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