common/idex.c

   1 /***********************************************************************
   2  Freeciv - Copyright (C) 1996 - A Kjeldberg, L Gregersen, P Unold
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation; either version 2, or (at your option)
   6    any later version.
   7
   8    This program is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11    GNU General Public License for more details.
  12 ***********************************************************************/
  13
  14 /***********************************************************************
  15    idex = ident index: a lookup table for quick mapping of unit and city
  16    id values to unit and city pointers.
  17
  18    Method: use separate hash tables for each type.
  19    Means code duplication for city/unit cases, but simplicity advantages.
  20    Don't have to manage memory at all: store pointers to unit and city
  21    structs allocated elsewhere, and keys are pointers to id values inside
  22    the structs.
  23
  24    Note id values should probably be unsigned int: here leave as plain int
  25    so can use pointers to pcity->id etc.
  26 ***********************************************************************/
  27
  28 #ifdef HAVE_CONFIG_H
  29 #include <fc_config.h>
  30 #endif
  31
  32 /* utility */
  33 #include "log.h"
  34
  35 /* common */
  36 #include "city.h"
  37 #include "unit.h"
  38
  39 #include "idex.h"
  40
  41 /**************************************************************************
  42    Initialize.  Should call this at the start before use.
  43 ***************************************************************************/
  44 void idex_init(struct world *iworld)
  45 {
  46   iworld->cities = city_hash_new();
  47   iworld->units = unit_hash_new();
  48 }
  49
  50 /**************************************************************************
  51    Free the hashs.
  52 ***************************************************************************/
  53 void idex_free(struct world *iworld)
  54 {
  55   city_hash_destroy(iworld->cities);
  56   iworld->cities = NULL;
  57
  58   unit_hash_destroy(iworld->units);
  59   iworld->units = NULL;
  60 }
  61
  62 /**************************************************************************
  63    Register a city into idex, with current pcity->id.
  64    Call this when pcity created.
  65 ***************************************************************************/
  66 void idex_register_city(struct world *iworld, struct city *pcity)
  67 {
  68   struct city *old;
  69
  70   city_hash_replace_full(iworld->cities, pcity->id, pcity, NULL, &old);
  71   fc_assert_ret_msg(NULL == old,
  72                     "IDEX: city collision: new %d %p %s, old %d %p %s",
  73                     pcity->id, (void *) pcity, city_name_get(pcity),
  74                     old->id, (void *) old, city_name_get(old));
  75 }
  76
  77 /**************************************************************************
  78    Register a unit into idex, with current punit->id.
  79    Call this when punit created.
  80 ***************************************************************************/
  81 void idex_register_unit(struct world *iworld, struct unit *punit)
  82 {
  83   struct unit *old;
  84
  85   unit_hash_replace_full(iworld->units, punit->id, punit, NULL, &old);
  86   fc_assert_ret_msg(NULL == old,
  87                     "IDEX: unit collision: new %d %p %s, old %d %p %s",
  88                     punit->id, (void *) punit, unit_rule_name(punit),
  89                     old->id, (void *) old, unit_rule_name(old));
  90 }
  91
  92 /**************************************************************************
  93    Remove a city from idex, with current pcity->id.
  94    Call this when pcity deleted.
  95 ***************************************************************************/
  96 void idex_unregister_city(struct world *iworld, struct city *pcity)
  97 {
  98   struct city *old;
  99
 100   city_hash_remove_full(iworld->cities, pcity->id, NULL, &old);
 101   fc_assert_ret_msg(NULL != old,
 102                     "IDEX: city unreg missing: %d %p %s",
 103                     pcity->id, (void *) pcity, city_name_get(pcity));
 104   fc_assert_ret_msg(old == pcity, "IDEX: city unreg mismatch: "
 105                     "unreg %d %p %s, old %d %p %s",
 106                     pcity->id, (void *) pcity, city_name_get(pcity),
 107                     old->id, (void *) old, city_name_get(old));
 108 }
 109
 110 /**************************************************************************
 111    Remove a unit from idex, with current punit->id.
 112    Call this when punit deleted.
 113 ***************************************************************************/
 114 void idex_unregister_unit(struct world *iworld, struct unit *punit)
 115 {
 116   struct unit *old;
 117
 118   unit_hash_remove_full(iworld->units, punit->id, NULL, &old);
 119   fc_assert_ret_msg(NULL != old,
 120                     "IDEX: unit unreg missing: %d %p %s",
 121                     punit->id, (void *) punit, unit_rule_name(punit));
 122   fc_assert_ret_msg(old == punit, "IDEX: unit unreg mismatch: "
 123                     "unreg %d %p %s, old %d %p %s",
 124                     punit->id, (void *) punit, unit_rule_name(punit),
 125                     old->id, (void*) old, unit_rule_name(old));
 126 }
 127
 128 /**************************************************************************
 129    Lookup city with given id.
 130    Returns NULL if the city is not registered (which is not an error).
 131 ***************************************************************************/
 132 struct city *idex_lookup_city(struct world *iworld, int id)
 133 {
 134   struct city *pcity;
 135
 136   city_hash_lookup(iworld->cities, id, &pcity);
 137
 138   return pcity;
 139 }
 140
 141 /**************************************************************************
 142    Lookup unit with given id.
 143    Returns NULL if the unit is not registered (which is not an error).
 144 ***************************************************************************/
 145 struct unit *idex_lookup_unit(struct world *iworld, int id)
 146 {
 147   struct unit *punit;
 148
 149   unit_hash_lookup(iworld->units, id, &punit);
 150
 151   return punit;
 152 }