diff options
Diffstat (limited to 'lib/lua/src/ltable.c')
| m--------- | lib/lua | 0 | ||||
| -rw-r--r-- | lib/lua/src/ltable.c | 588 |
2 files changed, 0 insertions, 588 deletions
diff --git a/lib/lua b/lib/lua new file mode 160000 +Subproject dd27acefcd98a28c68e686f414a42302113471f diff --git a/lib/lua/src/ltable.c b/lib/lua/src/ltable.c deleted file mode 100644 index ec84f4fab..000000000 --- a/lib/lua/src/ltable.c +++ /dev/null @@ -1,588 +0,0 @@ -/* -** $Id: ltable.c,v 2.32.1.2 2007/12/28 15:32:23 roberto Exp $ -** Lua tables (hash) -** See Copyright Notice in lua.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 at -** least half the slots between 0 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 <string.h> - -#define ltable_c -#define LUA_CORE - -#include "lua.h" - -#include "ldebug.h" -#include "ldo.h" -#include "lgc.h" -#include "lmem.h" -#include "lobject.h" -#include "lstate.h" -#include "ltable.h" - - -/* -** max size of array part is 2^MAXBITS -*/ -#if LUAI_BITSINT > 26 -#define MAXBITS 26 -#else -#define MAXBITS (LUAI_BITSINT-2) -#endif - -#define MAXASIZE (1 << MAXBITS) - - -#define hashpow2(t,n) (gnode(t, lmod((n), sizenode(t)))) - -#define hashstr(t,str) hashpow2(t, (str)->tsv.hash) -#define hashboolean(t,p) hashpow2(t, p) - - -/* -** 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, IntPoint(p)) - - -/* -** number of ints inside a lua_Number -*/ -#define numints cast_int(sizeof(lua_Number)/sizeof(int)) - - - -#define dummynode (&dummynode_) - -static const Node dummynode_ = { - {{NULL}, LUA_TNIL}, /* value */ - {{{NULL}, LUA_TNIL, NULL}} /* key */ -}; - - -/* -** hash for lua_Numbers -*/ -static Node *hashnum (const Table *t, lua_Number n) { - unsigned int a[numints]; - int i; - if (luai_numeq(n, 0)) /* avoid problems with -0 */ - return gnode(t, 0); - memcpy(a, &n, sizeof(a)); - for (i = 1; i < numints; i++) a[0] += a[i]; - return hashmod(t, a[0]); -} - - - -/* -** 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_TNUMBER: - return hashnum(t, nvalue(key)); - case LUA_TSTRING: - return hashstr(t, rawtsvalue(key)); - case LUA_TBOOLEAN: - return hashboolean(t, bvalue(key)); - case LUA_TLIGHTUSERDATA: - return hashpointer(t, pvalue(key)); - default: - 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, -1 otherwise. -*/ -static int arrayindex (const TValue *key) { - if (ttisnumber(key)) { - lua_Number n = nvalue(key); - int k; - lua_number2int(k, n); - if (luai_numeq(cast_num(k), n)) - return k; - } - return -1; /* `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 signalled by -1. -*/ -static int findindex (lua_State *L, Table *t, StkId key) { - int i; - if (ttisnil(key)) return -1; /* first iteration */ - i = arrayindex(key); - if (0 < i && i <= t->sizearray) /* is `key' inside array part? */ - return i-1; /* yes; that's the index (corrected to C) */ - else { - Node *n = mainposition(t, key); - do { /* check whether `key' is somewhere in the chain */ - /* key may be dead already, but it is ok to use it in `next' */ - if (luaO_rawequalObj(key2tval(n), key) || - (ttype(gkey(n)) == LUA_TDEADKEY && iscollectable(key) && - gcvalue(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 + t->sizearray; - } - else n = gnext(n); - } while (n); - luaG_runerror(L, "invalid key to " LUA_QL("next")); /* key not found */ - return 0; /* to avoid warnings */ - } -} - - -int luaH_next (lua_State *L, Table *t, StkId key) { - int i = findindex(L, t, key); /* find original element */ - for (i++; i < t->sizearray; i++) { /* try first array part */ - if (!ttisnil(&t->array[i])) { /* a non-nil value? */ - setnvalue(key, cast_num(i+1)); - setobj2s(L, key+1, &t->array[i]); - return 1; - } - } - for (i -= t->sizearray; i < sizenode(t); i++) { /* then hash part */ - if (!ttisnil(gval(gnode(t, i)))) { /* a non-nil value? */ - setobj2s(L, key, key2tval(gnode(t, i))); - setobj2s(L, key+1, gval(gnode(t, i))); - return 1; - } - } - return 0; /* no more elements */ -} - - -/* -** {============================================================= -** Rehash -** ============================================================== -*/ - - -static int computesizes (int nums[], int *narray) { - int i; - int twotoi; /* 2^i */ - int a = 0; /* number of elements smaller than 2^i */ - int na = 0; /* number of elements to go to array part */ - int n = 0; /* optimal size for array part */ - for (i = 0, twotoi = 1; twotoi/2 < *narray; i++, twotoi *= 2) { - if (nums[i] > 0) { - a += nums[i]; - if (a > twotoi/2) { /* more than half elements present? */ - n = twotoi; /* optimal size (till now) */ - na = a; /* all elements smaller than n will go to array part */ - } - } - if (a == *narray) break; /* all elements already counted */ - } - *narray = n; - lua_assert(*narray/2 <= na && na <= *narray); - return na; -} - - -static int countint (const TValue *key, int *nums) { - int k = arrayindex(key); - if (0 < k && k <= MAXASIZE) { /* is `key' an appropriate array index? */ - nums[ceillog2(k)]++; /* count as such */ - return 1; - } - else - return 0; -} - - -static int numusearray (const Table *t, int *nums) { - int lg; - int ttlg; /* 2^lg */ - int ause = 0; /* summation of `nums' */ - int i = 1; /* count to traverse all array keys */ - for (lg=0, ttlg=1; lg<=MAXBITS; lg++, ttlg*=2) { /* for each slice */ - int lc = 0; /* counter */ - 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, int *nums, int *pnasize) { - int totaluse = 0; /* total number of elements */ - int ause = 0; /* summation of `nums' */ - int i = sizenode(t); - while (i--) { - Node *n = &t->node[i]; - if (!ttisnil(gval(n))) { - ause += countint(key2tval(n), nums); - totaluse++; - } - } - *pnasize += ause; - return totaluse; -} - - -static void setarrayvector (lua_State *L, Table *t, int size) { - 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, int size) { - int lsize; - if (size == 0) { /* no elements to hash part? */ - t->node = cast(Node *, dummynode); /* use common `dummynode' */ - lsize = 0; - } - else { - int i; - lsize = ceillog2(size); - if (lsize > MAXBITS) - luaG_runerror(L, "table overflow"); - size = twoto(lsize); - t->node = luaM_newvector(L, size, Node); - for (i=0; i<size; i++) { - Node *n = gnode(t, i); - gnext(n) = NULL; - setnilvalue(gkey(n)); - setnilvalue(gval(n)); - } - } - t->lsizenode = cast_byte(lsize); - t->lastfree = gnode(t, size); /* all positions are free */ -} - - -static void resize (lua_State *L, Table *t, int nasize, int nhsize) { - int i; - int oldasize = t->sizearray; - int oldhsize = t->lsizenode; - 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])) - setobjt2t(L, luaH_setnum(L, t, i+1), &t->array[i]); - } - /* shrink array */ - luaM_reallocvector(L, t->array, oldasize, nasize, TValue); - } - /* re-insert elements from hash part */ - for (i = twoto(oldhsize) - 1; i >= 0; i--) { - Node *old = nold+i; - if (!ttisnil(gval(old))) - setobjt2t(L, luaH_set(L, t, key2tval(old)), gval(old)); - } - if (nold != dummynode) - luaM_freearray(L, nold, twoto(oldhsize), Node); /* free old array */ -} - - -void luaH_resizearray (lua_State *L, Table *t, int nasize) { - int nsize = (t->node == dummynode) ? 0 : sizenode(t); - resize(L, t, nasize, nsize); -} - - -static void rehash (lua_State *L, Table *t, const TValue *ek) { - int nasize, na; - int nums[MAXBITS+1]; /* nums[i] = number of keys between 2^(i-1) and 2^i */ - int i; - int totaluse; - for (i=0; i<=MAXBITS; i++) nums[i] = 0; /* reset counts */ - nasize = numusearray(t, nums); /* count keys in array part */ - totaluse = nasize; /* all those keys are integer keys */ - totaluse += numusehash(t, nums, &nasize); /* count keys in hash part */ - /* count extra key */ - nasize += countint(ek, nums); - totaluse++; - /* compute new size for array part */ - na = computesizes(nums, &nasize); - /* resize the table to new computed sizes */ - resize(L, t, nasize, totaluse - na); -} - - - -/* -** }============================================================= -*/ - - -Table *luaH_new (lua_State *L, int narray, int nhash) { - Table *t = luaM_new(L, Table); - luaC_link(L, obj2gco(t), LUA_TTABLE); - t->metatable = NULL; - t->flags = cast_byte(~0); - /* temporary values (kept only if some malloc fails) */ - t->array = NULL; - t->sizearray = 0; - t->lsizenode = 0; - t->node = cast(Node *, dummynode); - setarrayvector(L, t, narray); - setnodevector(L, t, nhash); - return t; -} - - -void luaH_free (lua_State *L, Table *t) { - if (t->node != dummynode) - luaM_freearray(L, t->node, sizenode(t), Node); - luaM_freearray(L, t->array, t->sizearray, TValue); - luaM_free(L, t); -} - - -static Node *getfreepos (Table *t) { - while (t->lastfree-- > t->node) { - 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. -*/ -static TValue *newkey (lua_State *L, Table *t, const TValue *key) { - Node *mp = mainposition(t, key); - if (!ttisnil(gval(mp)) || mp == dummynode) { - Node *othern; - Node *n = getfreepos(t); /* get a free place */ - if (n == NULL) { /* cannot find a free place? */ - rehash(L, t, key); /* grow table */ - return luaH_set(L, t, key); /* re-insert key into grown table */ - } - lua_assert(n != dummynode); - othern = mainposition(t, key2tval(mp)); - if (othern != mp) { /* is colliding node out of its main position? */ - /* yes; move colliding node into free position */ - while (gnext(othern) != mp) othern = gnext(othern); /* find previous */ - gnext(othern) = n; /* redo the chain with `n' in place of `mp' */ - *n = *mp; /* copy colliding node into free pos. (mp->next also goes) */ - gnext(mp) = NULL; /* now `mp' is free */ - setnilvalue(gval(mp)); - } - else { /* colliding node is in its own main position */ - /* new node will go into free position */ - gnext(n) = gnext(mp); /* chain new position */ - gnext(mp) = n; - mp = n; - } - } - gkey(mp)->value = key->value; gkey(mp)->tt = key->tt; - luaC_barriert(L, t, key); - lua_assert(ttisnil(gval(mp))); - return gval(mp); -} - - -/* -** search function for integers -*/ -const TValue *luaH_getnum (Table *t, int key) { - /* (1 <= key && key <= t->sizearray) */ - if (cast(unsigned int, key-1) < cast(unsigned int, t->sizearray)) - return &t->array[key-1]; - else { - lua_Number nk = cast_num(key); - Node *n = hashnum(t, nk); - do { /* check whether `key' is somewhere in the chain */ - if (ttisnumber(gkey(n)) && luai_numeq(nvalue(gkey(n)), nk)) - return gval(n); /* that's it */ - else n = gnext(n); - } while (n); - return luaO_nilobject; - } -} - - -/* -** search function for strings -*/ -const TValue *luaH_getstr (Table *t, TString *key) { - Node *n = hashstr(t, key); - do { /* check whether `key' is somewhere in the chain */ - if (ttisstring(gkey(n)) && rawtsvalue(gkey(n)) == key) - return gval(n); /* that's it */ - else n = gnext(n); - } while (n); - return luaO_nilobject; -} - - -/* -** main search function -*/ -const TValue *luaH_get (Table *t, const TValue *key) { - switch (ttype(key)) { - case LUA_TNIL: return luaO_nilobject; - case LUA_TSTRING: return luaH_getstr(t, rawtsvalue(key)); - case LUA_TNUMBER: { - int k; - lua_Number n = nvalue(key); - lua_number2int(k, n); - if (luai_numeq(cast_num(k), nvalue(key))) /* index is int? */ - return luaH_getnum(t, k); /* use specialized version */ - /* else go through */ - } - default: { - Node *n = mainposition(t, key); - do { /* check whether `key' is somewhere in the chain */ - if (luaO_rawequalObj(key2tval(n), key)) - return gval(n); /* that's it */ - else n = gnext(n); - } while (n); - return luaO_nilobject; - } - } -} - - -TValue *luaH_set (lua_State *L, Table *t, const TValue *key) { - const TValue *p = luaH_get(t, key); - t->flags = 0; - if (p != luaO_nilobject) - return cast(TValue *, p); - else { - if (ttisnil(key)) luaG_runerror(L, "table index is nil"); - else if (ttisnumber(key) && luai_numisnan(nvalue(key))) - luaG_runerror(L, "table index is NaN"); - return newkey(L, t, key); - } -} - - -TValue *luaH_setnum (lua_State *L, Table *t, int key) { - const TValue *p = luaH_getnum(t, key); - if (p != luaO_nilobject) - return cast(TValue *, p); - else { - TValue k; - setnvalue(&k, cast_num(key)); - return newkey(L, t, &k); - } -} - - -TValue *luaH_setstr (lua_State *L, Table *t, TString *key) { - const TValue *p = luaH_getstr(t, key); - if (p != luaO_nilobject) - return cast(TValue *, p); - else { - TValue k; - setsvalue(L, &k, key); - return newkey(L, t, &k); - } -} - - -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_getnum(t, j))) { - i = j; - j *= 2; - if (j > cast(unsigned int, MAX_INT)) { /* overflow? */ - /* table was built with bad purposes: resort to linear search */ - i = 1; - while (!ttisnil(luaH_getnum(t, i))) i++; - return i - 1; - } - } - /* now do a binary search between them */ - while (j - i > 1) { - unsigned int m = (i+j)/2; - if (ttisnil(luaH_getnum(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 (t->node == dummynode) /* 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 (Node *n) { return n == dummynode; } - -#endif |