#define lstring_c
#define LUA_CORE
#include "lprefix.h"
#include <string.h>
#include "lua.h"
#include "ldebug.h"
#include "ldo.h"
#include "lmem.h"
#include "lobject.h"
#include "lstate.h"
#include "lstring.h"
#define MEMERRMSG "not enough memory"
#if !defined(LUAI_HASHLIMIT)
#define LUAI_HASHLIMIT 5
#endif
int luaS_eqlngstr (TString *a, TString *b) {
size_t len = a->u.lnglen;
lua_assert(a->tt == LUA_TLNGSTR && b->tt == LUA_TLNGSTR);
return (a == b) ||
((len == b->u.lnglen) &&
(memcmp(getstr(a), getstr(b), len) == 0));
}
unsigned int luaS_hash (const char *str, size_t l, unsigned int seed) {
unsigned int h = seed ^ cast(unsigned int, l);
size_t step = (l >> LUAI_HASHLIMIT) + 1;
for (; l >= step; l -= step)
h ^= ((h<<5) + (h>>2) + cast_byte(str[l - 1]));
return h;
}
unsigned int luaS_hashlongstr (TString *ts) {
lua_assert(ts->tt == LUA_TLNGSTR);
if (ts->extra == 0) {
ts->hash = luaS_hash(getstr(ts), ts->u.lnglen, ts->hash);
ts->extra = 1;
}
return ts->hash;
}
void luaS_resize (lua_State *L, int newsize) {
int i;
stringtable *tb = &G(L)->strt;
if (newsize > tb->size) {
luaM_reallocvector(L, tb->hash, tb->size, newsize, TString *);
for (i = tb->size; i < newsize; i++)
tb->hash[i] = NULL;
}
for (i = 0; i < tb->size; i++) {
TString *p = tb->hash[i];
tb->hash[i] = NULL;
while (p) {
TString *hnext = p->u.hnext;
unsigned int h = lmod(p->hash, newsize);
p->u.hnext = tb->hash[h];
tb->hash[h] = p;
p = hnext;
}
}
if (newsize < tb->size) {
lua_assert(tb->hash[newsize] == NULL && tb->hash[tb->size - 1] == NULL);
luaM_reallocvector(L, tb->hash, tb->size, newsize, TString *);
}
tb->size = newsize;
}
void luaS_clearcache (global_State *g) {
int i, j;
for (i = 0; i < STRCACHE_N; i++)
for (j = 0; j < STRCACHE_M; j++) {
if (iswhite(g->strcache[i][j]))
g->strcache[i][j] = g->memerrmsg;
}
}
void luaS_init (lua_State *L) {
global_State *g = G(L);
int i, j;
luaS_resize(L, MINSTRTABSIZE);
g->memerrmsg = luaS_newliteral(L, MEMERRMSG);
luaC_fix(L, obj2gco(g->memerrmsg));
for (i = 0; i < STRCACHE_N; i++)
for (j = 0; j < STRCACHE_M; j++)
g->strcache[i][j] = g->memerrmsg;
}
static TString *createstrobj (lua_State *L, size_t l, int tag, unsigned int h) {
TString *ts;
GCObject *o;
size_t totalsize;
totalsize = sizelstring(l);
o = luaC_newobj(L, tag, totalsize);
ts = gco2ts(o);
ts->hash = h;
ts->extra = 0;
getstr(ts)[l] = '\0';
return ts;
}
TString *luaS_createlngstrobj (lua_State *L, size_t l) {
TString *ts = createstrobj(L, l, LUA_TLNGSTR, G(L)->seed);
ts->u.lnglen = l;
return ts;
}
void luaS_remove (lua_State *L, TString *ts) {
stringtable *tb = &G(L)->strt;
TString **p = &tb->hash[lmod(ts->hash, tb->size)];
while (*p != ts)
p = &(*p)->u.hnext;
*p = (*p)->u.hnext;
tb->nuse--;
}
static TString *internshrstr (lua_State *L, const char *str, size_t l) {
TString *ts;
global_State *g = G(L);
unsigned int h = luaS_hash(str, l, g->seed);
TString **list = &g->strt.hash[lmod(h, g->strt.size)];
lua_assert(str != NULL);
for (ts = *list; ts != NULL; ts = ts->u.hnext) {
if (l == ts->shrlen &&
(memcmp(str, getstr(ts), l * sizeof(char)) == 0)) {
if (isdead(g, ts))
changewhite(ts);
return ts;
}
}
if (g->strt.nuse >= g->strt.size && g->strt.size <= MAX_INT/2) {
luaS_resize(L, g->strt.size * 2);
list = &g->strt.hash[lmod(h, g->strt.size)];
}
ts = createstrobj(L, l, LUA_TSHRSTR, h);
memcpy(getstr(ts), str, l * sizeof(char));
ts->shrlen = cast_byte(l);
ts->u.hnext = *list;
*list = ts;
g->strt.nuse++;
return ts;
}
TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
if (l <= LUAI_MAXSHORTLEN)
return internshrstr(L, str, l);
else {
TString *ts;
if (l >= (MAX_SIZE - sizeof(TString))/sizeof(char))
luaM_toobig(L);
ts = luaS_createlngstrobj(L, l);
memcpy(getstr(ts), str, l * sizeof(char));
return ts;
}
}
TString *luaS_new (lua_State *L, const char *str) {
unsigned int i = point2uint(str) % STRCACHE_N;
int j;
TString **p = G(L)->strcache[i];
for (j = 0; j < STRCACHE_M; j++) {
if (strcmp(str, getstr(p[j])) == 0)
return p[j];
}
for (j = STRCACHE_M - 1; j > 0; j--)
p[j] = p[j - 1];
p[0] = luaS_newlstr(L, str, strlen(str));
return p[0];
}
Udata *luaS_newudata (lua_State *L, size_t s) {
Udata *u;
GCObject *o;
if (s > MAX_SIZE - sizeof(Udata))
luaM_toobig(L);
o = luaC_newobj(L, LUA_TUSERDATA, sizeludata(s));
u = gco2u(o);
u->len = s;
u->metatable = NULL;
setuservalue(L, u, luaO_nilobject);
return u;
}