yap-6.3/packages/myddas/myddas_shared.c

/*************************************************************************
*									 *
*	 YAP Prolog 							 *
*									 *
*	Yap Prolog was developed at NCCUP - Universidade do Porto	 *
*									 *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997	 *
*									 *
**************************************************************************
*									 *
* File:		myddas_shared.c						 *
* Last rev:	22/03/05						 *
* mods:									 *
* comments:	Predicates for maintaining MYDDAS                        *
*									 *
*************************************************************************/
#include "Yap.h"

#include "Yatom.h"
#include <stdlib.h>


#ifdef MYDDAS

#include "myddas.h"

#ifdef MYDDAS_STATS
#include "myddas_statistics.h"
#endif

extern void init_myddas(void);

static Int c_db_initialize_myddas(USES_REGS1);
static Int c_db_connection_type(USES_REGS1);
static Int c_db_add_preds(USES_REGS1);
static Int c_db_preds_conn_start(USES_REGS1);
static Int c_db_preds_conn_continue(USES_REGS1);
static Int c_db_connection_start(USES_REGS1);
static Int c_db_connection_continue(USES_REGS1);
static Int c_db_check_if_exists_pred(USES_REGS1);
static Int c_db_delete_predicate(USES_REGS1);
static Int c_db_multi_queries_number(USES_REGS1);
#ifdef MYDDAS_STATS
static Int c_db_stats(USES_REGS1);
static Int c_db_stats_walltime(USES_REGS1);
static Int c_db_stats_translate(USES_REGS1);
static Int c_db_stats_time(USES_REGS1);
#endif
#ifdef DEBUG
static Int c_db_check(USES_REGS1);
#endif

void Yap_InitMYDDAS_SharedPreds(void) {
  Term cm = CurrentModule;
  CurrentModule = MkAtomTerm(Yap_LookupAtom("myddas"));
  /* c_db_initialize_myddas */
  Yap_InitCPred("c_db_initialize_myddas", 0, c_db_initialize_myddas, 0);

  /* c_db_connection_type: Connection x Type */
  Yap_InitCPred("c_db_connection_type", 2, c_db_connection_type, 0);

  /* CORRECT THIS: db_add_preds : PredName * Arity * Connection */
  Yap_InitCPred("c_db_add_preds", 4, c_db_add_preds, 0);

  /* c_db_check_if_exists_pred : PredName * Arity * Connection */
  Yap_InitCPred("c_db_check_if_exists_pred", 3, c_db_check_if_exists_pred, 0);

  /* c_db_delete_pred : Module * PredName * Arity */
  Yap_InitCPred("c_db_delete_predicate", 3, c_db_delete_predicate, 0);

  /* c_db_delete_pred : Module * PredName * Arity */
  Yap_InitCPred("c_db_multi_queries_number", 2, c_db_multi_queries_number, 0);

#ifdef MYDDAS_STATS
  /* c_db_stats: Connection * Stats */
  Yap_InitCPred("c_db_stats", 2, c_db_stats, 0);

  /* c_db_stats_walltime */
  Yap_InitCPred("c_db_stats_walltime", 1, c_db_stats_walltime, 0);

  /* c_db_stats_translate */
  Yap_InitCPred("c_db_stats_translate", 2, c_db_stats_translate, 0);

  /* c_db_stats_time */
  Yap_InitCPred("c_db_stats_time", 2, c_db_stats_time, 0);
#endif

#ifdef DEBUG
  Yap_InitCPred("c_db_check", 0, c_db_check, 0);
#endif
  CurrentModule = cm;
}

void Yap_InitBackMYDDAS_SharedPreds(void) {
  Term cm = CurrentModule;
  CurrentModule = MkAtomTerm(Yap_LookupAtom("myddas"));
  /* Gives all the predicates associated to a given connection */
  Yap_InitCPredBack("c_db_preds_conn", 4, sizeof(Int), c_db_preds_conn_start,
                    c_db_preds_conn_continue, 0);
  /* Gives all the connections stored on the MYDDAS Structure*/
  Yap_InitCPredBack("c_db_connection", 1, sizeof(Int), c_db_connection_start,
                    c_db_connection_continue, 0);
  CurrentModule = cm;
}

static bool myddas_initialised;

/* Initialize all of the MYDDAS global structures */
static Int c_db_initialize_myddas(USES_REGS1) {
  if (!myddas_initialised) {
    myddas_initialised= true;
    init_myddas();
  }
  Yap_REGS.MYDDAS_GLOBAL_POINTER = myddas_init_initialize_myddas();
#ifdef MYDDAS_STATS
  Yap_REGS.MYDDAS_GLOBAL_POINTER =
      myddas_stats_initialize_global_stats(Yap_REGS.MYDDAS_GLOBAL_POINTER);
#endif /* MYDDAS_STATS */
  return TRUE;
}

/* Gives the type of a given connection,
   in other words, type will be mysql or odbc

   NOTE: In order to use this predicate, the connection*/
/* c_db_connection_type: +Connection * ?Type */
static Int c_db_connection_type(USES_REGS1) {
  Term arg_con = Deref(ARG1);
  Term arg_type = ARG2;

  Int *con = (Int *)IntegerOfTerm(arg_con);
  MYDDAS_API type = myddas_util_connection_type(con);
  switch (type) {
#if MYDDAS_MYSQL
  case API_MYSQL:
    /* MYSQL Connection */
    return Yap_unify(arg_type, MkAtomTerm(Yap_LookupAtom("mysql")));
#endif
    #if MYDDAS_ODBC
  case API_ODBC:
    /* ODBC Connection */
    return Yap_unify(arg_type, MkAtomTerm(Yap_LookupAtom("odbc")));
    #endif
#if USE_MYDDAS_SQLITE3
  case API_SQLITE3:
    /* SQLITE3 Connection */
    return Yap_unify(arg_type, MkAtomTerm(Yap_LookupAtom("sqlite3")));
#endif
#if MYDDAS_POSTGRES
    case API_POSTGRES:
    /* SQLITE3 Connection */
    return Yap_unify(arg_type, MkAtomTerm(Yap_LookupAtom("postgres")));

#endif
      default:
          return FALSE;

  }
}

/* db_add_preds: PredName * Arity * Module * Connection*/
static Int c_db_add_preds(USES_REGS1) {
  Term arg_nome = Deref(ARG1);
  Term arg_aridade = Deref(ARG2);
  Term arg_module = Deref(ARG3);
  Term arg_conn = Deref(ARG4);

  /*   PredEntry *pe; */
  /*   pe = RepPredProp(PredPropByFunc(FunctorOfTerm(arg_pred),arg_module)); */

  const char *nome = AtomName(AtomOfTerm(arg_nome));
  const char *module = AtomName(AtomOfTerm(arg_module));
  Int aridade = IntegerOfTerm(arg_aridade);
  Int *conn = (Int *)IntegerOfTerm(arg_conn);

  if (myddas_util_add_predicate(nome, aridade, module, conn) == NULL) {
#ifdef DEBUG
    printf("ERROR : Could not add Predicate: Line: %d File: %s\n", __LINE__,
           __FILE__);
#endif
    return FALSE;
  }

  return TRUE;
}

static Int c_db_check_if_exists_pred(USES_REGS1) {
  Term arg_nome = Deref(ARG1);
  Term arg_aridade = Deref(ARG2);
  Term arg_module = Deref(ARG3);

  const char *nome = AtomName(AtomOfTerm(arg_nome));
  const char *module = AtomName(AtomOfTerm(arg_module));
  Int aridade = IntegerOfTerm(arg_aridade);

  if (myddas_util_search_predicate(nome, aridade, module) == NULL)
    return FALSE;
  else
    return TRUE;
}

static Int c_db_delete_predicate(USES_REGS1) {
  Term arg_module = Deref(ARG1);
  Term arg_name = Deref(ARG2);
  Term arg_arity = Deref(ARG3);

  const char *module = AtomName(AtomOfTerm(arg_module));
  const char *name = AtomName(AtomOfTerm(arg_name));
  Int arity = IntegerOfTerm(arg_arity);

  MYDDAS_UTIL_PREDICATE predicate =
      myddas_util_search_predicate(name, arity, module);
  if (predicate == NULL)
    return FALSE;

  myddas_util_delete_predicate(predicate);

  return TRUE;
}

static Int c_db_multi_queries_number(USES_REGS1) {
  Term arg_conn = Deref(ARG1);
  Term arg_number = Deref(ARG2);

  Int *conn = (Int *)IntegerOfTerm(arg_conn);
  MYDDAS_UTIL_CONNECTION node = myddas_util_search_connection(conn);

  if (node == NULL)
    return FALSE;

  if (IsVarTerm(arg_number)) {
    Yap_unify(arg_number,
              MkIntegerTerm(
                  ((Int)myddas_util_get_total_multi_queries_number(node)) + 1));
  } else {
    Int number = IntegerOfTerm(arg_number);
    number--;
    myddas_util_set_total_multi_queries_number(node, number);
  }

  return TRUE;
}

static Int c_db_connection_start(USES_REGS1) {

  MYDDAS_UTIL_CONNECTION node =
      Yap_REGS.MYDDAS_GLOBAL_POINTER->myddas_top_connections;

  EXTRA_CBACK_ARG(1, 1) = (CELL)MkIntegerTerm((Int)node);

  return (c_db_connection_continue(PASS_REGS1));
}

static Int c_db_connection_continue(USES_REGS1) {
  Term arg_conn = Deref(ARG1);

  MYDDAS_UTIL_CONNECTION node;
  node = (MYDDAS_UTIL_CONNECTION)IntegerOfTerm(EXTRA_CBACK_ARG(1, 1));

  /* There is no connections */
  if (node == NULL) {
    cut_fail();
    return FALSE;
  }

  Yap_unify(arg_conn, MkIntegerTerm((Int)(node->connection)));
  EXTRA_CBACK_ARG(1, 1) = (CELL)MkIntegerTerm((Int)(node->next));

  return TRUE;
}

/* db_preds_conn : Connection(+) * Pred_name(-) * Pred_arity */
static Int c_db_preds_conn_start(USES_REGS1) {
  Term arg_conn = Deref(ARG1);

  Int *conn = (Int *)IntegerOfTerm(arg_conn);
  MYDDAS_UTIL_CONNECTION node = myddas_util_search_connection(conn);

  /* Caso a ligacao já tenha sido apagada*/
  if (node == NULL) {
    cut_fail();
    return FALSE;
  }

  void *pointer = myddas_util_get_list_pred(node);
  EXTRA_CBACK_ARG(4, 1) = (CELL)MkIntegerTerm((Int)pointer);

  return (c_db_preds_conn_continue(PASS_REGS1));
}

/* db_preds_conn : Connection(+) * Pred_name(-) * Pred_arity*/
static Int c_db_preds_conn_continue(USES_REGS1) {
  Term module = Deref(ARG2);
  Term name = Deref(ARG3);
  Term arity = Deref(ARG4);

  void *pointer;
  pointer = (void *)IntegerOfTerm(EXTRA_CBACK_ARG(4, 1));

  if (pointer != NULL) {
    EXTRA_CBACK_ARG(4, 1) =
        (CELL)MkIntegerTerm((Int)myddas_util_get_pred_next(pointer));

    if (!Yap_unify(module, MkAtomTerm(Yap_LookupAtom(
                               myddas_util_get_pred_module(pointer))))) {
      return FALSE;
    }
    if (!Yap_unify(name, MkAtomTerm(Yap_LookupAtom(
                             myddas_util_get_pred_name(pointer))))) {
      return FALSE;
    }
    if (!Yap_unify(arity,
                   MkIntegerTerm((Int)myddas_util_get_pred_arity(pointer)))) {
      return FALSE;
    }
    return TRUE;
  } else {
    cut_fail();
    return FALSE;
  }
}

#ifdef DEBUG
static Int c_db_check(USES_REGS1) {
  check_int();
  return TRUE;
}
#endif /*DEBUG*/

#ifdef MYDDAS_STATS

static Int c_db_stats_walltime(USES_REGS1) {
  Term arg_time = Deref(ARG1);

#ifdef DEBUG
  if (IsVarTerm(arg_time)) {
#endif
    Yap_unify(arg_time, MkIntegerTerm((Int)myddas_stats_walltime()));
    return TRUE;
#ifdef DEBUG
  } else {
    printf("ERROR: c_db_stats_walltime got a variable\n");
    return FALSE;
  }
#endif
}

static Int c_db_stats_translate(USES_REGS1) {
  Term arg_start = Deref(ARG1);
  Term arg_end = Deref(ARG2);

  MYDDAS_STATS_TIME start;
  MYDDAS_STATS_TIME end;

  MYDDAS_STATS_TIME total_time, diff;

#ifdef DEBUG
  // Both args must be instanciated
  if (IsNonVarTerm(arg_start) && IsNonVarTerm(arg_end)) {
#endif
    start = (MYDDAS_STATS_TIME)IntegerOfTerm(arg_start);
    end = (MYDDAS_STATS_TIME)IntegerOfTerm(arg_end);

    MYDDAS_STATS_GET_TRANSLATE(total_time);

    MYDDAS_STATS_INITIALIZE_TIME_STRUCT(diff, time_copy);
    myddas_stats_subtract_time(diff, end, start);

    diff = myddas_stats_time_copy_to_final(diff);
    myddas_stats_add_time(total_time, diff, total_time);
    MyddasULInt count;
    MYDDAS_STATS_GET_TRANSLATE_COUNT(count);
    MYDDAS_STATS_SET_TRANSLATE_COUNT(++count);

    MYDDAS_FREE(diff, struct myddas_stats_time_struct);
    MYDDAS_FREE(start, struct myddas_stats_time_struct);
    MYDDAS_FREE(end, struct myddas_stats_time_struct);

    return TRUE;
#ifdef DEBUG
  } else {
    printf("ERROR: c_db_stats_translate got a variable\n");
    return FALSE;
  }
#endif
}

static Int c_db_stats_time(USES_REGS1) {
  Term arg_reference = Deref(ARG1);
  Term arg_time = Deref(ARG2);

  Term final_term;

  MYDDAS_STATS_STRUCT struc = (MYDDAS_STATS_STRUCT)IntegerOfTerm(arg_reference);
  Functor functor_count = Yap_MkFunctor(Yap_LookupAtom("count"), 1);
  Term count_number[1];
  Functor unit;
  Term number[1];

  switch (struc->type) {

  case integer: {
    Functor functor = Yap_MkFunctor(Yap_LookupAtom("myddas_integer"), 2);
    Term integer_number[1];
    MyddasULInt integer;

    unit = Yap_MkFunctor(Yap_LookupAtom("number"), 1);
    integer = struc->u.integer.integer;
    number[0] = MkIntegerTerm(integer);
    integer_number[0] = Yap_MkApplTerm(unit, 1, number);
    ;

    count_number[0] = MkIntegerTerm(struc->count);
    integer_number[1] = Yap_MkApplTerm(functor_count, 1, count_number);
    final_term = Yap_MkApplTerm(functor, 2, integer_number);
    break;
  }

  case time_str: {
    MYDDAS_STATS_TIME time = struc->u.time_str.time_str;

    Functor functor = Yap_MkFunctor(Yap_LookupAtom("myddas_time"), 6);
    Term time_numbers[6];
    MyddasUInt time_number;

    unit = Yap_MkFunctor(Yap_LookupAtom("hours"), 1);
    time_number = MYDDAS_STATS_TIME_HOURS(time);
    number[0] = MkIntegerTerm(time_number);
    time_numbers[0] = Yap_MkApplTerm(unit, 1, number);
    ;

    unit = Yap_MkFunctor(Yap_LookupAtom("minutes"), 1);
    time_number = MYDDAS_STATS_TIME_MINUTES(time);
    number[0] = MkIntegerTerm(time_number);
    time_numbers[1] = Yap_MkApplTerm(unit, 1, number);
    ;

    unit = Yap_MkFunctor(Yap_LookupAtom("seconds"), 1);
    time_number = MYDDAS_STATS_TIME_SECONDS(time);
    number[0] = MkIntegerTerm(time_number);
    time_numbers[2] = Yap_MkApplTerm(unit, 1, number);
    ;

    unit = Yap_MkFunctor(Yap_LookupAtom("miliseconds"), 1);
    time_number = MYDDAS_STATS_TIME_MILISECONDS(time);
    number[0] = MkIntegerTerm(time_number);
    time_numbers[3] = Yap_MkApplTerm(unit, 1, number);
    ;

    unit = Yap_MkFunctor(Yap_LookupAtom("microseconds"), 1);
    time_number = MYDDAS_STATS_TIME_MICROSECONDS(time);
    number[0] = MkIntegerTerm(time_number);
    time_numbers[4] = Yap_MkApplTerm(unit, 1, number);
    ;

    count_number[0] = MkIntegerTerm(struc->count);
    time_numbers[5] = Yap_MkApplTerm(functor_count, 1, count_number);
    final_term = Yap_MkApplTerm(functor, 6, time_numbers);
    break;
  }

  default:
#ifdef DEBUG
    printf("ERROR: c_db_stats_time unknow option\n");
#endif
    return FALSE;
    break;
  }

  if (!Yap_unify(arg_time, final_term)) {
    return FALSE;
  }

  return TRUE;
}

// Returns the stats of this module in a list
static Int c_db_stats(USES_REGS1) {
  Term arg_conn = Deref(ARG1);
  Term arg_list = Deref(ARG2);

  MyddasPointer *conn = (MyddasPointer *)(IntegerOfTerm(arg_conn));

  // TODO
  if (get_myddas_top() == 0) { /* We want all the statistics */
    return FALSE;
  }

  MYDDAS_STATS_STRUCT str;
  MYDDAS_UTIL_CONNECTION
  node = myddas_util_search_connection(conn);
  Term head, list;
  list = arg_list;

#ifdef DEBUG
  MYDDAS_STATS_TIME time = NULL;
#endif
  //[Index 1] -> Total Number of Rows by connection
  // Total number of Rows returned by the server
  // WARNING: only works with store_result
  head = HeadOfTerm(list);
  list = TailOfTerm(list);
  str = myddas_stats_get_stat(node->stats, 5);
  Yap_unify(head, MkIntegerTerm((MyddasInt)str));
#ifdef DEBUG
  MyddasUInt number = 0;

  MYDDAS_STATS_CON_GET_TOTAL_ROWS(node, number);
  printf("Total Number of Rows returned from the Server\n");
  printf("%lu\n\n", (unsigned long)number);
#endif

  //[Index 2] -> Total of Time Spent by the DB Server
  // processing all the  SQL Querys
  head = HeadOfTerm(list);
  list = TailOfTerm(list);

  str = myddas_stats_get_stat(node->stats, 1);
  Yap_unify(head, MkIntegerTerm((MyddasInt)str));
#ifdef DEBUG
  MYDDAS_STATS_CON_GET_TOTAL_TIME_DBSERVER(node, time);
  printf("Reference to time Spent by the Server, on all the SQL Querys\n");
  MYDDAS_STATS_PRINT_TIME_STRUCT(time);
  printf("\n\n");
#endif

  //[Index 3] -> Total of Time Spent by the DB Server
  // processing a the last SQL Query
  head = HeadOfTerm(list);
  list = TailOfTerm(list);

  str = myddas_stats_get_stat(node->stats, 2);
  Yap_unify(head, MkIntegerTerm((MyddasInt)str));
#ifdef DEBUG
  MYDDAS_STATS_CON_GET_LAST_TIME_DBSERVER(node, time);
  printf("Reference to time Spent by the Server, on the last SQL Query\n");
  MYDDAS_STATS_PRINT_TIME_STRUCT(time);
  printf("\n\n");
#endif

  //[Index 4] -> Total of Time Spent by the DB Server
  // transfering all the results of the  SQL Querys
  head = HeadOfTerm(list);
  list = TailOfTerm(list);

  str = myddas_stats_get_stat(node->stats, 3);
  Yap_unify(head, MkIntegerTerm((MyddasInt)str));
#ifdef DEBUG
  MYDDAS_STATS_CON_GET_TOTAL_TIME_TRANSFERING(node, time);
  printf("Refence to time Spent by the Server, transfering all the results SQL "
         "Query\n");
  MYDDAS_STATS_PRINT_TIME_STRUCT(time);
  printf("\n\n");
#endif

  //[Index 5] -> Total of Time Spent by the DB Server
  // transfering the result of the last SQL Query
  head = HeadOfTerm(list);
  list = TailOfTerm(list);

  str = myddas_stats_get_stat(node->stats, 4);
  Yap_unify(head, MkIntegerTerm((MyddasInt)str));
#ifdef DEBUG
  MYDDAS_STATS_CON_GET_LAST_TIME_TRANSFERING(node, time);
  printf("Reference to time Spent by the Server, transfering the result of the "
         "last SQL Query\n");
  MYDDAS_STATS_PRINT_TIME_STRUCT(time);
  printf("\n\n");
#endif

  //[Index 6] -> Total of Time Spent by the
  // db_row_function
  head = HeadOfTerm(list);
  list = TailOfTerm(list);

  str = myddas_stats_get_stat(
      Yap_REGS.MYDDAS_GLOBAL_POINTER->myddas_statistics->stats, 1);

  Yap_unify(head, MkIntegerTerm((MyddasInt)str));
#ifdef DEBUG
  MYDDAS_STATS_GET_DB_ROW_FUNCTION(time);
  printf("Reference to time Spent by the db_row_function\n");
  MYDDAS_STATS_PRINT_TIME_STRUCT(time);
  printf("\n\n");
#endif

  //[Index 7] -> Total of Bytes Transfered by the
  // DB Server on all SQL Querys
  head = HeadOfTerm(list);
  list = TailOfTerm(list);

  str = myddas_stats_get_stat(node->stats, 6);
  Yap_unify(head, MkIntegerTerm((MyddasPointer)str));
#ifdef DEBUG
  MYDDAS_STATS_CON_GET_TOTAL_BYTES_TRANSFERING_FROM_DBSERVER(node, number);
  printf("Bytes Transfered by the DB Server from all querys\n");
  printf("%llu\n\n", (MyddasULInt)number);
#endif

  //[Index 8] -> Total of Bytes Transfered by the
  // DB Server on the last SQL Query
  head = HeadOfTerm(list);
  list = TailOfTerm(list);

  str = myddas_stats_get_stat(node->stats, 7);
  Yap_unify(head, MkIntegerTerm((MyddasPointer)str));
#ifdef DEBUG
  MYDDAS_STATS_CON_GET_LAST_BYTES_TRANSFERING_FROM_DBSERVER(node, number);
  printf("Bytes Transfered by the DB Server on the last query\n");
  printf("%llu\n\n", (MyddasULInt)number);
#endif
  //[Index 9] -> Number of querys made to the DBserver
  head = HeadOfTerm(list);
  list = TailOfTerm(list);

  str = myddas_stats_get_stat(node->stats, 8);
  Yap_unify(head, MkIntegerTerm((MyddasPointer)str));
#ifdef DEBUG
  MYDDAS_STATS_CON_GET_NUMBER_QUERIES_MADE(node, number);
  printf("Number of Querys made to the server\n");
  printf("%llu\n\n", (MyddasULInt)number);
#endif

  //[Index 10] -> Total of Time Spent by the
  // translate predicate
  head = HeadOfTerm(list);
  list = TailOfTerm(list);

  str = myddas_stats_get_stat(
      Yap_REGS.MYDDAS_GLOBAL_POINTER->myddas_statistics->stats, 2);
  Yap_unify(head, MkIntegerTerm((Int)str));

#ifdef DEBUG
  MYDDAS_STATS_GET_TRANSLATE(time);
  printf("Reference to time Spent by the translate predicate\n");
  MYDDAS_STATS_PRINT_TIME_STRUCT(time);
  printf("\n\n");
#endif

/* Memory management */
#ifdef DEBUG_MYDDAS_MEM
  MyddasULInt nr;
  MYDDAS_MEMORY_MALLOC_NR(nr);
  printf("Number of times malloc was called in MYDDAS: %lu \n", nr);
  MYDDAS_MEMORY_FREE_NR(nr);
  printf("Number of times free was called in MYDDAS  : %lu \n", nr);

  MYDDAS_MEMORY_MALLOC_SIZE(nr);
  printf("Total memory allocated in MYDDAS: %lu \n", nr);
  MYDDAS_MEMORY_FREE_SIZE(nr);
  printf("Total memory freed in MYDDAS    : %lu \n", nr);
#endif

  return TRUE;
}

#endif /* MYDDAS_STATS */

/* Function to delete all the temporary tables */
/* from the mysql server */
void Yap_MYDDAS_delete_all_myddas_structs(void) {
  CACHE_REGS

  /* NAO ESQUECER DE FAZER ISTO TB PARA O DB_CLOSE*/
  MYDDAS_GLOBAL global = Yap_REGS.MYDDAS_GLOBAL_POINTER;

  /* In case that the MYDDAS module isn't loaded */
  if (global == NULL)
    return;

  MYDDAS_UTIL_CONNECTION connections = global->myddas_top_connections;

  /* Delete all connections */
  for (; connections != NULL; connections = connections->next)
    myddas_util_delete_connection(connections->connection);

#ifdef MYDDAS_STATS
  myddas_stats_delete_stats_list(global->myddas_statistics->stats);
  MYDDAS_FREE(global->myddas_statistics, struct myddas_global_stats);
#endif

  MYDDAS_FREE(global, struct myddas_global);

#if defined(DEBUG) && 0
  MyddasULInt nr;
  MYDDAS_MEMORY_MALLOC_NR(nr);
  printf("Number of times malloc was called in MYDDAS: " UInt_FORMAT " \n",
         (UInt)nr);
  MYDDAS_MEMORY_FREE_NR(nr);
  printf("Number of times free was called in MYDDAS  : " UInt_FORMAT " \n",
         (UInt)nr);

  MYDDAS_MEMORY_MALLOC_SIZE(nr);
  printf("Total memory allocated in MYDDAS: " UInt_FORMAT " \n", (UInt)nr);
  MYDDAS_MEMORY_FREE_SIZE(nr);
  printf("Total memory freed in MYDDAS    : " UInt_FORMAT " \n", (UInt)nr);
#endif
}

#endif

void init_myddas(void) {
  CACHE_REGS
  if (myddas_initialised)
  {
    return;
  }
#if MYDDAS
Yap_InitMYDDAS_SharedPreds();
  Yap_InitBackMYDDAS_SharedPreds();
#define stringify(X) _stringify(X)
#define _stringify(X) #X
  Yap_REGS.MYDDAS_GLOBAL_POINTER = NULL;
  Yap_PutValue(AtomMyddasVersionName,
               MkAtomTerm(Yap_LookupAtom(stringify(MYDDAS_VERSION))));
  Yap_HaltRegisterHook((HaltHookFunc)Yap_MYDDAS_delete_all_myddas_structs,
                       NULL);
#undef stringify
#undef _stringify
  Yap_MYDDAS_delete_all_myddas_structs();
#if defined MYDDAS_TOP_LEVEL &&                                                \
    defined MYDDAS_MYSQL // && defined HAVE_LIBREADLINE
  Yap_InitMYDDAS_TopLevelPreds();
#endif
#endif
  myddas_initialised = true;
}

#ifdef _WIN32

#include <windows.h>

int WINAPI win_myddas(HANDLE hinst, DWORD reason, LPVOID reserved);

int WINAPI win_myddas(HANDLE hinst, DWORD reason, LPVOID reserved) {
  switch (reason) {
  case DLL_PROCESS_ATTACH:
    break;
  case DLL_PROCESS_DETACH:
    break;
  case DLL_THREAD_ATTACH:
    break;
  case DLL_THREAD_DETACH:
    break;
  }
  return 1;
}
#endif