text: /*
   * contrib/btree_gist/btree_inet.c
   */
  #include "postgres.h"
  #include "knl/knl_variable.h"
  
  #include "btree_gist.h"
  #include "btree_utils_num.h"
  #include "utils/builtins.h"
  #include "utils/inet.h"
  #include "catalog/pg_type.h"
  
  typedef struct inetkey {
      double lower;
      double upper;
  } inetKEY;
  
  /*
  ** inet ops
  */
  PG_FUNCTION_INFO_V1(gbt_inet_compress);
  PG_FUNCTION_INFO_V1(gbt_inet_union);
  PG_FUNCTION_INFO_V1(gbt_inet_picksplit);
  PG_FUNCTION_INFO_V1(gbt_inet_consistent);
  PG_FUNCTION_INFO_V1(gbt_inet_penalty);
  PG_FUNCTION_INFO_V1(gbt_inet_same);
  
  extern "C" Datum gbt_inet_compress(PG_FUNCTION_ARGS);
  extern "C" Datum gbt_inet_union(PG_FUNCTION_ARGS);
  extern "C" Datum gbt_inet_picksplit(PG_FUNCTION_ARGS);
  extern "C" Datum gbt_inet_consistent(PG_FUNCTION_ARGS);
  extern "C" Datum gbt_inet_penalty(PG_FUNCTION_ARGS);
  extern "C" Datum gbt_inet_same(PG_FUNCTION_ARGS);
  
  static bool gbt_inetgt(const void* a, const void* b)
  {
      return (*((const double*)a) > *((const double*)b));
  }
  static bool gbt_inetge(const void* a, const void* b)
  {
      return (*((const double*)a) >= *((const double*)b));
  }
  static bool gbt_ineteq(const void* a, const void* b)
  {
      return (*((const double*)a) == *((const double*)b));
  }
  static bool gbt_inetle(const void* a, const void* b)
  {
      return (*((const double*)a) <= *((const double*)b));
  }
  static bool gbt_inetlt(const void* a, const void* b)
  {
      return (*((const double*)a) < *((const double*)b));
  }
  
  static int gbt_inetkey_cmp(const void* a, const void* b)
  {
      inetKEY* ia = (inetKEY*)(((const Nsrt*)a)->t);
      inetKEY* ib = (inetKEY*)(((const Nsrt*)b)->t);
  
      if (ia->lower == ib->lower) {
          if (ia->upper == ib->upper)
              return 0;
  
          return (ia->upper > ib->upper) ? 1 : -1;
      }
  
      return (ia->lower > ib->lower) ? 1 : -1;
  }
  
  static const gbtree_ninfo tinfo = {
      gbt_t_inet, sizeof(double), gbt_inetgt, gbt_inetge, gbt_ineteq, gbt_inetle, gbt_inetlt, gbt_inetkey_cmp, NULL};
  
  /**************************************************
   * inet ops
   **************************************************/
  
  Datum gbt_inet_compress(PG_FUNCTION_ARGS)
  {
      GISTENTRY* entry = (GISTENTRY*)PG_GETARG_POINTER(0);
      GISTENTRY* retval = NULL;
  
      if (entry->leafkey) {
          inetKEY* r = (inetKEY*)palloc(sizeof(inetKEY));
  
          retval = (GISTENTRY*)palloc(sizeof(GISTENTRY));
          r->lower = convert_network_to_scalar(entry->key, INETOID);
          r->upper = r->lower;
          gistentryinit(*retval, PointerGetDatum(r), entry->rel, entry->page, entry->offset, FALSE);
      } else
          retval = entry;
  
      PG_RETURN_POINTER(retval);
  }
  
  Datum gbt_inet_consistent(PG_FUNCTION_ARGS)
  {
      GISTENTRY* entry = (GISTENTRY*)PG_GETARG_POINTER(0);
      double query = convert_network_to_scalar(PG_GETARG_DATUM(1), INETOID);
      StrategyNumber strategy = (StrategyNumber)PG_GETARG_UINT16(2);
  
      /* Oid		subtype = PG_GETARG_OID(3); */
      bool* recheck = (bool*)PG_GETARG_POINTER(4);
      inetKEY* kkk = (inetKEY*)DatumGetPointer(entry->key);
      GBT_NUMKEY_R key;
  
      /* All cases served by this function are inexact */
      *recheck = true;
  
      key.lower = (GBT_NUMKEY*)&kkk->lower;
      key.upper = (GBT_NUMKEY*)&kkk->upper;
  
      PG_RETURN_BOOL(gbt_num_consistent(&key, (void*)&query, &strategy, GIST_LEAF(entry), &tinfo));
  }
  
  Datum gbt_inet_union(PG_FUNCTION_ARGS)
  {
      GistEntryVector* entryvec = (GistEntryVector*)PG_GETARG_POINTER(0);
      void* out = palloc(sizeof(inetKEY));
  
      *(int*)PG_GETARG_POINTER(1) = sizeof(inetKEY);
      PG_RETURN_POINTER(gbt_num_union((GBT_NUMKEY*)out, entryvec, &tinfo));
  }
  
  Datum gbt_inet_penalty(PG_FUNCTION_ARGS)
  {
      inetKEY* origentry = (inetKEY*)DatumGetPointer(((GISTENTRY*)PG_GETARG_POINTER(0))->key);
      inetKEY* newentry = (inetKEY*)DatumGetPointer(((GISTENTRY*)PG_GETARG_POINTER(1))->key);
      float* result = (float*)PG_GETARG_POINTER(2);
  
      penalty_num(result, origentry->lower, origentry->upper, newentry->lower, newentry->upper);
  
      PG_RETURN_POINTER(result);
  }
  
  Datum gbt_inet_picksplit(PG_FUNCTION_ARGS)
  {
      PG_RETURN_POINTER(
          gbt_num_picksplit((GistEntryVector*)PG_GETARG_POINTER(0), (GIST_SPLITVEC*)PG_GETARG_POINTER(1), &tinfo));
  }
  
  Datum gbt_inet_same(PG_FUNCTION_ARGS)
  {
      inetKEY* b1 = (inetKEY*)PG_GETARG_POINTER(0);
      inetKEY* b2 = (inetKEY*)PG_GETARG_POINTER(1);
      bool* result = (bool*)PG_GETARG_POINTER(2);
  
      *result = gbt_num_same((GBT_NUMKEY*)b1, (GBT_NUMKEY*)b2, &tinfo);
      PG_RETURN_POINTER(result);
  }
  