Line data    Source code

       1             : /*
       2             :  * SPDX-License-Identifier: MPL-2.0
       3             :  *
       4             :  * This Source Code Form is subject to the terms of the Mozilla Public
       5             :  * License, v. 2.0.  If a copy of the MPL was not distributed with this
       6             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
       7             :  *
       8             :  * Copyright 2024 MonetDB Foundation;
       9             :  * Copyright August 2008 - 2023 MonetDB B.V.;
      10             :  * Copyright 1997 - July 2008 CWI.
      11             :  */
      12             : 
      13             : /*
      14             :  * @f identifier
      15             :  * @a Fabian Groffen, Martin Kersten
      16             :  * @+ Identifier Wrapper
      17             :  * The identifier atom is a shallow wrapper that contains an object's id.
      18             :  * Due to it being wrapped by this atom, methods can distinguish
      19             :  * it from a normal string.
      20             :  * The variable of this time can be further extended with properties
      21             :  * to further qualify the identifier referenced.
      22             :  *
      23             :  */
      24             : #include "monetdb_config.h"
      25             : #include "mal.h"
      26             : #include "mal_exception.h"
      27             : 
      28             : typedef str identifier;
      29             : 
      30             : static int TYPE_identifier;
      31             : 
      32             : static str
      33         336 : IDprelude(void)
      34             : {
      35         336 :         TYPE_identifier = ATOMindex("identifier");
      36         336 :         return MAL_SUCCEED;
      37             : }
      38             : 
      39             : /**
      40             :  * Creates a new identifier from the given string (stupid string copy).
      41             :  * Warning: GDK function, does NOT pass a string by reference, and wants
      42             :  * a pointer to a pointer for the retval!
      43             :  * Returns the number of chars read
      44             :  */
      45             : static ssize_t
      46           0 : IDfromString(const char *src, size_t *len, void **RETVAL, bool external)
      47             : {
      48           0 :         identifier *retval = (identifier *) RETVAL;
      49           0 :         size_t l = strlen(src) + 1;
      50           0 :         if (*retval == NULL || *len < l) {
      51           0 :                 GDKfree(*retval);
      52           0 :                 *retval = GDKmalloc(l);
      53           0 :                 if (*retval == NULL)
      54             :                         return -1;
      55           0 :                 *len = l;
      56             :         }
      57           0 :         if (external && strncmp(src, "nil", 3) == 0) {
      58           0 :                 memcpy(*retval, str_nil, 2);
      59           0 :                 return 3;
      60             :         }
      61           0 :         memcpy(*retval, src, l);
      62           0 :         return (ssize_t) l - 1;
      63             : }
      64             : 
      65             : /**
      66             :  * Returns the string representation of the given identifier.
      67             :  * Warning: GDK function
      68             :  * Returns the length of the string
      69             :  */
      70             : static ssize_t
      71           0 : IDtoString(char **retval, size_t *len, const void *HANDLE, bool external)
      72             : {
      73           0 :         const char *handle = HANDLE;
      74           0 :         size_t hl = strlen(handle) + 1;
      75           0 :         if (external && strNil(handle))
      76             :                 hl = 4;
      77           0 :         if (*len < hl || *retval == NULL) {
      78           0 :                 GDKfree(*retval);
      79           0 :                 *retval = GDKmalloc(hl);
      80           0 :                 if (*retval == NULL)
      81             :                         return -1;
      82           0 :                 *len = hl;
      83             :         }
      84           0 :         if (external && strNil(handle))
      85           0 :                 strcpy(*retval, "nil");
      86             :         else
      87           0 :                 memcpy(*retval, handle, hl);
      88           0 :         return (ssize_t) hl - 1;
      89             : }
      90             : 
      91             : /**
      92             :  * Returns an identifier, parsed from a string.  The fromStr function is used
      93             :  * to parse the string.
      94             :  */
      95             : static str
      96           0 : IDentifier(identifier *retval, str *in)
      97             : {
      98           0 :         size_t len = 0;
      99             : 
     100           0 :         if (IDfromString(*in, &len, (void **) retval, false) < 0)
     101           0 :                 throw(PARSE, "identifier.identifier", "Error while parsing %s", *in);
     102             : 
     103             :         return (MAL_SUCCEED);
     104             : }
     105             : 
     106             : #include "mel.h"
     107             : mel_atom identifier_init_atoms[] = {
     108             :  { .name="identifier", .basetype="str", .fromstr=IDfromString, .tostr=IDtoString, },  { .cmp=NULL }
     109             : };
     110             : mel_func identifier_init_funcs[] = {
     111             :  command("identifier", "identifier", IDentifier, false, "Cast a string to an identifer ", args(1,2, arg("",identifier),arg("s",str))),
     112             :  { .imp=NULL }
     113             : };
     114             : #include "mal_import.h"
     115             : #ifdef _MSC_VER
     116             : #undef read
     117             : #pragma section(".CRT$XCU",read)
     118             : #endif
     119         329 : LIB_STARTUP_FUNC(init_identifier_mal)
     120         329 : { mal_module2("identifier", identifier_init_atoms, identifier_init_funcs, IDprelude, NULL); }