Torque3D/Engine/source/console/consoleInternal.cpp

//-----------------------------------------------------------------------------
// Copyright (c) 2012 GarageGames, LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//-----------------------------------------------------------------------------

#include "platform/platform.h"
#include "console/console.h"

#include "console/ast.h"
#include "core/tAlgorithm.h"

#include "core/strings/findMatch.h"
#include "console/consoleInternal.h"
#include "core/stream/fileStream.h"
#include "console/compiler.h"
#include "console/engineAPI.h"

//#define DEBUG_SPEW

#define ST_INIT_SIZE 15

static char scratchBuffer[1024];
U32 Namespace::mCacheSequence = 0;
DataChunker Namespace::mCacheAllocator;
DataChunker Namespace::mAllocator;
Namespace *Namespace::mNamespaceList = NULL;
Namespace *Namespace::mGlobalNamespace = NULL;


bool canTabComplete(const char *prevText, const char *bestMatch,
               const char *newText, S32 baseLen, bool fForward)
{
   // test if it matches the first baseLen chars:
   if(dStrnicmp(newText, prevText, baseLen))
      return false;

   if (fForward)
   {
      if(!bestMatch)
         return dStricmp(newText, prevText) > 0;
      else
         return (dStricmp(newText, prevText) > 0) &&
                (dStricmp(newText, bestMatch) < 0);
   }
   else
   {
      if (dStrlen(prevText) == (U32) baseLen)
      {
         // look for the 'worst match'
         if(!bestMatch)
            return dStricmp(newText, prevText) > 0;
         else
            return dStricmp(newText, bestMatch) > 0;
      }
      else
      {
         if (!bestMatch)
            return (dStricmp(newText, prevText)  < 0);
         else
            return (dStricmp(newText, prevText)  < 0) &&
                   (dStricmp(newText, bestMatch) > 0);
      }
   }
}

//---------------------------------------------------------------
//
// Dictionary functions
//
//---------------------------------------------------------------
struct StringValue
{
   S32 size;
   char *val;

   operator char *() { return val; }
   StringValue &operator=(const char *string);

   StringValue() { size = 0; val = NULL; }
   ~StringValue() { dFree(val); }
};


StringValue & StringValue::operator=(const char *string)
{
   if(!val)
   {
      val = dStrdup(string);
      size = dStrlen(val);
   }
   else
   {
      S32 len = dStrlen(string);
      if(len < size)
         dStrcpy(val, string);
      else
      {
         size = len;
         dFree(val);
         val = dStrdup(string);
      }
   }
   return *this;
}

static S32 QSORT_CALLBACK varCompare(const void* a,const void* b)
{
   return dStricmp( (*((Dictionary::Entry **) a))->name, (*((Dictionary::Entry **) b))->name );
}

void Dictionary::exportVariables(const char *varString, const char *fileName, bool append)
{
   const char *searchStr = varString;
   Vector<Entry *> sortList(__FILE__, __LINE__);

   for(S32 i = 0; i < hashTable->size;i ++)
   {
      Entry *walk = hashTable->data[i];
      while(walk)
      {
         if(FindMatch::isMatch((char *) searchStr, (char *) walk->name))
            sortList.push_back(walk);

         walk = walk->nextEntry;
      }
   }

   if(!sortList.size())
      return;

   dQsort((void *) &sortList[0], sortList.size(), sizeof(Entry *), varCompare);

   Vector<Entry *>::iterator s;
   char expandBuffer[1024];
   FileStream *strm = NULL;

   if(fileName)
   {
      if((strm = FileStream::createAndOpen( fileName, append ? Torque::FS::File::ReadWrite : Torque::FS::File::Write )) == NULL)
      {
         Con::errorf(ConsoleLogEntry::General, "Unable to open file '%s for writing.", fileName);
         return;
      }
      if(append)
         strm->setPosition(strm->getStreamSize());
   }

   char buffer[1024];
   const char *cat = fileName ? "\r\n" : "";

   for(s = sortList.begin(); s != sortList.end(); s++)
   {
      switch((*s)->value.type)
      {
         case ConsoleValue::TypeInternalInt:
            dSprintf(buffer, sizeof(buffer), "%s = %d;%s", (*s)->name, (*s)->value.ival, cat);
            break;
         case ConsoleValue::TypeInternalFloat:
            dSprintf(buffer, sizeof(buffer), "%s = %g;%s", (*s)->name, (*s)->value.fval, cat);
            break;
         default:
            expandEscape(expandBuffer, (*s)->getStringValue());
            dSprintf(buffer, sizeof(buffer), "%s = \"%s\";%s", (*s)->name, expandBuffer, cat);
            break;
      }
      if(strm)
         strm->write(dStrlen(buffer), buffer);
      else
         Con::printf("%s", buffer);
   }
   if(strm)
      delete strm;
}

void Dictionary::exportVariables( const char *varString, Vector<String> *names, Vector<String> *values )
{
   const char *searchStr = varString;
   Vector<Entry *> sortList(__FILE__, __LINE__);

   for ( S32 i = 0; i < hashTable->size; i++ )
   {
      Entry *walk = hashTable->data[i];
      while ( walk )
      {
         if ( FindMatch::isMatch( (char*)searchStr, (char*)walk->name ) )
            sortList.push_back( walk );

         walk = walk->nextEntry;
      }
   }

   if ( !sortList.size() )
      return;

   dQsort((void *) &sortList[0], sortList.size(), sizeof(Entry *), varCompare);

   if ( names )
      names->reserve( sortList.size() );
   if ( values )
      values->reserve( sortList.size() );

   char expandBuffer[1024];

   Vector<Entry *>::iterator s;

   for ( s = sortList.begin(); s != sortList.end(); s++ )
   {
      if ( names )
         names->push_back( String( (*s)->name ) );

      if ( values )
      {
         switch ( (*s)->value.type )
         {
         case ConsoleValue::TypeInternalInt:
            values->push_back( String::ToString( (*s)->value.ival ) );         
            break;
         case ConsoleValue::TypeInternalFloat:
            values->push_back( String::ToString( (*s)->value.fval ) );         
            break;
         default:         
            expandEscape( expandBuffer, (*s)->getStringValue() );
            values->push_back( expandBuffer );  
            break;
         }
      }
   }
}

void Dictionary::deleteVariables(const char *varString)
{
   const char *searchStr = varString;

   for(S32 i = 0; i < hashTable->size; i++)
   {
      Entry *walk = hashTable->data[i];
      while(walk)
      {
         Entry *matchedEntry = (FindMatch::isMatch((char *) searchStr, (char *) walk->name)) ? walk : NULL;
         walk = walk->nextEntry;
         if (matchedEntry)
            remove(matchedEntry); // assumes remove() is a stable remove (will not reorder entries on remove)
      }
   }
}

S32 HashPointer(StringTableEntry ptr)
{
   return (S32)(((dsize_t)ptr) >> 2);
}

Dictionary::Entry *Dictionary::lookup(StringTableEntry name)
{
   Entry *walk = hashTable->data[HashPointer(name) % hashTable->size];
   while(walk)
   {
      if(walk->name == name)
         return walk;
      else
         walk = walk->nextEntry;
   }

   return NULL;
}

Dictionary::Entry *Dictionary::add(StringTableEntry name)
{
   // Try to find an existing match.
   //printf("Add Variable %s\n", name);
   
   Entry* ret = lookup( name );
   if( ret )
      return ret;
   
   // Rehash if the table get's too crowded.  Be aware that this might
   // modify a table that we don't own.

   hashTable->count ++;
   if( hashTable->count > hashTable->size * 2 )
   {
      // Allocate a new table.
      
      const U32 newTableSize = hashTable->size * 4 - 1;
      Entry** newTableData = new Entry*[ newTableSize ];
      dMemset( newTableData, 0, newTableSize * sizeof( Entry* ) );
      
      // Move the entries over.
      
      for( U32 i = 0; i < hashTable->size; ++ i )
         for( Entry* entry = hashTable->data[ i ]; entry != NULL; )
         {
            Entry* next = entry->nextEntry;
            U32 index = HashPointer( entry->name ) % newTableSize;
            
            entry->nextEntry = newTableData[ index ];
            newTableData[ index ] = entry;
            
            entry = next;
         }
         
      // Switch the tables.
      
      delete[] hashTable->data;
      hashTable->data = newTableData;
      hashTable->size = newTableSize;
   }
   
   #ifdef DEBUG_SPEW
   Platform::outputDebugString( "[ConsoleInternal] Adding entry '%s'", name );
   #endif
   
   // Add the new entry.

   ret = hashTable->mChunker.alloc();
   constructInPlace( ret, name );
   U32 idx = HashPointer(name) % hashTable->size;
   ret->nextEntry = hashTable->data[idx];
   hashTable->data[idx] = ret;
   
   return ret;
}

// deleteVariables() assumes remove() is a stable remove (will not reorder entries on remove)
void Dictionary::remove(Dictionary::Entry *ent)
{
   Entry **walk = &hashTable->data[HashPointer(ent->name) % hashTable->size];
   while(*walk != ent)
      walk = &((*walk)->nextEntry);
      
   #ifdef DEBUG_SPEW
   Platform::outputDebugString( "[ConsoleInternal] Removing entry '%s'", ent->name );
   #endif

   *walk = (ent->nextEntry);

   destructInPlace( ent );
   hashTable->mChunker.free( ent );

   hashTable->count--;
}

Dictionary::Dictionary()
   :  hashTable( NULL ),
#pragma warning( disable : 4355 )
      ownHashTable( this ), // Warning with VC++ but this is safe.
#pragma warning( default : 4355 )
      exprState( NULL ),
      scopeName( NULL ),
      scopeNamespace( NULL ),
      code( NULL ),
      ip( 0 )
{
}

void Dictionary::setState(ExprEvalState *state, Dictionary* ref)
{
   exprState = state;
   
   if( ref )
   {
      hashTable = ref->hashTable;
      return;
   }

   if( !ownHashTable.data )
   {
      ownHashTable.count = 0;
      ownHashTable.size = ST_INIT_SIZE;
      ownHashTable.data = new Entry *[ ownHashTable.size ];
      
      dMemset( ownHashTable.data, 0, ownHashTable.size * sizeof( Entry* ) );
   }
   
   hashTable = &ownHashTable;
}

Dictionary::~Dictionary()
{
   reset();
   if( ownHashTable.data )
      delete [] ownHashTable.data;
}

void Dictionary::reset()
{
   if( hashTable && hashTable->owner != this )
   {
      hashTable = NULL;
      return;
   }
      
   for( U32 i = 0; i < ownHashTable.size; ++ i )
   {
      Entry* walk = ownHashTable.data[i];
      while( walk )
      {
         Entry* temp = walk->nextEntry;
         destructInPlace( walk );
         walk = temp;
      }
   }

   dMemset( ownHashTable.data, 0, ownHashTable.size * sizeof( Entry* ) );
   ownHashTable.mChunker.freeBlocks( true );
   
   ownHashTable.count = 0;
   hashTable = NULL;
   
   scopeName = NULL;
   scopeNamespace = NULL;
   code = NULL;
   ip = 0;
}


const char *Dictionary::tabComplete(const char *prevText, S32 baseLen, bool fForward)
{
   S32 i;

   const char *bestMatch = NULL;
   for(i = 0; i < hashTable->size; i++)
   {
      Entry *walk = hashTable->data[i];
      while(walk)
      {
         if(canTabComplete(prevText, bestMatch, walk->name, baseLen, fForward))
            bestMatch = walk->name;
         walk = walk->nextEntry;
      }
   }
   return bestMatch;
}


char *typeValueEmpty = "";

Dictionary::Entry::Entry(StringTableEntry in_name)
{
   name = in_name;
   value.type = ConsoleValue::TypeInternalString;
   notify = NULL;
   nextEntry = NULL;
   mUsage = NULL;
   mIsConstant = false;

   // NOTE: This is data inside a nameless
   // union, so we don't need to init the rest.
   value.init();
}

Dictionary::Entry::~Entry()
{
   value.cleanup();

   if ( notify )
      delete notify;
}

const char *Dictionary::getVariable(StringTableEntry name, bool *entValid)
{
   Entry *ent = lookup(name);
   if(ent)
   {
      if(entValid)
         *entValid = true;
      return ent->getStringValue();
   }
   if(entValid)
      *entValid = false;

   // Warn users when they access a variable that isn't defined.
   if(gWarnUndefinedScriptVariables)
      Con::warnf(" *** Accessed undefined variable '%s'", name);

   return "";
}

void ConsoleValue::setStringValue(const char * value)
{
   if (value == NULL) value = typeValueEmpty;

   if(type <= ConsoleValue::TypeInternalString)
   {
      // Let's not remove empty-string-valued global vars from the dict.
      // If we remove them, then they won't be exported, and sometimes
      // it could be necessary to export such a global.  There are very
      // few empty-string global vars so there's no performance-related
      // need to remove them from the dict.
/*
      if(!value[0] && name[0] == '$')
      {
         gEvalState.globalVars.remove(this);
         return;
      }
*/
	   if (value == typeValueEmpty)
      {
            if (sval && sval != typeValueEmpty && type != TypeInternalStackString) dFree(sval);
            sval = typeValueEmpty;
            bufferLen = 0;
            fval = 0.f;
            ival = 0;
            type = TypeInternalString;
            return;
      }

      U32 stringLen = dStrlen(value);

      // If it's longer than 256 bytes, it's certainly not a number.
      //
      // (This decision may come back to haunt you. Shame on you if it
      // does.)
      if(stringLen < 256)
      {
         fval = dAtof(value);
         ival = dAtoi(value);
      }
      else
      {
         fval = 0.f;
         ival = 0;
      }

      // may as well pad to the next cache line
      U32 newLen = ((stringLen + 1) + 15) & ~15;
	  
      if(sval == typeValueEmpty || type == TypeInternalStackString)
         sval = (char *) dMalloc(newLen);
      else if(newLen > bufferLen)
         sval = (char *) dRealloc(sval, newLen);

      type = TypeInternalString;

      bufferLen = newLen;
      dStrcpy(sval, value);
   }
   else
      Con::setData(type, dataPtr, 0, 1, &value, enumTable);      
}


void ConsoleValue::setStackStringValue(const char * value)
{
   if (value == NULL) value = typeValueEmpty;

   if(type <= ConsoleValue::TypeInternalString)
   {
	   if (value == typeValueEmpty)
      {
         if (sval && sval != typeValueEmpty && type != ConsoleValue::TypeInternalStackString) dFree(sval);
         sval = typeValueEmpty;
         bufferLen = 0;
         fval = 0.f;
         ival = 0;
         type = TypeInternalString;
         return;
      }

      U32 stringLen = dStrlen(value);
      if(stringLen < 256)
      {
         fval = dAtof(value);
         ival = dAtoi(value);
      }
      else
      {
         fval = 0.f;
         ival = 0;
      }

      type = TypeInternalStackString;
	  sval = (char*)value;
      bufferLen = stringLen;
   }
   else
      Con::setData(type, dataPtr, 0, 1, &value, enumTable);      
}


S32 Dictionary::getIntVariable(StringTableEntry name, bool *entValid)
{
   Entry *ent = lookup(name);
   if(ent)
   {
      if(entValid)
         *entValid = true;
      return ent->getIntValue();
   }

   if(entValid)
      *entValid = false;

    return 0;
}

F32 Dictionary::getFloatVariable(StringTableEntry name, bool *entValid)
{
   Entry *ent = lookup(name);
   if(ent)
   {
      if(entValid)
         *entValid = true;
      return ent->getFloatValue();
   }

   if(entValid)
      *entValid = false;

   return 0;
}

void Dictionary::setVariable(StringTableEntry name, const char *value)
{
   Entry *ent = add(name);
   if(!value)
      value = "";
   ent->setStringValue(value);
}

Dictionary::Entry* Dictionary::addVariable(  const char *name, 
                                             S32 type, 
                                             void *dataPtr, 
                                             const char* usage )
{
   AssertFatal( type >= 0, "Dictionary::addVariable - Got bad type!" );

   if(name[0] != '$')
   {
      scratchBuffer[0] = '$';
      dStrcpy(scratchBuffer + 1, name);
      name = scratchBuffer;
   }

   Entry *ent = add(StringTable->insert(name));
   
   if (  ent->value.type <= ConsoleValue::TypeInternalString &&
         ent->value.sval != typeValueEmpty && ent->value.type != ConsoleValue::TypeInternalStackString )
      dFree(ent->value.sval);

   ent->value.type = type;
   ent->value.dataPtr = dataPtr;
   ent->mUsage = usage;
   
   // Fetch enum table, if any.
   
   ConsoleBaseType* conType = ConsoleBaseType::getType( type );
   AssertFatal( conType, "Dictionary::addVariable - invalid console type" );
   ent->value.enumTable = conType->getEnumTable();
   
   return ent;
}

bool Dictionary::removeVariable(StringTableEntry name)
{
   if( Entry *ent = lookup(name) )
   {
      remove( ent );
      return true;
   }
   return false;
}

void Dictionary::addVariableNotify( const char *name, const Con::NotifyDelegate &callback )
{
   Entry *ent = lookup(StringTable->insert(name));
   if ( !ent )
    return;

   if ( !ent->notify )
      ent->notify = new Entry::NotifySignal();

   ent->notify->notify( callback );
}

void Dictionary::removeVariableNotify( const char *name, const Con::NotifyDelegate &callback )
{
   Entry *ent = lookup(StringTable->insert(name));
   if ( ent && ent->notify )
      ent->notify->remove( callback );
}

void Dictionary::validate()
{
   AssertFatal( ownHashTable.owner == this,
      "Dictionary::validate() - Dictionary not owner of own hashtable!" );
}

void ExprEvalState::pushFrame(StringTableEntry frameName, Namespace *ns)
{   
   #ifdef DEBUG_SPEW
   validate();

   Platform::outputDebugString( "[ConsoleInternal] Pushing new frame for '%s' at %i",
      frameName, mStackDepth );
   #endif
   
   if( mStackDepth + 1 > stack.size() )
   {
      #ifdef DEBUG_SPEW
      Platform::outputDebugString( "[ConsoleInternal] Growing stack by one frame" );
      #endif
      
      stack.push_back( new Dictionary );
   }
      
   Dictionary& newFrame = *( stack[ mStackDepth ] );
   newFrame.setState( this );
      
   newFrame.scopeName = frameName;
   newFrame.scopeNamespace = ns;

   mStackDepth ++;
   currentVariable = NULL;
   
   AssertFatal( !newFrame.getCount(), "ExprEvalState::pushFrame - Dictionary not empty!" );
   
   #ifdef DEBUG_SPEW
   validate();
   #endif
}

void ExprEvalState::popFrame()
{
   AssertFatal( mStackDepth > 0, "ExprEvalState::popFrame - Stack Underflow!" );
   
   #ifdef DEBUG_SPEW
   validate();
   
   Platform::outputDebugString( "[ConsoleInternal] Popping %sframe at %i",
      getCurrentFrame().isOwner() ? "" : "shared ", mStackDepth - 1 );
   #endif

   mStackDepth --;
   stack[ mStackDepth ]->reset();
   currentVariable = NULL;

   #ifdef DEBUG_SPEW
   validate();
   #endif
}

void ExprEvalState::pushFrameRef(S32 stackIndex)
{
   AssertFatal( stackIndex >= 0 && stackIndex < stack.size(), "You must be asking for a valid frame!" );

   #ifdef DEBUG_SPEW
   validate();
   
   Platform::outputDebugString( "[ConsoleInternal] Cloning frame from %i to %i",
      stackIndex, mStackDepth );
   #endif

   if( mStackDepth + 1 > stack.size() )
   {
      #ifdef DEBUG_SPEW
      Platform::outputDebugString( "[ConsoleInternal] Growing stack by one frame" );
      #endif
      
      stack.push_back( new Dictionary );
   }

   Dictionary& newFrame = *( stack[ mStackDepth ] );
   newFrame.setState( this, stack[ stackIndex ] );
   
   mStackDepth ++;
   currentVariable = NULL;
   
   #ifdef DEBUG_SPEW
   validate();
   #endif
}

ExprEvalState::ExprEvalState()
{
   VECTOR_SET_ASSOCIATION(stack);
   globalVars.setState(this);
   thisObject = NULL;
   traceOn = false;
   currentVariable = NULL;
   mStackDepth = 0;
   stack.reserve( 64 );
}

ExprEvalState::~ExprEvalState()
{
   // Delete callframes.
   
   while( !stack.empty() )
   {
      delete stack.last();
      stack.decrement();
   }
}

void ExprEvalState::validate()
{
   AssertFatal( mStackDepth <= stack.size(),
      "ExprEvalState::validate() - Stack depth pointing beyond last stack frame!" );
      
   for( U32 i = 0; i < stack.size(); ++ i )
      stack[ i ]->validate();
}

DefineEngineFunction(backtrace, void, ( ),,
   "@brief Prints the scripting call stack to the console log.\n\n"
   "Used to trace functions called from within functions. Can help discover what functions were called "
   "(and not yet exited) before the current point in scripts.\n\n"
   "@ingroup Debugging")
{
   U32 totalSize = 1;

   for(U32 i = 0; i < gEvalState.getStackDepth(); i++)
   {
      if(gEvalState.stack[i]->scopeNamespace && gEvalState.stack[i]->scopeNamespace->mEntryList->mPackage)  
         totalSize += dStrlen(gEvalState.stack[i]->scopeNamespace->mEntryList->mPackage) + 2;  
      if(gEvalState.stack[i]->scopeName)  
      totalSize += dStrlen(gEvalState.stack[i]->scopeName) + 3;
      if(gEvalState.stack[i]->scopeNamespace && gEvalState.stack[i]->scopeNamespace->mName)
         totalSize += dStrlen(gEvalState.stack[i]->scopeNamespace->mName) + 2;
   }

   char *buf = Con::getReturnBuffer(totalSize);
   buf[0] = 0;
   for(U32 i = 0; i < gEvalState.getStackDepth(); i++)
   {
      dStrcat(buf, "->");
      
      if(gEvalState.stack[i]->scopeNamespace && gEvalState.stack[i]->scopeNamespace->mEntryList->mPackage)  
      {  
         dStrcat(buf, "[");  
         dStrcat(buf, gEvalState.stack[i]->scopeNamespace->mEntryList->mPackage);  
         dStrcat(buf, "]");  
      }  
      if(gEvalState.stack[i]->scopeNamespace && gEvalState.stack[i]->scopeNamespace->mName)
      {
         dStrcat(buf, gEvalState.stack[i]->scopeNamespace->mName);
         dStrcat(buf, "::");
      }
      if(gEvalState.stack[i]->scopeName)  
         dStrcat(buf, gEvalState.stack[i]->scopeName);
   }

   Con::printf("BackTrace: %s", buf);
}

Namespace::Entry::Entry()
{
   mCode = NULL;
   mType = InvalidFunctionType;
   mUsage = NULL;
   mHeader = NULL;
   mNamespace = NULL;
}

void Namespace::Entry::clear()
{
   if(mCode)
   {
      mCode->decRefCount();
      mCode = NULL;
   }

   // Clean up usage strings generated for script functions.
   if( ( mType == Namespace::Entry::ConsoleFunctionType ) && mUsage )
   {
      delete mUsage;
      mUsage = NULL;
   }
}

Namespace::Namespace()
{
   mPackage = NULL;
   mUsage = NULL;
   mCleanUpUsage = false;
   mName = NULL;
   mParent = NULL;
   mNext = NULL;
   mEntryList = NULL;
   mHashSize = 0;
   mHashTable = 0;
   mHashSequence = 0;
   mRefCountToParent = 0;
   mClassRep = 0;
}

Namespace::~Namespace()
{
   clearEntries();
   if( mUsage && mCleanUpUsage )
   {
      delete mUsage;
      mUsage = NULL;
      mCleanUpUsage = false;
   }
}

void Namespace::clearEntries()
{
   for(Entry *walk = mEntryList; walk; walk = walk->mNext)
      walk->clear();
}

Namespace *Namespace::find(StringTableEntry name, StringTableEntry package)
{
   if ( name == NULL && package == NULL )
      return mGlobalNamespace;

   for(Namespace *walk = mNamespaceList; walk; walk = walk->mNext)
   {
      if(walk->mName == name && walk->mPackage == package)
         return walk;
   }

   Namespace *ret = (Namespace *) mAllocator.alloc(sizeof(Namespace));
   constructInPlace(ret);
   ret->mPackage = package;
   ret->mName = name;
   ret->mNext = mNamespaceList;
   mNamespaceList = ret;
   return ret;
}

bool Namespace::unlinkClass( Namespace *parent )
{
   AssertFatal( mPackage == NULL, "Namespace::unlinkClass - Must not be called on a namespace coming from a package!" );

   // Skip additions to this namespace coming from packages.

   Namespace* walk = getPackageRoot();

   // Make sure "parent" is the direct parent namespace.

   if( parent != NULL && walk->mParent && walk->mParent != parent )
   {
      Con::errorf(ConsoleLogEntry::General, "Namespace::unlinkClass - cannot unlink namespace parent linkage for %s for %s.",
         walk->mName, walk->mParent->mName);
      return false;
   }

   // Decrease the reference count.  Note that we do this on
   // the bottom-most namespace, i.e. the one guaranteed not 
   // to come from a package.

   mRefCountToParent --;
   AssertFatal( mRefCountToParent >= 0, "Namespace::unlinkClass - reference count to parent is less than 0" );

   // Unlink if the count dropped to zero.

   if( mRefCountToParent == 0 )
   {
      walk->mParent = NULL;
      trashCache();
   }

   return true;
}


bool Namespace::classLinkTo(Namespace *parent)
{
   Namespace* walk = getPackageRoot();

   if(walk->mParent && walk->mParent != parent)
   {
      Con::errorf(ConsoleLogEntry::General, "Error: cannot change namespace parent linkage of %s from %s to %s.",
         walk->mName, walk->mParent->mName, parent->mName);
      return false;
   }

   trashCache();
   walk->mParent = parent;

   mRefCountToParent++;

   return true;
}

void Namespace::buildHashTable()
{
   if(mHashSequence == mCacheSequence)
      return;

   if(!mEntryList && mParent)
   {
      mParent->buildHashTable();
      mHashTable = mParent->mHashTable;
      mHashSize = mParent->mHashSize;
      mHashSequence = mCacheSequence;
      return;
   }

   U32 entryCount = 0;
   Namespace * ns;
   for(ns = this; ns; ns = ns->mParent)
      for(Entry *walk = ns->mEntryList; walk; walk = walk->mNext)
         if(lookupRecursive(walk->mFunctionName) == walk)
            entryCount++;

   mHashSize = entryCount + (entryCount >> 1) + 1;

   if(!(mHashSize & 1))
      mHashSize++;

   mHashTable = (Entry **) mCacheAllocator.alloc(sizeof(Entry *) * mHashSize);
   for(U32 i = 0; i < mHashSize; i++)
      mHashTable[i] = NULL;

   for(ns = this; ns; ns = ns->mParent)
   {
      for(Entry *walk = ns->mEntryList; walk; walk = walk->mNext)
      {
         U32 index = HashPointer(walk->mFunctionName) % mHashSize;
         while(mHashTable[index] && mHashTable[index]->mFunctionName != walk->mFunctionName)
         {
            index++;
            if(index >= mHashSize)
               index = 0;
         }

         if(!mHashTable[index])
            mHashTable[index] = walk;
      }
   }

   mHashSequence = mCacheSequence;
}

void Namespace::getUniqueEntryLists( Namespace *other, VectorPtr<Entry *> *outThisList, VectorPtr<Entry *> *outOtherList )
{
   // All namespace entries in the common ACR should be
   // ignored when checking for duplicate entry names.
   static VectorPtr<Namespace::Entry *> commonEntries;
   commonEntries.clear();

   AbstractClassRep *commonACR = mClassRep->getCommonParent( other->mClassRep );
   commonACR->getNameSpace()->getEntryList( &commonEntries );

   // Make life easier
   VectorPtr<Namespace::Entry *> &thisEntries = *outThisList;
   VectorPtr<Namespace::Entry *> &compEntries = *outOtherList;

   // Clear, just in case they aren't
   thisEntries.clear();
   compEntries.clear();

   getEntryList( &thisEntries );
   other->getEntryList( &compEntries );

   // Run through all of the entries in the common ACR, and remove them from
   // the other two entry lists
   for( NamespaceEntryListIterator itr = commonEntries.begin(); itr != commonEntries.end(); itr++ )
   {
      // Check this entry list
      for( NamespaceEntryListIterator thisItr = thisEntries.begin(); thisItr != thisEntries.end(); thisItr++ )
      {
         if( *thisItr == *itr )
         {
            thisEntries.erase( thisItr );
            break;
         }
      }

      // Same check for component entry list
      for( NamespaceEntryListIterator compItr = compEntries.begin(); compItr != compEntries.end(); compItr++ )
      {
         if( *compItr == *itr )
         {
            compEntries.erase( compItr );
            break;
         }
      }
   }
}

void Namespace::init()
{
   // create the global namespace
   mGlobalNamespace = (Namespace *) mAllocator.alloc(sizeof(Namespace));
   constructInPlace(mGlobalNamespace);
   mGlobalNamespace->mPackage = NULL;
   mGlobalNamespace->mName = NULL;
   mGlobalNamespace->mNext = NULL;
   mNamespaceList = mGlobalNamespace;
}

Namespace *Namespace::global()
{
   return mGlobalNamespace;
}

void Namespace::shutdown()
{
   // The data chunker will release all memory in one go
   // without calling destructors, so we do this manually here.

   for(Namespace *walk = mNamespaceList; walk; walk = walk->mNext)
      walk->~Namespace();
}

void Namespace::trashCache()
{
   mCacheSequence++;
   mCacheAllocator.freeBlocks();
}

const char *Namespace::tabComplete(const char *prevText, S32 baseLen, bool fForward)
{
   if(mHashSequence != mCacheSequence)
      buildHashTable();

   const char *bestMatch = NULL;
   for(U32 i = 0; i < mHashSize; i++)
      if(mHashTable[i] && canTabComplete(prevText, bestMatch, mHashTable[i]->mFunctionName, baseLen, fForward))
         bestMatch = mHashTable[i]->mFunctionName;
   return bestMatch;
}

Namespace::Entry *Namespace::lookupRecursive(StringTableEntry name)
{
   for(Namespace *ns = this; ns; ns = ns->mParent)
      for(Entry *walk = ns->mEntryList; walk; walk = walk->mNext)
         if(walk->mFunctionName == name)
            return walk;

   return NULL;
}

Namespace::Entry *Namespace::lookup(StringTableEntry name)
{
   if(mHashSequence != mCacheSequence)
      buildHashTable();

   U32 index = HashPointer(name) % mHashSize;
   while(mHashTable[index] && mHashTable[index]->mFunctionName != name)
   {
      index++;
      if(index >= mHashSize)
         index = 0;
   }
   return mHashTable[index];
}

static S32 QSORT_CALLBACK compareEntries(const void* a,const void* b)
{
   const Namespace::Entry* fa = *((Namespace::Entry**)a);
   const Namespace::Entry* fb = *((Namespace::Entry**)b);

   return dStricmp(fa->mFunctionName, fb->mFunctionName);
}

void Namespace::getEntryList(VectorPtr<Entry *> *vec)
{
   if(mHashSequence != mCacheSequence)
      buildHashTable();

   for(U32 i = 0; i < mHashSize; i++)
      if(mHashTable[i])
         vec->push_back(mHashTable[i]);

   dQsort(vec->address(),vec->size(),sizeof(Namespace::Entry *),compareEntries);
}

Namespace::Entry *Namespace::createLocalEntry(StringTableEntry name)
{
   for(Entry *walk = mEntryList; walk; walk = walk->mNext)
   {
      if(walk->mFunctionName == name)
      {
         walk->clear();
         return walk;
      }
   }

   Entry *ent = (Entry *) mAllocator.alloc(sizeof(Entry));
   constructInPlace(ent);

   ent->mNamespace = this;
   ent->mFunctionName = name;
   ent->mNext = mEntryList;
   ent->mPackage = mPackage;
   ent->mToolOnly = false;
   mEntryList = ent;
   return ent;
}

void Namespace::addFunction( StringTableEntry name, CodeBlock *cb, U32 functionOffset, const char* usage, U32 lineNumber )
{
   Entry *ent = createLocalEntry(name);
   trashCache();

   ent->mUsage = usage;
   ent->mCode = cb;
   ent->mFunctionOffset = functionOffset;
   ent->mCode->incRefCount();
   ent->mType = Entry::ConsoleFunctionType;
   ent->mFunctionLineNumber = lineNumber;   
}

void Namespace::addCommand( StringTableEntry name, StringCallback cb, const char *usage, S32 minArgs, S32 maxArgs, bool isToolOnly, ConsoleFunctionHeader* header )
{
   Entry *ent = createLocalEntry(name);
   trashCache();

   ent->mUsage = usage;
   ent->mHeader = header;
   ent->mMinArgs = minArgs;
   ent->mMaxArgs = maxArgs;
   ent->mToolOnly = isToolOnly;

   ent->mType = Entry::StringCallbackType;
   ent->cb.mStringCallbackFunc = cb;
}

void Namespace::addCommand( StringTableEntry name, IntCallback cb, const char *usage, S32 minArgs, S32 maxArgs, bool isToolOnly, ConsoleFunctionHeader* header )
{
   Entry *ent = createLocalEntry(name);
   trashCache();

   ent->mUsage = usage;
   ent->mHeader = header;
   ent->mMinArgs = minArgs;
   ent->mMaxArgs = maxArgs;
   ent->mToolOnly = isToolOnly;

   ent->mType = Entry::IntCallbackType;
   ent->cb.mIntCallbackFunc = cb;
}

void Namespace::addCommand( StringTableEntry name, VoidCallback cb, const char *usage, S32 minArgs, S32 maxArgs, bool isToolOnly, ConsoleFunctionHeader* header )
{
   Entry *ent = createLocalEntry(name);
   trashCache();

   ent->mUsage = usage;
   ent->mHeader = header;
   ent->mMinArgs = minArgs;
   ent->mMaxArgs = maxArgs;
   ent->mToolOnly = isToolOnly;

   ent->mType = Entry::VoidCallbackType;
   ent->cb.mVoidCallbackFunc = cb;
}

void Namespace::addCommand( StringTableEntry name, FloatCallback cb, const char *usage, S32 minArgs, S32 maxArgs, bool isToolOnly, ConsoleFunctionHeader* header )
{
   Entry *ent = createLocalEntry(name);
   trashCache();

   ent->mUsage = usage;
   ent->mHeader = header;
   ent->mMinArgs = minArgs;
   ent->mMaxArgs = maxArgs;
   ent->mToolOnly = isToolOnly;

   ent->mType = Entry::FloatCallbackType;
   ent->cb.mFloatCallbackFunc = cb;
}

void Namespace::addCommand( StringTableEntry name, BoolCallback cb, const char *usage, S32 minArgs, S32 maxArgs, bool isToolOnly, ConsoleFunctionHeader* header )
{
   Entry *ent = createLocalEntry(name);
   trashCache();

   ent->mUsage = usage;
   ent->mHeader = header;
   ent->mMinArgs = minArgs;
   ent->mMaxArgs = maxArgs;
   ent->mToolOnly = isToolOnly;

   ent->mType = Entry::BoolCallbackType;
   ent->cb.mBoolCallbackFunc = cb;
}

void Namespace::addScriptCallback( const char *funcName, const char *usage, ConsoleFunctionHeader* header )
{
   static U32 uid=0;
   char buffer[1024];
   char lilBuffer[32];
   dStrcpy(buffer, funcName);
   dSprintf(lilBuffer, 32, "_%d_cb", uid++);
   dStrcat(buffer, lilBuffer);

   Entry *ent = createLocalEntry(StringTable->insert( buffer ));
   trashCache();

   ent->mUsage = usage;
   ent->mHeader = header;
   ent->mMinArgs = -2;
   ent->mMaxArgs = -3;

   ent->mType = Entry::ScriptCallbackType;
   ent->cb.mCallbackName = funcName;
}

void Namespace::markGroup(const char* name, const char* usage)
{
   static U32 uid=0;
   char buffer[1024];
   char lilBuffer[32];
   dStrcpy(buffer, name);
   dSprintf(lilBuffer, 32, "_%d", uid++);
   dStrcat(buffer, lilBuffer);

   Entry *ent = createLocalEntry(StringTable->insert( buffer ));
   trashCache();

   if(usage != NULL)
      lastUsage = (char*)(ent->mUsage = usage);
   else
      ent->mUsage = lastUsage;

   ent->mMinArgs = -1; // Make sure it explodes if somehow we run this entry.
   ent->mMaxArgs = -2;

   ent->mType = Entry::GroupMarker;
   ent->cb.mGroupName = name;
}

extern S32 executeBlock(StmtNode *block, ExprEvalState *state);

const char *Namespace::Entry::execute(S32 argc, ConsoleValueRef *argv, ExprEvalState *state)
{
   if(mType == ConsoleFunctionType)
   {
      if(mFunctionOffset)
         return mCode->exec(mFunctionOffset, argv[0], mNamespace, argc, argv, false, mPackage);
      else
         return "";
   }

#ifndef TORQUE_DEBUG
   // [tom, 12/13/2006] This stops tools functions from working in the console,
   // which is useful behavior when debugging so I'm ifdefing this out for debug builds.
   if(mToolOnly && ! Con::isCurrentScriptToolScript())
   {
      Con::errorf(ConsoleLogEntry::Script, "%s::%s - attempting to call tools only function from outside of tools", mNamespace->mName, mFunctionName);
      return "";
   }
#endif

   if((mMinArgs && argc < mMinArgs) || (mMaxArgs && argc > mMaxArgs))
   {
      Con::warnf(ConsoleLogEntry::Script, "%s::%s - wrong number of arguments.", mNamespace->mName, mFunctionName);
      Con::warnf(ConsoleLogEntry::Script, "usage: %s", mUsage);
      return "";
   }

   static char returnBuffer[32];
   switch(mType)
   {
      case StringCallbackType:
         return cb.mStringCallbackFunc(state->thisObject, argc, argv);
      case IntCallbackType:
         dSprintf(returnBuffer, sizeof(returnBuffer), "%d",
            cb.mIntCallbackFunc(state->thisObject, argc, argv));
         return returnBuffer;
      case FloatCallbackType:
         dSprintf(returnBuffer, sizeof(returnBuffer), "%g",
            cb.mFloatCallbackFunc(state->thisObject, argc, argv));
         return returnBuffer;
      case VoidCallbackType:
         cb.mVoidCallbackFunc(state->thisObject, argc, argv);
         return "";
      case BoolCallbackType:
         dSprintf(returnBuffer, sizeof(returnBuffer), "%d",
            (U32)cb.mBoolCallbackFunc(state->thisObject, argc, argv));
         return returnBuffer;
   }

   return "";
}

//-----------------------------------------------------------------------------
// Doc string code.

namespace {

   /// Scan the given usage string for an argument list description.  With the
   /// old console macros, these were usually included as the first part of the
   /// usage string.
   bool sFindArgumentListSubstring( const char* usage, const char*& start, const char*& end )
   {
      if( !usage )
         return false;
         
      const char* ptr = usage;
      while( *ptr && *ptr != '(' && *ptr != '\n' ) // Only scan first line of usage string.
      {
         // Stop on the first alphanumeric character as we expect
         // argument lists to precede descriptions.
         if( dIsalnum( *ptr ) )
            return false;
            
         ptr ++;
      }
         
      if( *ptr != '(' )
         return false;

      start = ptr;
      ptr ++;
      
      bool inString = false;
      U32 nestingCount = 0;
      
      while( *ptr && ( *ptr != ')' || nestingCount > 0 || inString ) )
      {
         if( *ptr == '(' )
            nestingCount ++;
         else if( *ptr == ')' )
            nestingCount --;
         else if( *ptr == '"' )
            inString = !inString;
         else if( *ptr == '\\' && ptr[ 1 ] == '"' )
            ptr ++;
         ptr ++;
      }
      
      if( *ptr )
         ptr ++;
      end = ptr;
      
      return true;
   }
   
   ///
   void sParseList( const char* str, Vector< String >& outList )
   {
      // Skip the initial '( '.
      
      const char* ptr = str;
      while( *ptr && dIsspace( *ptr ) )
         ptr ++;
      
      if( *ptr == '(' )
      {
         ptr ++;
         while( *ptr && dIsspace( *ptr ) )
            ptr ++;
      }
      
      // Parse out list items.
      
      while( *ptr && *ptr != ')' )
      {
         // Find end of element.
         
         const char* start = ptr;

         bool inString = false;
         U32 nestingCount = 0;

         while( *ptr && ( ( *ptr != ')' && *ptr != ',' ) || nestingCount > 0 || inString ) )
         {
            if( *ptr == '(' )
               nestingCount ++;
            else if( *ptr == ')' )
               nestingCount --;
            else if( *ptr == '"' )
               inString = !inString;
            else if( *ptr == '\\' && ptr[ 1 ] == '"' )
               ptr ++;
            ptr ++;
         }
            
         // Backtrack to remove trailing whitespace.
            
         const char* end = ptr;
         if( *end == ',' || *end == ')' )
            end --;
         while( end > start && dIsspace( *end ) )
            end --;
         if( *end )
            end ++;
            
         // Add to list.
            
         if( start != end )
            outList.push_back( String( start, end - start ) );
            
         // Skip comma and whitespace.
         
         if( *ptr == ',' )
            ptr ++;
         while( *ptr && dIsspace( *ptr ) )
            ptr ++;
      }
   }
   
   ///
   void sGetArgNameAndType( const String& str, String& outType, String& outName )
   {
      if( !str.length() )
      {
         outType = String::EmptyString;
         outName = String::EmptyString;
         return;
      }
      
      // Find first non-ID character from right.
      
      S32 index = str.length() - 1;
      while( index >= 0 && ( dIsalnum( str[ index ] ) || str[ index ] == '_' ) )
         index --;
         
      const U32 nameStartIndex = index + 1;
      
      // Find end of type name by skipping rightmost whitespace inwards.
      
      while( index >= 0 && dIsspace( str[ index ] ) )
         index --;
         
      //
      
      outName = String( &( ( const char* ) str )[ nameStartIndex ] );
      outType = String( str, index + 1 );
   }
   
   /// Return the type name to show in documentation for the given C++ type.
   const char* sGetDocTypeString( const char* nativeType )
   {
      if( dStrncmp( nativeType, "const ", 6 ) == 0 )
         nativeType += 6;

      if( dStrcmp( nativeType, "char*" ) == 0 || dStrcmp( nativeType, "char *" ) == 0 )
         return "string";
      else if( dStrcmp( nativeType, "S32" ) == 0 || dStrcmp( nativeType, "U32" ) == 0 )
         return "int";
      else if( dStrcmp( nativeType, "F32" ) == 0 )
         return "float";
         
      const U32 length = dStrlen( nativeType );
      if( nativeType[ length - 1 ] == '&' || nativeType[ length - 1 ] == '*' )
         return StringTable->insertn( nativeType, length - 1 );
         
      return nativeType;
   }
}

String Namespace::Entry::getBriefDescription( String* outRemainingDocText ) const
{
   String docString = getDocString();
   
   S32 newline = docString.find( '\n' );
   if( newline == -1 )
   {
      if( outRemainingDocText )
         *outRemainingDocText = String();
      return docString;
   }
      
   String brief = docString.substr( 0, newline );
   if( outRemainingDocText )
      *outRemainingDocText = docString.substr( newline + 1 );
      
   return brief;
}

String Namespace::Entry::getDocString() const
{
   const char* argListStart;
   const char* argListEnd;
   
   if( sFindArgumentListSubstring( mUsage, argListStart, argListEnd ) )
   {
      // Skip the " - " part present in some old doc strings.
      
      const char* ptr = argListEnd;
      while( *ptr && dIsspace( *ptr ) )
         ptr ++;
         
      if( *ptr == '-' )
      {
         ptr ++;
         while( *ptr && dIsspace( *ptr ) )
            ptr ++;
      }
      
      return ptr;
   }
   
   return mUsage;
}

String Namespace::Entry::getArgumentsString() const
{
   StringBuilder str;
   
   if( mHeader )
   {
      // Parse out the argument list string supplied with the extended
      // function header and add default arguments as we go.
      
      Vector< String > argList;
      Vector< String > defaultArgList;
      
      sParseList( mHeader->mArgString, argList );
      sParseList( mHeader->mDefaultArgString, defaultArgList );
      
      str.append( '(' );
      
      const U32 numArgs = argList.size();
      const U32 numDefaultArgs = defaultArgList.size();
      const U32 firstDefaultArgIndex = numArgs - numDefaultArgs;
      
      for( U32 i = 0; i < numArgs; ++ i )
      {
         // Add separator if not first arg.
         
         if( i > 0 )
            str.append( ',' );
                     
         // Add type and name.
         
         String name;
         String type;
         
         sGetArgNameAndType( argList[ i ], type, name );
         
         str.append( ' ' );
         str.append( sGetDocTypeString( type ) );
         str.append( ' ' );
         str.append( name );
         
         // Add default value, if any.
         
         if( i >= firstDefaultArgIndex )
         {
            str.append( '=' );
            str.append( defaultArgList[ i - firstDefaultArgIndex ] );
         }
      }
      
      if( numArgs > 0 )
         str.append( ' ' );
      str.append( ')' );
   }
   else
   {
      // No extended function header.  Try to parse out the argument
      // list from the usage string.
      
      const char* argListStart;
      const char* argListEnd;
      
      if( sFindArgumentListSubstring( mUsage, argListStart, argListEnd ) )
         str.append( argListStart, argListEnd - argListStart );
      else if( mType == ConsoleFunctionType && mCode )
      {
         // This isn't correct but the nonsense console stuff is set up such that all
         // functions that have no function bodies are keyed to offset 0 to indicate "no code."
         // This loses the association with the original function definition so we can't really
         // tell here what the actual prototype is except if we searched though the entire opcode
         // stream for the corresponding OP_FUNC_DECL (which would require dealing with the
         // variable-size instructions).
         
         if( !mFunctionOffset )
            return "()";
            
         String args = mCode->getFunctionArgs( mFunctionOffset );
         if( args.isEmpty() )
            return "()";
            
         str.append( "( " );
         str.append( args );
         str.append( " )" );
      }
   }
   
   return str.end();
}

String Namespace::Entry::getPrototypeString() const
{
   StringBuilder str;
   
   // Start with return type.
   
   if( mHeader && mHeader->mReturnString )
   {
      str.append( sGetDocTypeString( mHeader->mReturnString ) );
      str.append( ' ' );
   }
   else
      switch( mType )
      {
         case StringCallbackType:
            str.append( "string " );
            break;
            
         case IntCallbackType:
            str.append( "int " );
            break;

         case FloatCallbackType:
            str.append( "float " );
            break;

         case VoidCallbackType:
            str.append( "void " );
            break;

         case BoolCallbackType:
            str.append( "bool " );
            break;
            
         case ScriptCallbackType:
            break;
      }
   
   // Add function name and arguments.

   if( mType == ScriptCallbackType )
      str.append( cb.mCallbackName );
   else
      str.append( mFunctionName );
      
   str.append( getArgumentsString() );
      
   return str.end();
}

//-----------------------------------------------------------------------------

StringTableEntry Namespace::mActivePackages[Namespace::MaxActivePackages];
U32 Namespace::mNumActivePackages = 0;
U32 Namespace::mOldNumActivePackages = 0;

bool Namespace::isPackage(StringTableEntry name)
{
   for(Namespace *walk = mNamespaceList; walk; walk = walk->mNext)
      if(walk->mPackage == name)
         return true;
   return false;
}

U32 Namespace::getActivePackagesCount()
{
   return mNumActivePackages;
}

StringTableEntry Namespace::getActivePackage(U32 index)
{
   if( index >= mNumActivePackages )
      return StringTable->EmptyString();

   return mActivePackages[index];
}

void Namespace::activatePackage(StringTableEntry name)
{
   if(mNumActivePackages == MaxActivePackages)
   {
      Con::printf("ActivatePackage(%s) failed - Max package limit reached: %d", name, MaxActivePackages);
      return;
   }
   if(!name)
      return;

   // see if this one's already active
   for(U32 i = 0; i < mNumActivePackages; i++)
      if(mActivePackages[i] == name)
         return;

   // kill the cache
   trashCache();

   // find all the package namespaces...
   for(Namespace *walk = mNamespaceList; walk; walk = walk->mNext)
   {
      if(walk->mPackage == name)
      {
         Namespace *parent = Namespace::find(walk->mName);
         // hook the parent
         walk->mParent = parent->mParent;
         parent->mParent = walk;

         // now swap the entries:
         Entry *ew;
         for(ew = parent->mEntryList; ew; ew = ew->mNext)
            ew->mNamespace = walk;

         for(ew = walk->mEntryList; ew; ew = ew->mNext)
            ew->mNamespace = parent;

         ew = walk->mEntryList;
         walk->mEntryList = parent->mEntryList;
         parent->mEntryList = ew;
      }
   }
   mActivePackages[mNumActivePackages++] = name;
}

void Namespace::deactivatePackage(StringTableEntry name)
{
   U32 oldNumActivePackages = mNumActivePackages;

   // Remove all packages down to the given one
   deactivatePackageStack( name );

   // Now add back all packages that followed the given one
   if(!oldNumActivePackages)
      return;
   for(U32 i = mNumActivePackages+1; i < oldNumActivePackages; i++)
      activatePackage(mActivePackages[i]);
}

void Namespace::deactivatePackageStack(StringTableEntry name)
{
   S32 i, j;
   for(i = 0; i < mNumActivePackages; i++)
      if(mActivePackages[i] == name)
         break;
   if(i == mNumActivePackages)
      return;

   trashCache();

   // Remove all packages down to the given one
   for(j = mNumActivePackages - 1; j >= i; j--)
   {
      // gotta unlink em in reverse order...
      for(Namespace *walk = mNamespaceList; walk; walk = walk->mNext)
      {
         if(walk->mPackage == mActivePackages[j])
         {
            Namespace *parent = Namespace::find(walk->mName);
            // hook the parent
            parent->mParent = walk->mParent;
            walk->mParent = NULL;

            // now swap the entries:
            Entry *ew;
            for(ew = parent->mEntryList; ew; ew = ew->mNext)
               ew->mNamespace = walk;

            for(ew = walk->mEntryList; ew; ew = ew->mNext)
               ew->mNamespace = parent;

            ew = walk->mEntryList;
            walk->mEntryList = parent->mEntryList;
            parent->mEntryList = ew;
         }
      }
   }
   mNumActivePackages = i;
}

void Namespace::unlinkPackages()
{
   mOldNumActivePackages = mNumActivePackages;
   if(!mNumActivePackages)
      return;
   deactivatePackageStack(mActivePackages[0]);
}

void Namespace::relinkPackages()
{
   if(!mOldNumActivePackages)
      return;
   for(U32 i = 0; i < mOldNumActivePackages; i++)
      activatePackage(mActivePackages[i]);
}


DefineEngineFunction(isPackage, bool, ( String identifier ),,
   "@brief Returns true if the identifier is the name of a declared package.\n\n"
   "@ingroup Packages\n")
{
   StringTableEntry name = StringTable->insert(identifier.c_str());
   return Namespace::isPackage(name);
}

DefineEngineFunction(activatePackage, void, ( String packageName ),,
   "@brief Activates an existing package.\n\n"
   "The activation occurs by updating the namespace linkage of existing functions and methods. "
   "If the package is already activated the function does nothing.\n"
   "@ingroup Packages\n")
{
   StringTableEntry name = StringTable->insert(packageName.c_str());
   Namespace::activatePackage(name);
}

DefineEngineFunction(deactivatePackage, void, ( String packageName ),,
   "@brief Deactivates a previously activated package.\n\n"
   "The package is deactivated by removing its namespace linkages to any function or method. "
   "If there are any packages above this one in the stack they are deactivated as well. "
   "If the package is not on the stack this function does nothing.\n"
   "@ingroup Packages\n")
{
   StringTableEntry name = StringTable->insert(packageName.c_str());
   Namespace::deactivatePackage(name);
}

DefineEngineFunction(getPackageList, const char*, (),,
   "@brief Returns a space delimited list of the active packages in stack order.\n\n"
   "@ingroup Packages\n")
{
   if( Namespace::getActivePackagesCount() == 0 )
      return "";

   // Determine size of return buffer
   dsize_t buffersize = 0;
   for( U32 i = 0; i < Namespace::getActivePackagesCount(); ++i )
   {
      buffersize += dStrlen(Namespace::getActivePackage(i)) + 1;
   }

   U32 maxBufferSize = buffersize + 1;
   char* returnBuffer = Con::getReturnBuffer(maxBufferSize);
   U32 returnLen = 0;
   for( U32 i = 0; i < Namespace::getActivePackagesCount(); ++i )
   {
      dSprintf(returnBuffer + returnLen, maxBufferSize - returnLen, "%s ", Namespace::getActivePackage(i));
      returnLen = dStrlen(returnBuffer);
   }

   // Trim off the last extra space
   if (returnLen > 0 && returnBuffer[returnLen - 1] == ' ')
      returnBuffer[returnLen - 1] = '\0';

   return returnBuffer;
}