gdataset.c

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * gdataset.c: Generic dataset mechanism, similar to GtkObject data.
   5  * Copyright (C) 1998 Tim Janik
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
  20  */
  21
  22 /*
  23  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  24  * file for a list of people on the GLib Team.  See the ChangeLog
  25  * files for a list of changes.  These files are distributed with
  26  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  27  */
  28
  29 /*
  30  * MT safe ; FIXME: might still freeze, watch out, not thoroughly
  31  * looked at yet.
  32  */
  33
  34 #include        <string.h>
  35 #include        "glib.h"
  36
  37
  38
  39 /* --- defines --- */
  40 #define G_QUARK_BLOCK_SIZE                      (512)
  41 #define G_DATA_MEM_CHUNK_PREALLOC               (128)
  42 #define G_DATA_CACHE_MAX                        (512)
  43 #define G_DATASET_MEM_CHUNK_PREALLOC            (32)
  44
  45
  46 /* --- structures --- */
  47 typedef struct _GDataset GDataset;
  48 struct _GData
  49 {
  50   GData *next;
  51   GQuark id;
  52   gpointer data;
  53   GDestroyNotify destroy_func;
  54 };
  55
  56 struct _GDataset
  57 {
  58   gconstpointer location;
  59   GData        *datalist;
  60 };
  61
  62
  63 /* --- prototypes --- */
  64 static inline GDataset* g_dataset_lookup                (gconstpointer    dataset_location);
  65 static inline void      g_datalist_clear_i              (GData          **datalist);
  66 static void             g_dataset_destroy_internal      (GDataset        *dataset);
  67 static inline gpointer  g_data_set_internal             (GData          **datalist,
  68                                                          GQuark           key_id,
  69                                                          gpointer         data,
  70                                                          GDestroyNotify   destroy_func,
  71                                                          GDataset        *dataset);
  72 static void             g_data_initialize               (void);
  73 static inline GQuark    g_quark_new                     (gchar          *string);
  74
  75
  76 /* --- variables --- */
  77 G_LOCK_DEFINE_STATIC (g_dataset_global);
  78 static GHashTable   *g_dataset_location_ht = NULL;
  79 static GDataset     *g_dataset_cached = NULL; /* should this be
  80                                                  threadspecific? */
  81 static GMemChunk    *g_dataset_mem_chunk = NULL;
  82 static GMemChunk    *g_data_mem_chunk = NULL;
  83 static GData        *g_data_cache = NULL;
  84 static guint         g_data_cache_length = 0;
  85
  86 G_LOCK_DEFINE_STATIC (g_quark_global);
  87 static GHashTable   *g_quark_ht = NULL;
  88 static gchar       **g_quarks = NULL;
  89 static GQuark        g_quark_seq_id = 0;
  90
  91
  92 /* --- functions --- */
  93
  94 /* HOLDS: g_dataset_global_lock */
  95 static inline void
  96 g_datalist_clear_i (GData **datalist)
  97 {
  98   register GData *list;
  99
 100   /* unlink *all* items before walking their destructors
 101    */
 102   list = *datalist;
 103   *datalist = NULL;
 104
 105   while (list)
 106     {
 107       register GData *prev;
 108
 109       prev = list;
 110       list = prev->next;
 111
 112       if (prev->destroy_func)
 113         {
 114           G_UNLOCK (g_dataset_global);
 115           prev->destroy_func (prev->data);
 116           G_LOCK (g_dataset_global);
 117         }
 118
 119       if (g_data_cache_length < G_DATA_CACHE_MAX)
 120         {
 121           prev->next = g_data_cache;
 122           g_data_cache = prev;
 123           g_data_cache_length++;
 124         }
 125       else
 126         g_mem_chunk_free (g_data_mem_chunk, prev);
 127     }
 128 }
 129
 130 void
 131 g_datalist_clear (GData **datalist)
 132 {
 133   g_return_if_fail (datalist != NULL);
 134
 135   G_LOCK (g_dataset_global);
 136   if (!g_dataset_location_ht)
 137     g_data_initialize ();
 138
 139   while (*datalist)
 140     g_datalist_clear_i (datalist);
 141   G_UNLOCK (g_dataset_global);
 142 }
 143
 144 /* HOLDS: g_dataset_global_lock */
 145 static inline GDataset*
 146 g_dataset_lookup (gconstpointer dataset_location)
 147 {
 148   register GDataset *dataset;
 149
 150   if (g_dataset_cached && g_dataset_cached->location == dataset_location)
 151     return g_dataset_cached;
 152
 153   dataset = g_hash_table_lookup (g_dataset_location_ht, dataset_location);
 154   if (dataset)
 155     g_dataset_cached = dataset;
 156
 157   return dataset;
 158 }
 159
 160 /* HOLDS: g_dataset_global_lock */
 161 static void
 162 g_dataset_destroy_internal (GDataset *dataset)
 163 {
 164   register gconstpointer dataset_location;
 165
 166   dataset_location = dataset->location;
 167   while (dataset)
 168     {
 169       if (!dataset->datalist)
 170         {
 171           if (dataset == g_dataset_cached)
 172             g_dataset_cached = NULL;
 173           g_hash_table_remove (g_dataset_location_ht, dataset_location);
 174           g_mem_chunk_free (g_dataset_mem_chunk, dataset);
 175           break;
 176         }
 177
 178       g_datalist_clear_i (&dataset->datalist);
 179       dataset = g_dataset_lookup (dataset_location);
 180     }
 181 }
 182
 183 void
 184 g_dataset_destroy (gconstpointer  dataset_location)
 185 {
 186   g_return_if_fail (dataset_location != NULL);
 187
 188   G_LOCK (g_dataset_global);
 189   if (g_dataset_location_ht)
 190     {
 191       register GDataset *dataset;
 192
 193       dataset = g_dataset_lookup (dataset_location);
 194       if (dataset)
 195         g_dataset_destroy_internal (dataset);
 196     }
 197   G_UNLOCK (g_dataset_global);
 198 }
 199
 200 /* HOLDS: g_dataset_global_lock */
 201 static inline gpointer
 202 g_data_set_internal (GData        **datalist,
 203                      GQuark         key_id,
 204                      gpointer       data,
 205                      GDestroyNotify destroy_func,
 206                      GDataset      *dataset)
 207 {
 208   register GData *list;
 209
 210   list = *datalist;
 211   if (!data)
 212     {
 213       register GData *prev;
 214
 215       prev = NULL;
 216       while (list)
 217         {
 218           if (list->id == key_id)
 219             {
 220               gpointer ret_data = NULL;
 221
 222               if (prev)
 223                 prev->next = list->next;
 224               else
 225                 {
 226                   *datalist = list->next;
 227
 228                   /* the dataset destruction *must* be done
 229                    * prior to invokation of the data destroy function
 230                    */
 231                   if (!*datalist && dataset)
 232                     g_dataset_destroy_internal (dataset);
 233                 }
 234
 235               /* the GData struct *must* already be unlinked
 236                * when invoking the destroy function.
 237                * we use (data==NULL && destroy_func!=NULL) as
 238                * a special hint combination to "steal"
 239                * data without destroy notification
 240                */
 241               if (list->destroy_func && !destroy_func)
 242                 {
 243                   G_UNLOCK (g_dataset_global);
 244                   list->destroy_func (list->data);
 245                   G_LOCK (g_dataset_global);
 246                 }
 247               else
 248                 ret_data = list->data;
 249
 250               if (g_data_cache_length < G_DATA_CACHE_MAX)
 251                 {
 252                   list->next = g_data_cache;
 253                   g_data_cache = list;
 254                   g_data_cache_length++;
 255                 }
 256               else
 257                 g_mem_chunk_free (g_data_mem_chunk, list);
 258
 259               return ret_data;
 260             }
 261
 262           prev = list;
 263           list = list->next;
 264         }
 265     }
 266   else
 267     {
 268       while (list)
 269         {
 270           if (list->id == key_id)
 271             {
 272               if (!list->destroy_func)
 273                 {
 274                   list->data = data;
 275                   list->destroy_func = destroy_func;
 276                 }
 277               else
 278                 {
 279                   register GDestroyNotify dfunc;
 280                   register gpointer ddata;
 281
 282                   dfunc = list->destroy_func;
 283                   ddata = list->data;
 284                   list->data = data;
 285                   list->destroy_func = destroy_func;
 286
 287                   /* we need to have updated all structures prior to
 288                    * invokation of the destroy function
 289                    */
 290                   G_UNLOCK (g_dataset_global);
 291                   dfunc (ddata);
 292                   G_LOCK (g_dataset_global);
 293                 }
 294
 295               return NULL;
 296             }
 297
 298           list = list->next;
 299         }
 300
 301       if (g_data_cache)
 302         {
 303           list = g_data_cache;
 304           g_data_cache = list->next;
 305           g_data_cache_length--;
 306         }
 307       else
 308         list = g_chunk_new (GData, g_data_mem_chunk);
 309       list->next = *datalist;
 310       list->id = key_id;
 311       list->data = data;
 312       list->destroy_func = destroy_func;
 313       *datalist = list;
 314     }
 315
 316   return NULL;
 317 }
 318
 319 void
 320 g_dataset_id_set_data_full (gconstpointer  dataset_location,
 321                             GQuark         key_id,
 322                             gpointer       data,
 323                             GDestroyNotify destroy_func)
 324 {
 325   register GDataset *dataset;
 326
 327   g_return_if_fail (dataset_location != NULL);
 328   if (!data)
 329     g_return_if_fail (destroy_func == NULL);
 330   if (!key_id)
 331     {
 332       if (data)
 333         g_return_if_fail (key_id > 0);
 334       else
 335         return;
 336     }
 337
 338   G_LOCK (g_dataset_global);
 339   if (!g_dataset_location_ht)
 340     g_data_initialize ();
 341
 342   dataset = g_dataset_lookup (dataset_location);
 343   if (!dataset)
 344     {
 345       dataset = g_chunk_new (GDataset, g_dataset_mem_chunk);
 346       dataset->location = dataset_location;
 347       g_datalist_init (&dataset->datalist);
 348       g_hash_table_insert (g_dataset_location_ht,
 349                            (gpointer) dataset->location,
 350                            dataset);
 351     }
 352
 353   g_data_set_internal (&dataset->datalist, key_id, data, destroy_func, dataset);
 354   G_UNLOCK (g_dataset_global);
 355 }
 356
 357 void
 358 g_datalist_id_set_data_full (GData        **datalist,
 359                              GQuark         key_id,
 360                              gpointer       data,
 361                              GDestroyNotify destroy_func)
 362 {
 363   g_return_if_fail (datalist != NULL);
 364   if (!data)
 365     g_return_if_fail (destroy_func == NULL);
 366   if (!key_id)
 367     {
 368       if (data)
 369         g_return_if_fail (key_id > 0);
 370       else
 371         return;
 372     }
 373
 374   G_LOCK (g_dataset_global);
 375   if (!g_dataset_location_ht)
 376     g_data_initialize ();
 377
 378   g_data_set_internal (datalist, key_id, data, destroy_func, NULL);
 379   G_UNLOCK (g_dataset_global);
 380 }
 381
 382 gpointer
 383 g_dataset_id_remove_no_notify (gconstpointer  dataset_location,
 384                                GQuark         key_id)
 385 {
 386   gpointer ret_data = NULL;
 387
 388   g_return_val_if_fail (dataset_location != NULL, NULL);
 389
 390   G_LOCK (g_dataset_global);
 391   if (key_id && g_dataset_location_ht)
 392     {
 393       GDataset *dataset;
 394
 395       dataset = g_dataset_lookup (dataset_location);
 396       if (dataset)
 397         ret_data = g_data_set_internal (&dataset->datalist, key_id, NULL, (GDestroyNotify) 42, dataset);
 398     }
 399   G_UNLOCK (g_dataset_global);
 400
 401   return ret_data;
 402 }
 403
 404 gpointer
 405 g_datalist_id_remove_no_notify (GData   **datalist,
 406                                 GQuark    key_id)
 407 {
 408   gpointer ret_data = NULL;
 409
 410   g_return_val_if_fail (datalist != NULL, NULL);
 411
 412   G_LOCK (g_dataset_global);
 413   if (key_id && g_dataset_location_ht)
 414     ret_data = g_data_set_internal (datalist, key_id, NULL, (GDestroyNotify) 42, NULL);
 415   G_UNLOCK (g_dataset_global);
 416
 417   return ret_data;
 418 }
 419
 420 gpointer
 421 g_dataset_id_get_data (gconstpointer  dataset_location,
 422                        GQuark         key_id)
 423 {
 424   g_return_val_if_fail (dataset_location != NULL, NULL);
 425
 426   G_LOCK (g_dataset_global);
 427   if (key_id && g_dataset_location_ht)
 428     {
 429       register GDataset *dataset;
 430
 431       dataset = g_dataset_lookup (dataset_location);
 432       if (dataset)
 433         {
 434           register GData *list;
 435
 436           for (list = dataset->datalist; list; list = list->next)
 437             if (list->id == key_id)
 438               {
 439                 G_UNLOCK (g_dataset_global);
 440                 return list->data;
 441               }
 442         }
 443     }
 444   G_UNLOCK (g_dataset_global);
 445
 446   return NULL;
 447 }
 448
 449 gpointer
 450 g_datalist_id_get_data (GData    **datalist,
 451                         GQuark     key_id)
 452 {
 453   g_return_val_if_fail (datalist != NULL, NULL);
 454
 455   if (key_id)
 456     {
 457       register GData *list;
 458
 459       for (list = *datalist; list; list = list->next)
 460         if (list->id == key_id)
 461           return list->data;
 462     }
 463
 464   return NULL;
 465 }
 466
 467 void
 468 g_dataset_foreach (gconstpointer    dataset_location,
 469                    GDataForeachFunc func,
 470                    gpointer         user_data)
 471 {
 472   register GDataset *dataset;
 473
 474   g_return_if_fail (dataset_location != NULL);
 475   g_return_if_fail (func != NULL);
 476
 477   G_LOCK (g_dataset_global);
 478   if (g_dataset_location_ht)
 479     {
 480       dataset = g_dataset_lookup (dataset_location);
 481       G_UNLOCK (g_dataset_global);
 482       if (dataset)
 483         {
 484           register GData *list;
 485
 486           for (list = dataset->datalist; list; list = list->next)
 487               func (list->id, list->data, user_data);
 488         }
 489     }
 490   else
 491     {
 492       G_UNLOCK (g_dataset_global);
 493     }
 494 }
 495
 496 void
 497 g_datalist_foreach (GData          **datalist,
 498                     GDataForeachFunc func,
 499                     gpointer         user_data)
 500 {
 501   register GData *list;
 502
 503   g_return_if_fail (datalist != NULL);
 504   g_return_if_fail (func != NULL);
 505
 506   for (list = *datalist; list; list = list->next)
 507     func (list->id, list->data, user_data);
 508 }
 509
 510 void
 511 g_datalist_init (GData **datalist)
 512 {
 513   g_return_if_fail (datalist != NULL);
 514
 515   *datalist = NULL;
 516 }
 517
 518 /* HOLDS: g_dataset_global_lock */
 519 static void
 520 g_data_initialize (void)
 521 {
 522   g_return_if_fail (g_dataset_location_ht == NULL);
 523
 524   g_dataset_location_ht = g_hash_table_new (g_direct_hash, NULL);
 525   g_dataset_cached = NULL;
 526   g_dataset_mem_chunk =
 527     g_mem_chunk_new ("GDataset MemChunk",
 528                      sizeof (GDataset),
 529                      sizeof (GDataset) * G_DATASET_MEM_CHUNK_PREALLOC,
 530                      G_ALLOC_AND_FREE);
 531   g_data_mem_chunk =
 532     g_mem_chunk_new ("GData MemChunk",
 533                      sizeof (GData),
 534                      sizeof (GData) * G_DATA_MEM_CHUNK_PREALLOC,
 535                      G_ALLOC_AND_FREE);
 536 }
 537
 538 GQuark
 539 g_quark_try_string (const gchar *string)
 540 {
 541   GQuark quark = 0;
 542   g_return_val_if_fail (string != NULL, 0);
 543
 544   G_LOCK (g_quark_global);
 545   if (g_quark_ht)
 546     quark = GPOINTER_TO_UINT (g_hash_table_lookup (g_quark_ht, string));
 547   G_UNLOCK (g_quark_global);
 548
 549   return quark;
 550 }
 551
 552 GQuark
 553 g_quark_from_string (const gchar *string)
 554 {
 555   GQuark quark;
 556
 557   g_return_val_if_fail (string != NULL, 0);
 558
 559   G_LOCK (g_quark_global);
 560   if (g_quark_ht)
 561     quark = (gulong) g_hash_table_lookup (g_quark_ht, string);
 562   else
 563     {
 564       g_quark_ht = g_hash_table_new (g_str_hash, g_str_equal);
 565       quark = 0;
 566     }
 567
 568   if (!quark)
 569     quark = g_quark_new (g_strdup (string));
 570   G_UNLOCK (g_quark_global);
 571
 572   return quark;
 573 }
 574
 575 GQuark
 576 g_quark_from_static_string (const gchar *string)
 577 {
 578   GQuark quark;
 579
 580   g_return_val_if_fail (string != NULL, 0);
 581
 582   G_LOCK (g_quark_global);
 583   if (g_quark_ht)
 584     quark = (gulong) g_hash_table_lookup (g_quark_ht, string);
 585   else
 586     {
 587       g_quark_ht = g_hash_table_new (g_str_hash, g_str_equal);
 588       quark = 0;
 589     }
 590
 591   if (!quark)
 592     quark = g_quark_new ((gchar*) string);
 593   G_UNLOCK (g_quark_global);
 594
 595   return quark;
 596 }
 597
 598 gchar*
 599 g_quark_to_string (GQuark quark)
 600 {
 601   gchar* result = NULL;
 602   G_LOCK (g_quark_global);
 603   if (quark > 0 && quark <= g_quark_seq_id)
 604     result = g_quarks[quark - 1];
 605   G_UNLOCK (g_quark_global);
 606
 607   return result;
 608 }
 609
 610 /* HOLDS: g_quark_global_lock */
 611 static inline GQuark
 612 g_quark_new (gchar *string)
 613 {
 614   GQuark quark;
 615
 616   if (g_quark_seq_id % G_QUARK_BLOCK_SIZE == 0)
 617     g_quarks = g_renew (gchar*, g_quarks, g_quark_seq_id + G_QUARK_BLOCK_SIZE);
 618
 619   g_quarks[g_quark_seq_id] = string;
 620   g_quark_seq_id++;
 621   quark = g_quark_seq_id;
 622   g_hash_table_insert (g_quark_ht, string, GUINT_TO_POINTER (quark));
 623
 624   return quark;
 625 }