/*
** About the realloc function:
** void * frealloc (void *ud, void *ptr, size_t osize, size_t nsize);
** (`osize' is the old size, `nsize' is the new size)
**
** Lua ensures that (ptr == NULL) iff (osize == 0).
**
** * frealloc(ud, NULL, 0, x) creates a new block of size `x'
**
** * frealloc(ud, p, x, 0) frees the block `p'
** (in this specific case, frealloc must return NULL).
** particularly, frealloc(ud, NULL, 0, 0) does nothing
** (which is equivalent to free(NULL) in ANSI C)
**
** frealloc returns NULL if it cannot create or reallocate the area
** (any reallocation to an equal or smaller size cannot fail!)
*/
#define MINSIZEARRAY 4
void *luaM_growaux_ (lua_State *L, void *block, int *size, size_t size_elems,
int limit, const char *errormsg) {
void *newblock;
int newsize;
if (*size >= limit/2) { /* cannot double it? */
if (*size >= limit) /* cannot grow even a little? */
luaG_runerror(L, errormsg);
newsize = limit; /* still have at least one free place */
}
else {
newsize = (*size)*2;
if (newsize < MINSIZEARRAY)
newsize = MINSIZEARRAY; /* minimum size */
}
newblock = luaM_reallocv(L, block, *size, newsize, size_elems);
*size = newsize; /* update only when everything else is OK */
return newblock;
}
void *luaM_toobig (lua_State *L) {
luaG_runerror(L, "memory allocation error: block too big");
return NULL; /* to avoid warnings */
}
