diff options
Diffstat (limited to '3rdparty/lua/src/ltable.c')
-rw-r--r-- | 3rdparty/lua/src/ltable.c | 669 |
1 files changed, 0 insertions, 669 deletions
diff --git a/3rdparty/lua/src/ltable.c b/3rdparty/lua/src/ltable.c deleted file mode 100644 index d080189..0000000 --- a/3rdparty/lua/src/ltable.c +++ /dev/null @@ -1,669 +0,0 @@ -/* -** $Id: ltable.c,v 2.118 2016/11/07 12:38:35 roberto Exp $ -** Lua tables (hash) -** See Copyright Notice in lua.h -*/ - -#define ltable_c -#define LUA_CORE - -#include "lprefix.h" - - -/* -** Implementation of tables (aka arrays, objects, or hash tables). -** Tables keep its elements in two parts: an array part and a hash part. -** Non-negative integer keys are all candidates to be kept in the array -** part. The actual size of the array is the largest 'n' such that -** more than half the slots between 1 and n are in use. -** Hash uses a mix of chained scatter table with Brent's variation. -** A main invariant of these tables is that, if an element is not -** in its main position (i.e. the 'original' position that its hash gives -** to it), then the colliding element is in its own main position. -** Hence even when the load factor reaches 100%, performance remains good. -*/ - -#include <math.h> -#include <limits.h> - -#include "lua.h" - -#include "ldebug.h" -#include "ldo.h" -#include "lgc.h" -#include "lmem.h" -#include "lobject.h" -#include "lstate.h" -#include "lstring.h" -#include "ltable.h" -#include "lvm.h" - - -/* -** Maximum size of array part (MAXASIZE) is 2^MAXABITS. MAXABITS is -** the largest integer such that MAXASIZE fits in an unsigned int. -*/ -#define MAXABITS cast_int(sizeof(int) * CHAR_BIT - 1) -#define MAXASIZE (1u << MAXABITS) - -/* -** Maximum size of hash part is 2^MAXHBITS. MAXHBITS is the largest -** integer such that 2^MAXHBITS fits in a signed int. (Note that the -** maximum number of elements in a table, 2^MAXABITS + 2^MAXHBITS, still -** fits comfortably in an unsigned int.) -*/ -#define MAXHBITS (MAXABITS - 1) - - -#define hashpow2(t,n) (gnode(t, lmod((n), sizenode(t)))) - -#define hashstr(t,str) hashpow2(t, (str)->hash) -#define hashboolean(t,p) hashpow2(t, p) -#define hashint(t,i) hashpow2(t, i) - - -/* -** for some types, it is better to avoid modulus by power of 2, as -** they tend to have many 2 factors. -*/ -#define hashmod(t,n) (gnode(t, ((n) % ((sizenode(t)-1)|1)))) - - -#define hashpointer(t,p) hashmod(t, point2uint(p)) - - -#define dummynode (&dummynode_) - -static const Node dummynode_ = { - {NILCONSTANT}, /* value */ - {{NILCONSTANT, 0}} /* key */ -}; - - -/* -** Hash for floating-point numbers. -** The main computation should be just -** n = frexp(n, &i); return (n * INT_MAX) + i -** but there are some numerical subtleties. -** In a two-complement representation, INT_MAX does not has an exact -** representation as a float, but INT_MIN does; because the absolute -** value of 'frexp' is smaller than 1 (unless 'n' is inf/NaN), the -** absolute value of the product 'frexp * -INT_MIN' is smaller or equal -** to INT_MAX. Next, the use of 'unsigned int' avoids overflows when -** adding 'i'; the use of '~u' (instead of '-u') avoids problems with -** INT_MIN. -*/ -#if !defined(l_hashfloat) -static int l_hashfloat (lua_Number n) { - int i; - lua_Integer ni; - n = l_mathop(frexp)(n, &i) * -cast_num(INT_MIN); - if (!lua_numbertointeger(n, &ni)) { /* is 'n' inf/-inf/NaN? */ - lua_assert(luai_numisnan(n) || l_mathop(fabs)(n) == cast_num(HUGE_VAL)); - return 0; - } - else { /* normal case */ - unsigned int u = cast(unsigned int, i) + cast(unsigned int, ni); - return cast_int(u <= cast(unsigned int, INT_MAX) ? u : ~u); - } -} -#endif - - -/* -** returns the 'main' position of an element in a table (that is, the index -** of its hash value) -*/ -static Node *mainposition (const Table *t, const TValue *key) { - switch (ttype(key)) { - case LUA_TNUMINT: - return hashint(t, ivalue(key)); - case LUA_TNUMFLT: - return hashmod(t, l_hashfloat(fltvalue(key))); - case LUA_TSHRSTR: - return hashstr(t, tsvalue(key)); - case LUA_TLNGSTR: - return hashpow2(t, luaS_hashlongstr(tsvalue(key))); - case LUA_TBOOLEAN: - return hashboolean(t, bvalue(key)); - case LUA_TLIGHTUSERDATA: - return hashpointer(t, pvalue(key)); - case LUA_TLCF: - return hashpointer(t, fvalue(key)); - default: - lua_assert(!ttisdeadkey(key)); - return hashpointer(t, gcvalue(key)); - } -} - - -/* -** returns the index for 'key' if 'key' is an appropriate key to live in -** the array part of the table, 0 otherwise. -*/ -static unsigned int arrayindex (const TValue *key) { - if (ttisinteger(key)) { - lua_Integer k = ivalue(key); - if (0 < k && (lua_Unsigned)k <= MAXASIZE) - return cast(unsigned int, k); /* 'key' is an appropriate array index */ - } - return 0; /* 'key' did not match some condition */ -} - - -/* -** returns the index of a 'key' for table traversals. First goes all -** elements in the array part, then elements in the hash part. The -** beginning of a traversal is signaled by 0. -*/ -static unsigned int findindex (lua_State *L, Table *t, StkId key) { - unsigned int i; - if (ttisnil(key)) return 0; /* first iteration */ - i = arrayindex(key); - if (i != 0 && i <= t->sizearray) /* is 'key' inside array part? */ - return i; /* yes; that's the index */ - else { - int nx; - Node *n = mainposition(t, key); - for (;;) { /* check whether 'key' is somewhere in the chain */ - /* key may be dead already, but it is ok to use it in 'next' */ - if (luaV_rawequalobj(gkey(n), key) || - (ttisdeadkey(gkey(n)) && iscollectable(key) && - deadvalue(gkey(n)) == gcvalue(key))) { - i = cast_int(n - gnode(t, 0)); /* key index in hash table */ - /* hash elements are numbered after array ones */ - return (i + 1) + t->sizearray; - } - nx = gnext(n); - if (nx == 0) - luaG_runerror(L, "invalid key to 'next'"); /* key not found */ - else n += nx; - } - } -} - - -int luaH_next (lua_State *L, Table *t, StkId key) { - unsigned int i = findindex(L, t, key); /* find original element */ - for (; i < t->sizearray; i++) { /* try first array part */ - if (!ttisnil(&t->array[i])) { /* a non-nil value? */ - setivalue(key, i + 1); - setobj2s(L, key+1, &t->array[i]); - return 1; - } - } - for (i -= t->sizearray; cast_int(i) < sizenode(t); i++) { /* hash part */ - if (!ttisnil(gval(gnode(t, i)))) { /* a non-nil value? */ - setobj2s(L, key, gkey(gnode(t, i))); - setobj2s(L, key+1, gval(gnode(t, i))); - return 1; - } - } - return 0; /* no more elements */ -} - - -/* -** {============================================================= -** Rehash -** ============================================================== -*/ - -/* -** Compute the optimal size for the array part of table 't'. 'nums' is a -** "count array" where 'nums[i]' is the number of integers in the table -** between 2^(i - 1) + 1 and 2^i. 'pna' enters with the total number of -** integer keys in the table and leaves with the number of keys that -** will go to the array part; return the optimal size. -*/ -static unsigned int computesizes (unsigned int nums[], unsigned int *pna) { - int i; - unsigned int twotoi; /* 2^i (candidate for optimal size) */ - unsigned int a = 0; /* number of elements smaller than 2^i */ - unsigned int na = 0; /* number of elements to go to array part */ - unsigned int optimal = 0; /* optimal size for array part */ - /* loop while keys can fill more than half of total size */ - for (i = 0, twotoi = 1; *pna > twotoi / 2; i++, twotoi *= 2) { - if (nums[i] > 0) { - a += nums[i]; - if (a > twotoi/2) { /* more than half elements present? */ - optimal = twotoi; /* optimal size (till now) */ - na = a; /* all elements up to 'optimal' will go to array part */ - } - } - } - lua_assert((optimal == 0 || optimal / 2 < na) && na <= optimal); - *pna = na; - return optimal; -} - - -static int countint (const TValue *key, unsigned int *nums) { - unsigned int k = arrayindex(key); - if (k != 0) { /* is 'key' an appropriate array index? */ - nums[luaO_ceillog2(k)]++; /* count as such */ - return 1; - } - else - return 0; -} - - -/* -** Count keys in array part of table 't': Fill 'nums[i]' with -** number of keys that will go into corresponding slice and return -** total number of non-nil keys. -*/ -static unsigned int numusearray (const Table *t, unsigned int *nums) { - int lg; - unsigned int ttlg; /* 2^lg */ - unsigned int ause = 0; /* summation of 'nums' */ - unsigned int i = 1; /* count to traverse all array keys */ - /* traverse each slice */ - for (lg = 0, ttlg = 1; lg <= MAXABITS; lg++, ttlg *= 2) { - unsigned int lc = 0; /* counter */ - unsigned int lim = ttlg; - if (lim > t->sizearray) { - lim = t->sizearray; /* adjust upper limit */ - if (i > lim) - break; /* no more elements to count */ - } - /* count elements in range (2^(lg - 1), 2^lg] */ - for (; i <= lim; i++) { - if (!ttisnil(&t->array[i-1])) - lc++; - } - nums[lg] += lc; - ause += lc; - } - return ause; -} - - -static int numusehash (const Table *t, unsigned int *nums, unsigned int *pna) { - int totaluse = 0; /* total number of elements */ - int ause = 0; /* elements added to 'nums' (can go to array part) */ - int i = sizenode(t); - while (i--) { - Node *n = &t->node[i]; - if (!ttisnil(gval(n))) { - ause += countint(gkey(n), nums); - totaluse++; - } - } - *pna += ause; - return totaluse; -} - - -static void setarrayvector (lua_State *L, Table *t, unsigned int size) { - unsigned int i; - luaM_reallocvector(L, t->array, t->sizearray, size, TValue); - for (i=t->sizearray; i<size; i++) - setnilvalue(&t->array[i]); - t->sizearray = size; -} - - -static void setnodevector (lua_State *L, Table *t, unsigned int size) { - if (size == 0) { /* no elements to hash part? */ - t->node = cast(Node *, dummynode); /* use common 'dummynode' */ - t->lsizenode = 0; - t->lastfree = NULL; /* signal that it is using dummy node */ - } - else { - int i; - int lsize = luaO_ceillog2(size); - if (lsize > MAXHBITS) - luaG_runerror(L, "table overflow"); - size = twoto(lsize); - t->node = luaM_newvector(L, size, Node); - for (i = 0; i < (int)size; i++) { - Node *n = gnode(t, i); - gnext(n) = 0; - setnilvalue(wgkey(n)); - setnilvalue(gval(n)); - } - t->lsizenode = cast_byte(lsize); - t->lastfree = gnode(t, size); /* all positions are free */ - } -} - - -void luaH_resize (lua_State *L, Table *t, unsigned int nasize, - unsigned int nhsize) { - unsigned int i; - int j; - unsigned int oldasize = t->sizearray; - int oldhsize = allocsizenode(t); - Node *nold = t->node; /* save old hash ... */ - if (nasize > oldasize) /* array part must grow? */ - setarrayvector(L, t, nasize); - /* create new hash part with appropriate size */ - setnodevector(L, t, nhsize); - if (nasize < oldasize) { /* array part must shrink? */ - t->sizearray = nasize; - /* re-insert elements from vanishing slice */ - for (i=nasize; i<oldasize; i++) { - if (!ttisnil(&t->array[i])) - luaH_setint(L, t, i + 1, &t->array[i]); - } - /* shrink array */ - luaM_reallocvector(L, t->array, oldasize, nasize, TValue); - } - /* re-insert elements from hash part */ - for (j = oldhsize - 1; j >= 0; j--) { - Node *old = nold + j; - if (!ttisnil(gval(old))) { - /* doesn't need barrier/invalidate cache, as entry was - already present in the table */ - setobjt2t(L, luaH_set(L, t, gkey(old)), gval(old)); - } - } - if (oldhsize > 0) /* not the dummy node? */ - luaM_freearray(L, nold, cast(size_t, oldhsize)); /* free old hash */ -} - - -void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize) { - int nsize = allocsizenode(t); - luaH_resize(L, t, nasize, nsize); -} - -/* -** nums[i] = number of keys 'k' where 2^(i - 1) < k <= 2^i -*/ -static void rehash (lua_State *L, Table *t, const TValue *ek) { - unsigned int asize; /* optimal size for array part */ - unsigned int na; /* number of keys in the array part */ - unsigned int nums[MAXABITS + 1]; - int i; - int totaluse; - for (i = 0; i <= MAXABITS; i++) nums[i] = 0; /* reset counts */ - na = numusearray(t, nums); /* count keys in array part */ - totaluse = na; /* all those keys are integer keys */ - totaluse += numusehash(t, nums, &na); /* count keys in hash part */ - /* count extra key */ - na += countint(ek, nums); - totaluse++; - /* compute new size for array part */ - asize = computesizes(nums, &na); - /* resize the table to new computed sizes */ - luaH_resize(L, t, asize, totaluse - na); -} - - - -/* -** }============================================================= -*/ - - -Table *luaH_new (lua_State *L) { - GCObject *o = luaC_newobj(L, LUA_TTABLE, sizeof(Table)); - Table *t = gco2t(o); - t->metatable = NULL; - t->flags = cast_byte(~0); - t->array = NULL; - t->sizearray = 0; - setnodevector(L, t, 0); - return t; -} - - -void luaH_free (lua_State *L, Table *t) { - if (!isdummy(t)) - luaM_freearray(L, t->node, cast(size_t, sizenode(t))); - luaM_freearray(L, t->array, t->sizearray); - luaM_free(L, t); -} - - -static Node *getfreepos (Table *t) { - if (!isdummy(t)) { - while (t->lastfree > t->node) { - t->lastfree--; - if (ttisnil(gkey(t->lastfree))) - return t->lastfree; - } - } - return NULL; /* could not find a free place */ -} - - - -/* -** inserts a new key into a hash table; first, check whether key's main -** position is free. If not, check whether colliding node is in its main -** position or not: if it is not, move colliding node to an empty place and -** put new key in its main position; otherwise (colliding node is in its main -** position), new key goes to an empty position. -*/ -TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) { - Node *mp; - TValue aux; - if (ttisnil(key)) luaG_runerror(L, "table index is nil"); - else if (ttisfloat(key)) { - lua_Integer k; - if (luaV_tointeger(key, &k, 0)) { /* does index fit in an integer? */ - setivalue(&aux, k); - key = &aux; /* insert it as an integer */ - } - else if (luai_numisnan(fltvalue(key))) - luaG_runerror(L, "table index is NaN"); - } - mp = mainposition(t, key); - if (!ttisnil(gval(mp)) || isdummy(t)) { /* main position is taken? */ - Node *othern; - Node *f = getfreepos(t); /* get a free place */ - if (f == NULL) { /* cannot find a free place? */ - rehash(L, t, key); /* grow table */ - /* whatever called 'newkey' takes care of TM cache */ - return luaH_set(L, t, key); /* insert key into grown table */ - } - lua_assert(!isdummy(t)); - othern = mainposition(t, gkey(mp)); - if (othern != mp) { /* is colliding node out of its main position? */ - /* yes; move colliding node into free position */ - while (othern + gnext(othern) != mp) /* find previous */ - othern += gnext(othern); - gnext(othern) = cast_int(f - othern); /* rechain to point to 'f' */ - *f = *mp; /* copy colliding node into free pos. (mp->next also goes) */ - if (gnext(mp) != 0) { - gnext(f) += cast_int(mp - f); /* correct 'next' */ - gnext(mp) = 0; /* now 'mp' is free */ - } - setnilvalue(gval(mp)); - } - else { /* colliding node is in its own main position */ - /* new node will go into free position */ - if (gnext(mp) != 0) - gnext(f) = cast_int((mp + gnext(mp)) - f); /* chain new position */ - else lua_assert(gnext(f) == 0); - gnext(mp) = cast_int(f - mp); - mp = f; - } - } - setnodekey(L, &mp->i_key, key); - luaC_barrierback(L, t, key); - lua_assert(ttisnil(gval(mp))); - return gval(mp); -} - - -/* -** search function for integers -*/ -const TValue *luaH_getint (Table *t, lua_Integer key) { - /* (1 <= key && key <= t->sizearray) */ - if (l_castS2U(key) - 1 < t->sizearray) - return &t->array[key - 1]; - else { - Node *n = hashint(t, key); - for (;;) { /* check whether 'key' is somewhere in the chain */ - if (ttisinteger(gkey(n)) && ivalue(gkey(n)) == key) - return gval(n); /* that's it */ - else { - int nx = gnext(n); - if (nx == 0) break; - n += nx; - } - } - return luaO_nilobject; - } -} - - -/* -** search function for short strings -*/ -const TValue *luaH_getshortstr (Table *t, TString *key) { - Node *n = hashstr(t, key); - lua_assert(key->tt == LUA_TSHRSTR); - for (;;) { /* check whether 'key' is somewhere in the chain */ - const TValue *k = gkey(n); - if (ttisshrstring(k) && eqshrstr(tsvalue(k), key)) - return gval(n); /* that's it */ - else { - int nx = gnext(n); - if (nx == 0) - return luaO_nilobject; /* not found */ - n += nx; - } - } -} - - -/* -** "Generic" get version. (Not that generic: not valid for integers, -** which may be in array part, nor for floats with integral values.) -*/ -static const TValue *getgeneric (Table *t, const TValue *key) { - Node *n = mainposition(t, key); - for (;;) { /* check whether 'key' is somewhere in the chain */ - if (luaV_rawequalobj(gkey(n), key)) - return gval(n); /* that's it */ - else { - int nx = gnext(n); - if (nx == 0) - return luaO_nilobject; /* not found */ - n += nx; - } - } -} - - -const TValue *luaH_getstr (Table *t, TString *key) { - if (key->tt == LUA_TSHRSTR) - return luaH_getshortstr(t, key); - else { /* for long strings, use generic case */ - TValue ko; - setsvalue(cast(lua_State *, NULL), &ko, key); - return getgeneric(t, &ko); - } -} - - -/* -** main search function -*/ -const TValue *luaH_get (Table *t, const TValue *key) { - switch (ttype(key)) { - case LUA_TSHRSTR: return luaH_getshortstr(t, tsvalue(key)); - case LUA_TNUMINT: return luaH_getint(t, ivalue(key)); - case LUA_TNIL: return luaO_nilobject; - case LUA_TNUMFLT: { - lua_Integer k; - if (luaV_tointeger(key, &k, 0)) /* index is int? */ - return luaH_getint(t, k); /* use specialized version */ - /* else... */ - } /* FALLTHROUGH */ - default: - return getgeneric(t, key); - } -} - - -/* -** beware: when using this function you probably need to check a GC -** barrier and invalidate the TM cache. -*/ -TValue *luaH_set (lua_State *L, Table *t, const TValue *key) { - const TValue *p = luaH_get(t, key); - if (p != luaO_nilobject) - return cast(TValue *, p); - else return luaH_newkey(L, t, key); -} - - -void luaH_setint (lua_State *L, Table *t, lua_Integer key, TValue *value) { - const TValue *p = luaH_getint(t, key); - TValue *cell; - if (p != luaO_nilobject) - cell = cast(TValue *, p); - else { - TValue k; - setivalue(&k, key); - cell = luaH_newkey(L, t, &k); - } - setobj2t(L, cell, value); -} - - -static int unbound_search (Table *t, unsigned int j) { - unsigned int i = j; /* i is zero or a present index */ - j++; - /* find 'i' and 'j' such that i is present and j is not */ - while (!ttisnil(luaH_getint(t, j))) { - i = j; - if (j > cast(unsigned int, MAX_INT)/2) { /* overflow? */ - /* table was built with bad purposes: resort to linear search */ - i = 1; - while (!ttisnil(luaH_getint(t, i))) i++; - return i - 1; - } - j *= 2; - } - /* now do a binary search between them */ - while (j - i > 1) { - unsigned int m = (i+j)/2; - if (ttisnil(luaH_getint(t, m))) j = m; - else i = m; - } - return i; -} - - -/* -** Try to find a boundary in table 't'. A 'boundary' is an integer index -** such that t[i] is non-nil and t[i+1] is nil (and 0 if t[1] is nil). -*/ -int luaH_getn (Table *t) { - unsigned int j = t->sizearray; - if (j > 0 && ttisnil(&t->array[j - 1])) { - /* there is a boundary in the array part: (binary) search for it */ - unsigned int i = 0; - while (j - i > 1) { - unsigned int m = (i+j)/2; - if (ttisnil(&t->array[m - 1])) j = m; - else i = m; - } - return i; - } - /* else must find a boundary in hash part */ - else if (isdummy(t)) /* hash part is empty? */ - return j; /* that is easy... */ - else return unbound_search(t, j); -} - - - -#if defined(LUA_DEBUG) - -Node *luaH_mainposition (const Table *t, const TValue *key) { - return mainposition(t, key); -} - -int luaH_isdummy (const Table *t) { return isdummy(t); } - -#endif |