2 ** $Id: lstring.c,v 2.8.1.1 2007/12/27 13:02:25 roberto Exp $
3 ** String table (keeps all strings handled by Lua)
4 ** See Copyright Notice in lua.h
22 void luaS_resize (lua_State *L, int newsize) {
26 if (G(L)->gcstate == GCSsweepstring)
27 return; /* cannot resize during GC traverse */
28 newhash = luaM_newvector(L, newsize, GCObject *);
30 for (i=0; i<newsize; i++) newhash[i] = NULL;
32 for (i=0; i<tb->size; i++) {
33 GCObject *p = tb->hash[i];
34 while (p) { /* for each node in the list */
35 GCObject *next = p->gch.next; /* save next */
36 unsigned int h = gco2ts(p)->hash;
37 int h1 = lmod(h, newsize); /* new position */
38 lua_assert(cast_int(h%newsize) == lmod(h, newsize));
39 p->gch.next = newhash[h1]; /* chain it */
44 luaM_freearray(L, tb->hash, tb->size, TString *);
50 static TString *newlstr (lua_State *L, const char *str, size_t l,
54 if (l+1 > (MAX_SIZET - sizeof(TString))/sizeof(char))
56 ts = cast(TString *, luaM_malloc(L, (l+1)*sizeof(char)+sizeof(TString)));
59 ts->tsv.marked = luaC_white(G(L));
60 ts->tsv.tt = LUA_TSTRING;
62 memcpy(ts+1, str, l*sizeof(char));
63 ((char *)(ts+1))[l] = '\0'; /* ending 0 */
65 h = lmod(h, tb->size);
66 ts->tsv.next = tb->hash[h]; /* chain new entry */
67 tb->hash[h] = obj2gco(ts);
69 if (tb->nuse > cast(lu_int32, tb->size) && tb->size <= MAX_INT/2)
70 luaS_resize(L, tb->size*2); /* too crowded */
75 TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
77 unsigned int h = cast(unsigned int, l); /* seed */
78 size_t step = (l>>5)+1; /* if string is too long, don't hash all its chars */
80 for (l1=l; l1>=step; l1-=step) /* compute hash */
81 h = h ^ ((h<<5)+(h>>2)+cast(unsigned char, str[l1-1]));
82 for (o = G(L)->strt.hash[lmod(h, G(L)->strt.size)];
85 TString *ts = rawgco2ts(o);
86 if (ts->tsv.len == l && (memcmp(str, getstr(ts), l) == 0)) {
87 /* string may be dead */
88 if (isdead(G(L), o)) changewhite(o);
92 return newlstr(L, str, l, h); /* not found */
96 Udata *luaS_newudata (lua_State *L, size_t s, Table *e) {
98 if (s > MAX_SIZET - sizeof(Udata))
100 u = cast(Udata *, luaM_malloc(L, s + sizeof(Udata)));
101 u->uv.marked = luaC_white(G(L)); /* is not finalized */
102 u->uv.tt = LUA_TUSERDATA;
104 u->uv.metatable = NULL;
106 /* chain it on udata list (after main thread) */
107 u->uv.next = G(L)->mainthread->next;
108 G(L)->mainthread->next = obj2gco(u);