symbol.c

clips源代码

   /*******************************************************/
   /*      "C" Language Integrated Production System      */
   /*                                                     */
   /*             CLIPS Version 6.24  06/05/06            */
   /*                                                     */
   /*                    SYMBOL MODULE                    */
   /*******************************************************/

/*************************************************************/
/* Purpose: Manages the atomic data value hash tables for    */
/*   storing symbols, integers, floats, and bit maps.        */
/*   Contains routines for adding entries, examining the     */
/*   hash tables, and performing garbage collection to       */
/*   remove entries no longer in use.                        */
/*                                                           */
/* Principal Programmer(s):                                  */
/*      Gary D. Riley                                        */
/*                                                           */
/* Contributing Programmer(s):                               */
/*      Brian L. Donnell                                     */
/*                                                           */
/* Revision History:                                         */
/*      6.23: Correction for FalseSymbol/TrueSymbol. DR0859  */
/*                                                           */
/*      6.24: CLIPS crashing on AMD64 processor in the       */
/*            function used to generate a hash value for     */
/*            integers. DR0871                               */
/*                                                           */
/*            Support for run-time programs directly passing */
/*            the hash tables for initialization.            */
/*                                                           */
/*            Corrected code generating compilation          */
/*            warnings.                                      */
/*                                                           */
/*************************************************************/

#define _SYMBOL_SOURCE_
                                                                                
#include <stdio.h>
#define _STDIO_INCLUDED_
#include <stdlib.h>
#include <string.h>

#include "setup.h"

#include "constant.h"
#include "envrnmnt.h"
#include "memalloc.h"
#include "router.h"
#include "utility.h"
#include "argacces.h"
#include "sysdep.h"

#include "symbol.h"

/***************/
/* DEFINITIONS */
/***************/

#define FALSE_STRING "FALSE"
#define TRUE_STRING  "TRUE"
#define POSITIVE_INFINITY_STRING "+oo"
#define NEGATIVE_INFINITY_STRING "-oo"

#define AVERAGE_STRING_SIZE 10
#define AVERAGE_BITMAP_SIZE sizeof(long)
#define NUMBER_OF_LONGS_FOR_HASH 25

/***************************************/
/* LOCAL INTERNAL FUNCTION DEFINITIONS */
/***************************************/

   static void                    RemoveHashNode(void *,GENERIC_HN *,GENERIC_HN **,int,int);
   static void                    AddEphemeralHashNode(void *,GENERIC_HN *,struct ephemeron **,
                                                       int,int);
   static void                    RemoveEphemeralHashNodes(void *,struct ephemeron **,
                                                           GENERIC_HN **,
                                                           int,int,int);
   static char                   *StringWithinString(char *,char *);
   static size_t                  CommonPrefixLength(char *,char *);
   static void                    DeallocateSymbolData(void *);

/*******************************************************/
/* InitializeAtomTables: Initializes the SymbolTable,  */
/*   IntegerTable, and FloatTable. It also initializes */
/*   the TrueSymbol and FalseSymbol.                   */
/*******************************************************/
#if IBM_TBC && (! RUN_TIME)
#pragma argsused
#endif
globle void InitializeAtomTables(
  void *theEnv,
  struct symbolHashNode **symbolTable,
  struct floatHashNode **floatTable,
  struct integerHashNode **integerTable,
  struct bitMapHashNode **bitmapTable)
  {
#if ! RUN_TIME
#if MAC_MCW || IBM_MCW || MAC_XCD
#pragma unused(symbolTable)
#pragma unused(floatTable)
#pragma unused(integerTable)
#pragma unused(bitmapTable)
#endif
   unsigned long i;
#endif
   
   AllocateEnvironmentData(theEnv,SYMBOL_DATA,sizeof(struct symbolData),DeallocateSymbolData);

#if ! RUN_TIME
   /*=========================*/
   /* Create the hash tables. */
   /*=========================*/

   SymbolData(theEnv)->SymbolTable = (SYMBOL_HN **)
                  gm3(theEnv,sizeof (SYMBOL_HN *) * SYMBOL_HASH_SIZE);

   SymbolData(theEnv)->FloatTable = (FLOAT_HN **)
                  gm2(theEnv,(int) sizeof (FLOAT_HN *) * FLOAT_HASH_SIZE);

   SymbolData(theEnv)->IntegerTable = (INTEGER_HN **)
                   gm2(theEnv,(int) sizeof (INTEGER_HN *) * INTEGER_HASH_SIZE);

   SymbolData(theEnv)->BitMapTable = (BITMAP_HN **)
                   gm2(theEnv,(int) sizeof (BITMAP_HN *) * BITMAP_HASH_SIZE);

   /*===================================================*/
   /* Initialize all of the hash table entries to NULL. */
   /*===================================================*/

   for (i = 0; i < SYMBOL_HASH_SIZE; i++) SymbolData(theEnv)->SymbolTable[i] = NULL;
   for (i = 0; i < FLOAT_HASH_SIZE; i++) SymbolData(theEnv)->FloatTable[i] = NULL;
   for (i = 0; i < INTEGER_HASH_SIZE; i++) SymbolData(theEnv)->IntegerTable[i] = NULL;
   for (i = 0; i < BITMAP_HASH_SIZE; i++) SymbolData(theEnv)->BitMapTable[i] = NULL;

   /*========================*/
   /* Predefine some values. */
   /*========================*/

   SymbolData(theEnv)->TrueSymbolHN = EnvAddSymbol(theEnv,TRUE_STRING);
   IncrementSymbolCount(SymbolData(theEnv)->TrueSymbolHN);
   SymbolData(theEnv)->FalseSymbolHN = EnvAddSymbol(theEnv,FALSE_STRING);
   IncrementSymbolCount(SymbolData(theEnv)->FalseSymbolHN);
   SymbolData(theEnv)->PositiveInfinity = EnvAddSymbol(theEnv,POSITIVE_INFINITY_STRING);
   IncrementSymbolCount(SymbolData(theEnv)->PositiveInfinity);
   SymbolData(theEnv)->NegativeInfinity = EnvAddSymbol(theEnv,NEGATIVE_INFINITY_STRING);
   IncrementSymbolCount(SymbolData(theEnv)->NegativeInfinity);
   SymbolData(theEnv)->Zero = EnvAddLong(theEnv,0LL);
   IncrementIntegerCount(SymbolData(theEnv)->Zero);
#else
   SetSymbolTable(theEnv,symbolTable);
   SetFloatTable(theEnv,floatTable);
   SetIntegerTable(theEnv,integerTable);
   SetBitMapTable(theEnv,bitmapTable);
#endif
  }

/*************************************************/
/* DeallocateSymbolData: Deallocates environment */
/*    data for symbols.                          */
/*************************************************/
static void DeallocateSymbolData(
  void *theEnv)
  {
   int i;
   SYMBOL_HN *shPtr, *nextSHPtr;
   INTEGER_HN *ihPtr, *nextIHPtr;
   FLOAT_HN *fhPtr, *nextFHPtr;
   BITMAP_HN *bmhPtr, *nextBMHPtr;
   struct ephemeron *edPtr, *nextEDPtr;

   if ((SymbolData(theEnv)->SymbolTable == NULL) ||
       (SymbolData(theEnv)->FloatTable == NULL) ||
       (SymbolData(theEnv)->IntegerTable == NULL) ||
       (SymbolData(theEnv)->BitMapTable == NULL))
     { return; }
     
   for (i = 0; i < SYMBOL_HASH_SIZE; i++) 
     {
      shPtr = SymbolData(theEnv)->SymbolTable[i];
      
      while (shPtr != NULL)
        {
         nextSHPtr = shPtr->next;
         if (! shPtr->permanent)
           {
            rm(theEnv,shPtr->contents,strlen(shPtr->contents)+1);
            rtn_struct(theEnv,symbolHashNode,shPtr);
           }  
         shPtr = nextSHPtr;
        } 
     }
      
   for (i = 0; i < FLOAT_HASH_SIZE; i++) 
     {
      fhPtr = SymbolData(theEnv)->FloatTable[i];

      while (fhPtr != NULL)
        {
         nextFHPtr = fhPtr->next;
         if (! fhPtr->permanent)
           { rtn_struct(theEnv,floatHashNode,fhPtr); }
         fhPtr = nextFHPtr;
        }
     }
     
   for (i = 0; i < INTEGER_HASH_SIZE; i++) 
     {
      ihPtr = SymbolData(theEnv)->IntegerTable[i];

      while (ihPtr != NULL)
        {
         nextIHPtr = ihPtr->next;
         if (! ihPtr->permanent)
           { rtn_struct(theEnv,integerHashNode,ihPtr); }
         ihPtr = nextIHPtr;
        }
     }
     
   for (i = 0; i < BITMAP_HASH_SIZE; i++) 
     {
      bmhPtr = SymbolData(theEnv)->BitMapTable[i];

      while (bmhPtr != NULL)
        {
         nextBMHPtr = bmhPtr->next;
         if (! bmhPtr->permanent)
           {
            rm(theEnv,bmhPtr->contents,bmhPtr->size);
            rtn_struct(theEnv,bitMapHashNode,bmhPtr); 
           } 
         bmhPtr = nextBMHPtr;
        }
     }

   /*=========================================*/
   /* Remove the ephemeral symbol structures. */
   /*=========================================*/
   
   edPtr = SymbolData(theEnv)->EphemeralSymbolList;

   while (edPtr != NULL)
     {
      nextEDPtr = edPtr->next;
      rtn_struct(theEnv,ephemeron,edPtr);
      edPtr = nextEDPtr;
     }

   edPtr = SymbolData(theEnv)->EphemeralFloatList;

   while (edPtr != NULL)
     {
      nextEDPtr = edPtr->next;
      rtn_struct(theEnv,ephemeron,edPtr);
      edPtr = nextEDPtr;
     }

   edPtr = SymbolData(theEnv)->EphemeralIntegerList;

   while (edPtr != NULL)
     {
      nextEDPtr = edPtr->next;
      rtn_struct(theEnv,ephemeron,edPtr);
      edPtr = nextEDPtr;
     }

   edPtr = SymbolData(theEnv)->EphemeralBitMapList;

   while (edPtr != NULL)
     {
      nextEDPtr = edPtr->next;
      rtn_struct(theEnv,ephemeron,edPtr);
      edPtr = nextEDPtr;
     }

   /*================================*/
   /* Remove the symbol hash tables. */
   /*================================*/
   
 #if ! RUN_TIME  
   rm3(theEnv,SymbolData(theEnv)->SymbolTable,sizeof (SYMBOL_HN *) * SYMBOL_HASH_SIZE);

   genfree(theEnv,SymbolData(theEnv)->FloatTable,(int) sizeof (FLOAT_HN *) * FLOAT_HASH_SIZE);

   genfree(theEnv,SymbolData(theEnv)->IntegerTable,(int) sizeof (INTEGER_HN *) * INTEGER_HASH_SIZE);

   genfree(theEnv,SymbolData(theEnv)->BitMapTable,(int) sizeof (BITMAP_HN *) * BITMAP_HASH_SIZE);
#endif
   
   /*==============================*/
   /* Remove binary symbol tables. */
   /*==============================*/
   
#if BLOAD || BLOAD_ONLY || BLOAD_AND_BSAVE || BLOAD_INSTANCES || BSAVE_INSTANCES
   if (SymbolData(theEnv)->SymbolArray != NULL)
     rm3(theEnv,(void *) SymbolData(theEnv)->SymbolArray,(long) sizeof(SYMBOL_HN *) * SymbolData(theEnv)->NumberOfSymbols);
   if (SymbolData(theEnv)->FloatArray != NULL)
     rm3(theEnv,(void *) SymbolData(theEnv)->FloatArray,(long) sizeof(FLOAT_HN *) * SymbolData(theEnv)->NumberOfFloats);
   if (SymbolData(theEnv)->IntegerArray != NULL)
     rm3(theEnv,(void *) SymbolData(theEnv)->IntegerArray,(long) sizeof(INTEGER_HN *) * SymbolData(theEnv)->NumberOfIntegers);
   if (SymbolData(theEnv)->BitMapArray != NULL)
     rm3(theEnv,(void *) SymbolData(theEnv)->BitMapArray,(long) sizeof(BITMAP_HN *) * SymbolData(theEnv)->NumberOfBitMaps);
#endif
  }

/*********************************************************************/
/* EnvAddSymbol: Searches for the string in the symbol table. If the */
/*   string is already in the symbol table, then the address of the  */
/*   string's location in the symbol table is returned. Otherwise,   */
/*   the string is added to the symbol table and then the address    */
/*   of the string's location in the symbol table is returned.       */
/*********************************************************************/
globle void *EnvAddSymbol(
  void *theEnv,
  char *str)
  {
   unsigned long tally;
   size_t length;
   SYMBOL_HN *past = NULL, *peek;

    /*====================================*/
    /* Get the hash value for the string. */
    /*====================================*/

    if (str == NULL)
      {
       SystemError(theEnv,"SYMBOL",1);
       EnvExitRouter(theEnv,EXIT_FAILURE);
      }

    tally = HashSymbol(str,SYMBOL_HASH_SIZE);
    peek = SymbolData(theEnv)->SymbolTable[tally];

    /*==================================================*/
    /* Search for the string in the list of entries for */
    /* this symbol table location.  If the string is    */
    /* found, then return the address of the string.    */
    /*==================================================*/

    while (peek != NULL)
      {
       if (strcmp(str,peek->contents) == 0)
         { return((void *) peek); }
       past = peek;
       peek = peek->next;
      }

    /*==================================================*/
    /* Add the string at the end of the list of entries */
    /* for this symbol table location.                  */
    /*==================================================*/

    peek = get_struct(theEnv,symbolHashNode);

    if (past == NULL) SymbolData(theEnv)->SymbolTable[tally] = peek;
    else past->next = peek;

    length = strlen(str) + 1;
    peek->contents = (char *) gm2(theEnv,length);
    peek->next = NULL;
    peek->bucket = tally;
    peek->count = 0;
    peek->permanent = FALSE;
    genstrcpy(peek->contents,str);
      
    /*================================================*/
    /* Add the string to the list of ephemeral items. */
    /*================================================*/

    AddEphemeralHashNode(theEnv,(GENERIC_HN *) peek,&SymbolData(theEnv)->EphemeralSymbolList,
                         sizeof(SYMBOL_HN),AVERAGE_STRING_SIZE);
    peek->depth = EvaluationData(theEnv)->CurrentEvaluationDepth;

    /*===================================*/
    /* Return the address of the symbol. */
    /*===================================*/

    return((void *) peek);
   }

/*****************************************************************/
/* FindSymbolHN: Searches for the string in the symbol table and */
/*   returns a pointer to it if found, otherwise returns NULL.   */
/*****************************************************************/
globle SYMBOL_HN *FindSymbolHN(
  void *theEnv,
  char *str)
  {
   unsigned long tally;
   SYMBOL_HN *peek;

    tally = HashSymbol(str,SYMBOL_HASH_SIZE);

    for (peek = SymbolData(theEnv)->SymbolTable[tally];
         peek != NULL;
         peek = peek->next)
      {