From 7b1fba69b7a887e37e57744309299d134e76e06e Mon Sep 17 00:00:00 2001 From: Roberto Ierusalimschy Date: Mon, 7 Nov 2016 10:38:35 -0200 Subject: [PATCH] using 'lastfree == NULL' to signal that table is using the dummy node for its hash part + new macro 'allocsizenode' --- lgc.c | 4 ++-- ltable.c | 46 +++++++++++++++++++++++----------------------- ltable.h | 12 ++++++++++-- ltests.c | 6 +++--- 4 files changed, 38 insertions(+), 30 deletions(-) diff --git a/lgc.c b/lgc.c index 7da00442..55a51870 100644 --- a/lgc.c +++ b/lgc.c @@ -1,5 +1,5 @@ /* -** $Id: lgc.c,v 2.212 2016/03/31 19:02:03 roberto Exp roberto $ +** $Id: lgc.c,v 2.213 2016/10/19 12:31:42 roberto Exp roberto $ ** Garbage Collector ** See Copyright Notice in lua.h */ @@ -467,7 +467,7 @@ static lu_mem traversetable (global_State *g, Table *h) { else /* not weak */ traversestrongtable(g, h); return sizeof(Table) + sizeof(TValue) * h->sizearray + - sizeof(Node) * cast(size_t, sizenode(h)); + sizeof(Node) * cast(size_t, allocsizenode(h)); } diff --git a/ltable.c b/ltable.c index 03318a5d..92c165ad 100644 --- a/ltable.c +++ b/ltable.c @@ -1,5 +1,5 @@ /* -** $Id: ltable.c,v 2.116 2015/11/03 18:35:21 roberto Exp roberto $ +** $Id: ltable.c,v 2.117 2015/11/19 19:16:22 roberto Exp roberto $ ** Lua tables (hash) ** See Copyright Notice in lua.h */ @@ -74,8 +74,6 @@ #define dummynode (&dummynode_) -#define isdummy(n) ((n) == dummynode) - static const Node dummynode_ = { {NILCONSTANT}, /* value */ {{NILCONSTANT, 0}} /* key */ @@ -308,14 +306,14 @@ static void setarrayvector (lua_State *L, Table *t, unsigned int size) { static void setnodevector (lua_State *L, Table *t, unsigned int size) { - int lsize; if (size == 0) { /* no elements to hash part? */ t->node = cast(Node *, dummynode); /* use common 'dummynode' */ - lsize = 0; + t->lsizenode = 0; + t->lastfree = NULL; /* signal that it is using dummy node */ } else { int i; - lsize = luaO_ceillog2(size); + int lsize = luaO_ceillog2(size); if (lsize > MAXHBITS) luaG_runerror(L, "table overflow"); size = twoto(lsize); @@ -326,9 +324,9 @@ static void setnodevector (lua_State *L, Table *t, unsigned int size) { setnilvalue(wgkey(n)); setnilvalue(gval(n)); } + t->lsizenode = cast_byte(lsize); + t->lastfree = gnode(t, size); /* all positions are free */ } - t->lsizenode = cast_byte(lsize); - t->lastfree = gnode(t, size); /* all positions are free */ } @@ -337,7 +335,7 @@ void luaH_resize (lua_State *L, Table *t, unsigned int nasize, unsigned int i; int j; unsigned int oldasize = t->sizearray; - int oldhsize = t->lsizenode; + int oldhsize = allocsizenode(t); Node *nold = t->node; /* save old hash ... */ if (nasize > oldasize) /* array part must grow? */ setarrayvector(L, t, nasize); @@ -354,7 +352,7 @@ void luaH_resize (lua_State *L, Table *t, unsigned int nasize, luaM_reallocvector(L, t->array, oldasize, nasize, TValue); } /* re-insert elements from hash part */ - for (j = twoto(oldhsize) - 1; j >= 0; j--) { + for (j = oldhsize - 1; j >= 0; j--) { Node *old = nold + j; if (!ttisnil(gval(old))) { /* doesn't need barrier/invalidate cache, as entry was @@ -362,13 +360,13 @@ void luaH_resize (lua_State *L, Table *t, unsigned int nasize, setobjt2t(L, luaH_set(L, t, gkey(old)), gval(old)); } } - if (!isdummy(nold)) - luaM_freearray(L, nold, cast(size_t, twoto(oldhsize))); /* free old hash */ + if (oldhsize > 0) /* not the dummy node? */ + luaM_freearray(L, nold, cast(size_t, oldhsize)); /* free old hash */ } void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize) { - int nsize = isdummy(t->node) ? 0 : sizenode(t); + int nsize = allocsizenode(t); luaH_resize(L, t, nasize, nsize); } @@ -414,7 +412,7 @@ Table *luaH_new (lua_State *L) { void luaH_free (lua_State *L, Table *t) { - if (!isdummy(t->node)) + if (!isdummy(t)) luaM_freearray(L, t->node, cast(size_t, sizenode(t))); luaM_freearray(L, t->array, t->sizearray); luaM_free(L, t); @@ -422,10 +420,12 @@ void luaH_free (lua_State *L, Table *t) { static Node *getfreepos (Table *t) { - while (t->lastfree > t->node) { - t->lastfree--; - if (ttisnil(gkey(t->lastfree))) - return t->lastfree; + if (!isdummy(t)) { + while (t->lastfree > t->node) { + t->lastfree--; + if (ttisnil(gkey(t->lastfree))) + return t->lastfree; + } } return NULL; /* could not find a free place */ } @@ -445,7 +445,7 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) { if (ttisnil(key)) luaG_runerror(L, "table index is nil"); else if (ttisfloat(key)) { lua_Integer k; - if (luaV_tointeger(key, &k, 0)) { /* index is int? */ + if (luaV_tointeger(key, &k, 0)) { /* does index fit in an integer? */ setivalue(&aux, k); key = &aux; /* insert it as an integer */ } @@ -453,7 +453,7 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) { luaG_runerror(L, "table index is NaN"); } mp = mainposition(t, key); - if (!ttisnil(gval(mp)) || isdummy(mp)) { /* main position is taken? */ + if (!ttisnil(gval(mp)) || isdummy(t)) { /* main position is taken? */ Node *othern; Node *f = getfreepos(t); /* get a free place */ if (f == NULL) { /* cannot find a free place? */ @@ -461,7 +461,7 @@ TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) { /* whatever called 'newkey' takes care of TM cache */ return luaH_set(L, t, key); /* insert key into grown table */ } - lua_assert(!isdummy(f)); + lua_assert(!isdummy(t)); othern = mainposition(t, gkey(mp)); if (othern != mp) { /* is colliding node out of its main position? */ /* yes; move colliding node into free position */ @@ -651,7 +651,7 @@ int luaH_getn (Table *t) { return i; } /* else must find a boundary in hash part */ - else if (isdummy(t->node)) /* hash part is empty? */ + else if (isdummy(t)) /* hash part is empty? */ return j; /* that is easy... */ else return unbound_search(t, j); } @@ -664,6 +664,6 @@ Node *luaH_mainposition (const Table *t, const TValue *key) { return mainposition(t, key); } -int luaH_isdummy (Node *n) { return isdummy(n); } +int luaH_isdummy (const Table *t) { return isdummy(t); } #endif diff --git a/ltable.h b/ltable.h index bad66516..8b80a6df 100644 --- a/ltable.h +++ b/ltable.h @@ -1,5 +1,5 @@ /* -** $Id: ltable.h,v 2.20 2014/09/04 18:15:29 roberto Exp roberto $ +** $Id: ltable.h,v 2.21 2015/11/03 15:47:30 roberto Exp roberto $ ** Lua tables (hash) ** See Copyright Notice in lua.h */ @@ -27,6 +27,14 @@ #define invalidateTMcache(t) ((t)->flags = 0) +/* true when 't' is using 'dummynode' as its hash part */ +#define isdummy(t) ((t)->lastfree == NULL) + + +/* allocated size for hash nodes */ +#define allocsizenode(t) (isdummy(t) ? 0 : sizenode(t)) + + /* returns the key, given the value of a table entry */ #define keyfromval(v) \ (gkey(cast(Node *, cast(char *, (v)) - offsetof(Node, i_val)))) @@ -51,7 +59,7 @@ LUAI_FUNC int luaH_getn (Table *t); #if defined(LUA_DEBUG) LUAI_FUNC Node *luaH_mainposition (const Table *t, const TValue *key); -LUAI_FUNC int luaH_isdummy (Node *n); +LUAI_FUNC int luaH_isdummy (const Table *t); #endif diff --git a/ltests.c b/ltests.c index 98fdf223..e796fac3 100644 --- a/ltests.c +++ b/ltests.c @@ -1,5 +1,5 @@ /* -** $Id: ltests.c,v 2.208 2015/09/08 16:55:43 roberto Exp roberto $ +** $Id: ltests.c,v 2.209 2015/10/12 16:38:19 roberto Exp roberto $ ** Internal Module for Debugging of the Lua Implementation ** See Copyright Notice in lua.h */ @@ -687,8 +687,8 @@ static int table_query (lua_State *L) { t = hvalue(obj_at(L, 1)); if (i == -1) { lua_pushinteger(L, t->sizearray); - lua_pushinteger(L, luaH_isdummy(t->node) ? 0 : sizenode(t)); - lua_pushinteger(L, t->lastfree - t->node); + lua_pushinteger(L, allocsizenode(t)); + lua_pushinteger(L, isdummy(t) ? 0 : t->lastfree - t->node); } else if ((unsigned int)i < t->sizearray) { lua_pushinteger(L, i);