/* ** $Id: lstring.c,v 2.8.1.1 2007/12/27 13:02:25 roberto Exp $ ** String table (keeps all strings handled by Lua) ** See Copyright Notice in lua.h */ #include <string.h> #define lstring_c #define LUA_CORE #include "lua.h" #include "lmem.h" #include "lobject.h" #include "lstate.h" #include "lstring.h" void luaS_resize (lua_State *L, int newsize) { GCObject **newhash; stringtable *tb; int i; if (G(L)->gcstate == GCSsweepstring) return; /* cannot resize during GC traverse */ newhash = luaM_newvector(L, newsize, GCObject *); tb = &G(L)->strt; for (i=0; i<newsize; i++) newhash[i] = NULL; /* rehash */ for (i=0; i<tb->size; i++) { GCObject *p = tb->hash[i]; while (p) { /* for each node in the list */ GCObject *next = p->gch.next; /* save next */ unsigned int h = gco2ts(p)->hash; int h1 = lmod(h, newsize); /* new position */ lua_assert(cast_int(h%newsize) == lmod(h, newsize)); p->gch.next = newhash[h1]; /* chain it */ newhash[h1] = p; p = next; } } luaM_freearray(L, tb->hash, tb->size, TString *); tb->size = newsize; tb->hash = newhash; } static TString *newlstr (lua_State *L, const char *str, size_t l, unsigned int h) { TString *ts; stringtable *tb; if (l+1 > (MAX_SIZET - sizeof(TString))/sizeof(char)) luaM_toobig(L); ts = cast(TString *, luaM_malloc(L, (l+1)*sizeof(char)+sizeof(TString))); ts->tsv.len = l; ts->tsv.hash = h; ts->tsv.marked = luaC_white(G(L)); ts->tsv.tt = LUA_TSTRING; ts->tsv.reserved = 0; memcpy(ts+1, str, l*sizeof(char)); ((char *)(ts+1))[l] = '\0'; /* ending 0 */ tb = &G(L)->strt; h = lmod(h, tb->size); ts->tsv.next = tb->hash[h]; /* chain new entry */ tb->hash[h] = obj2gco(ts); tb->nuse++; if (tb->nuse > cast(lu_int32, tb->size) && tb->size <= MAX_INT/2) luaS_resize(L, tb->size*2); /* too crowded */ return ts; } TString *luaS_newlstr (lua_State *L, const char *str, size_t l) { GCObject *o; unsigned int h = cast(unsigned int, l); /* seed */ size_t step = (l>>5)+1; /* if string is too long, don't hash all its chars */ size_t l1; for (l1=l; l1>=step; l1-=step) /* compute hash */ h = h ^ ((h<<5)+(h>>2)+cast(unsigned char, str[l1-1])); for (o = G(L)->strt.hash[lmod(h, G(L)->strt.size)]; o != NULL; o = o->gch.next) { TString *ts = rawgco2ts(o); if (ts->tsv.len == l && (memcmp(str, getstr(ts), l) == 0)) { /* string may be dead */ if (isdead(G(L), o)) changewhite(o); return ts; } } return newlstr(L, str, l, h); /* not found */ } Udata *luaS_newudata (lua_State *L, size_t s, Table *e) { Udata *u; if (s > MAX_SIZET - sizeof(Udata)) luaM_toobig(L); u = cast(Udata *, luaM_malloc(L, s + sizeof(Udata))); u->uv.marked = luaC_white(G(L)); /* is not finalized */ u->uv.tt = LUA_TUSERDATA; u->uv.len = s; u->uv.metatable = NULL; u->uv.env = e; /* chain it on udata list (after main thread) */ u->uv.next = G(L)->mainthread->next; G(L)->mainthread->next = obj2gco(u); return u; }