GCC Code Coverage Report

Directory: ./
File: firmware/ext/lua/ltable.c
Date: 2025-10-24 14:26:41
Coverage Exec Excl Total
Lines: 64.7% 257 0 397
Functions: 78.4% 29 0 37
Branches: 48.5% 114 0 235
Decisions: 54.0% 95 - 176
Line Branch Decision Exec Source
1 /*
2 ** $Id: ltable.c $
3 ** Lua tables (hash)
4 ** See Copyright Notice in lua.h
5 */
6
7 #define ltable_c
8 #define LUA_CORE
9
10 #include "lprefix.h"
11
12
13 /*
14 ** Implementation of tables (aka arrays, objects, or hash tables).
15 ** Tables keep its elements in two parts: an array part and a hash part.
16 ** Non-negative integer keys are all candidates to be kept in the array
17 ** part. The actual size of the array is the largest 'n' such that
18 ** more than half the slots between 1 and n are in use.
19 ** Hash uses a mix of chained scatter table with Brent's variation.
20 ** A main invariant of these tables is that, if an element is not
21 ** in its main position (i.e. the 'original' position that its hash gives
22 ** to it), then the colliding element is in its own main position.
23 ** Hence even when the load factor reaches 100%, performance remains good.
24 */
25
26 #include <math.h>
27 #include <limits.h>
28
29 #include "lua.h"
30
31 #include "ldebug.h"
32 #include "ldo.h"
33 #include "lgc.h"
34 #include "lmem.h"
35 #include "lobject.h"
36 #include "lstate.h"
37 #include "lstring.h"
38 #include "ltable.h"
39 #include "lvm.h"
40
41
42 /*
43 ** MAXABITS is the largest integer such that MAXASIZE fits in an
44 ** unsigned int.
45 */
46 #define MAXABITS cast_int(sizeof(int) * CHAR_BIT - 1)
47
48
49 /*
50 ** MAXASIZE is the maximum size of the array part. It is the minimum
51 ** between 2^MAXABITS and the maximum size that, measured in bytes,
52 ** fits in a 'size_t'.
53 */
54 #define MAXASIZE luaM_limitN(1u << MAXABITS, TValue)
55
56 /*
57 ** MAXHBITS is the largest integer such that 2^MAXHBITS fits in a
58 ** signed int.
59 */
60 #define MAXHBITS (MAXABITS - 1)
61
62
63 /*
64 ** MAXHSIZE is the maximum size of the hash part. It is the minimum
65 ** between 2^MAXHBITS and the maximum size such that, measured in bytes,
66 ** it fits in a 'size_t'.
67 */
68 #define MAXHSIZE luaM_limitN(1u << MAXHBITS, Node)
69
70
71 /*
72 ** When the original hash value is good, hashing by a power of 2
73 ** avoids the cost of '%'.
74 */
75 #define hashpow2(t,n) (gnode(t, lmod((n), sizenode(t))))
76
77 /*
78 ** for other types, it is better to avoid modulo by power of 2, as
79 ** they can have many 2 factors.
80 */
81 #define hashmod(t,n) (gnode(t, ((n) % ((sizenode(t)-1)|1))))
82
83
84 #define hashstr(t,str) hashpow2(t, (str)->hash)
85 #define hashboolean(t,p) hashpow2(t, p)
86
87
88 #define hashpointer(t,p) hashmod(t, point2uint(p))
89
90
91 #define dummynode (&dummynode_)
92
93 static const Node dummynode_ = {
94 {{NULL}, LUA_VEMPTY, /* value's value and type */
95 LUA_VNIL, 0, {NULL}} /* key type, next, and key value */
96 };
97
98
99 static const TValue absentkey = {ABSTKEYCONSTANT};
100
101
102 /*
103 ** Hash for integers. To allow a good hash, use the remainder operator
104 ** ('%'). If integer fits as a non-negative int, compute an int
105 ** remainder, which is faster. Otherwise, use an unsigned-integer
106 ** remainder, which uses all bits and ensures a non-negative result.
107 */
108 704 static Node *hashint (const Table *t, lua_Integer i) {
109 704 lua_Unsigned ui = l_castS2U(i);
110
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 704 if (ui <= cast_uint(INT_MAX))
111 704 return hashmod(t, cast_int(ui));
112 else
113 ✗ return hashmod(t, ui);
114 }
115
116
117 /*
118 ** Hash for floating-point numbers.
119 ** The main computation should be just
120 ** n = frexp(n, &i); return (n * INT_MAX) + i
121 ** but there are some numerical subtleties.
122 ** In a two-complement representation, INT_MAX does not has an exact
123 ** representation as a float, but INT_MIN does; because the absolute
124 ** value of 'frexp' is smaller than 1 (unless 'n' is inf/NaN), the
125 ** absolute value of the product 'frexp * -INT_MIN' is smaller or equal
126 ** to INT_MAX. Next, the use of 'unsigned int' avoids overflows when
127 ** adding 'i'; the use of '~u' (instead of '-u') avoids problems with
128 ** INT_MIN.
129 */
130 #if !defined(l_hashfloat)
131 156 static int l_hashfloat (lua_Number n) {
132 int i;
133 lua_Integer ni;
134 156 n = l_mathop(frexp)(n, &i) * -cast_num(INT_MIN);
135
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 156 if (!lua_numbertointeger(n, &ni)) { /* is 'n' inf/-inf/NaN? */
136 lua_assert(luai_numisnan(n) || l_mathop(fabs)(n) == cast_num(HUGE_VAL));
137 ✗ return 0;
138 }
139 else { /* normal case */
140 156 unsigned int u = cast_uint(i) + cast_uint(ni);
141
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 156 return cast_int(u <= cast_uint(INT_MAX) ? u : ~u);
142 }
143 }
144 #endif
145
146
147 /*
148 ** returns the 'main' position of an element in a table (that is,
149 ** the index of its hash value).
150 */
151 136331 static Node *mainpositionTV (const Table *t, const TValue *key) {
152
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 136331 switch (ttypetag(key)) {
153
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 356 case LUA_VNUMINT: {
154 356 lua_Integer i = ivalue(key);
155 356 return hashint(t, i);
156 }
157
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 156 case LUA_VNUMFLT: {
158 156 lua_Number n = fltvalue(key);
159 156 return hashmod(t, l_hashfloat(n));
160 }
161
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 135703 case LUA_VSHRSTR: {
162 135703 TString *ts = tsvalue(key);
163 135703 return hashstr(t, ts);
164 }
165 ✗ case LUA_VLNGSTR: {
166 ✗ TString *ts = tsvalue(key);
167 ✗ return hashpow2(t, luaS_hashlongstr(ts));
168 }
169 ✗ case LUA_VFALSE:
170 ✗ return hashboolean(t, 0);
171 ✗ case LUA_VTRUE:
172 ✗ return hashboolean(t, 1);
173 ✗ case LUA_VLIGHTUSERDATA: {
174 ✗ void *p = pvalue(key);
175 ✗ return hashpointer(t, p);
176 }
177 ✗ case LUA_VLCF: {
178 ✗ lua_CFunction f = fvalue(key);
179 ✗ return hashpointer(t, f);
180 }
181
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 116 default: {
182 116 GCObject *o = gcvalue(key);
183 116 return hashpointer(t, o);
184 }
185 }
186 }
187
188
189 35333 l_sinline Node *mainpositionfromnode (const Table *t, Node *nd) {
190 TValue key;
191 35333 getnodekey(cast(lua_State *, NULL), &key, nd);
192 35333 return mainpositionTV(t, &key);
193 }
194
195
196 /*
197 ** Check whether key 'k1' is equal to the key in node 'n2'. This
198 ** equality is raw, so there are no metamethods. Floats with integer
199 ** values have been normalized, so integers cannot be equal to
200 ** floats. It is assumed that 'eqshrstr' is simply pointer equality, so
201 ** that short strings are handled in the default case.
202 ** A true 'deadok' means to accept dead keys as equal to their original
203 ** values. All dead keys are compared in the default case, by pointer
204 ** identity. (Only collectable objects can produce dead keys.) Note that
205 ** dead long strings are also compared by identity.
206 ** Once a key is dead, its corresponding value may be collected, and
207 ** then another value can be created with the same address. If this
208 ** other value is given to 'next', 'equalkey' will signal a false
209 ** positive. In a regular traversal, this situation should never happen,
210 ** as all keys given to 'next' came from the table itself, and therefore
211 ** could not have been collected. Outside a regular traversal, we
212 ** have garbage in, garbage out. What is relevant is that this false
213 ** positive does not break anything. (In particular, 'next' will return
214 ** some other valid item on the table or nil.)
215 */
216 170 static int equalkey (const TValue *k1, const Node *n2, int deadok) {
217
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 170 if ((rawtt(k1) != keytt(n2)) && /* not the same variants? */
218 ✗ !(deadok && keyisdead(n2) && iscollectable(k1)))
219 123 return 0; /* cannot be same key */
220
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 47 switch (keytt(n2)) {
221 ✗ case LUA_VNIL: case LUA_VFALSE: case LUA_VTRUE:
222 ✗ return 1;
223 ✗ case LUA_VNUMINT:
224 ✗ return (ivalue(k1) == keyival(n2));
225
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 8 case LUA_VNUMFLT:
226 8 return luai_numeq(fltvalue(k1), fltvalueraw(keyval(n2)));
227 ✗ case LUA_VLIGHTUSERDATA:
228 ✗ return pvalue(k1) == pvalueraw(keyval(n2));
229 ✗ case LUA_VLCF:
230 ✗ return fvalue(k1) == fvalueraw(keyval(n2));
231 ✗ case ctb(LUA_VLNGSTR):
232 ✗ return luaS_eqlngstr(tsvalue(k1), keystrval(n2));
233
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 39 default:
234 39 return gcvalue(k1) == gcvalueraw(keyval(n2));
235 }
236 }
237
238
239 /*
240 ** True if value of 'alimit' is equal to the real size of the array
241 ** part of table 't'. (Otherwise, the array part must be larger than
242 ** 'alimit'.)
243 */
244 #define limitequalsasize(t) (isrealasize(t) || ispow2((t)->alimit))
245
246
247 /*
248 ** Returns the real size of the 'array' array
249 */
250 42965 LUAI_FUNC unsigned int luaH_realasize (const Table *t) {
251
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 42965 if (limitequalsasize(t))
252 42965 return t->alimit; /* this is the size */
253 else {
254 ✗ unsigned int size = t->alimit;
255 /* compute the smallest power of 2 not smaller than 'n' */
256 ✗ size |= (size >> 1);
257 ✗ size |= (size >> 2);
258 ✗ size |= (size >> 4);
259 ✗ size |= (size >> 8);
260 #if (UINT_MAX >> 14) > 3 /* unsigned int has more than 16 bits */
261 ✗ size |= (size >> 16);
262 #if (UINT_MAX >> 30) > 3
263 size |= (size >> 32); /* unsigned int has more than 32 bits */
264 #endif
265 #endif
266 ✗ size++;
267 lua_assert(ispow2(size) && size/2 < t->alimit && t->alimit < size);
268 ✗ return size;
269 }
270 }
271
272
273 /*
274 ** Check whether real size of the array is a power of 2.
275 ** (If it is not, 'alimit' cannot be changed to any other value
276 ** without changing the real size.)
277 */
278 ✗ static int ispow2realasize (const Table *t) {
279 ✗ return (!isrealasize(t) || ispow2(t->alimit));
280 }
281
282
283 24637 static unsigned int setlimittosize (Table *t) {
284 24637 t->alimit = luaH_realasize(t);
285 24637 setrealasize(t);
286 24637 return t->alimit;
287 }
288
289
290 #define limitasasize(t) check_exp(isrealasize(t), t->alimit)
291
292
293
294 /*
295 ** "Generic" get version. (Not that generic: not valid for integers,
296 ** which may be in array part, nor for floats with integral values.)
297 ** See explanation about 'deadok' in function 'equalkey'.
298 */
299 147 static const TValue *getgeneric (Table *t, const TValue *key, int deadok) {
300 147 Node *n = mainpositionTV(t, key);
301 for (;;) { /* check whether 'key' is somewhere in the chain */
302
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 170 if (equalkey(key, n, deadok))
303 46 return gval(n); /* that's it */
304 else {
305 124 int nx = gnext(n);
306
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 124 if (nx == 0)
307 101 return &absentkey; /* not found */
308 23 n += nx;
309 }
310 }
311 }
312
313
314 /*
315 ** returns the index for 'k' if 'k' is an appropriate key to live in
316 ** the array part of a table, 0 otherwise.
317 */
318 127 static unsigned int arrayindex (lua_Integer k) {
319
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 127 if (l_castS2U(k) - 1u < MAXASIZE) /* 'k' in [1, MAXASIZE]? */
320 127 return cast_uint(k); /* 'key' is an appropriate array index */
321 else
322 ✗ return 0;
323 }
324
325
326 /*
327 ** returns the index of a 'key' for table traversals. First goes all
328 ** elements in the array part, then elements in the hash part. The
329 ** beginning of a traversal is signaled by 0.
330 */
331 ✗ static unsigned int findindex (lua_State *L, Table *t, TValue *key,
332 unsigned int asize) {
333 unsigned int i;
334 ✗ if (ttisnil(key)) return 0; /* first iteration */
335 ✗ i = ttisinteger(key) ? arrayindex(ivalue(key)) : 0;
336 ✗ if (i - 1u < asize) /* is 'key' inside array part? */
337 ✗ return i; /* yes; that's the index */
338 else {
339 ✗ const TValue *n = getgeneric(t, key, 1);
340 ✗ if (l_unlikely(isabstkey(n)))
341 ✗ luaG_runerror(L, "invalid key to 'next'"); /* key not found */
342 ✗ i = cast_int(nodefromval(n) - gnode(t, 0)); /* key index in hash table */
343 /* hash elements are numbered after array ones */
344 ✗ return (i + 1) + asize;
345 }
346 }
347
348
349 ✗ int luaH_next (lua_State *L, Table *t, StkId key) {
350 ✗ unsigned int asize = luaH_realasize(t);
351 ✗ unsigned int i = findindex(L, t, s2v(key), asize); /* find original key */
352 ✗ for (; i < asize; i++) { /* try first array part */
353 ✗ if (!isempty(&t->array[i])) { /* a non-empty entry? */
354 ✗ setivalue(s2v(key), i + 1);
355 ✗ setobj2s(L, key + 1, &t->array[i]);
356 ✗ return 1;
357 }
358 }
359 ✗ for (i -= asize; cast_int(i) < sizenode(t); i++) { /* hash part */
360 ✗ if (!isempty(gval(gnode(t, i)))) { /* a non-empty entry? */
361 ✗ Node *n = gnode(t, i);
362 ✗ getnodekey(L, s2v(key), n);
363 ✗ setobj2s(L, key + 1, gval(n));
364 ✗ return 1;
365 }
366 }
367 ✗ return 0; /* no more elements */
368 }
369
370
371 21387 static void freehash (lua_State *L, Table *t) {
372
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 21387 if (!isdummy(t))
373 14048 luaM_freearray(L, t->node, cast_sizet(sizenode(t)));
374 21387 }
375
376
377 /*
378 ** {=============================================================
379 ** Rehash
380 ** ==============================================================
381 */
382
383 /*
384 ** Compute the optimal size for the array part of table 't'. 'nums' is a
385 ** "count array" where 'nums[i]' is the number of integers in the table
386 ** between 2^(i - 1) + 1 and 2^i. 'pna' enters with the total number of
387 ** integer keys in the table and leaves with the number of keys that
388 ** will go to the array part; return the optimal size. (The condition
389 ** 'twotoi > 0' in the for loop stops the loop if 'twotoi' overflows.)
390 */
391 10187 static unsigned int computesizes (unsigned int nums[], unsigned int *pna) {
392 int i;
393 unsigned int twotoi; /* 2^i (candidate for optimal size) */
394 10187 unsigned int a = 0; /* number of elements smaller than 2^i */
395 10187 unsigned int na = 0; /* number of elements to go to array part */
396 10187 unsigned int optimal = 0; /* optimal size for array part */
397 /* loop while keys can fill more than half of total size */
398 10187 for (i = 0, twotoi = 1;
399
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 13280 twotoi > 0 && *pna > twotoi / 2;
400 3093 i++, twotoi *= 2) {
401 3093 a += nums[i];
402
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 3093 if (a > twotoi/2) { /* more than half elements present? */
403 2970 optimal = twotoi; /* optimal size (till now) */
404 2970 na = a; /* all elements up to 'optimal' will go to array part */
405 }
406 }
407 lua_assert((optimal == 0 || optimal / 2 < na) && na <= optimal);
408 10187 *pna = na;
409 10187 return optimal;
410 }
411
412
413 127 static int countint (lua_Integer key, unsigned int *nums) {
414 127 unsigned int k = arrayindex(key);
415
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 127 if (k != 0) { /* is 'key' an appropriate array index? */
416 127 nums[luaO_ceillog2(k)]++; /* count as such */
417 127 return 1;
418 }
419 else
420 ✗ return 0;
421 }
422
423
424 /*
425 ** Count keys in array part of table 't': Fill 'nums[i]' with
426 ** number of keys that will go into corresponding slice and return
427 ** total number of non-nil keys.
428 */
429 10187 static unsigned int numusearray (const Table *t, unsigned int *nums) {
430 int lg;
431 unsigned int ttlg; /* 2^lg */
432 10187 unsigned int ause = 0; /* summation of 'nums' */
433 10187 unsigned int i = 1; /* count to traverse all array keys */
434 10187 unsigned int asize = limitasasize(t); /* real array size */
435 /* traverse each slice */
436
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 13157 for (lg = 0, ttlg = 1; lg <= MAXABITS; lg++, ttlg *= 2) {
437 13157 unsigned int lc = 0; /* counter */
438 13157 unsigned int lim = ttlg;
439
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 13157 if (lim > asize) {
440 10187 lim = asize; /* adjust upper limit */
441
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 10187 if (i > lim)
442 10187 break; /* no more elements to count */
443 }
444 /* count elements in range (2^(lg - 1), 2^lg] */
445
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 5940 for (; i <= lim; i++) {
446
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 2970 if (!isempty(&t->array[i-1]))
447 2970 lc++;
448 }
449 2970 nums[lg] += lc;
450 2970 ause += lc;
451 }
452 10187 return ause;
453 }
454
455
456 10187 static int numusehash (const Table *t, unsigned int *nums, unsigned int *pna) {
457 10187 int totaluse = 0; /* total number of elements */
458 10187 int ause = 0; /* elements added to 'nums' (can go to array part) */
459 10187 int i = sizenode(t);
460
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 54316 while (i--) {
461 44129 Node *n = &t->node[i];
462
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 44129 if (!isempty(gval(n))) {
463
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 41159 if (keyisinteger(n))
464 102 ause += countint(keyival(n), nums);
465 41159 totaluse++;
466 }
467 }
468 10187 *pna += ause;
469 10187 return totaluse;
470 }
471
472
473 /*
474 ** Creates an array for the hash part of a table with the given
475 ** size, or reuses the dummy node if size is zero.
476 ** The computation for size overflow is in two steps: the first
477 ** comparison ensures that the shift in the second one does not
478 ** overflow.
479 */
480 21387 static void setnodevector (lua_State *L, Table *t, unsigned int size) {
481
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 21387 if (size == 0) { /* no elements to hash part? */
482 7339 t->node = cast(Node *, dummynode); /* use common 'dummynode' */
483 7339 t->lsizenode = 0;
484 7339 t->lastfree = NULL; /* signal that it is using dummy node */
485 }
486 else {
487 int i;
488 14048 int lsize = luaO_ceillog2(size);
489
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 14048 if (lsize > MAXHBITS || (1u << lsize) > MAXHSIZE)
490 ✗ luaG_runerror(L, "table overflow");
491 14048 size = twoto(lsize);
492 14048 t->node = luaM_newvector(L, size, Node);
493
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 115968 for (i = 0; i < cast_int(size); i++) {
494 101920 Node *n = gnode(t, i);
495 101920 gnext(n) = 0;
496 101920 setnilkey(n);
497 101920 setempty(gval(n));
498 }
499 14048 t->lsizenode = cast_byte(lsize);
500 14048 t->lastfree = gnode(t, size); /* all positions are free */
501 }
502 21387 }
503
504
505 /*
506 ** (Re)insert all elements from the hash part of 'ot' into table 't'.
507 */
508 14450 static void reinsert (lua_State *L, Table *ot, Table *t) {
509 int j;
510 14450 int size = sizenode(ot);
511
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 62842 for (j = 0; j < size; j++) {
512 48392 Node *old = gnode(ot, j);
513
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 48392 if (!isempty(gval(old))) {
514 /* doesn't need barrier/invalidate cache, as entry was
515 already present in the table */
516 TValue k;
517 41159 getnodekey(L, &k, old);
518 41159 luaH_set(L, t, &k, gval(old));
519 }
520 }
521 14450 }
522
523
524 /*
525 ** Exchange the hash part of 't1' and 't2'.
526 */
527 14450 static void exchangehashpart (Table *t1, Table *t2) {
528 14450 lu_byte lsizenode = t1->lsizenode;
529 14450 Node *node = t1->node;
530 14450 Node *lastfree = t1->lastfree;
531 14450 t1->lsizenode = t2->lsizenode;
532 14450 t1->node = t2->node;
533 14450 t1->lastfree = t2->lastfree;
534 14450 t2->lsizenode = lsizenode;
535 14450 t2->node = node;
536 14450 t2->lastfree = lastfree;
537 14450 }
538
539
540 /*
541 ** Resize table 't' for the new given sizes. Both allocations (for
542 ** the hash part and for the array part) can fail, which creates some
543 ** subtleties. If the first allocation, for the hash part, fails, an
544 ** error is raised and that is it. Otherwise, it copies the elements from
545 ** the shrinking part of the array (if it is shrinking) into the new
546 ** hash. Then it reallocates the array part. If that fails, the table
547 ** is in its original state; the function frees the new hash part and then
548 ** raises the allocation error. Otherwise, it sets the new hash part
549 ** into the table, initializes the new part of the array (if any) with
550 ** nils and reinserts the elements of the old hash back into the new
551 ** parts of the table.
552 */
553 14450 void luaH_resize (lua_State *L, Table *t, unsigned int newasize,
554 unsigned int nhsize) {
555 unsigned int i;
556 Table newt; /* to keep the new hash part */
557 14450 unsigned int oldasize = setlimittosize(t);
558 TValue *newarray;
559 /* create new hash part with appropriate size into 'newt' */
560 14450 setnodevector(L, &newt, nhsize);
561
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 14450 if (newasize < oldasize) { /* will array shrink? */
562 ✗ t->alimit = newasize; /* pretend array has new size... */
563 ✗ exchangehashpart(t, &newt); /* and new hash */
564 /* re-insert into the new hash the elements from vanishing slice */
565 ✗ for (i = newasize; i < oldasize; i++) {
566 ✗ if (!isempty(&t->array[i]))
567 ✗ luaH_setint(L, t, i + 1, &t->array[i]);
568 }
569 ✗ t->alimit = oldasize; /* restore current size... */
570 ✗ exchangehashpart(t, &newt); /* and hash (in case of errors) */
571 }
572 /* allocate new array */
573 14450 newarray = luaM_reallocvector(L, t->array, oldasize, newasize, TValue);
574
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 14450 if (l_unlikely(newarray == NULL && newasize > 0)) { /* allocation failed? */
575 ✗ freehash(L, &newt); /* release new hash part */
576 ✗ luaM_error(L); /* raise error (with array unchanged) */
577 }
578 /* allocation ok; initialize new part of the array */
579 14450 exchangehashpart(t, &newt); /* 't' has the new hash ('newt' has the old) */
580 14450 t->array = newarray; /* set new array part */
581 14450 t->alimit = newasize;
582
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 15840 for (i = oldasize; i < newasize; i++) /* clear new slice of the array */
583 1390 setempty(&t->array[i]);
584 /* re-insert elements from old hash part into new parts */
585 14450 reinsert(L, &newt, t); /* 'newt' now has the old hash */
586 14450 freehash(L, &newt); /* free old hash part */
587 14450 }
588
589
590 ✗ void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize) {
591 ✗ int nsize = allocsizenode(t);
592 ✗ luaH_resize(L, t, nasize, nsize);
593 ✗ }
594
595 /*
596 ** nums[i] = number of keys 'k' where 2^(i - 1) < k <= 2^i
597 */
598 10187 static void rehash (lua_State *L, Table *t, const TValue *ek) {
599 unsigned int asize; /* optimal size for array part */
600 unsigned int na; /* number of keys in the array part */
601 unsigned int nums[MAXABITS + 1];
602 int i;
603 int totaluse;
604
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 336171 for (i = 0; i <= MAXABITS; i++) nums[i] = 0; /* reset counts */
605 10187 setlimittosize(t);
606 10187 na = numusearray(t, nums); /* count keys in array part */
607 10187 totaluse = na; /* all those keys are integer keys */
608 10187 totaluse += numusehash(t, nums, &na); /* count keys in hash part */
609 /* count extra key */
610
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 10187 if (ttisinteger(ek))
611 25 na += countint(ivalue(ek), nums);
612 10187 totaluse++;
613 /* compute new size for array part */
614 10187 asize = computesizes(nums, &na);
615 /* resize the table to new computed sizes */
616 10187 luaH_resize(L, t, asize, totaluse - na);
617 10187 }
618
619
620
621 /*
622 ** }=============================================================
623 */
624
625
626 6937 Table *luaH_new (lua_State *L) {
627 6937 GCObject *o = luaC_newobj(L, LUA_VTABLE, sizeof(Table));
628 6937 Table *t = gco2t(o);
629 6937 t->metatable = NULL;
630 6937 t->flags = cast_byte(maskflags); /* table has no metamethod fields */
631 6937 t->array = NULL;
632 6937 t->alimit = 0;
633 6937 setnodevector(L, t, 0);
634 6937 return t;
635 }
636
637
638 6937 void luaH_free (lua_State *L, Table *t) {
639 6937 freehash(L, t);
640 6937 luaM_freearray(L, t->array, luaH_realasize(t));
641 6937 luaM_free(L, t);
642 6937 }
643
644
645 45520 static Node *getfreepos (Table *t) {
646
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 45520 if (!isdummy(t)) {
647
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 79823 while (t->lastfree > t->node) {
648 72606 t->lastfree--;
649
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 72606 if (keyisnil(t->lastfree))
650 35333 return t->lastfree;
651 }
652 }
653 10187 return NULL; /* could not find a free place */
654 }
655
656
657
658 /*
659 ** inserts a new key into a hash table; first, check whether key's main
660 ** position is free. If not, check whether colliding node is in its main
661 ** position or not: if it is not, move colliding node to an empty place and
662 ** put new key in its main position; otherwise (colliding node is in its main
663 ** position), new key goes to an empty position.
664 */
665 100851 void luaH_newkey (lua_State *L, Table *t, const TValue *key, TValue *value) {
666 Node *mp;
667 TValue aux;
668
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 100851 if (l_unlikely(ttisnil(key)))
669 ✗ luaG_runerror(L, "table index is nil");
670
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 100851 else if (ttisfloat(key)) {
671 68 lua_Number f = fltvalue(key);
672 lua_Integer k;
673
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 68 if (luaV_flttointeger(f, &k, F2Ieq)) { /* does key fit in an integer? */
674 ✗ setivalue(&aux, k);
675 ✗ key = &aux; /* insert it as an integer */
676 }
677
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 68 else if (l_unlikely(luai_numisnan(f)))
678 ✗ luaG_runerror(L, "table index is NaN");
679 }
680
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 100851 if (ttisnil(value))
681 10187 return; /* do not insert nil values */
682 100851 mp = mainpositionTV(t, key);
683
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 100851 if (!isempty(gval(mp)) || isdummy(t)) { /* main position is taken? */
684 Node *othern;
685 45520 Node *f = getfreepos(t); /* get a free place */
686
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 45520 if (f == NULL) { /* cannot find a free place? */
687 10187 rehash(L, t, key); /* grow table */
688 /* whatever called 'newkey' takes care of TM cache */
689 10187 luaH_set(L, t, key, value); /* insert key into grown table */
690 10187 return;
691 }
692 lua_assert(!isdummy(t));
693 35333 othern = mainpositionfromnode(t, mp);
694
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 35333 if (othern != mp) { /* is colliding node out of its main position? */
695 /* yes; move colliding node into free position */
696
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 9123 while (othern + gnext(othern) != mp) /* find previous */
697 1545 othern += gnext(othern);
698 7578 gnext(othern) = cast_int(f - othern); /* rechain to point to 'f' */
699 7578 *f = *mp; /* copy colliding node into free pos. (mp->next also goes) */
700
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 7578 if (gnext(mp) != 0) {
701 1226 gnext(f) += cast_int(mp - f); /* correct 'next' */
702 1226 gnext(mp) = 0; /* now 'mp' is free */
703 }
704 7578 setempty(gval(mp));
705 }
706 else { /* colliding node is in its own main position */
707 /* new node will go into free position */
708
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 27755 if (gnext(mp) != 0)
709 5887 gnext(f) = cast_int((mp + gnext(mp)) - f); /* chain new position */
710 else lua_assert(gnext(f) == 0);
711 27755 gnext(mp) = cast_int(f - mp);
712 27755 mp = f;
713 }
714 }
715 90664 setnodekey(L, mp, key);
716
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 90664 luaC_barrierback(L, obj2gco(t), key);
717 lua_assert(isempty(gval(mp)));
718 90664 setobj2t(L, gval(mp), value);
719 }
720
721
722 /*
723 ** Search function for integers. If integer is inside 'alimit', get it
724 ** directly from the array part. Otherwise, if 'alimit' is not equal to
725 ** the real size of the array, key still can be in the array part. In
726 ** this case, try to avoid a call to 'luaH_realasize' when key is just
727 ** one more than the limit (so that it can be incremented without
728 ** changing the real size of the array).
729 */
730 390 const TValue *luaH_getint (Table *t, lua_Integer key) {
731
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 390 if (l_castS2U(key) - 1u < t->alimit) /* 'key' in [1, t->alimit]? */
732 42 return &t->array[key - 1];
733
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 348 else if (!limitequalsasize(t) && /* key still may be in the array part? */
734 ✗ (l_castS2U(key) == t->alimit + 1 ||
735 ✗ l_castS2U(key) - 1u < luaH_realasize(t))) {
736 ✗ t->alimit = cast_uint(key); /* probably '#t' is here now */
737 ✗ return &t->array[key - 1];
738 }
739 else {
740 348 Node *n = hashint(t, key);
741 for (;;) { /* check whether 'key' is somewhere in the chain */
742
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 407 if (keyisinteger(n) && keyival(n) == key)
743 36 return gval(n); /* that's it */
744 else {
745 371 int nx = gnext(n);
746
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 371 if (nx == 0) break;
747 59 n += nx;
748 }
749 }
750 312 return &absentkey;
751 }
752 }
753
754
755 /*
756 ** search function for short strings
757 */
758 123342 const TValue *luaH_getshortstr (Table *t, TString *key) {
759 123342 Node *n = hashstr(t, key);
760 lua_assert(key->tt == LUA_VSHRSTR);
761 for (;;) { /* check whether 'key' is somewhere in the chain */
762
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 142727 if (keyisshrstr(n) && eqshrstr(keystrval(n), key))
763 16909 return gval(n); /* that's it */
764 else {
765 125818 int nx = gnext(n);
766
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 125818 if (nx == 0)
767 106433 return &absentkey; /* not found */
768 19385 n += nx;
769 }
770 }
771 }
772
773
774 60009 const TValue *luaH_getstr (Table *t, TString *key) {
775
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 60009 if (key->tt == LUA_VSHRSTR)
776 60009 return luaH_getshortstr(t, key);
777 else { /* for long strings, use generic case */
778 TValue ko;
779 ✗ setsvalue(cast(lua_State *, NULL), &ko, key);
780 ✗ return getgeneric(t, &ko, 0);
781 }
782 }
783
784
785 /*
786 ** main search function
787 */
788 58424 const TValue *luaH_get (Table *t, const TValue *key) {
789
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 58424 switch (ttypetag(key)) {
790
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 57932 case LUA_VSHRSTR: return luaH_getshortstr(t, tsvalue(key));
791
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 294 case LUA_VNUMINT: return luaH_getint(t, ivalue(key));
792 ✗ case LUA_VNIL: return &absentkey;
793
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 126 case LUA_VNUMFLT: {
794 lua_Integer k;
795
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 126 if (luaV_flttointeger(fltvalue(key), &k, F2Ieq)) /* integral index? */
796 51 return luaH_getint(t, k); /* use specialized version */
797 /* else... */
798 } /* FALLTHROUGH */
799 default:
800
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 147 return getgeneric(t, key, 0);
801 }
802 }
803
804
805 /*
806 ** Finish a raw "set table" operation, where 'slot' is where the value
807 ** should have been (the result of a previous "get table").
808 ** Beware: when using this function you probably need to check a GC
809 ** barrier and invalidate the TM cache.
810 */
811 101921 void luaH_finishset (lua_State *L, Table *t, const TValue *key,
812 const TValue *slot, TValue *value) {
813
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 101921 if (isabstkey(slot))
814 100851 luaH_newkey(L, t, key, value);
815 else
816 1070 setobj2t(L, cast(TValue *, slot), value);
817 101921 }
818
819
820 /*
821 ** beware: when using this function you probably need to check a GC
822 ** barrier and invalidate the TM cache.
823 */
824 51346 void luaH_set (lua_State *L, Table *t, const TValue *key, TValue *value) {
825 51346 const TValue *slot = luaH_get(t, key);
826 51346 luaH_finishset(L, t, key, slot, value);
827 51346 }
828
829
830 ✗ void luaH_setint (lua_State *L, Table *t, lua_Integer key, TValue *value) {
831 ✗ const TValue *p = luaH_getint(t, key);
832 ✗ if (isabstkey(p)) {
833 TValue k;
834 ✗ setivalue(&k, key);
835 ✗ luaH_newkey(L, t, &k, value);
836 }
837 else
838 ✗ setobj2t(L, cast(TValue *, p), value);
839 ✗ }
840
841
842 /*
843 ** Try to find a boundary in the hash part of table 't'. From the
844 ** caller, we know that 'j' is zero or present and that 'j + 1' is
845 ** present. We want to find a larger key that is absent from the
846 ** table, so that we can do a binary search between the two keys to
847 ** find a boundary. We keep doubling 'j' until we get an absent index.
848 ** If the doubling would overflow, we try LUA_MAXINTEGER. If it is
849 ** absent, we are ready for the binary search. ('j', being max integer,
850 ** is larger or equal to 'i', but it cannot be equal because it is
851 ** absent while 'i' is present; so 'j > i'.) Otherwise, 'j' is a
852 ** boundary. ('j + 1' cannot be a present integer key because it is
853 ** not a valid integer in Lua.)
854 */
855 ✗ static lua_Unsigned hash_search (Table *t, lua_Unsigned j) {
856 lua_Unsigned i;
857 ✗ if (j == 0) j++; /* the caller ensures 'j + 1' is present */
858 do {
859 ✗ i = j; /* 'i' is a present index */
860 ✗ if (j <= l_castS2U(LUA_MAXINTEGER) / 2)
861 ✗ j *= 2;
862 else {
863 ✗ j = LUA_MAXINTEGER;
864 ✗ if (isempty(luaH_getint(t, j))) /* t[j] not present? */
865 ✗ break; /* 'j' now is an absent index */
866 else /* weird case */
867 ✗ return j; /* well, max integer is a boundary... */
868 }
869 ✗ } while (!isempty(luaH_getint(t, j))); /* repeat until an absent t[j] */
870 /* i < j && t[i] present && t[j] absent */
871 ✗ while (j - i > 1u) { /* do a binary search between them */
872 ✗ lua_Unsigned m = (i + j) / 2;
873 ✗ if (isempty(luaH_getint(t, m))) j = m;
874 ✗ else i = m;
875 }
876 ✗ return i;
877 }
878
879
880 ✗ static unsigned int binsearch (const TValue *array, unsigned int i,
881 unsigned int j) {
882 ✗ while (j - i > 1u) { /* binary search */
883 ✗ unsigned int m = (i + j) / 2;
884 ✗ if (isempty(&array[m - 1])) j = m;
885 ✗ else i = m;
886 }
887 ✗ return i;
888 }
889
890
891 /*
892 ** Try to find a boundary in table 't'. (A 'boundary' is an integer index
893 ** such that t[i] is present and t[i+1] is absent, or 0 if t[1] is absent
894 ** and 'maxinteger' if t[maxinteger] is present.)
895 ** (In the next explanation, we use Lua indices, that is, with base 1.
896 ** The code itself uses base 0 when indexing the array part of the table.)
897 ** The code starts with 'limit = t->alimit', a position in the array
898 ** part that may be a boundary.
899 **
900 ** (1) If 't[limit]' is empty, there must be a boundary before it.
901 ** As a common case (e.g., after 't[#t]=nil'), check whether 'limit-1'
902 ** is present. If so, it is a boundary. Otherwise, do a binary search
903 ** between 0 and limit to find a boundary. In both cases, try to
904 ** use this boundary as the new 'alimit', as a hint for the next call.
905 **
906 ** (2) If 't[limit]' is not empty and the array has more elements
907 ** after 'limit', try to find a boundary there. Again, try first
908 ** the special case (which should be quite frequent) where 'limit+1'
909 ** is empty, so that 'limit' is a boundary. Otherwise, check the
910 ** last element of the array part. If it is empty, there must be a
911 ** boundary between the old limit (present) and the last element
912 ** (absent), which is found with a binary search. (This boundary always
913 ** can be a new limit.)
914 **
915 ** (3) The last case is when there are no elements in the array part
916 ** (limit == 0) or its last element (the new limit) is present.
917 ** In this case, must check the hash part. If there is no hash part
918 ** or 'limit+1' is absent, 'limit' is a boundary. Otherwise, call
919 ** 'hash_search' to find a boundary in the hash part of the table.
920 ** (In those cases, the boundary is not inside the array part, and
921 ** therefore cannot be used as a new limit.)
922 */
923 ✗ lua_Unsigned luaH_getn (Table *t) {
924 ✗ unsigned int limit = t->alimit;
925 ✗ if (limit > 0 && isempty(&t->array[limit - 1])) { /* (1)? */
926 /* there must be a boundary before 'limit' */
927 ✗ if (limit >= 2 && !isempty(&t->array[limit - 2])) {
928 /* 'limit - 1' is a boundary; can it be a new limit? */
929 ✗ if (ispow2realasize(t) && !ispow2(limit - 1)) {
930 ✗ t->alimit = limit - 1;
931 ✗ setnorealasize(t); /* now 'alimit' is not the real size */
932 }
933 ✗ return limit - 1;
934 }
935 else { /* must search for a boundary in [0, limit] */
936 ✗ unsigned int boundary = binsearch(t->array, 0, limit);
937 /* can this boundary represent the real size of the array? */
938 ✗ if (ispow2realasize(t) && boundary > luaH_realasize(t) / 2) {
939 ✗ t->alimit = boundary; /* use it as the new limit */
940 ✗ setnorealasize(t);
941 }
942 ✗ return boundary;
943 }
944 }
945 /* 'limit' is zero or present in table */
946 ✗ if (!limitequalsasize(t)) { /* (2)? */
947 /* 'limit' > 0 and array has more elements after 'limit' */
948 ✗ if (isempty(&t->array[limit])) /* 'limit + 1' is empty? */
949 ✗ return limit; /* this is the boundary */
950 /* else, try last element in the array */
951 ✗ limit = luaH_realasize(t);
952 ✗ if (isempty(&t->array[limit - 1])) { /* empty? */
953 /* there must be a boundary in the array after old limit,
954 and it must be a valid new limit */
955 ✗ unsigned int boundary = binsearch(t->array, t->alimit, limit);
956 ✗ t->alimit = boundary;
957 ✗ return boundary;
958 }
959 /* else, new limit is present in the table; check the hash part */
960 }
961 /* (3) 'limit' is the last element and either is zero or present in table */
962 lua_assert(limit == luaH_realasize(t) &&
963 (limit == 0 || !isempty(&t->array[limit - 1])));
964 ✗ if (isdummy(t) || isempty(luaH_getint(t, cast(lua_Integer, limit + 1))))
965 ✗ return limit; /* 'limit + 1' is absent */
966 else /* 'limit + 1' is also present */
967 ✗ return hash_search(t, limit);
968 }
969
970
971
972 #if defined(LUA_DEBUG)
973
974 /* export these functions for the test library */
975
976 Node *luaH_mainposition (const Table *t, const TValue *key) {
977 return mainpositionTV(t, key);
978 }
979
980 #endif
981