nodemcu-firmware/app/lua/lrotable.c

137 lines
4.0 KiB
C

/* Read-only tables for Lua */
#define LUAC_CROSS_FILE
#include "lua.h"
#include C_HEADER_STRING
#include "lrotable.h"
#include "lauxlib.h"
#include "lstring.h"
#include "lobject.h"
#include "lapi.h"
/* Local defines */
#define LUAR_FINDFUNCTION 0
#define LUAR_FINDVALUE 1
/* Externally defined read-only table array */
extern const luaR_table lua_rotable[];
/* Find a global "read only table" in the constant lua_rotable array */
void* luaR_findglobal(const char *name, unsigned len) {
unsigned i;
if (c_strlen(name) > LUA_MAX_ROTABLE_NAME)
return NULL;
for (i=0; lua_rotable[i].name; i ++)
if (*lua_rotable[i].name != '\0' && c_strlen(lua_rotable[i].name) == len && !c_strncmp(lua_rotable[i].name, name, len)) {
return (void*)(lua_rotable[i].pentries);
}
return NULL;
}
/* Find an entry in a rotable and return it */
static const TValue* luaR_auxfind(const luaR_entry *pentry, const char *strkey, luaR_numkey numkey, unsigned *ppos) {
const TValue *res = NULL;
unsigned i = 0;
if (pentry == NULL)
return NULL;
while(pentry->key.type != LUA_TNIL) {
if ((strkey && (pentry->key.type == LUA_TSTRING) && (!c_strcmp(pentry->key.id.strkey, strkey))) ||
(!strkey && (pentry->key.type == LUA_TNUMBER) && ((luaR_numkey)pentry->key.id.numkey == numkey))) {
res = &pentry->value;
break;
}
i ++; pentry ++;
}
if (res && ppos)
*ppos = i;
return res;
}
int luaR_findfunction(lua_State *L, const luaR_entry *ptable) {
const TValue *res = NULL;
const char *key = luaL_checkstring(L, 2);
res = luaR_auxfind(ptable, key, 0, NULL);
if (res && ttislightfunction(res)) {
luaA_pushobject(L, res);
return 1;
}
else
return 0;
}
/* Find an entry in a rotable and return its type
If "strkey" is not NULL, the function will look for a string key,
otherwise it will look for a number key */
const TValue* luaR_findentry(void *data, const char *strkey, luaR_numkey numkey, unsigned *ppos) {
return luaR_auxfind((const luaR_entry*)data, strkey, numkey, ppos);
}
/* Find the metatable of a given table */
void* luaR_getmeta(void *data) {
#ifdef LUA_META_ROTABLES
const TValue *res = luaR_auxfind((const luaR_entry*)data, "__metatable", 0, NULL);
return res && ttisrotable(res) ? rvalue(res) : NULL;
#else
return NULL;
#endif
}
static void luaR_next_helper(lua_State *L, const luaR_entry *pentries, int pos, TValue *key, TValue *val) {
setnilvalue(key);
setnilvalue(val);
if (pentries[pos].key.type != LUA_TNIL) {
/* Found an entry */
if (pentries[pos].key.type == LUA_TSTRING)
setsvalue(L, key, luaS_newro(L, pentries[pos].key.id.strkey))
else
setnvalue(key, (lua_Number)pentries[pos].key.id.numkey)
setobj2s(L, val, &pentries[pos].value);
}
}
/* next (used for iteration) */
void luaR_next(lua_State *L, void *data, TValue *key, TValue *val) {
const luaR_entry* pentries = (const luaR_entry*)data;
char strkey[LUA_MAX_ROTABLE_NAME + 1], *pstrkey = NULL;
luaR_numkey numkey = 0;
unsigned keypos;
/* Special case: if key is nil, return the first element of the rotable */
if (ttisnil(key))
luaR_next_helper(L, pentries, 0, key, val);
else if (ttisstring(key) || ttisnumber(key)) {
/* Find the previoud key again */
if (ttisstring(key)) {
luaR_getcstr(strkey, rawtsvalue(key), LUA_MAX_ROTABLE_NAME);
pstrkey = strkey;
} else
numkey = (luaR_numkey)nvalue(key);
luaR_findentry(data, pstrkey, numkey, &keypos);
/* Advance to next key */
keypos ++;
luaR_next_helper(L, pentries, keypos, key, val);
}
}
/* Convert a Lua string to a C string */
void luaR_getcstr(char *dest, const TString *src, size_t maxsize) {
if (src->tsv.len+1 > maxsize)
dest[0] = '\0';
else {
c_memcpy(dest, getstr(src), src->tsv.len);
dest[src->tsv.len] = '\0';
}
}
/* Return 1 if the given pointer is a rotable */
#ifdef LUA_META_ROTABLES
#include "compiler.h"
int luaR_isrotable(void *p) {
return RODATA_START_ADDRESS <= (char*)p && (char*)p <= RODATA_END_ADDRESS;
}
#endif