diff options
Diffstat (limited to 'libs/liblua/src/ltable.c')
| -rw-r--r-- | libs/liblua/src/ltable.c | 672 |
1 files changed, 454 insertions, 218 deletions
diff --git a/libs/liblua/src/ltable.c b/libs/liblua/src/ltable.c index ea4fe7fcb3..d7eb69a2e1 100644 --- a/libs/liblua/src/ltable.c +++ b/libs/liblua/src/ltable.c @@ -1,5 +1,5 @@ /* -** $Id: ltable.c,v 2.118.1.4 2018/06/08 16:22:51 roberto Exp $ +** $Id: ltable.c $ ** Lua tables (hash) ** See Copyright Notice in lua.h */ @@ -40,21 +40,34 @@ /* -** Maximum size of array part (MAXASIZE) is 2^MAXABITS. MAXABITS is -** the largest integer such that MAXASIZE fits in an unsigned int. +** 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.) +** MAXASIZE is the maximum size of the array part. It is the minimum +** between 2^MAXABITS and the maximum size that, measured in bytes, +** fits in a 'size_t'. +*/ +#define MAXASIZE luaM_limitN(1u << MAXABITS, TValue) + +/* +** MAXHBITS is the largest integer such that 2^MAXHBITS fits in a +** signed int. */ #define MAXHBITS (MAXABITS - 1) +/* +** MAXHSIZE is the maximum size of the hash part. It is the minimum +** between 2^MAXHBITS and the maximum size such that, measured in bytes, +** it fits in a 'size_t'. +*/ +#define MAXHSIZE luaM_limitN(1u << MAXHBITS, Node) + + #define hashpow2(t,n) (gnode(t, lmod((n), sizenode(t)))) #define hashstr(t,str) hashpow2(t, (str)->hash) @@ -75,11 +88,15 @@ #define dummynode (&dummynode_) static const Node dummynode_ = { - {NILCONSTANT}, /* value */ - {{NILCONSTANT, 0}} /* key */ + {{NULL}, LUA_VEMPTY, /* value's value and type */ + LUA_VNIL, 0, {NULL}} /* key type, next, and key value */ }; +static const TValue absentkey = {ABSTKEYCONSTANT}; + + + /* ** Hash for floating-point numbers. ** The main computation should be just @@ -103,51 +120,162 @@ static int l_hashfloat (lua_Number n) { 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); + unsigned int u = cast_uint(i) + cast_uint(ni); + return cast_int(u <= cast_uint(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)); +** returns the 'main' position of an element in a table (that is, +** the index of its hash value). The key comes broken (tag in 'ktt' +** and value in 'vkl') so that we can call it on keys inserted into +** nodes. +*/ +static Node *mainposition (const Table *t, int ktt, const Value *kvl) { + switch (withvariant(ktt)) { + case LUA_VNUMINT: + return hashint(t, ivalueraw(*kvl)); + case LUA_VNUMFLT: + return hashmod(t, l_hashfloat(fltvalueraw(*kvl))); + case LUA_VSHRSTR: + return hashstr(t, tsvalueraw(*kvl)); + case LUA_VLNGSTR: + return hashpow2(t, luaS_hashlongstr(tsvalueraw(*kvl))); + case LUA_VFALSE: + return hashboolean(t, 0); + case LUA_VTRUE: + return hashboolean(t, 1); + case LUA_VLIGHTUSERDATA: + return hashpointer(t, pvalueraw(*kvl)); + case LUA_VLCF: + return hashpointer(t, fvalueraw(*kvl)); default: - lua_assert(!ttisdeadkey(key)); - return hashpointer(t, gcvalue(key)); + return hashpointer(t, gcvalueraw(*kvl)); + } +} + + +/* +** Returns the main position of an element given as a 'TValue' +*/ +static Node *mainpositionTV (const Table *t, const TValue *key) { + return mainposition(t, rawtt(key), valraw(key)); +} + + +/* +** Check whether key 'k1' is equal to the key in node 'n2'. +** This equality is raw, so there are no metamethods. Floats +** with integer values have been normalized, so integers cannot +** be equal to floats. It is assumed that 'eqshrstr' is simply +** pointer equality, so that short strings are handled in the +** default case. +*/ +static int equalkey (const TValue *k1, const Node *n2) { + if (rawtt(k1) != keytt(n2)) /* not the same variants? */ + return 0; /* cannot be same key */ + switch (ttypetag(k1)) { + case LUA_VNIL: case LUA_VFALSE: case LUA_VTRUE: + return 1; + case LUA_VNUMINT: + return (ivalue(k1) == keyival(n2)); + case LUA_VNUMFLT: + return luai_numeq(fltvalue(k1), fltvalueraw(keyval(n2))); + case LUA_VLIGHTUSERDATA: + return pvalue(k1) == pvalueraw(keyval(n2)); + case LUA_VLCF: + return fvalue(k1) == fvalueraw(keyval(n2)); + case LUA_VLNGSTR: + return luaS_eqlngstr(tsvalue(k1), keystrval(n2)); + default: + return gcvalue(k1) == gcvalueraw(keyval(n2)); + } +} + + +/* +** True if value of 'alimit' is equal to the real size of the array +** part of table 't'. (Otherwise, the array part must be larger than +** 'alimit'.) +*/ +#define limitequalsasize(t) (isrealasize(t) || ispow2((t)->alimit)) + + +/* +** Returns the real size of the 'array' array +*/ +LUAI_FUNC unsigned int luaH_realasize (const Table *t) { + if (limitequalsasize(t)) + return t->alimit; /* this is the size */ + else { + unsigned int size = t->alimit; + /* compute the smallest power of 2 not smaller than 'n' */ + size |= (size >> 1); + size |= (size >> 2); + size |= (size >> 4); + size |= (size >> 8); + size |= (size >> 16); +#if (UINT_MAX >> 30) > 3 + size |= (size >> 32); /* unsigned int has more than 32 bits */ +#endif + size++; + lua_assert(ispow2(size) && size/2 < t->alimit && t->alimit < size); + return size; } } /* -** returns the index for 'key' if 'key' is an appropriate key to live in -** the array part of the table, 0 otherwise. +** Check whether real size of the array is a power of 2. +** (If it is not, 'alimit' cannot be changed to any other value +** without changing the real size.) +*/ +static int ispow2realasize (const Table *t) { + return (!isrealasize(t) || ispow2(t->alimit)); +} + + +static unsigned int setlimittosize (Table *t) { + t->alimit = luaH_realasize(t); + setrealasize(t); + return t->alimit; +} + + +#define limitasasize(t) check_exp(isrealasize(t), t->alimit) + + + +/* +** "Generic" get version. (Not that generic: not valid for integers, +** which may be in array part, nor for floats with integral values.) */ -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 */ +static const TValue *getgeneric (Table *t, const TValue *key) { + Node *n = mainpositionTV(t, key); + for (;;) { /* check whether 'key' is somewhere in the chain */ + if (equalkey(key, n)) + return gval(n); /* that's it */ + else { + int nx = gnext(n); + if (nx == 0) + return &absentkey; /* not found */ + n += nx; + } } - return 0; /* 'key' did not match some condition */ +} + + +/* +** returns the index for 'k' if 'k' is an appropriate key to live in +** the array part of a table, 0 otherwise. +*/ +static unsigned int arrayindex (lua_Integer k) { + if (l_castS2U(k) - 1u < MAXASIZE) /* 'k' in [1, MAXASIZE]? */ + return cast_uint(k); /* 'key' is an appropriate array index */ + else + return 0; } @@ -156,46 +284,39 @@ static unsigned int arrayindex (const TValue *key) { ** 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) { +static unsigned int findindex (lua_State *L, Table *t, TValue *key, + unsigned int asize) { unsigned int i; if (ttisnil(key)) return 0; /* first iteration */ - i = arrayindex(key); - if (i != 0 && i <= t->sizearray) /* is 'key' inside array part? */ + i = ttisinteger(key) ? arrayindex(ivalue(key)) : 0; + if (i - 1u < asize) /* 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; - } + const TValue *n = getgeneric(t, key); + if (unlikely(isabstkey(n))) + luaG_runerror(L, "invalid key to 'next'"); /* key not found */ + i = cast_int(nodefromval(n) - gnode(t, 0)); /* key index in hash table */ + /* hash elements are numbered after array ones */ + return (i + 1) + asize; } } 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]); + unsigned int asize = luaH_realasize(t); + unsigned int i = findindex(L, t, s2v(key), asize); /* find original key */ + for (; i < asize; i++) { /* try first array part */ + if (!isempty(&t->array[i])) { /* a non-empty entry? */ + setivalue(s2v(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))); + for (i -= asize; cast_int(i) < sizenode(t); i++) { /* hash part */ + if (!isempty(gval(gnode(t, i)))) { /* a non-empty entry? */ + Node *n = gnode(t, i); + getnodekey(L, s2v(key), n); + setobj2s(L, key + 1, gval(n)); return 1; } } @@ -203,6 +324,12 @@ int luaH_next (lua_State *L, Table *t, StkId key) { } +static void freehash (lua_State *L, Table *t) { + if (!isdummy(t)) + luaM_freearray(L, t->node, cast_sizet(sizenode(t))); +} + + /* ** {============================================================= ** Rehash @@ -214,7 +341,8 @@ int luaH_next (lua_State *L, Table *t, StkId key) { ** "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. +** will go to the array part; return the optimal size. (The condition +** 'twotoi > 0' in the for loop stops the loop if 'twotoi' overflows.) */ static unsigned int computesizes (unsigned int nums[], unsigned int *pna) { int i; @@ -226,12 +354,10 @@ static unsigned int computesizes (unsigned int nums[], unsigned int *pna) { for (i = 0, twotoi = 1; twotoi > 0 && *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 */ - } + 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); @@ -240,7 +366,7 @@ static unsigned int computesizes (unsigned int nums[], unsigned int *pna) { } -static int countint (const TValue *key, unsigned int *nums) { +static int countint (lua_Integer 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 */ @@ -261,18 +387,19 @@ static unsigned int numusearray (const Table *t, unsigned int *nums) { unsigned int ttlg; /* 2^lg */ unsigned int ause = 0; /* summation of 'nums' */ unsigned int i = 1; /* count to traverse all array keys */ + unsigned int asize = limitasasize(t); /* real array size */ /* 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 (lim > asize) { + lim = asize; /* 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])) + if (!isempty(&t->array[i-1])) lc++; } nums[lg] += lc; @@ -288,8 +415,9 @@ static int numusehash (const Table *t, unsigned int *nums, unsigned int *pna) { int i = sizenode(t); while (i--) { Node *n = &t->node[i]; - if (!ttisnil(gval(n))) { - ause += countint(gkey(n), nums); + if (!isempty(gval(n))) { + if (keyisinteger(n)) + ause += countint(keyival(n), nums); totaluse++; } } @@ -298,15 +426,13 @@ static int numusehash (const Table *t, unsigned int *nums, unsigned int *pna) { } -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; -} - - +/* +** Creates an array for the hash part of a table with the given +** size, or reuses the dummy node if size is zero. +** The computation for size overflow is in two steps: the first +** comparison ensures that the shift in the second one does not +** overflow. +*/ 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' */ @@ -316,15 +442,15 @@ static void setnodevector (lua_State *L, Table *t, unsigned int size) { else { int i; int lsize = luaO_ceillog2(size); - if (lsize > MAXHBITS) + if (lsize > MAXHBITS || (1u << lsize) > MAXHSIZE) 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)); + setnilkey(n); + setempty(gval(n)); } t->lsizenode = cast_byte(lsize); t->lastfree = gnode(t, size); /* all positions are free */ @@ -332,55 +458,88 @@ static void setnodevector (lua_State *L, Table *t, unsigned int size) { } -typedef struct { - Table *t; - unsigned int nhsize; -} AuxsetnodeT; +/* +** (Re)insert all elements from the hash part of 'ot' into table 't'. +*/ +static void reinsert (lua_State *L, Table *ot, Table *t) { + int j; + int size = sizenode(ot); + for (j = 0; j < size; j++) { + Node *old = gnode(ot, j); + if (!isempty(gval(old))) { + /* doesn't need barrier/invalidate cache, as entry was + already present in the table */ + TValue k; + getnodekey(L, &k, old); + setobjt2t(L, luaH_set(L, t, &k), gval(old)); + } + } +} -static void auxsetnode (lua_State *L, void *ud) { - AuxsetnodeT *asn = cast(AuxsetnodeT *, ud); - setnodevector(L, asn->t, asn->nhsize); +/* +** Exchange the hash part of 't1' and 't2'. +*/ +static void exchangehashpart (Table *t1, Table *t2) { + lu_byte lsizenode = t1->lsizenode; + Node *node = t1->node; + Node *lastfree = t1->lastfree; + t1->lsizenode = t2->lsizenode; + t1->node = t2->node; + t1->lastfree = t2->lastfree; + t2->lsizenode = lsizenode; + t2->node = node; + t2->lastfree = lastfree; } -void luaH_resize (lua_State *L, Table *t, unsigned int nasize, +/* +** Resize table 't' for the new given sizes. Both allocations (for +** the hash part and for the array part) can fail, which creates some +** subtleties. If the first allocation, for the hash part, fails, an +** error is raised and that is it. Otherwise, it copies the elements from +** the shrinking part of the array (if it is shrinking) into the new +** hash. Then it reallocates the array part. If that fails, the table +** is in its original state; the function frees the new hash part and then +** raises the allocation error. Otherwise, it sets the new hash part +** into the table, initializes the new part of the array (if any) with +** nils and reinserts the elements of the old hash back into the new +** parts of the table. +*/ +void luaH_resize (lua_State *L, Table *t, unsigned int newasize, unsigned int nhsize) { unsigned int i; - int j; - AuxsetnodeT asn; - 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 */ - asn.t = t; asn.nhsize = nhsize; - if (luaD_rawrunprotected(L, auxsetnode, &asn) != LUA_OK) { /* mem. error? */ - setarrayvector(L, t, oldasize); /* array back to its original size */ - luaD_throw(L, LUA_ERRMEM); /* rethrow memory error */ - } - 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])) + Table newt; /* to keep the new hash part */ + unsigned int oldasize = setlimittosize(t); + TValue *newarray; + /* create new hash part with appropriate size into 'newt' */ + setnodevector(L, &newt, nhsize); + if (newasize < oldasize) { /* will array shrink? */ + t->alimit = newasize; /* pretend array has new size... */ + exchangehashpart(t, &newt); /* and new hash */ + /* re-insert into the new hash the elements from vanishing slice */ + for (i = newasize; i < oldasize; i++) { + if (!isempty(&t->array[i])) luaH_setint(L, t, i + 1, &t->array[i]); } - /* shrink array */ - luaM_reallocvector(L, t->array, oldasize, nasize, TValue); + t->alimit = oldasize; /* restore current size... */ + exchangehashpart(t, &newt); /* and hash (in case of errors) */ } - /* 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)); - } + /* allocate new array */ + newarray = luaM_reallocvector(L, t->array, oldasize, newasize, TValue); + if (unlikely(newarray == NULL && newasize > 0)) { /* allocation failed? */ + freehash(L, &newt); /* release new hash part */ + luaM_error(L); /* raise error (with array unchanged) */ } - if (oldhsize > 0) /* not the dummy node? */ - luaM_freearray(L, nold, cast(size_t, oldhsize)); /* free old hash */ + /* allocation ok; initialize new part of the array */ + exchangehashpart(t, &newt); /* 't' has the new hash ('newt' has the old) */ + t->array = newarray; /* set new array part */ + t->alimit = newasize; + for (i = oldasize; i < newasize; i++) /* clear new slice of the array */ + setempty(&t->array[i]); + /* re-insert elements from old hash part into new parts */ + reinsert(L, &newt, t); /* 'newt' now has the old hash */ + freehash(L, &newt); /* free old hash part */ } @@ -399,11 +558,13 @@ static void rehash (lua_State *L, Table *t, const TValue *ek) { int i; int totaluse; for (i = 0; i <= MAXABITS; i++) nums[i] = 0; /* reset counts */ + setlimittosize(t); 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); + if (ttisinteger(ek)) + na += countint(ivalue(ek), nums); totaluse++; /* compute new size for array part */ asize = computesizes(nums, &na); @@ -419,21 +580,20 @@ static void rehash (lua_State *L, Table *t, const TValue *ek) { Table *luaH_new (lua_State *L) { - GCObject *o = luaC_newobj(L, LUA_TTABLE, sizeof(Table)); + GCObject *o = luaC_newobj(L, LUA_VTABLE, sizeof(Table)); Table *t = gco2t(o); t->metatable = NULL; t->flags = cast_byte(~0); t->array = NULL; - t->sizearray = 0; + t->alimit = 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); + freehash(L, t); + luaM_freearray(L, t->array, luaH_realasize(t)); luaM_free(L, t); } @@ -442,7 +602,7 @@ static Node *getfreepos (Table *t) { if (!isdummy(t)) { while (t->lastfree > t->node) { t->lastfree--; - if (ttisnil(gkey(t->lastfree))) + if (keyisnil(t->lastfree)) return t->lastfree; } } @@ -461,18 +621,20 @@ static Node *getfreepos (Table *t) { 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"); + if (unlikely(ttisnil(key))) + luaG_runerror(L, "table index is nil"); else if (ttisfloat(key)) { + lua_Number f = fltvalue(key); lua_Integer k; - if (luaV_tointeger(key, &k, 0)) { /* does index fit in an integer? */ + if (luaV_flttointeger(f, &k, F2Ieq)) { /* does key fit in an integer? */ setivalue(&aux, k); key = &aux; /* insert it as an integer */ } - else if (luai_numisnan(fltvalue(key))) + else if (unlikely(luai_numisnan(f))) luaG_runerror(L, "table index is NaN"); } - mp = mainposition(t, key); - if (!ttisnil(gval(mp)) || isdummy(t)) { /* main position is taken? */ + mp = mainpositionTV(t, key); + if (!isempty(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? */ @@ -481,7 +643,7 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) { return luaH_set(L, t, key); /* insert key into grown table */ } lua_assert(!isdummy(t)); - othern = mainposition(t, gkey(mp)); + othern = mainposition(t, keytt(mp), &keyval(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 */ @@ -492,7 +654,7 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) { gnext(f) += cast_int(mp - f); /* correct 'next' */ gnext(mp) = 0; /* now 'mp' is free */ } - setnilvalue(gval(mp)); + setempty(gval(mp)); } else { /* colliding node is in its own main position */ /* new node will go into free position */ @@ -503,24 +665,34 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) { mp = f; } } - setnodekey(L, &mp->i_key, key); - luaC_barrierback(L, t, key); - lua_assert(ttisnil(gval(mp))); + setnodekey(L, mp, key); + luaC_barrierback(L, obj2gco(t), key); + lua_assert(isempty(gval(mp))); return gval(mp); } /* -** search function for integers +** Search function for integers. If integer is inside 'alimit', get it +** directly from the array part. Otherwise, if 'alimit' is not equal to +** the real size of the array, key still can be in the array part. In +** this case, try to avoid a call to 'luaH_realasize' when key is just +** one more than the limit (so that it can be incremented without +** changing the real size of the array). */ const TValue *luaH_getint (Table *t, lua_Integer key) { - /* (1 <= key && key <= t->sizearray) */ - if (l_castS2U(key) - 1 < t->sizearray) + if (l_castS2U(key) - 1u < t->alimit) /* 'key' in [1, t->alimit]? */ return &t->array[key - 1]; + else if (!limitequalsasize(t) && /* key still may be in the array part? */ + (l_castS2U(key) == t->alimit + 1 || + l_castS2U(key) - 1u < luaH_realasize(t))) { + t->alimit = cast_uint(key); /* probably '#t' is here now */ + 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) + if (keyisinteger(n) && keyival(n) == key) return gval(n); /* that's it */ else { int nx = gnext(n); @@ -528,7 +700,7 @@ const TValue *luaH_getint (Table *t, lua_Integer key) { n += nx; } } - return luaO_nilobject; + return &absentkey; } } @@ -538,34 +710,14 @@ const TValue *luaH_getint (Table *t, lua_Integer key) { */ 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); + lua_assert(key->tt == LUA_VSHRSTR); for (;;) { /* check whether 'key' is somewhere in the chain */ - if (luaV_rawequalobj(gkey(n), key)) + if (keyisshrstr(n) && eqshrstr(keystrval(n), key)) return gval(n); /* that's it */ else { int nx = gnext(n); if (nx == 0) - return luaO_nilobject; /* not found */ + return &absentkey; /* not found */ n += nx; } } @@ -573,7 +725,7 @@ static const TValue *getgeneric (Table *t, const TValue *key) { const TValue *luaH_getstr (Table *t, TString *key) { - if (key->tt == LUA_TSHRSTR) + if (key->tt == LUA_VSHRSTR) return luaH_getshortstr(t, key); else { /* for long strings, use generic case */ TValue ko; @@ -587,13 +739,13 @@ const TValue *luaH_getstr (Table *t, TString *key) { ** 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: { + switch (ttypetag(key)) { + case LUA_VSHRSTR: return luaH_getshortstr(t, tsvalue(key)); + case LUA_VNUMINT: return luaH_getint(t, ivalue(key)); + case LUA_VNIL: return &absentkey; + case LUA_VNUMFLT: { lua_Integer k; - if (luaV_tointeger(key, &k, 0)) /* index is int? */ + if (luaV_flttointeger(fltvalue(key), &k, F2Ieq)) /* integral index? */ return luaH_getint(t, k); /* use specialized version */ /* else... */ } /* FALLTHROUGH */ @@ -609,7 +761,7 @@ const TValue *luaH_get (Table *t, const TValue *key) { */ TValue *luaH_set (lua_State *L, Table *t, const TValue *key) { const TValue *p = luaH_get(t, key); - if (p != luaO_nilobject) + if (!isabstkey(p)) return cast(TValue *, p); else return luaH_newkey(L, t, key); } @@ -618,7 +770,7 @@ TValue *luaH_set (lua_State *L, Table *t, const TValue *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) + if (!isabstkey(p)) cell = cast(TValue *, p); else { TValue k; @@ -629,24 +781,49 @@ void luaH_setint (lua_State *L, Table *t, lua_Integer key, TValue *value) { } -static lua_Unsigned unbound_search (Table *t, lua_Unsigned j) { - lua_Unsigned 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 > l_castS2U(LUA_MAXINTEGER) / 2) { /* overflow? */ - /* table was built with bad purposes: resort to linear search */ - i = 1; - while (!ttisnil(luaH_getint(t, i))) i++; - return i - 1; +/* +** Try to find a boundary in the hash part of table 't'. From the +** caller, we know that 'j' is zero or present and that 'j + 1' is +** present. We want to find a larger key that is absent from the +** table, so that we can do a binary search between the two keys to +** find a boundary. We keep doubling 'j' until we get an absent index. +** If the doubling would overflow, we try LUA_MAXINTEGER. If it is +** absent, we are ready for the binary search. ('j', being max integer, +** is larger or equal to 'i', but it cannot be equal because it is +** absent while 'i' is present; so 'j > i'.) Otherwise, 'j' is a +** boundary. ('j + 1' cannot be a present integer key because it is +** not a valid integer in Lua.) +*/ +static lua_Unsigned hash_search (Table *t, lua_Unsigned j) { + lua_Unsigned i; + if (j == 0) j++; /* the caller ensures 'j + 1' is present */ + do { + i = j; /* 'i' is a present index */ + if (j <= l_castS2U(LUA_MAXINTEGER) / 2) + j *= 2; + else { + j = LUA_MAXINTEGER; + if (isempty(luaH_getint(t, j))) /* t[j] not present? */ + break; /* 'j' now is an absent index */ + else /* weird case */ + return j; /* well, max integer is a boundary... */ } - j *= 2; + } while (!isempty(luaH_getint(t, j))); /* repeat until an absent t[j] */ + /* i < j && t[i] present && t[j] absent */ + while (j - i > 1u) { /* do a binary search between them */ + lua_Unsigned m = (i + j) / 2; + if (isempty(luaH_getint(t, m))) j = m; + else i = m; } - /* now do a binary search between them */ - while (j - i > 1) { - lua_Unsigned m = (i+j)/2; - if (ttisnil(luaH_getint(t, m))) j = m; + return i; +} + + +static unsigned int binsearch (const TValue *array, unsigned int i, + unsigned int j) { + while (j - i > 1u) { /* binary search */ + unsigned int m = (i + j) / 2; + if (isempty(&array[m - 1])) j = m; else i = m; } return i; @@ -654,33 +831,92 @@ static lua_Unsigned unbound_search (Table *t, lua_Unsigned j) { /* -** 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). +** Try to find a boundary in table 't'. (A 'boundary' is an integer index +** such that t[i] is present and t[i+1] is absent, or 0 if t[1] is absent +** and 'maxinteger' if t[maxinteger] is present.) +** (In the next explanation, we use Lua indices, that is, with base 1. +** The code itself uses base 0 when indexing the array part of the table.) +** The code starts with 'limit = t->alimit', a position in the array +** part that may be a boundary. +** +** (1) If 't[limit]' is empty, there must be a boundary before it. +** As a common case (e.g., after 't[#t]=nil'), check whether 'limit-1' +** is present. If so, it is a boundary. Otherwise, do a binary search +** between 0 and limit to find a boundary. In both cases, try to +** use this boundary as the new 'alimit', as a hint for the next call. +** +** (2) If 't[limit]' is not empty and the array has more elements +** after 'limit', try to find a boundary there. Again, try first +** the special case (which should be quite frequent) where 'limit+1' +** is empty, so that 'limit' is a boundary. Otherwise, check the +** last element of the array part. If it is empty, there must be a +** boundary between the old limit (present) and the last element +** (absent), which is found with a binary search. (This boundary always +** can be a new limit.) +** +** (3) The last case is when there are no elements in the array part +** (limit == 0) or its last element (the new limit) is present. +** In this case, must check the hash part. If there is no hash part +** or 'limit+1' is absent, 'limit' is a boundary. Otherwise, call +** 'hash_search' to find a boundary in the hash part of the table. +** (In those cases, the boundary is not inside the array part, and +** therefore cannot be used as a new limit.) */ lua_Unsigned 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; + unsigned int limit = t->alimit; + if (limit > 0 && isempty(&t->array[limit - 1])) { /* (1)? */ + /* there must be a boundary before 'limit' */ + if (limit >= 2 && !isempty(&t->array[limit - 2])) { + /* 'limit - 1' is a boundary; can it be a new limit? */ + if (ispow2realasize(t) && !ispow2(limit - 1)) { + t->alimit = limit - 1; + setnorealasize(t); /* now 'alimit' is not the real size */ + } + return limit - 1; + } + else { /* must search for a boundary in [0, limit] */ + unsigned int boundary = binsearch(t->array, 0, limit); + /* can this boundary represent the real size of the array? */ + if (ispow2realasize(t) && boundary > luaH_realasize(t) / 2) { + t->alimit = boundary; /* use it as the new limit */ + setnorealasize(t); + } + return boundary; + } + } + /* 'limit' is zero or present in table */ + if (!limitequalsasize(t)) { /* (2)? */ + /* 'limit' > 0 and array has more elements after 'limit' */ + if (isempty(&t->array[limit])) /* 'limit + 1' is empty? */ + return limit; /* this is the boundary */ + /* else, try last element in the array */ + limit = luaH_realasize(t); + if (isempty(&t->array[limit - 1])) { /* empty? */ + /* there must be a boundary in the array after old limit, + and it must be a valid new limit */ + unsigned int boundary = binsearch(t->array, t->alimit, limit); + t->alimit = boundary; + return boundary; } - return i; + /* else, new limit is present in the table; check the hash part */ } - /* 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); + /* (3) 'limit' is the last element and either is zero or present in table */ + lua_assert(limit == luaH_realasize(t) && + (limit == 0 || !isempty(&t->array[limit - 1]))); + if (isdummy(t) || isempty(luaH_getint(t, cast(lua_Integer, limit + 1)))) + return limit; /* 'limit + 1' is absent */ + else /* 'limit + 1' is also present */ + return hash_search(t, limit); } #if defined(LUA_DEBUG) +/* export these functions for the test library */ + Node *luaH_mainposition (const Table *t, const TValue *key) { - return mainposition(t, key); + return mainpositionTV(t, key); } int luaH_isdummy (const Table *t) { return isdummy(t); } |