diff options
Diffstat (limited to 'lib/lua/src/ltable.c')
| -rw-r--r-- | lib/lua/src/ltable.c | 1018 |
1 files changed, 509 insertions, 509 deletions
diff --git a/lib/lua/src/ltable.c b/lib/lua/src/ltable.c index cd5e576..9f4cb6c 100644 --- a/lib/lua/src/ltable.c +++ b/lib/lua/src/ltable.c @@ -1,509 +1,509 @@ -/* -** $Id: ltable.c,v 1.2 2003-12-11 16:53:30 pixel 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. -** In other words, there are collisions only when two elements have the -** same main position (i.e. the same hash values for that table size). -** Because of that, the load factor of these tables can be 100% without -** performance penalties. -*/ - -#include <string.h> - -#define ltable_c - -#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 BITS_INT > 26 -#define MAXBITS 24 -#else -#define MAXBITS (BITS_INT-2) -#endif - -/* check whether `x' < 2^MAXBITS */ -#define toobig(x) ((((x)-1) >> MAXBITS) != 0) - - -/* function to convert a lua_Number to int (with any rounding method) */ -#ifndef lua_number2int -#define lua_number2int(i,n) ((i)=(int)(n)) -#endif - - -#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)) - - -/* -** hash for lua_Numbers -*/ -static Node *hashnum (const Table *t, lua_Number n) { - unsigned int a[numints]; - int i; - n += 1; /* normalize number (avoid -0) */ - lua_assert(sizeof(a) <= sizeof(n)); - memcpy(a, &n, sizeof(a)); - for (i = 1; i < numints; i++) a[0] += a[i]; - return hashmod(t, cast(lu_hash, a[0])); -} - - - -/* -** returns the `main' position of an element in a table (that is, the index -** of its hash value) -*/ -Node *luaH_mainposition (const Table *t, const TObject *key) { - switch (ttype(key)) { - case LUA_TNUMBER: - return hashnum(t, nvalue(key)); - case LUA_TSTRING: - return hashstr(t, tsvalue(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 TObject *key) { - if (ttisnumber(key)) { - int k; - lua_number2int(k, (nvalue(key))); - if (cast(lua_Number, k) == nvalue(key) && k >= 1 && !toobig(k)) - 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 and end of a traversal are signalled by -1. -*/ -static int luaH_index (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 { - const TObject *v = luaH_get(t, key); - if (v == &luaO_nilobject) - luaG_runerror(L, "invalid key for `next'"); - i = cast(int, (cast(const lu_byte *, v) - - cast(const lu_byte *, gval(gnode(t, 0)))) / sizeof(Node)); - return i + t->sizearray; /* hash elements are numbered after array ones */ - } -} - - -int luaH_next (lua_State *L, Table *t, StkId key) { - int i = luaH_index(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(lua_Number, i+1)); - setobj2s(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(key, gkey(gnode(t, i))); - setobj2s(key+1, gval(gnode(t, i))); - return 1; - } - } - return 0; /* no more elements */ -} - - -/* -** {============================================================= -** Rehash -** ============================================================== -*/ - - -static void computesizes (int nums[], int ntotal, int *narray, int *nhash) { - int i; - int a = nums[0]; /* number of elements smaller than 2^i */ - int na = a; /* number of elements to go to array part */ - int n = (na == 0) ? -1 : 0; /* (log of) optimal size for array part */ - for (i = 1; a < *narray && *narray >= twoto(i-1); i++) { - if (nums[i] > 0) { - a += nums[i]; - if (a >= twoto(i-1)) { /* more than half elements in use? */ - n = i; - na = a; - } - } - } - lua_assert(na <= *narray && *narray <= ntotal); - *nhash = ntotal - na; - *narray = (n == -1) ? 0 : twoto(n); - lua_assert(na <= *narray && na >= *narray/2); -} - - -static void numuse (const Table *t, int *narray, int *nhash) { - int nums[MAXBITS+1]; - int i, lg; - int totaluse = 0; - /* count elements in array part */ - for (i=0, lg=0; lg<=MAXBITS; lg++) { /* for each slice [2^(lg-1) to 2^lg) */ - int ttlg = twoto(lg); /* 2^lg */ - if (ttlg > t->sizearray) { - ttlg = t->sizearray; - if (i >= ttlg) break; - } - nums[lg] = 0; - for (; i<ttlg; i++) { - if (!ttisnil(&t->array[i])) { - nums[lg]++; - totaluse++; - } - } - } - for (; lg<=MAXBITS; lg++) nums[lg] = 0; /* reset other counts */ - *narray = totaluse; /* all previous uses were in array part */ - /* count elements in hash part */ - i = sizenode(t); - while (i--) { - Node *n = &t->node[i]; - if (!ttisnil(gval(n))) { - int k = arrayindex(gkey(n)); - if (k >= 0) { /* is `key' an appropriate array index? */ - nums[luaO_log2(k-1)+1]++; /* count as such */ - (*narray)++; - } - totaluse++; - } - } - computesizes(nums, totaluse, narray, nhash); -} - - -static void setarrayvector (lua_State *L, Table *t, int size) { - int i; - luaM_reallocvector(L, t->array, t->sizearray, size, TObject); - for (i=t->sizearray; i<size; i++) - setnilvalue(&t->array[i]); - t->sizearray = size; -} - - -static void setnodevector (lua_State *L, Table *t, int lsize) { - int i; - int size = twoto(lsize); - if (lsize > MAXBITS) - luaG_runerror(L, "table overflow"); - if (lsize == 0) { /* no elements to hash part? */ - t->node = G(L)->dummynode; /* use common `dummynode' */ - lua_assert(ttisnil(gkey(t->node))); /* assert invariants: */ - lua_assert(ttisnil(gval(t->node))); - lua_assert(t->node->next == NULL); /* (`dummynode' must be empty) */ - } - else { - t->node = luaM_newvector(L, size, Node); - for (i=0; i<size; i++) { - t->node[i].next = NULL; - setnilvalue(gkey(gnode(t, i))); - setnilvalue(gval(gnode(t, i))); - } - } - t->lsizenode = cast(lu_byte, lsize); - t->firstfree = gnode(t, size-1); /* first free position to be used */ -} - - -static void resize (lua_State *L, Table *t, int nasize, int nhsize) { - int i; - int oldasize = t->sizearray; - int oldhsize = t->lsizenode; - Node *nold; - Node temp[1]; - if (oldhsize) - nold = t->node; /* save old hash ... */ - else { /* old hash is `dummynode' */ - lua_assert(t->node == G(L)->dummynode); - temp[0] = t->node[0]; /* copy it to `temp' */ - nold = temp; - setnilvalue(gkey(G(L)->dummynode)); /* restate invariant */ - setnilvalue(gval(G(L)->dummynode)); - lua_assert(G(L)->dummynode->next == NULL); - } - if (nasize > oldasize) /* array part must grow? */ - setarrayvector(L, t, nasize); - /* create new hash part with appropriate size */ - setnodevector(L, t, nhsize); - /* re-insert elements */ - 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(luaH_setnum(L, t, i+1), &t->array[i]); - } - /* shrink array */ - luaM_reallocvector(L, t->array, oldasize, nasize, TObject); - } - /* re-insert elements in hash part */ - for (i = twoto(oldhsize) - 1; i >= 0; i--) { - Node *old = nold+i; - if (!ttisnil(gval(old))) - setobjt2t(luaH_set(L, t, gkey(old)), gval(old)); - } - if (oldhsize) - luaM_freearray(L, nold, twoto(oldhsize), Node); /* free old array */ -} - - -static void rehash (lua_State *L, Table *t) { - int nasize, nhsize; - numuse(t, &nasize, &nhsize); /* compute new sizes for array and hash parts */ - resize(L, t, nasize, luaO_log2(nhsize)+1); -} - - - -/* -** }============================================================= -*/ - - -Table *luaH_new (lua_State *L, int narray, int lnhash) { - Table *t = luaM_new(L, Table); - luaC_link(L, valtogco(t), LUA_TTABLE); - t->metatable = hvalue(defaultmeta(L)); - t->flags = cast(lu_byte, ~0); - /* temporary values (kept only if some malloc fails) */ - t->array = NULL; - t->sizearray = 0; - t->lsizenode = 0; - t->node = NULL; - setarrayvector(L, t, narray); - setnodevector(L, t, lnhash); - return t; -} - - -void luaH_free (lua_State *L, Table *t) { - if (t->lsizenode) - luaM_freearray(L, t->node, sizenode(t), Node); - luaM_freearray(L, t->array, t->sizearray, TObject); - luaM_freelem(L, t); -} - - -#if 0 -/* -** try to remove an element from a hash table; cannot move any element -** (because gc can call `remove' during a table traversal) -*/ -void luaH_remove (Table *t, Node *e) { - Node *mp = luaH_mainposition(t, gkey(e)); - if (e != mp) { /* element not in its main position? */ - while (mp->next != e) mp = mp->next; /* find previous */ - mp->next = e->next; /* remove `e' from its list */ - } - else { - if (e->next != NULL) ?? - } - lua_assert(ttisnil(gval(node))); - setnilvalue(gkey(e)); /* clear node `e' */ - e->next = NULL; -} -#endif - - -/* -** 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 TObject *newkey (lua_State *L, Table *t, const TObject *key) { - TObject *val; - Node *mp = luaH_mainposition(t, key); - if (!ttisnil(gval(mp))) { /* main position is not free? */ - Node *othern = luaH_mainposition(t, gkey(mp)); /* `mp' of colliding node */ - Node *n = t->firstfree; /* get a free place */ - if (othern != mp) { /* is colliding node out of its main position? */ - /* yes; move colliding node into free position */ - while (othern->next != mp) othern = othern->next; /* find previous */ - othern->next = n; /* redo the chain with `n' in place of `mp' */ - *n = *mp; /* copy colliding node into free pos. (mp->next also goes) */ - mp->next = NULL; /* now `mp' is free */ - setnilvalue(gval(mp)); - } - else { /* colliding node is in its own main position */ - /* new node will go into free position */ - n->next = mp->next; /* chain new position */ - mp->next = n; - mp = n; - } - } - setobj2t(gkey(mp), key); /* write barrier */ - lua_assert(ttisnil(gval(mp))); - for (;;) { /* correct `firstfree' */ - if (ttisnil(gkey(t->firstfree))) - return gval(mp); /* OK; table still has a free place */ - else if (t->firstfree == t->node) break; /* cannot decrement from here */ - else (t->firstfree)--; - } - /* no more free places; must create one */ - setbvalue(gval(mp), 0); /* avoid new key being removed */ - rehash(L, t); /* grow table */ - val = cast(TObject *, luaH_get(t, key)); /* get new position */ - lua_assert(ttisboolean(val)); - setnilvalue(val); - return val; -} - - -/* -** generic search function -*/ -static const TObject *luaH_getany (Table *t, const TObject *key) { - if (ttisnil(key)) return &luaO_nilobject; - else { - Node *n = luaH_mainposition(t, key); - do { /* check whether `key' is somewhere in the chain */ - if (luaO_rawequalObj(gkey(n), key)) return gval(n); /* that's it */ - else n = n->next; - } while (n); - return &luaO_nilobject; - } -} - - -/* -** search function for integers -*/ -const TObject *luaH_getnum (Table *t, int key) { - if (1 <= key && key <= t->sizearray) - return &t->array[key-1]; - else { - lua_Number nk = cast(lua_Number, key); - Node *n = hashnum(t, nk); - do { /* check whether `key' is somewhere in the chain */ - if (ttisnumber(gkey(n)) && nvalue(gkey(n)) == nk) - return gval(n); /* that's it */ - else n = n->next; - } while (n); - return &luaO_nilobject; - } -} - - -/* -** search function for strings -*/ -const TObject *luaH_getstr (Table *t, TString *key) { - Node *n = hashstr(t, key); - do { /* check whether `key' is somewhere in the chain */ - if (ttisstring(gkey(n)) && tsvalue(gkey(n)) == key) - return gval(n); /* that's it */ - else n = n->next; - } while (n); - return &luaO_nilobject; -} - - -/* -** main search function -*/ -const TObject *luaH_get (Table *t, const TObject *key) { - switch (ttype(key)) { - case LUA_TSTRING: return luaH_getstr(t, tsvalue(key)); - case LUA_TNUMBER: { - int k; - lua_number2int(k, (nvalue(key))); - if (cast(lua_Number, k) == nvalue(key)) /* is an integer index? */ - return luaH_getnum(t, k); /* use specialized version */ - /* else go through */ - } - default: return luaH_getany(t, key); - } -} - - -TObject *luaH_set (lua_State *L, Table *t, const TObject *key) { - const TObject *p = luaH_get(t, key); - t->flags = 0; - if (p != &luaO_nilobject) - return cast(TObject *, p); - else { - if (ttisnil(key)) luaG_runerror(L, "table index is nil"); - else if (ttisnumber(key) && nvalue(key) != nvalue(key)) - luaG_runerror(L, "table index is NaN"); - return newkey(L, t, key); - } -} - - -TObject *luaH_setnum (lua_State *L, Table *t, int key) { - const TObject *p = luaH_getnum(t, key); - if (p != &luaO_nilobject) - return cast(TObject *, p); - else { - TObject k; - setnvalue(&k, cast(lua_Number, key)); - return newkey(L, t, &k); - } -} - +/*
+** $Id: ltable.c,v 1.3 2004-11-27 21:35:20 pixel 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.
+** In other words, there are collisions only when two elements have the
+** same main position (i.e. the same hash values for that table size).
+** Because of that, the load factor of these tables can be 100% without
+** performance penalties.
+*/
+
+#include <string.h>
+
+#define ltable_c
+
+#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 BITS_INT > 26
+#define MAXBITS 24
+#else
+#define MAXBITS (BITS_INT-2)
+#endif
+
+/* check whether `x' < 2^MAXBITS */
+#define toobig(x) ((((x)-1) >> MAXBITS) != 0)
+
+
+/* function to convert a lua_Number to int (with any rounding method) */
+#ifndef lua_number2int
+#define lua_number2int(i,n) ((i)=(int)(n))
+#endif
+
+
+#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))
+
+
+/*
+** hash for lua_Numbers
+*/
+static Node *hashnum (const Table *t, lua_Number n) {
+ unsigned int a[numints];
+ int i;
+ n += 1; /* normalize number (avoid -0) */
+ lua_assert(sizeof(a) <= sizeof(n));
+ memcpy(a, &n, sizeof(a));
+ for (i = 1; i < numints; i++) a[0] += a[i];
+ return hashmod(t, cast(lu_hash, a[0]));
+}
+
+
+
+/*
+** returns the `main' position of an element in a table (that is, the index
+** of its hash value)
+*/
+Node *luaH_mainposition (const Table *t, const TObject *key) {
+ switch (ttype(key)) {
+ case LUA_TNUMBER:
+ return hashnum(t, nvalue(key));
+ case LUA_TSTRING:
+ return hashstr(t, tsvalue(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 TObject *key) {
+ if (ttisnumber(key)) {
+ int k;
+ lua_number2int(k, (nvalue(key)));
+ if (cast(lua_Number, k) == nvalue(key) && k >= 1 && !toobig(k))
+ 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 and end of a traversal are signalled by -1.
+*/
+static int luaH_index (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 {
+ const TObject *v = luaH_get(t, key);
+ if (v == &luaO_nilobject)
+ luaG_runerror(L, "invalid key for `next'");
+ i = cast(int, (cast(const lu_byte *, v) -
+ cast(const lu_byte *, gval(gnode(t, 0)))) / sizeof(Node));
+ return i + t->sizearray; /* hash elements are numbered after array ones */
+ }
+}
+
+
+int luaH_next (lua_State *L, Table *t, StkId key) {
+ int i = luaH_index(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(lua_Number, i+1));
+ setobj2s(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(key, gkey(gnode(t, i)));
+ setobj2s(key+1, gval(gnode(t, i)));
+ return 1;
+ }
+ }
+ return 0; /* no more elements */
+}
+
+
+/*
+** {=============================================================
+** Rehash
+** ==============================================================
+*/
+
+
+static void computesizes (int nums[], int ntotal, int *narray, int *nhash) {
+ int i;
+ int a = nums[0]; /* number of elements smaller than 2^i */
+ int na = a; /* number of elements to go to array part */
+ int n = (na == 0) ? -1 : 0; /* (log of) optimal size for array part */
+ for (i = 1; a < *narray && *narray >= twoto(i-1); i++) {
+ if (nums[i] > 0) {
+ a += nums[i];
+ if (a >= twoto(i-1)) { /* more than half elements in use? */
+ n = i;
+ na = a;
+ }
+ }
+ }
+ lua_assert(na <= *narray && *narray <= ntotal);
+ *nhash = ntotal - na;
+ *narray = (n == -1) ? 0 : twoto(n);
+ lua_assert(na <= *narray && na >= *narray/2);
+}
+
+
+static void numuse (const Table *t, int *narray, int *nhash) {
+ int nums[MAXBITS+1];
+ int i, lg;
+ int totaluse = 0;
+ /* count elements in array part */
+ for (i=0, lg=0; lg<=MAXBITS; lg++) { /* for each slice [2^(lg-1) to 2^lg) */
+ int ttlg = twoto(lg); /* 2^lg */
+ if (ttlg > t->sizearray) {
+ ttlg = t->sizearray;
+ if (i >= ttlg) break;
+ }
+ nums[lg] = 0;
+ for (; i<ttlg; i++) {
+ if (!ttisnil(&t->array[i])) {
+ nums[lg]++;
+ totaluse++;
+ }
+ }
+ }
+ for (; lg<=MAXBITS; lg++) nums[lg] = 0; /* reset other counts */
+ *narray = totaluse; /* all previous uses were in array part */
+ /* count elements in hash part */
+ i = sizenode(t);
+ while (i--) {
+ Node *n = &t->node[i];
+ if (!ttisnil(gval(n))) {
+ int k = arrayindex(gkey(n));
+ if (k >= 0) { /* is `key' an appropriate array index? */
+ nums[luaO_log2(k-1)+1]++; /* count as such */
+ (*narray)++;
+ }
+ totaluse++;
+ }
+ }
+ computesizes(nums, totaluse, narray, nhash);
+}
+
+
+static void setarrayvector (lua_State *L, Table *t, int size) {
+ int i;
+ luaM_reallocvector(L, t->array, t->sizearray, size, TObject);
+ for (i=t->sizearray; i<size; i++)
+ setnilvalue(&t->array[i]);
+ t->sizearray = size;
+}
+
+
+static void setnodevector (lua_State *L, Table *t, int lsize) {
+ int i;
+ int size = twoto(lsize);
+ if (lsize > MAXBITS)
+ luaG_runerror(L, "table overflow");
+ if (lsize == 0) { /* no elements to hash part? */
+ t->node = G(L)->dummynode; /* use common `dummynode' */
+ lua_assert(ttisnil(gkey(t->node))); /* assert invariants: */
+ lua_assert(ttisnil(gval(t->node)));
+ lua_assert(t->node->next == NULL); /* (`dummynode' must be empty) */
+ }
+ else {
+ t->node = luaM_newvector(L, size, Node);
+ for (i=0; i<size; i++) {
+ t->node[i].next = NULL;
+ setnilvalue(gkey(gnode(t, i)));
+ setnilvalue(gval(gnode(t, i)));
+ }
+ }
+ t->lsizenode = cast(lu_byte, lsize);
+ t->firstfree = gnode(t, size-1); /* first free position to be used */
+}
+
+
+static void resize (lua_State *L, Table *t, int nasize, int nhsize) {
+ int i;
+ int oldasize = t->sizearray;
+ int oldhsize = t->lsizenode;
+ Node *nold;
+ Node temp[1];
+ if (oldhsize)
+ nold = t->node; /* save old hash ... */
+ else { /* old hash is `dummynode' */
+ lua_assert(t->node == G(L)->dummynode);
+ temp[0] = t->node[0]; /* copy it to `temp' */
+ nold = temp;
+ setnilvalue(gkey(G(L)->dummynode)); /* restate invariant */
+ setnilvalue(gval(G(L)->dummynode));
+ lua_assert(G(L)->dummynode->next == NULL);
+ }
+ if (nasize > oldasize) /* array part must grow? */
+ setarrayvector(L, t, nasize);
+ /* create new hash part with appropriate size */
+ setnodevector(L, t, nhsize);
+ /* re-insert elements */
+ 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(luaH_setnum(L, t, i+1), &t->array[i]);
+ }
+ /* shrink array */
+ luaM_reallocvector(L, t->array, oldasize, nasize, TObject);
+ }
+ /* re-insert elements in hash part */
+ for (i = twoto(oldhsize) - 1; i >= 0; i--) {
+ Node *old = nold+i;
+ if (!ttisnil(gval(old)))
+ setobjt2t(luaH_set(L, t, gkey(old)), gval(old));
+ }
+ if (oldhsize)
+ luaM_freearray(L, nold, twoto(oldhsize), Node); /* free old array */
+}
+
+
+static void rehash (lua_State *L, Table *t) {
+ int nasize, nhsize;
+ numuse(t, &nasize, &nhsize); /* compute new sizes for array and hash parts */
+ resize(L, t, nasize, luaO_log2(nhsize)+1);
+}
+
+
+
+/*
+** }=============================================================
+*/
+
+
+Table *luaH_new (lua_State *L, int narray, int lnhash) {
+ Table *t = luaM_new(L, Table);
+ luaC_link(L, valtogco(t), LUA_TTABLE);
+ t->metatable = hvalue(defaultmeta(L));
+ t->flags = cast(lu_byte, ~0);
+ /* temporary values (kept only if some malloc fails) */
+ t->array = NULL;
+ t->sizearray = 0;
+ t->lsizenode = 0;
+ t->node = NULL;
+ setarrayvector(L, t, narray);
+ setnodevector(L, t, lnhash);
+ return t;
+}
+
+
+void luaH_free (lua_State *L, Table *t) {
+ if (t->lsizenode)
+ luaM_freearray(L, t->node, sizenode(t), Node);
+ luaM_freearray(L, t->array, t->sizearray, TObject);
+ luaM_freelem(L, t);
+}
+
+
+#if 0
+/*
+** try to remove an element from a hash table; cannot move any element
+** (because gc can call `remove' during a table traversal)
+*/
+void luaH_remove (Table *t, Node *e) {
+ Node *mp = luaH_mainposition(t, gkey(e));
+ if (e != mp) { /* element not in its main position? */
+ while (mp->next != e) mp = mp->next; /* find previous */
+ mp->next = e->next; /* remove `e' from its list */
+ }
+ else {
+ if (e->next != NULL) ??
+ }
+ lua_assert(ttisnil(gval(node)));
+ setnilvalue(gkey(e)); /* clear node `e' */
+ e->next = NULL;
+}
+#endif
+
+
+/*
+** 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 TObject *newkey (lua_State *L, Table *t, const TObject *key) {
+ TObject *val;
+ Node *mp = luaH_mainposition(t, key);
+ if (!ttisnil(gval(mp))) { /* main position is not free? */
+ Node *othern = luaH_mainposition(t, gkey(mp)); /* `mp' of colliding node */
+ Node *n = t->firstfree; /* get a free place */
+ if (othern != mp) { /* is colliding node out of its main position? */
+ /* yes; move colliding node into free position */
+ while (othern->next != mp) othern = othern->next; /* find previous */
+ othern->next = n; /* redo the chain with `n' in place of `mp' */
+ *n = *mp; /* copy colliding node into free pos. (mp->next also goes) */
+ mp->next = NULL; /* now `mp' is free */
+ setnilvalue(gval(mp));
+ }
+ else { /* colliding node is in its own main position */
+ /* new node will go into free position */
+ n->next = mp->next; /* chain new position */
+ mp->next = n;
+ mp = n;
+ }
+ }
+ setobj2t(gkey(mp), key); /* write barrier */
+ lua_assert(ttisnil(gval(mp)));
+ for (;;) { /* correct `firstfree' */
+ if (ttisnil(gkey(t->firstfree)))
+ return gval(mp); /* OK; table still has a free place */
+ else if (t->firstfree == t->node) break; /* cannot decrement from here */
+ else (t->firstfree)--;
+ }
+ /* no more free places; must create one */
+ setbvalue(gval(mp), 0); /* avoid new key being removed */
+ rehash(L, t); /* grow table */
+ val = cast(TObject *, luaH_get(t, key)); /* get new position */
+ lua_assert(ttisboolean(val));
+ setnilvalue(val);
+ return val;
+}
+
+
+/*
+** generic search function
+*/
+static const TObject *luaH_getany (Table *t, const TObject *key) {
+ if (ttisnil(key)) return &luaO_nilobject;
+ else {
+ Node *n = luaH_mainposition(t, key);
+ do { /* check whether `key' is somewhere in the chain */
+ if (luaO_rawequalObj(gkey(n), key)) return gval(n); /* that's it */
+ else n = n->next;
+ } while (n);
+ return &luaO_nilobject;
+ }
+}
+
+
+/*
+** search function for integers
+*/
+const TObject *luaH_getnum (Table *t, int key) {
+ if (1 <= key && key <= t->sizearray)
+ return &t->array[key-1];
+ else {
+ lua_Number nk = cast(lua_Number, key);
+ Node *n = hashnum(t, nk);
+ do { /* check whether `key' is somewhere in the chain */
+ if (ttisnumber(gkey(n)) && nvalue(gkey(n)) == nk)
+ return gval(n); /* that's it */
+ else n = n->next;
+ } while (n);
+ return &luaO_nilobject;
+ }
+}
+
+
+/*
+** search function for strings
+*/
+const TObject *luaH_getstr (Table *t, TString *key) {
+ Node *n = hashstr(t, key);
+ do { /* check whether `key' is somewhere in the chain */
+ if (ttisstring(gkey(n)) && tsvalue(gkey(n)) == key)
+ return gval(n); /* that's it */
+ else n = n->next;
+ } while (n);
+ return &luaO_nilobject;
+}
+
+
+/*
+** main search function
+*/
+const TObject *luaH_get (Table *t, const TObject *key) {
+ switch (ttype(key)) {
+ case LUA_TSTRING: return luaH_getstr(t, tsvalue(key));
+ case LUA_TNUMBER: {
+ int k;
+ lua_number2int(k, (nvalue(key)));
+ if (cast(lua_Number, k) == nvalue(key)) /* is an integer index? */
+ return luaH_getnum(t, k); /* use specialized version */
+ /* else go through */
+ }
+ default: return luaH_getany(t, key);
+ }
+}
+
+
+TObject *luaH_set (lua_State *L, Table *t, const TObject *key) {
+ const TObject *p = luaH_get(t, key);
+ t->flags = 0;
+ if (p != &luaO_nilobject)
+ return cast(TObject *, p);
+ else {
+ if (ttisnil(key)) luaG_runerror(L, "table index is nil");
+ else if (ttisnumber(key) && nvalue(key) != nvalue(key))
+ luaG_runerror(L, "table index is NaN");
+ return newkey(L, t, key);
+ }
+}
+
+
+TObject *luaH_setnum (lua_State *L, Table *t, int key) {
+ const TObject *p = luaH_getnum(t, key);
+ if (p != &luaO_nilobject)
+ return cast(TObject *, p);
+ else {
+ TObject k;
+ setnvalue(&k, cast(lua_Number, key));
+ return newkey(L, t, &k);
+ }
+}
+
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