SQLite

** serve as the underlying representation of a cursor that scans
** over rows of the result
*/
typedef struct carray_cursor carray_cursor;
struct carray_cursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  sqlite3_int64 iRowid;      /* The rowid */
  void *pPtr;                /* Pointer to the array of values */
  sqlite3_int64 iCnt;        /* Number of integers in the array */
  unsigned char eType;       /* One of the CARRAY_type values */
};

/*
** The carrayConnect() method is invoked to create a new
** carray_vtab that describes the carray virtual table.

  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  carray_cursor *pCur = (carray_cursor*)cur;
  sqlite3_int64 x = 0;
  switch( i ){
    case CARRAY_COLUMN_POINTER:   return SQLITE_OK;
    case CARRAY_COLUMN_COUNT:     x = pCur->iCnt;   break;
    case CARRAY_COLUMN_CTYPE: {
      sqlite3_result_text(ctx, azType[pCur->eType], -1, SQLITE_STATIC);
      return SQLITE_OK;
    }
    default: {
      switch( pCur->eType ){
        case CARRAY_INT32: {
          int *p = (int*)pCur->pPtr;
          sqlite3_result_int(ctx, p[pCur->iRowid-1]);
          return SQLITE_OK;
        }
        case CARRAY_INT64: {
          sqlite3_int64 *p = (sqlite3_int64*)pCur->pPtr;
          sqlite3_result_int64(ctx, p[pCur->iRowid-1]);
          return SQLITE_OK;
        }
        case CARRAY_DOUBLE: {
          double *p = (double*)pCur->pPtr;
          sqlite3_result_double(ctx, p[pCur->iRowid-1]);
          return SQLITE_OK;
        }
        case CARRAY_TEXT: {
          const char **p = (const char**)pCur->pPtr;
          sqlite3_result_text(ctx, p[pCur->iRowid-1], -1, SQLITE_TRANSIENT);
          return SQLITE_OK;
        }
      }
    }
  }
  sqlite3_result_int64(ctx, x);

static int carrayFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  carray_cursor *pCur = (carray_cursor *)pVtabCursor;
  if( idxNum ){
    pCur->pPtr = sqlite3_value_pointer(argv[0]);
    pCur->iCnt = pCur->pPtr ? sqlite3_value_int64(argv[1]) : 0;
    if( idxNum<3 ){
      pCur->eType = CARRAY_INT32;
    }else{
      unsigned char i;
      const char *zType = (const char*)sqlite3_value_text(argv[2]);
      for(i=0; i<sizeof(azType)/sizeof(azType[0]); i++){
        if( sqlite3_stricmp(zType, azType[i])==0 ) break;
      }
      if( i>=sizeof(azType)/sizeof(azType[0]) ){
        pVtabCursor->pVtab->zErrMsg = sqlite3_mprintf(
          "unknown datatype: %Q", zType);
        return SQLITE_ERROR;
      }else{
        pCur->eType = i;
      }
    }
  }else{
    pCur->pPtr = 0;
    pCur->iCnt = 0;
  }
  pCur->iRowid = 1;
  return SQLITE_OK;
}

/*

  0,                         /* xSync */
  0,                         /* xCommit */
  0,                         /* xRollback */
  0,                         /* xFindMethod */
  0,                         /* xRename */
};

/*
** For testing purpose in the TCL test harness, we need a method for
** setting the pointer value.  The inttoptr(X) SQL function accomplishes
** this.  Tcl script will bind an integer to X and the inttoptr() SQL
** function will use sqlite3_result_pointer() to convert that integer into
** a pointer.
**
** This is for testing on TCL only.
*/
#ifdef SQLITE_TEST
static void inttoptrFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  void *p;
  sqlite3_int64 i64;
  i64 = sqlite3_value_int64(argv[0]);
  if( sizeof(i64)==sizeof(p) ){
    memcpy(&p, &i64, sizeof(p));
  }else{
    int i32 = i64 & 0xffffffff;
    memcpy(&p, &i32, sizeof(p));
  }
  sqlite3_result_pointer(context, p);
}
#endif /* SQLITE_TEST */

#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_carray_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
#ifndef SQLITE_OMIT_VIRTUALTABLE
  rc = sqlite3_create_module(db, "carray", &carrayModule, 0);
#ifdef SQLITE_TEST
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_function(db, "inttoptr", 1, SQLITE_UTF8, 0,
                                 inttoptrFunc, 0, 0);
  }
#endif /* SQLITE_TEST */
#endif /* SQLITE_OMIT_VIRTUALTABLE */
  return rc;
}

*/
static void rememberFunc(
  sqlite3_context *pCtx,
  int argc,
  sqlite3_value **argv
){
  sqlite3_int64 v;
  sqlite3_int64 *ptr;
  assert( argc==2 );
  v = sqlite3_value_int64(argv[0]);
  ptr = sqlite3_value_pointer(argv[1]);
  if( ptr ) *ptr = v;
  sqlite3_result_int64(pCtx, v);
}

#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_remember_init(

  SELECT b FROM t600 WHERE a IN generate_series(2,52,10);
} {(002) (012) (022) (032) (042) (052)}


do_test tabfunc01-700 {
  set PTR1 [intarray_addr 5 7 13 17 23]
  db eval {
    SELECT b FROM t600, carray(inttoptr($PTR1),5) WHERE a=value;
  }
} {(005) (007) (013) (017) (023)}
do_test tabfunc01-701 {
  db eval {
    SELECT b FROM t600 WHERE a IN carray(inttoptr($PTR1),5,'int32');
  }
} {(005) (007) (013) (017) (023)}
do_test tabfunc01-702 {
  db eval {
    SELECT b FROM t600 WHERE a IN carray(inttoptr($PTR1),4,'int32');
  }
} {(005) (007) (013) (017)}
do_catchsql_test tabfunc01-710 {
  SELECT b FROM t600 WHERE a IN carray(inttoptr($PTR1),5,'int33');
} {1 {unknown datatype: 'int33'}}

do_test tabfunc01-720 {
  set PTR2 [int64array_addr 5 7 13 17 23]
  db eval {
    SELECT b FROM t600, carray(inttoptr($PTR2),5,'int64') WHERE a=value;
  }
} {(005) (007) (013) (017) (023)}
do_test tabfunc01-721 {
  db eval {
    SELECT remember(123,inttoptr($PTR2));
    SELECT value FROM carray(inttoptr($PTR2),5,'int64');
  }
} {123 123 7 13 17 23}
do_test tabfunc01-722 {
  set PTR3 [expr {$PTR2+16}]
  db eval {
    SELECT remember(987,inttoptr($PTR3));
    SELECT value FROM carray(inttoptr($PTR2),5,'int64');
  }
} {987 123 7 987 17 23}

do_test tabfunc01-730 {
  set PTR4 [doublearray_addr 5.0 7.0 13.0 17.0 23.0]
  db eval {
    SELECT b FROM t600, carray(inttoptr($PTR4),5,'double') WHERE a=value;
  }
} {(005) (007) (013) (017) (023)}

do_test tabfunc01-740 {
  set PTR5 [textarray_addr x5 x7 x13 x17 x23]
  db eval {
    SELECT b FROM t600, carray(inttoptr($PTR5),5,'char*')
     WHERE a=trim(value,'x');
  }
} {(005) (007) (013) (017) (023)}

do_test tabfunc01-750 {
  db eval {
    SELECT aa.value, bb.value, '|'
      FROM carray(inttoptr($PTR4),5,'double') AS aa
      JOIN carray(inttoptr($PTR5),5,'char*') AS bb ON aa.rowid=bb.rowid;
  }
} {5.0 x5 | 7.0 x7 | 13.0 x13 | 17.0 x17 | 23.0 x23 |}

# Free up memory allocations
intarray_addr
int64array_addr
doublearray_addr