Ruby  3.4.0dev (2024-11-22 revision 37a72b0150ec36b4ea27175039afc28c62207b0c)
id_table.c (37a72b0150ec36b4ea27175039afc28c62207b0c)
1 /* This file is included by symbol.c */
2 
3 #include "id_table.h"
4 
5 #ifndef ID_TABLE_DEBUG
6 #define ID_TABLE_DEBUG 0
7 #endif
8 
9 #if ID_TABLE_DEBUG == 0
10 #undef NDEBUG
11 #define NDEBUG
12 #endif
13 #include "ruby_assert.h"
14 
15 typedef rb_id_serial_t id_key_t;
16 
17 static inline ID
18 key2id(id_key_t key)
19 {
20  return rb_id_serial_to_id(key);
21 }
22 
23 static inline id_key_t
24 id2key(ID id)
25 {
26  return rb_id_to_serial(id);
27 }
28 
29 /* simple open addressing with quadratic probing.
30  uses mark-bit on collisions - need extra 1 bit,
31  ID is strictly 3 bits larger than rb_id_serial_t */
32 
33 typedef struct rb_id_item {
34  id_key_t key;
35 #if SIZEOF_VALUE == 8
36  int collision;
37 #endif
38  VALUE val;
39 } item_t;
40 
41 struct rb_id_table {
42  int capa;
43  int num;
44  int used;
45  item_t *items;
46 };
47 
48 #if SIZEOF_VALUE == 8
49 #define ITEM_GET_KEY(tbl, i) ((tbl)->items[i].key)
50 #define ITEM_KEY_ISSET(tbl, i) ((tbl)->items[i].key)
51 #define ITEM_COLLIDED(tbl, i) ((tbl)->items[i].collision)
52 #define ITEM_SET_COLLIDED(tbl, i) ((tbl)->items[i].collision = 1)
53 static inline void
54 ITEM_SET_KEY(struct rb_id_table *tbl, int i, id_key_t key)
55 {
56  tbl->items[i].key = key;
57 }
58 #else
59 #define ITEM_GET_KEY(tbl, i) ((tbl)->items[i].key >> 1)
60 #define ITEM_KEY_ISSET(tbl, i) ((tbl)->items[i].key > 1)
61 #define ITEM_COLLIDED(tbl, i) ((tbl)->items[i].key & 1)
62 #define ITEM_SET_COLLIDED(tbl, i) ((tbl)->items[i].key |= 1)
63 static inline void
64 ITEM_SET_KEY(struct rb_id_table *tbl, int i, id_key_t key)
65 {
66  tbl->items[i].key = (key << 1) | ITEM_COLLIDED(tbl, i);
67 }
68 #endif
69 
70 static inline int
71 round_capa(int capa)
72 {
73  /* minsize is 4 */
74  capa >>= 2;
75  capa |= capa >> 1;
76  capa |= capa >> 2;
77  capa |= capa >> 4;
78  capa |= capa >> 8;
79  capa |= capa >> 16;
80  return (capa + 1) << 2;
81 }
82 
83 static struct rb_id_table *
84 rb_id_table_init(struct rb_id_table *tbl, int capa)
85 {
86  MEMZERO(tbl, struct rb_id_table, 1);
87  if (capa > 0) {
88  capa = round_capa(capa);
89  tbl->capa = (int)capa;
90  tbl->items = ZALLOC_N(item_t, capa);
91  }
92  return tbl;
93 }
94 
95 struct rb_id_table *
96 rb_id_table_create(size_t capa)
97 {
98  struct rb_id_table *tbl = ALLOC(struct rb_id_table);
99  return rb_id_table_init(tbl, (int)capa);
100 }
101 
102 void
103 rb_id_table_free(struct rb_id_table *tbl)
104 {
105  xfree(tbl->items);
106  xfree(tbl);
107 }
108 
109 void
110 rb_id_table_clear(struct rb_id_table *tbl)
111 {
112  tbl->num = 0;
113  tbl->used = 0;
114  MEMZERO(tbl->items, item_t, tbl->capa);
115 }
116 
117 size_t
118 rb_id_table_size(const struct rb_id_table *tbl)
119 {
120  return (size_t)tbl->num;
121 }
122 
123 size_t
124 rb_id_table_memsize(const struct rb_id_table *tbl)
125 {
126  return sizeof(item_t) * tbl->capa + sizeof(struct rb_id_table);
127 }
128 
129 static int
130 hash_table_index(struct rb_id_table* tbl, id_key_t key)
131 {
132  if (tbl->capa > 0) {
133  int mask = tbl->capa - 1;
134  int ix = key & mask;
135  int d = 1;
136  while (key != ITEM_GET_KEY(tbl, ix)) {
137  if (!ITEM_COLLIDED(tbl, ix))
138  return -1;
139  ix = (ix + d) & mask;
140  d++;
141  }
142  return ix;
143  }
144  return -1;
145 }
146 
147 static void
148 hash_table_raw_insert(struct rb_id_table *tbl, id_key_t key, VALUE val)
149 {
150  int mask = tbl->capa - 1;
151  int ix = key & mask;
152  int d = 1;
153  RUBY_ASSERT(key != 0);
154  while (ITEM_KEY_ISSET(tbl, ix)) {
155  ITEM_SET_COLLIDED(tbl, ix);
156  ix = (ix + d) & mask;
157  d++;
158  }
159  tbl->num++;
160  if (!ITEM_COLLIDED(tbl, ix)) {
161  tbl->used++;
162  }
163  ITEM_SET_KEY(tbl, ix, key);
164  tbl->items[ix].val = val;
165 }
166 
167 static int
168 hash_delete_index(struct rb_id_table *tbl, int ix)
169 {
170  if (ix >= 0) {
171  if (!ITEM_COLLIDED(tbl, ix)) {
172  tbl->used--;
173  }
174  tbl->num--;
175  ITEM_SET_KEY(tbl, ix, 0);
176  tbl->items[ix].val = 0;
177  return TRUE;
178  }
179  else {
180  return FALSE;
181  }
182 }
183 
184 static void
185 hash_table_extend(struct rb_id_table* tbl)
186 {
187  if (tbl->used + (tbl->used >> 1) >= tbl->capa) {
188  int new_cap = round_capa(tbl->num + (tbl->num >> 1));
189  int i;
190  item_t* old;
191  struct rb_id_table tmp_tbl = {0, 0, 0};
192  if (new_cap < tbl->capa) {
193  new_cap = round_capa(tbl->used + (tbl->used >> 1));
194  }
195  tmp_tbl.capa = new_cap;
196  tmp_tbl.items = ZALLOC_N(item_t, new_cap);
197  for (i = 0; i < tbl->capa; i++) {
198  id_key_t key = ITEM_GET_KEY(tbl, i);
199  if (key != 0) {
200  hash_table_raw_insert(&tmp_tbl, key, tbl->items[i].val);
201  }
202  }
203  old = tbl->items;
204  *tbl = tmp_tbl;
205  xfree(old);
206  }
207 }
208 
209 #if ID_TABLE_DEBUG && 0
210 static void
211 hash_table_show(struct rb_id_table *tbl)
212 {
213  const id_key_t *keys = tbl->keys;
214  const int capa = tbl->capa;
215  int i;
216 
217  fprintf(stderr, "tbl: %p (capa: %d, num: %d, used: %d)\n", tbl, tbl->capa, tbl->num, tbl->used);
218  for (i=0; i<capa; i++) {
219  if (ITEM_KEY_ISSET(tbl, i)) {
220  fprintf(stderr, " -> [%d] %s %d\n", i, rb_id2name(key2id(keys[i])), (int)keys[i]);
221  }
222  }
223 }
224 #endif
225 
226 int
227 rb_id_table_lookup(struct rb_id_table *tbl, ID id, VALUE *valp)
228 {
229  id_key_t key = id2key(id);
230  int index = hash_table_index(tbl, key);
231 
232  if (index >= 0) {
233  *valp = tbl->items[index].val;
234  return TRUE;
235  }
236  else {
237  return FALSE;
238  }
239 }
240 
241 static int
242 rb_id_table_insert_key(struct rb_id_table *tbl, const id_key_t key, const VALUE val)
243 {
244  const int index = hash_table_index(tbl, key);
245 
246  if (index >= 0) {
247  tbl->items[index].val = val;
248  }
249  else {
250  hash_table_extend(tbl);
251  hash_table_raw_insert(tbl, key, val);
252  }
253  return TRUE;
254 }
255 
256 int
257 rb_id_table_insert(struct rb_id_table *tbl, ID id, VALUE val)
258 {
259  return rb_id_table_insert_key(tbl, id2key(id), val);
260 }
261 
262 int
263 rb_id_table_delete(struct rb_id_table *tbl, ID id)
264 {
265  const id_key_t key = id2key(id);
266  int index = hash_table_index(tbl, key);
267  return hash_delete_index(tbl, index);
268 }
269 
270 void
271 rb_id_table_foreach(struct rb_id_table *tbl, rb_id_table_foreach_func_t *func, void *data)
272 {
273  int i, capa = tbl->capa;
274 
275  for (i=0; i<capa; i++) {
276  if (ITEM_KEY_ISSET(tbl, i)) {
277  const id_key_t key = ITEM_GET_KEY(tbl, i);
278  enum rb_id_table_iterator_result ret = (*func)(key2id(key), tbl->items[i].val, data);
279  RUBY_ASSERT(key != 0);
280 
281  if (ret == ID_TABLE_DELETE)
282  hash_delete_index(tbl, i);
283  else if (ret == ID_TABLE_STOP)
284  return;
285  }
286  }
287 }
288 
289 void
290 rb_id_table_foreach_values(struct rb_id_table *tbl, rb_id_table_foreach_values_func_t *func, void *data)
291 {
292  int i, capa = tbl->capa;
293 
294  for (i=0; i<capa; i++) {
295  if (ITEM_KEY_ISSET(tbl, i)) {
296  enum rb_id_table_iterator_result ret = (*func)(tbl->items[i].val, data);
297 
298  if (ret == ID_TABLE_DELETE)
299  hash_delete_index(tbl, i);
300  else if (ret == ID_TABLE_STOP)
301  return;
302  }
303  }
304 }
305 
306 void
307 rb_id_table_foreach_values_with_replace(struct rb_id_table *tbl, rb_id_table_foreach_values_func_t *func, rb_id_table_update_value_callback_func_t *replace, void *data)
308 {
309  int i, capa = tbl->capa;
310 
311  for (i = 0; i < capa; i++) {
312  if (ITEM_KEY_ISSET(tbl, i)) {
313  enum rb_id_table_iterator_result ret = (*func)(tbl->items[i].val, data);
314 
315  if (ret == ID_TABLE_REPLACE) {
316  VALUE val = tbl->items[i].val;
317  ret = (*replace)(&val, data, TRUE);
318  tbl->items[i].val = val;
319  }
320 
321  if (ret == ID_TABLE_STOP)
322  return;
323  }
324  }
325 }
326 
#define RUBY_ASSERT(...)
Asserts that the given expression is truthy if and only if RUBY_DEBUG is truthy.
Definition: assert.h:219
#define ALLOC
Old name of RB_ALLOC.
Definition: memory.h:395
#define xfree
Old name of ruby_xfree.
Definition: xmalloc.h:58
#define ZALLOC_N
Old name of RB_ZALLOC_N.
Definition: memory.h:396
const char * rb_id2name(ID id)
Retrieves the name mapped to the given id.
Definition: symbol.c:992
int capa
Designed capacity of the buffer.
Definition: io.h:11
#define MEMZERO(p, type, n)
Handy macro to erase a region of memory.
Definition: memory.h:355
uintptr_t ID
Type that represents a Ruby identifier such as a variable name.
Definition: value.h:52
uintptr_t VALUE
Type that represents a Ruby object.
Definition: value.h:40