML file format.
+ 1 is added to keep '\0'
Removed several spaces in source files.
PLib_LocalArray is renamed to NCollection_LocalArray and became a template. It is used as a local array for Standard_Character in XML OCAF drivers, and as a local array of Standard_Real in PLib package.
Small correction of test case for this fix

src/XmlMDataStd/XmlMDataStd_BooleanArrayDriver.cxx

@@ -21,6 +21,7 @@
 #include <XmlMDataStd_BooleanArrayDriver.ixx>
 #include <TDataStd_BooleanArray.hxx>
 #include <TColStd_HArray1OfByte.hxx>
+#include <NCollection_LocalArray.hxx>
 #include <XmlObjMgt.hxx>
 
 IMPLEMENT_DOMSTRING (FirstIndexString, "first")
@@ -93,9 +94,10 @@ Standard_Boolean XmlMDataStd_BooleanArrayDriver::Paste(const XmlObjMgt_Persisten
   Handle(TDataStd_BooleanArray) aBooleanArray = Handle(TDataStd_BooleanArray)::DownCast(theTarget);
   aBooleanArray->Init(aFirstInd, aLastInd);
   Standard_Integer length = aLastInd - aFirstInd + 1;
-  Handle(TColStd_HArray1OfByte) array = new TColStd_HArray1OfByte(0, length >> 3);
+  Handle(TColStd_HArray1OfByte) hArr = new TColStd_HArray1OfByte(0, length >> 3);
+  TColStd_Array1OfByte& arr = hArr->ChangeArray1();
 
-  Standard_Integer i = 0, upper = array->Upper();
+  Standard_Integer i = 0, upper = arr.Upper();
   Standard_CString aValueStr = Standard_CString(XmlObjMgt::GetStringValue(anElement).GetString());
   for (; i <= upper; i++)
   {
@@ -108,9 +110,9 @@ Standard_Boolean XmlMDataStd_BooleanArrayDriver::Paste(const XmlObjMgt_Persisten
       WriteMessage (aMessageString);
       return Standard_False;
     }
-    array->SetValue(i, (Standard_Byte) aValue);
+    arr.SetValue(i, (Standard_Byte) aValue);
   }
-  aBooleanArray->SetInternalArray(array);
+  aBooleanArray->SetInternalArray(hArr);
   
   return Standard_True;
 }
@@ -127,17 +129,27 @@ void XmlMDataStd_BooleanArrayDriver::Paste(const Handle(TDF_Attribute)& theSourc
 
   Standard_Integer aL = aBooleanArray->Lower();
   Standard_Integer anU = aBooleanArray->Upper();
-  TCollection_AsciiString aValueStr;
 
   theTarget.Element().setAttribute(::FirstIndexString(), aL);
   theTarget.Element().setAttribute(::LastIndexString(), anU);
 
-  const Handle(TColStd_HArray1OfByte)& array = aBooleanArray->InternalArray();
-  Standard_Integer lower = array->Lower(), i = lower, upper = array->Upper();
+  const Handle(TColStd_HArray1OfByte)& hArr = aBooleanArray->InternalArray();
+  const TColStd_Array1OfByte& arr = hArr->Array1();
+
+  // Allocation of 4 chars for each byte.
+  Standard_Integer iChar = 0;
+  NCollection_LocalArray<Standard_Character> str;
+  if (arr.Length())
+    str.Allocate(4 * arr.Length() + 1);
+
+  // Convert integers - compressed boolean values, to a string.
+  Standard_Integer lower = arr.Lower(), i = lower, upper = arr.Upper();
   for (; i <= upper; i++)
   {
-    aValueStr += TCollection_AsciiString((Standard_Integer) array->Value(i));
-    aValueStr += ' ';
+    const Standard_Byte& byte = arr.Value(i);
+    iChar += Sprintf(&(str[iChar]), "%d ", byte);
   }
-  XmlObjMgt::SetStringValue (theTarget, aValueStr.ToCString(), Standard_True);
+
+  if (arr.Length())
+    XmlObjMgt::SetStringValue (theTarget, (Standard_Character*)str, Standard_True);
 }

src/XmlMDataStd/XmlMDataStd_BooleanListDriver.cxx

@@ -21,6 +21,7 @@
 #include <XmlMDataStd_BooleanListDriver.ixx>
 #include <TDataStd_BooleanList.hxx>
 #include <TDataStd_ListIteratorOfListOfByte.hxx>
+#include <NCollection_LocalArray.hxx>
 #include <XmlObjMgt.hxx>
 
 IMPLEMENT_DOMSTRING (FirstIndexString, "first")
@@ -127,18 +128,18 @@ void XmlMDataStd_BooleanListDriver::Paste(const Handle(TDF_Attribute)& theSource
   Handle(TDataStd_BooleanList) aBooleanList = Handle(TDataStd_BooleanList)::DownCast(theSource);
 
   Standard_Integer anU = aBooleanList->Extent();
-  TCollection_AsciiString aValueStr;
-
   theTarget.Element().setAttribute(::LastIndexString(), anU);
   if (anU >= 1)
   {
+    // Allocation of 1 char for each boolean value + a space.
+    Standard_Integer iChar = 0;
+    NCollection_LocalArray<Standard_Character> str(2 * anU + 1);
     TDataStd_ListIteratorOfListOfByte itr(aBooleanList->List());
     for (; itr.More(); itr.Next())
     {
-      aValueStr += TCollection_AsciiString(itr.Value());
-      aValueStr += ' ';
+      const Standard_Byte& byte = itr.Value();
+      iChar += Sprintf(&(str[iChar]), "%d ", byte);
     }
+    XmlObjMgt::SetStringValue (theTarget, (Standard_Character*)str, Standard_True);
   }
-  // No occurrence of '&', '<' and other irregular XML characters
-  XmlObjMgt::SetStringValue (theTarget, aValueStr.ToCString(), Standard_True);
 }

src/XmlMDataStd/XmlMDataStd_ByteArrayDriver.cxx

@@ -21,6 +21,7 @@
 #include <XmlMDataStd_ByteArrayDriver.ixx>
 #include <TDataStd_ByteArray.hxx>
 #include <TColStd_HArray1OfByte.hxx>
+#include <NCollection_LocalArray.hxx>
 #include <XmlObjMgt.hxx>
 #include <XmlMDataStd.hxx>
 
@@ -93,10 +94,11 @@ Standard_Boolean XmlMDataStd_ByteArrayDriver::Paste(const XmlObjMgt_Persistent&
 
 
   Handle(TDataStd_ByteArray) aByteArray = Handle(TDataStd_ByteArray)::DownCast(theTarget);
-  Handle(TColStd_HArray1OfByte) array = new TColStd_HArray1OfByte(aFirstInd, aLastInd);
+  Handle(TColStd_HArray1OfByte) hArr = new TColStd_HArray1OfByte(aFirstInd, aLastInd);
+  TColStd_Array1OfByte& arr = hArr->ChangeArray1();
 
   Standard_CString aValueStr = Standard_CString(XmlObjMgt::GetStringValue(anElement).GetString());
-  Standard_Integer i = array->Lower(), upper = array->Upper();
+  Standard_Integer i = arr.Lower(), upper = arr.Upper();
   for (; i <= upper; i++)
   {
     if (!XmlObjMgt::GetInteger(aValueStr, aValue)) 
@@ -108,9 +110,9 @@ Standard_Boolean XmlMDataStd_ByteArrayDriver::Paste(const XmlObjMgt_Persistent&
       WriteMessage (aMessageString);
       return Standard_False;
     }
-    array->SetValue(i, (Standard_Byte) aValue);
+    arr.SetValue(i, (Standard_Byte) aValue);
   }
-  aByteArray->ChangeArray(array);
+  aByteArray->ChangeArray(hArr);
   
 #ifdef DEB
   //cout << "CurDocVersion = " << XmlMDataStd::DocumentVersion() <<endl;
@@ -152,19 +154,32 @@ void XmlMDataStd_ByteArrayDriver::Paste(const Handle(TDF_Attribute)& theSource,
 
   Standard_Integer aL = aByteArray->Lower();
   Standard_Integer anU = aByteArray->Upper();
-  TCollection_AsciiString aValueStr;
 
   theTarget.Element().setAttribute(::FirstIndexString(), aL);
   theTarget.Element().setAttribute(::LastIndexString(), anU);
   theTarget.Element().setAttribute(::IsDeltaOn(),aByteArray->GetDelta());
 
-  const Handle(TColStd_HArray1OfByte)& array = aByteArray->InternalArray();
-  Standard_Integer lower = array->Lower(), i = lower, upper = array->Upper();
-  for (; i <= upper; i++)
+  const Handle(TColStd_HArray1OfByte)& hArr = aByteArray->InternalArray();
+  if (!hArr.IsNull() && hArr->Length())
   {
-    aValueStr += TCollection_AsciiString((Standard_Integer) array->Value(i));
-    aValueStr += ' ';
-  }
-  XmlObjMgt::SetStringValue (theTarget, aValueStr.ToCString(), Standard_True);
+    // Access to data through an internal reprsentation of the array is faster.
+    const TColStd_Array1OfByte& arr = hArr->Array1();
 
+    // Allocate 4 characters (including a space ' ') for each byte (unsigned char) from the array.
+    NCollection_LocalArray<Standard_Character> str(4 * arr.Length() + 1);
+
+    // Char counter in the array of chars.
+    Standard_Integer iChar = 0;
+
+    // Iterate on the array of bytes and fill-in the array of chars inserting spacing between the chars.
+    Standard_Integer iByte = arr.Lower(); // position inside the byte array
+    for (; iByte <= arr.Upper(); ++iByte)
+    {
+      const Standard_Byte& byte = arr.Value(iByte);
+      iChar += Sprintf(&(str[iChar]), "%d ", byte);
+    }
+
+    // Transfer the string (array of chars) to XML.
+    XmlObjMgt::SetStringValue (theTarget, (Standard_Character*)str, Standard_True);
+  }
 }

src/XmlMDataStd/XmlMDataStd_IntPackedMapDriver.cxx

@@ -29,6 +29,7 @@
 #include <XmlMDF_ADriver.hxx>
 #include <TDF_Attribute.hxx>
 #include <TDataStd_IntPackedMap.hxx>
+#include <NCollection_LocalArray.hxx>
 #include <XmlMDataStd.hxx>
 
 IMPLEMENT_DOMSTRING (IntPackedMapSize, "mapsize")
@@ -154,14 +155,21 @@ void XmlMDataStd_IntPackedMapDriver::Paste (const Handle(TDF_Attribute)& theSour
   theTarget.Element().setAttribute(::IntPackedMapSize(), aSize);
   theTarget.Element().setAttribute(::IsDeltaOn(),aS->GetDelta());
 
-  TCollection_AsciiString aValueString;
-  if(aSize) {
+  if(aSize)
+  {
+    // Allocation of 12 chars for each integer including the space.
+    // An example: -2 147 483 648
+    Standard_Integer iChar = 0;
+    NCollection_LocalArray<Standard_Character> str(12 * aSize + 1);
+
     TColStd_MapIteratorOfPackedMapOfInteger anIt(aS->GetMap());
-    for(;anIt.More();anIt.Next()) {
-      aValueString += TCollection_AsciiString(anIt.Key());
-      aValueString += ' ';
+    for(;anIt.More();anIt.Next()) 
+    {
+      const Standard_Integer intValue = anIt.Key();
+      iChar += Sprintf(&(str[iChar]), "%d ", intValue);
     }
+
     // No occurrence of '&', '<' and other irregular XML characters
-    XmlObjMgt::SetStringValue (theTarget, aValueString.ToCString(), Standard_True);
+    XmlObjMgt::SetStringValue (theTarget, (Standard_Character*)str, Standard_True);
   }
 }

src/XmlMDataStd/XmlMDataStd_IntegerArrayDriver.cxx

@@ -21,6 +21,7 @@
 
 #include <XmlMDataStd_IntegerArrayDriver.ixx>
 #include <TDataStd_IntegerArray.hxx>
+#include <NCollection_LocalArray.hxx>
 #include <XmlObjMgt.hxx>
 #include <XmlMDataStd.hxx>
 
@@ -154,21 +155,36 @@ void XmlMDataStd_IntegerArrayDriver::Paste
 {
   Handle(TDataStd_IntegerArray) anIntArray =
     Handle(TDataStd_IntegerArray)::DownCast(theSource);
+  const Handle(TColStd_HArray1OfInteger)& hIntArray = anIntArray->Array();
+  const TColStd_Array1OfInteger& intArray = hIntArray->Array1();
+  Standard_Integer aL = intArray.Lower(), anU = intArray.Upper();
 
-  Standard_Integer aL = anIntArray->Lower(), anU = anIntArray->Upper();
-  TCollection_AsciiString aValueStr;
-
-  if (aL != 1) theTarget.Element().setAttribute (::FirstIndexString(), aL);
+  if (aL != 1) 
+    theTarget.Element().setAttribute(::FirstIndexString(), aL);
   theTarget.Element().setAttribute(::LastIndexString(), anU);
   theTarget.Element().setAttribute(::IsDeltaOn(), anIntArray->GetDelta());
 
+  // Allocation of 12 chars for each integer including the space.
+  // An example: -2 147 483 648
+  Standard_Integer iChar = 0;
+  NCollection_LocalArray<Standard_Character> str;
+  if (intArray.Length())
+    str.Allocate(12 * intArray.Length() + 1);
+
   Standard_Integer i = aL;
-  while (1) {
-    aValueStr += TCollection_AsciiString(anIntArray->Value(i));
-    if (i >= anU) break;
-    aValueStr += ' ';
+  while (1) 
+  {
+    const Standard_Integer& intValue = intArray.Value(i);
+    iChar += Sprintf(&(str[iChar]), "%d ", intValue);
+    if (i >= anU)
+      break;
     ++i;
   }
-  // No occurrence of '&', '<' and other irregular XML characters
-  XmlObjMgt::SetStringValue (theTarget, aValueStr.ToCString(), Standard_True);
+
+  if (intArray.Length())
+  {
+    // No occurrence of '&', '<' and other irregular XML characters
+    str[iChar - 1] = '\0';
+    XmlObjMgt::SetStringValue (theTarget, (Standard_Character*)str, Standard_True);
+  }
 }

src/XmlMDataStd/XmlMDataStd_IntegerListDriver.cxx

@@ -21,6 +21,7 @@
 #include <XmlMDataStd_IntegerListDriver.ixx>
 #include <TDataStd_IntegerList.hxx>
 #include <TColStd_ListIteratorOfListOfInteger.hxx>
+#include <NCollection_LocalArray.hxx>
 #include <XmlObjMgt.hxx>
 
 IMPLEMENT_DOMSTRING (FirstIndexString, "first")
@@ -127,18 +128,21 @@ void XmlMDataStd_IntegerListDriver::Paste(const Handle(TDF_Attribute)& theSource
   Handle(TDataStd_IntegerList) anIntList = Handle(TDataStd_IntegerList)::DownCast(theSource);
 
   Standard_Integer anU = anIntList->Extent();
-  TCollection_AsciiString aValueStr;
-
   theTarget.Element().setAttribute(::LastIndexString(), anU);
   if (anU >= 1)
   {
+    // Allocation of 12 chars for each integer including the space.
+    // An example: -2 147 483 648
+    Standard_Integer iChar = 0;
+    NCollection_LocalArray<Standard_Character> str(12 * anU + 1);
     TColStd_ListIteratorOfListOfInteger itr(anIntList->List());
     for (; itr.More(); itr.Next())
     {
-      aValueStr += TCollection_AsciiString(itr.Value());
-      aValueStr += ' ';
+      const Standard_Integer& intValue = itr.Value();
+      iChar += Sprintf(&(str[iChar]), "%d ", intValue);
     }
+
+    // No occurrence of '&', '<' and other irregular XML characters
+    XmlObjMgt::SetStringValue (theTarget, (Standard_Character*)str, Standard_True);
   }
-  // No occurrence of '&', '<' and other irregular XML characters
-  XmlObjMgt::SetStringValue (theTarget, aValueStr.ToCString(), Standard_True);
 }

src/XmlMDataStd/XmlMDataStd_RealArrayDriver.cxx

@@ -19,13 +19,13 @@
 
 //AGV 150202: Changed prototype XmlObjMgt::SetStringValue()
 
-#define OCC6010 // vro 01.06.2004
-
 # include <stdio.h>
 #include <XmlMDataStd_RealArrayDriver.ixx>
 #include <TDataStd_RealArray.hxx>
 #include <XmlObjMgt.hxx>
 #include <XmlMDataStd.hxx>
+#include <TColStd_HArray1OfReal.hxx>
+#include <NCollection_LocalArray.hxx>
 
 IMPLEMENT_DOMSTRING (FirstIndexString, "first")
 IMPLEMENT_DOMSTRING (LastIndexString, "last")
@@ -158,27 +158,35 @@ void XmlMDataStd_RealArrayDriver::Paste (const Handle(TDF_Attribute)& theSource,
 {
   Handle(TDataStd_RealArray) aRealArray =
     Handle(TDataStd_RealArray)::DownCast(theSource);
-
-  Standard_Integer aL = aRealArray->Lower(), anU = aRealArray->Upper();
-  TCollection_AsciiString aValueStr;
+  const Handle(TColStd_HArray1OfReal)& hRealArray = aRealArray->Array();
+  const TColStd_Array1OfReal& realArray = hRealArray->Array1();
+  Standard_Integer aL = realArray.Lower(), anU = realArray.Upper();
 
   if (aL != 1) theTarget.Element().setAttribute(::FirstIndexString(), aL);
   theTarget.Element().setAttribute(::LastIndexString(), anU);
   theTarget.Element().setAttribute(::IsDeltaOn(), aRealArray->GetDelta());
 
+  // Allocation of 25 chars for each double value including the space:
+  // An example: -3.1512678732195273e+020
+  Standard_Integer iChar = 0;
+  NCollection_LocalArray<Standard_Character> str;
+  if (realArray.Length())
+    str.Allocate(25 * realArray.Length() + 1);
+
   Standard_Integer i = aL;
-  while (1) {
-#ifndef OCC6010
-    aValueStr += TCollection_AsciiString(aRealArray->Value(i));
-#else
-    char aValueChar[32];
-    Sprintf(aValueChar, "%.15g", aRealArray->Value(i));
-    aValueStr += aValueChar;
-#endif
-    if (i >= anU) break;
-    aValueStr += ' ';
+  while (1) 
+  {
+    const Standard_Real& dblValue = realArray.Value(i);
+    iChar += Sprintf(&(str[iChar]), "%.17g ", dblValue);
+    if (i >= anU)
+      break;
     ++i;
   }
+
   // No occurrence of '&', '<' and other irregular XML characters
-  XmlObjMgt::SetStringValue (theTarget, aValueStr.ToCString(), Standard_True);
+  if (realArray.Length())
+  {
+    str[iChar - 1] = '\0';
+    XmlObjMgt::SetStringValue (theTarget, (Standard_Character*)str, Standard_True);
+  }
 }

src/XmlMDataStd/XmlMDataStd_RealDriver.cxx

@@ -84,7 +84,7 @@ void XmlMDataStd_RealDriver::Paste (const Handle(TDF_Attribute)& theSource,
   TCollection_AsciiString aValueStr (anInt->Get());
 #else
   char aValueChar[32];
-  Sprintf(aValueChar, "%.15g", anInt->Get());
+  Sprintf(aValueChar, "%.17g", anInt->Get());
   TCollection_AsciiString aValueStr(aValueChar);
 #endif
   // No occurrence of '&', '<' and other irregular XML characters

src/XmlMDataStd/XmlMDataStd_RealListDriver.cxx

@@ -21,6 +21,7 @@
 #include <XmlMDataStd_RealListDriver.ixx>
 #include <TDataStd_RealList.hxx>
 #include <TColStd_ListIteratorOfListOfReal.hxx>
+#include <NCollection_LocalArray.hxx>
 #include <XmlObjMgt.hxx>
 
 IMPLEMENT_DOMSTRING (FirstIndexString, "first")
@@ -135,18 +136,19 @@ void XmlMDataStd_RealListDriver::Paste(const Handle(TDF_Attribute)& theSource,
   Handle(TDataStd_RealList) aRealList = Handle(TDataStd_RealList)::DownCast(theSource);
 
   Standard_Integer anU = aRealList->Extent();
-  TCollection_AsciiString aValueStr;
-
   theTarget.Element().setAttribute(::LastIndexString(), anU);
   if (anU >= 1)
   {
+    // Allocation of 25 chars for each double value including the space:
+    // An example: -3.1512678732195273e+020
+    Standard_Integer iChar = 0;
+    NCollection_LocalArray<Standard_Character> str(25 * anU + 1);
     TColStd_ListIteratorOfListOfReal itr(aRealList->List());
     for (; itr.More(); itr.Next())
     {
-      aValueStr += TCollection_AsciiString(itr.Value());
-      aValueStr += ' ';
+      const Standard_Real& realValue = itr.Value();
+      iChar += Sprintf(&(str[iChar]), "%.17g ", realValue);
     }
+    XmlObjMgt::SetStringValue (theTarget, (Standard_Character*)str, Standard_True);
   }
-  // No occurrence of '&', '<' and other irregular XML characters
-  XmlObjMgt::SetStringValue (theTarget, aValueStr.ToCString(), Standard_True);
 }

src/XmlMDataStd/XmlMDataStd_TreeNodeDriver.cxx

@@ -19,6 +19,7 @@
 
 
 #include <XmlMDataStd_TreeNodeDriver.ixx>
+#include <NCollection_LocalArray.hxx>
 #include <TDataStd_TreeNode.hxx>
 #include <XmlObjMgt.hxx>
 
@@ -108,20 +109,24 @@ void XmlMDataStd_TreeNodeDriver::Paste
 {
   Handle(TDataStd_TreeNode) aS = Handle(TDataStd_TreeNode)::DownCast(theSource);
 
-  Standard_Integer aNb;
-
-  TCollection_AsciiString aChildrenStr;
-
   // tree id
+  Standard_Integer aNb;
   Standard_Character aGuidStr [40];
   Standard_PCharacter pGuidStr=aGuidStr;
   aS->ID().ToCString (pGuidStr);
   theTarget.Element().setAttribute(::TreeIdString(), aGuidStr);
 
-  // first child
-  Handle(TDataStd_TreeNode) aF = aS->First();
+  // Find number of children.
+  int nbChildren = aS->NbChildren();
+  
+  // Allocate 11 digits for each ID (an integer) of the child + a space.
+  Standard_Integer iChar = 0;
+  NCollection_LocalArray<Standard_Character> str;
+  if (nbChildren)
+    str.Allocate(11 * nbChildren + 1);
 
   // form the string of numbers for the list of children
+  Handle(TDataStd_TreeNode) aF = aS->First();
   while (!aF.IsNull())
   {
     aNb = theRelocTable.FindIndex(aF);
@@ -129,14 +134,16 @@ void XmlMDataStd_TreeNodeDriver::Paste
     {
       aNb = theRelocTable.Add(aF);
     }
-    TCollection_AsciiString aNbStr (aNb);
-    aChildrenStr += aNbStr + " ";
+
+    // Add number to the long string.
+    iChar += Sprintf(&(str[iChar]), "%d ", aNb);
 
     // next child
     aF = aF->Next();
   }
 
-  if (aChildrenStr.Length() > 0)
-    theTarget.Element().setAttribute(::ChildrenString(),
-                                      aChildrenStr.ToCString());
+  if (nbChildren)
+  {
+    theTarget.Element().setAttribute(::ChildrenString(), (Standard_Character*)str);
+  }
 }