classfun.c

一套美国国家宇航局人工智能中心NASA的专家系统工具源代码

     }
  }
  
#endif

#if (! BLOAD_ONLY) && (! RUN_TIME)

/***************************************************
  NAME         : IsClassBeingUsed
  DESCRIPTION  : Checks the busy flag of a class
                   and ALL classes that inherit from
                   it to make sure that it is not
                   in use before deletion
  INPUTS       : The class
  RETURNS      : CLIPS_TRUE if in use, CLIPS_FALSE otherwise
  SIDE EFFECTS : None
  NOTES        : Recursively examines all subclasses
 ***************************************************/
globle int IsClassBeingUsed(cls)
  DEFCLASS *cls;
  {
   register unsigned i;
   
   if (cls->busy > 0)
     return(CLIPS_TRUE);
   for (i = 0 ; i < cls->directSubclasses.classCount ; i++)
     if (IsClassBeingUsed(cls->directSubclasses.classArray[i]))
       return(CLIPS_TRUE);
   return(CLIPS_FALSE);
  }
  
/***************************************************
  NAME         : RemoveAllUserClasses
  DESCRIPTION  : Removes all classes
  INPUTS       : None
  RETURNS      : CLIPS_TRUE if succesful, CLIPS_FALSE otherwise
  SIDE EFFECTS : The class hash table is cleared
  NOTES        : None
 ***************************************************/
globle int RemoveAllUserClasses()
  {
   VOID *userClasses,*ctmp;
   int success = CLIPS_TRUE;
   
#if BLOAD || BLOAD_AND_BSAVE
   if (Bloaded())
     return(CLIPS_FALSE);
#endif   
   /* ====================================================
      Don't delete built-in system classes at head of list
      ==================================================== */
   userClasses = GetNextDefclass(NULL);
   while (userClasses != NULL)
     {
      if (((DEFCLASS *) userClasses)->system == 0)
        break;
      userClasses = GetNextDefclass(userClasses);
     }
   while (userClasses != NULL)
     {
      ctmp = userClasses;
      userClasses = GetNextDefclass(userClasses);
      if (IsDefclassDeletable(ctmp))
        {
         RemoveConstructFromModule((struct constructHeader *) ctmp);
         RemoveDefclass(ctmp);
        }
      else
        {
         success = CLIPS_FALSE;
         CantDeleteItemErrorMessage("defclass",GetDefclassName(ctmp));
        }
     }
   return(success);
  }
  
/****************************************************
  NAME         : DeleteClassUAG
  DESCRIPTION  : Deallocates a class and all its 
                 subclasses
  INPUTS       : The address of the class
  RETURNS      : 1 if successful, 0 otherwise
  SIDE EFFECTS : Removes the class from each of
                 its superclasses' subclass lists
  NOTES        : None
 ****************************************************/
globle int DeleteClassUAG(cls)
  DEFCLASS *cls;
  {
   unsigned subCount;
   
   while (cls->directSubclasses.classCount != 0)
     {
      subCount = cls->directSubclasses.classCount;
      DeleteClassUAG(cls->directSubclasses.classArray[0]);
      if (cls->directSubclasses.classCount == subCount)
        return(CLIPS_FALSE);
     }
   if (IsDefclassDeletable((VOID *) cls))
     {
      RemoveConstructFromModule((struct constructHeader *) cls);
      RemoveDefclass((VOID *) cls);
      return(CLIPS_TRUE);
     }
   return(CLIPS_FALSE);
  }

/*********************************************************
  NAME         : MarkBitMapSubclasses
  DESCRIPTION  : Recursively marks the ids of a class
                 and all its subclasses in a bitmap
  INPUTS       : 1) The bitmap
                 2) The class
                 3) A code indicating whether to set
                    or clear the bits of the map
                    corresponding to the class ids
  RETURNS      : Nothing useful
  SIDE EFFECTS : BitMap marked
  NOTES        : IMPORTANT!!!!  Assumes the bitmap is
                 large enough to hold all ids encountered!
 *********************************************************/
globle VOID MarkBitMapSubclasses(map,cls,set)
  char *map;
  DEFCLASS *cls;
  int set;
  {
   register unsigned i;
   
   if (set)
     SetBitMap(map,cls->id);
   else
     ClearBitMap(map,cls->id);
   for (i = 0 ; i < cls->directSubclasses.classCount ; i++)
     MarkBitMapSubclasses(map,cls->directSubclasses.classArray[i],set);
  }
  
#endif

/***************************************************
  NAME         : FindSlotNameID
  DESCRIPTION  : Finds the id of a slot name
  INPUTS       : The slot name
  RETURNS      : The slot name id (-1 if not found)
  SIDE EFFECTS : None
  NOTES        : A slot name always has the same
                 id regardless of what class uses
                 it.  In this way, a slot can
                 be referred to by index independent
                 of class.  Each class stores a
                 map showing which slot name indices
                 go to which slot.  This provides
                 for immediate lookup of slots
                 given the index (object pattern
                 matching uses this).
 ***************************************************/
globle int FindSlotNameID(slotName)
  SYMBOL_HN *slotName;
  {
   SLOT_NAME *snp;
   
   snp = SlotNameTable[HashSlotName(slotName)];
   while ((snp != NULL) ? (snp->name != slotName) : CLIPS_FALSE)
     snp = snp->nxt;
   return((snp != NULL) ? (int) snp->id : -1);
  }

/***************************************************
  NAME         : FindIDSlotName
  DESCRIPTION  : Finds the slot anme for an id
  INPUTS       : The id
  RETURNS      : The slot name (NULL if not found)
  SIDE EFFECTS : None
  NOTES        : None
 ***************************************************/
globle SYMBOL_HN *FindIDSlotName(id)
  unsigned id;
  {
   SLOT_NAME *snp;
   
   snp = FindIDSlotNameHash(id);
   return((snp != NULL) ? snp->name : NULL);
  }
  
/***************************************************
  NAME         : FindIDSlotNameHash
  DESCRIPTION  : Finds the slot anme for an id
  INPUTS       : The id
  RETURNS      : The slot name (NULL if not found)
  SIDE EFFECTS : None
  NOTES        : None
 ***************************************************/
globle SLOT_NAME *FindIDSlotNameHash(id)
  unsigned id;
  {
   register int i;
   SLOT_NAME *snp;
   
   for (i = 0 ; i < SLOT_NAME_TABLE_HASH_SIZE ; i++)
     {
      snp = SlotNameTable[i];
      while (snp != NULL)
        {
         if (snp->id == id)
           return(snp);
         snp = snp->nxt;
        }
     }
   return(NULL);
  }
  
/***************************************************
  NAME         : GetTraversalID
  DESCRIPTION  : Returns a unique integer ID for a
                  traversal into the class hierarchy
  INPUTS       : None
  RETURNS      : The id, or -1 if none available
  SIDE EFFECTS : EvaluationError set when no ids
                   available
  NOTES        : Used for recursive traversals of
                  class hierarchy to assure that a
                  class is only visited once
 ***************************************************/
globle int GetTraversalID()
  {
   register unsigned i;
   register DEFCLASS *cls;
   
   if (CTID >= MAX_TRAVERSALS)
     {
      PrintErrorID("CLASSFUN",2,CLIPS_FALSE);
      PrintCLIPS(WERROR,"Maximum number of simultaneous class hierarchy\n  traversals exceeded ");
      PrintLongInteger(WERROR,(long) MAX_TRAVERSALS);
      PrintCLIPS(WERROR,".\n");
      SetEvaluationError(CLIPS_TRUE);
      return(-1);
     }
     
   for (i = 0 ; i < CLASS_TABLE_HASH_SIZE ; i++)
     for (cls = ClassTable[i] ; cls != NULL ; cls = cls->nxtHash)
       ClearTraversalID(cls->traversalRecord,CTID);
   return(CTID++);
  }
  
/***************************************************
  NAME         : ReleaseTraversalID
  DESCRIPTION  : Releases an ID for future use
                 Also clears id from all classes
  INPUTS       : None
  RETURNS      : Nothing useful
  SIDE EFFECTS : Old ID released for later reuse
  NOTES        : Releases ID returned by most recent
                   call to GetTraversalID()
 ***************************************************/
globle VOID ReleaseTraversalID()
  {
   CTID--;
  }
  
/*******************************************************
  NAME         : HashClass
  DESCRIPTION  : Generates a hash index for a given
                 class name
  INPUTS       : The address of the class name SYMBOL_HN
  RETURNS      : The hash index value
  SIDE EFFECTS : None 
  NOTES        : Counts on the fact that the symbol
                 has already been hashed into the CLIPS
                 symbol table - uses that hash value
                 multiplied by a prime for a new hash
 *******************************************************/
globle unsigned HashClass(cname)
  SYMBOL_HN *cname;
  {
   unsigned long tally;
   
   tally = ((unsigned long) cname->bucket) * BIG_PRIME;
   return((unsigned) (tally % CLASS_TABLE_HASH_SIZE));
  }

/* =========================================
   *****************************************
          INTERNALLY VISIBLE FUNCTIONS
   =========================================
   ***************************************** */

/*******************************************************
  NAME         : HashSlotName
  DESCRIPTION  : Generates a hash index for a given
                 slot name
  INPUTS       : The address of the slot name SYMBOL_HN
  RETURNS      : The hash index value
  SIDE EFFECTS : None 
  NOTES        : Counts on the fact that the symbol
                 has already been hashed into the CLIPS
                 symbol table - uses that hash value
                 multiplied by a prime for a new hash
 *******************************************************/
static unsigned HashSlotName(sname)
  SYMBOL_HN *sname;
  {
   unsigned long tally;
   
   tally = ((unsigned long) sname->bucket) * BIG_PRIME;
   return((unsigned) (tally % SLOT_NAME_TABLE_HASH_SIZE));
  }

#if (! RUN_TIME)

/***********************************************
  NAME         : NewSlotNameID
  DESCRIPTION  : Returns  an unused slot name id
                 as close to 1 as possible
  INPUTS       : None
  RETURNS      : The new unused id
  SIDE EFFECTS : None
  NOTES        : None
 ***********************************************/
static unsigned NewSlotNameID()
  {
   unsigned newid = 0;
   register unsigned i;
   SLOT_NAME *snp;
   
   while (CLIPS_TRUE)
     {
      for (i = 0 ; i < SLOT_NAME_TABLE_HASH_SIZE ; i++)
        {
         snp = SlotNameTable[i];
         while ((snp != NULL) ? (snp->id != newid) : CLIPS_FALSE)
           snp = snp->nxt;
         if (snp != NULL)
           break;
        }
      if (i < SLOT_NAME_TABLE_HASH_SIZE)
        newid++;
      else
        break;
     }
   return(newid);
  }
    
/***************************************************
  NAME         : DeassignClassID
  DESCRIPTION  : Reduces id map and MaxClassID if
                 no ids in use above the one being
                 released.
  INPUTS       : The id
  RETURNS      : Nothing useful
  SIDE EFFECTS : ID map and MaxClassID possibly
                 reduced
  NOTES        : None
 ***************************************************/
static VOID DeassignClassID(id)
  unsigned id;
  {
   register unsigned i;
   int reallocReqd;
   unsigned oldChunk,newChunk;
      
   ClassIDMap[id] = NULL;
   for (i = id + 1 ; i < MaxClassID ; i++)
     if (ClassIDMap[i] != NULL)
       return;
   reallocReqd = CLIPS_FALSE;
   while (ClassIDMap[id] == NULL)
     {
      MaxClassID = (unsigned short) id;
      if ((MaxClassID % CLASS_ID_MAP_CHUNK) == 0)
        {
         newChunk = MaxClassID;
         if (reallocReqd == CLIPS_FALSE)
           {
            oldChunk = MaxClassID + CLASS_ID_MAP_CHUNK;
            reallocReqd = CLIPS_TRUE;
           }
        }
      if (id == 0)
        break;
      id--;
     }
   if (reallocReqd)
     ClassIDMap = (DEFCLASS **) genrealloc((VOID *) ClassIDMap,
                      (unsigned) (oldChunk * sizeof(DEFCLASS *)),
                      (unsigned) (newChunk * sizeof(DEFCLASS *)));
  }
  
#endif

#endif

/***************************************************
  NAME         : 
  DESCRIPTION  : 
  INPUTS       : 
  RETURNS      : 
  SIDE EFFECTS : 
  NOTES        : 
 ***************************************************/