blob: 6db197badd8a19f5e1e2a3d69461d830edeba090 [file] [log] [blame]
** $Id: ltable.h $
** Lua tables (hash)
** See Copyright Notice in lua.h
#ifndef ltable_h
#define ltable_h
#include "lobject.h"
#define gnode(t,i) (&(t)->node[i])
#define gval(n) (&(n)->i_val)
#define gnext(n) ((n)->
** Clear all bits of fast-access metamethods, which means that the table
** may have any of these metamethods. (First access that fails after the
** clearing will set the bit again.)
#define invalidateTMcache(t) ((t)->flags &= ~maskflags)
** Bit BITDUMMY set in 'flags' means the table is using the dummy node
** for its hash part.
#define BITDUMMY (1 << 6)
#define NOTBITDUMMY cast_byte(~BITDUMMY)
#define isdummy(t) ((t)->flags & BITDUMMY)
#define setnodummy(t) ((t)->flags &= NOTBITDUMMY)
#define setdummy(t) ((t)->flags |= BITDUMMY)
/* allocated size for hash nodes */
#define allocsizenode(t) (isdummy(t) ? 0 : sizenode(t))
/* returns the Node, given the value of a table entry */
#define nodefromval(v) cast(Node *, (v))
#define luaH_fastgeti(t,k,res,tag) \
{ Table *h = t; lua_Unsigned u = l_castS2U(k); \
if ((u - 1u < h->alimit)) { \
tag = *getArrTag(h,(u)-1u); \
if (!tagisempty(tag)) { farr2val(h, u, tag, res); }} \
else { tag = luaH_getint(h, u, res); }}
#define luaH_fastseti(t,k,val,hres) \
{ Table *h = t; lua_Unsigned u = l_castS2U(k); \
if ((u - 1u < h->alimit)) { \
lu_byte *tag = getArrTag(h,(u)-1u); \
if (tagisempty(*tag)) hres = ~cast_int(u); \
else { fval2arr(h, u, tag, val); hres = HOK; }} \
else { hres = luaH_psetint(h, u, val); }}
/* results from pset */
#define HOK 0
#define HNOTFOUND 1
#define HNOTATABLE 2
#define HFIRSTNODE 3
** 'luaH_get*' operations set 'res', unless the value is absent, and
** return the tag of the result.
** The 'luaH_pset*' (pre-set) operations set the given value and return
** HOK, unless the original value is absent. In that case, if the key
** is really absent, they return HNOTFOUND. Otherwise, if there is a
** slot with that key but with no value, 'luaH_pset*' return an encoding
** of where the key is (usually called 'hres'). (pset cannot set that
** value because there might be a metamethod.) If the slot is in the
** hash part, the encoding is (HFIRSTNODE + hash index); if the slot is
** in the array part, the encoding is (~array index), a negative value.
** The value HNOTATABLE is used by the fast macros to signal that the
** value being indexed is not a table.
** The array part of a table is represented by an inverted array of
** values followed by an array of tags, to avoid wasting space with
** padding. The 'array' pointer points to the junction of the two
** arrays, so that values are indexed with negative indices and tags
** with non-negative indices.
Values Tags
... | Value 1 | Value 0 |0|1|...
^ t->array
** All accesses to 't->array' should be through the macros 'getArrTag'
** and 'getArrVal'.
/* Computes the address of the tag for the abstract index 'k' */
#define getArrTag(t,k) (cast(lu_byte*, (t)->array) + (k))
/* Computes the address of the value for the abstract index 'k' */
#define getArrVal(t,k) ((t)->array - 1 - (k))
** Move TValues to/from arrays, using Lua indices
#define arr2obj(h,k,val) \
((val)->tt_ = *getArrTag(h,(k)-1u), (val)->value_ = *getArrVal(h,(k)-1u))
#define obj2arr(h,k,val) \
(*getArrTag(h,(k)-1u) = (val)->tt_, *getArrVal(h,(k)-1u) = (val)->value_)
** Often, we need to check the tag of a value before moving it. The
** following macros also move TValues to/from arrays, but receive the
** precomputed tag value or address as an extra argument.
#define farr2val(h,k,tag,res) \
((res)->tt_ = tag, (res)->value_ = *getArrVal(h,(k)-1u))
#define fval2arr(h,k,tag,val) \
(*tag = (val)->tt_, *getArrVal(h,(k)-1u) = (val)->value_)
LUAI_FUNC int luaH_get (Table *t, const TValue *key, TValue *res);
LUAI_FUNC int luaH_getshortstr (Table *t, TString *key, TValue *res);
LUAI_FUNC int luaH_getstr (Table *t, TString *key, TValue *res);
LUAI_FUNC int luaH_getint (Table *t, lua_Integer key, TValue *res);
/* Special get for metamethods */
LUAI_FUNC const TValue *luaH_Hgetshortstr (Table *t, TString *key);
LUAI_FUNC TString *luaH_getstrkey (Table *t, TString *key);
LUAI_FUNC int luaH_psetint (Table *t, lua_Integer key, TValue *val);
LUAI_FUNC int luaH_psetshortstr (Table *t, TString *key, TValue *val);
LUAI_FUNC int luaH_psetstr (Table *t, TString *key, TValue *val);
LUAI_FUNC int luaH_pset (Table *t, const TValue *key, TValue *val);
LUAI_FUNC void luaH_setint (lua_State *L, Table *t, lua_Integer key,
TValue *value);
LUAI_FUNC void luaH_set (lua_State *L, Table *t, const TValue *key,
TValue *value);
LUAI_FUNC void luaH_finishset (lua_State *L, Table *t, const TValue *key,
TValue *value, int hres);
LUAI_FUNC Table *luaH_new (lua_State *L);
LUAI_FUNC void luaH_resize (lua_State *L, Table *t, unsigned nasize,
unsigned nhsize);
LUAI_FUNC void luaH_resizearray (lua_State *L, Table *t, unsigned nasize);
LUAI_FUNC void luaH_free (lua_State *L, Table *t);
LUAI_FUNC int luaH_next (lua_State *L, Table *t, StkId key);
LUAI_FUNC lua_Unsigned luaH_getn (Table *t);
LUAI_FUNC unsigned luaH_realasize (const Table *t);
#if defined(LUA_DEBUG)
LUAI_FUNC Node *luaH_mainposition (const Table *t, const TValue *key);