mirror of
https://github.com/lua/lua
synced 2024-11-26 22:59:35 +03:00
114 lines
3.3 KiB
C
114 lines
3.3 KiB
C
/*
|
|
** $Id: lstring.c,v 2.17 2010/04/03 20:24:18 roberto Exp roberto $
|
|
** 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) {
|
|
int i;
|
|
stringtable *tb = &G(L)->strt;
|
|
/* cannot resize while GC is traversing strings */
|
|
luaC_runtilstate(L, ~bitmask(GCSsweepstring));
|
|
if (newsize > tb->size) {
|
|
luaM_reallocvector(L, tb->hash, tb->size, newsize, GCObject *);
|
|
for (i = tb->size; i < newsize; i++) tb->hash[i] = NULL;
|
|
}
|
|
/* rehash */
|
|
for (i=0; i<tb->size; i++) {
|
|
GCObject *p = tb->hash[i];
|
|
tb->hash[i] = NULL;
|
|
while (p) { /* for each node in the list */
|
|
GCObject *next = gch(p)->next; /* save next */
|
|
unsigned int h = lmod(gco2ts(p)->hash, newsize); /* new position */
|
|
gch(p)->next = tb->hash[h]; /* chain it */
|
|
tb->hash[h] = p;
|
|
resetoldbit(p); /* see MOVE OLD rule */
|
|
p = next;
|
|
}
|
|
}
|
|
if (newsize < tb->size) {
|
|
/* shrinking slice must be empty */
|
|
lua_assert(tb->hash[newsize] == NULL && tb->hash[tb->size - 1] == NULL);
|
|
luaM_reallocvector(L, tb->hash, tb->size, newsize, GCObject *);
|
|
}
|
|
tb->size = newsize;
|
|
}
|
|
|
|
|
|
static TString *newlstr (lua_State *L, const char *str, size_t l,
|
|
unsigned int h) {
|
|
size_t totalsize; /* total size of TString object */
|
|
GCObject **list; /* (pointer to) list where it will be inserted */
|
|
TString *ts;
|
|
stringtable *tb = &G(L)->strt;
|
|
if (l+1 > (MAX_SIZET - sizeof(TString))/sizeof(char))
|
|
luaM_toobig(L);
|
|
if (tb->nuse >= cast(lu_int32, tb->size) && tb->size <= MAX_INT/2)
|
|
luaS_resize(L, tb->size*2); /* too crowded */
|
|
totalsize = sizeof(TString) + ((l + 1) * sizeof(char));
|
|
list = &tb->hash[lmod(h, tb->size)];
|
|
ts = &luaC_newobj(L, LUA_TSTRING, totalsize, list, 0)->ts;
|
|
ts->tsv.len = l;
|
|
ts->tsv.hash = h;
|
|
ts->tsv.reserved = 0;
|
|
memcpy(ts+1, str, l*sizeof(char));
|
|
((char *)(ts+1))[l] = '\0'; /* ending 0 */
|
|
tb->nuse++;
|
|
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 = gch(o)->next) {
|
|
TString *ts = rawgco2ts(o);
|
|
if (h == ts->tsv.hash && ts->tsv.len == l &&
|
|
(memcmp(str, getstr(ts), l) == 0)) {
|
|
if (isdead(G(L), o)) /* string is dead (but was not collected yet)? */
|
|
changewhite(o); /* resurrect it */
|
|
return ts;
|
|
}
|
|
}
|
|
return newlstr(L, str, l, h); /* not found; create a new string */
|
|
}
|
|
|
|
|
|
TString *luaS_new (lua_State *L, const char *str) {
|
|
return luaS_newlstr(L, str, strlen(str));
|
|
}
|
|
|
|
|
|
Udata *luaS_newudata (lua_State *L, size_t s, Table *e) {
|
|
Udata *u;
|
|
if (s > MAX_SIZET - sizeof(Udata))
|
|
luaM_toobig(L);
|
|
u = &luaC_newobj(L, LUA_TUSERDATA, sizeof(Udata) + s, NULL, 0)->u;
|
|
u->uv.len = s;
|
|
u->uv.metatable = NULL;
|
|
u->uv.env = e;
|
|
return u;
|
|
}
|
|
|