Add TMcache

4 files changed, 37 insertions, 12 deletions

diff --git a/src/lapi.js b/src/lapi.js
index d2f5c95..9aacb10 100644
--- a/src/lapi.js
+++ b/src/lapi.js
@@ -424,6 +424,7 @@ const lua_rawset = function(L, idx) {
         let slot = ltable.luaH_set(o.value, k);
         slot.setfrom(v);
     }
+    ltable.invalidateTMcache(o.value);
     L.top -= 2;
 };
 
diff --git a/src/ltable.js b/src/ltable.js
index e4d21e2..0ed56ab 100644
--- a/src/ltable.js
+++ b/src/ltable.js
@@ -39,9 +39,14 @@ class Table {
         this.f = void 0; /* first entry */
         this.l = void 0; /* last entry */
         this.metatable = null;
+        this.flags = ~0;
     }
 }
 
+const invalidateTMcache = function(t) {
+    t.flags = 0;
+};
+
 const add = function(t, hash, key, value) {
     t.dead_strong.clear();
     t.dead_weak = void 0;
@@ -204,6 +209,7 @@ const luaH_next = function(L, table, keyI) {
     return true;
 };
 
+module.exports.invalidateTMcache = invalidateTMcache;
 module.exports.luaH_delete  = luaH_delete;
 module.exports.luaH_get     = luaH_get;
 module.exports.luaH_getint  = luaH_getint;
diff --git a/src/ltm.js b/src/ltm.js
index 3e24c9c..ad09c26 100644
--- a/src/ltm.js
+++ b/src/ltm.js
@@ -166,6 +166,21 @@ const luaT_callorderTM = function(L, p1, p2, event) {
         return !L.stack[L.top].l_isfalse() ? 1 : 0;
 };
 
+const fasttm = function(l, et, e) {
+    return et === null ? null :
+        (et.flags & (1 << e)) ? null : luaT_gettm(et, e, l.l_G.tmname[e]);
+};
+
+const luaT_gettm = function(events, event, ename) {
+    const tm = ltable.luaH_getstr(events, ename);
+    assert(event <= TMS.TM_EQ);
+    if (tm.ttisnil()) {  /* no tag method? */
+        events.flags |= 1<<event;  /* cache this fact */
+        return null;
+    }
+    else return tm;
+};
+
 const luaT_gettmbyobj = function(L, o, event) {
     let mt;
     switch(o.ttnov()) {
@@ -180,11 +195,13 @@ const luaT_gettmbyobj = function(L, o, event) {
     return mt ? ltable.luaH_getstr(mt, L.l_G.tmname[event]) : lobject.luaO_nilobject;
 };
 
+module.exports.fasttm           = fasttm;
 module.exports.TMS              = TMS;
 module.exports.luaT_callTM      = luaT_callTM;
 module.exports.luaT_callbinTM   = luaT_callbinTM;
 module.exports.luaT_trybinTM    = luaT_trybinTM;
 module.exports.luaT_callorderTM = luaT_callorderTM;
+module.exports.luaT_gettm       = luaT_gettm;
 module.exports.luaT_gettmbyobj  = luaT_gettmbyobj;
 module.exports.luaT_init        = luaT_init;
 module.exports.luaT_objtypename = luaT_objtypename;
diff --git a/src/lvm.js b/src/lvm.js
index c89714e..a5b10e0 100644
--- a/src/lvm.js
+++ b/src/lvm.js
@@ -725,6 +725,7 @@ const luaV_equalobj = function(L, t1, t2) {
             return 1;
         case CT.LUA_TBOOLEAN:
             return t1.value == t2.value ? 1 : 0; // Might be 1 or true
+        case CT.LUA_TLIGHTUSERDATA:
         case CT.LUA_TNUMINT:
         case CT.LUA_TNUMFLT:
         case CT.LUA_TLCF:
@@ -733,22 +734,20 @@ const luaV_equalobj = function(L, t1, t2) {
         case CT.LUA_TLNGSTR: {
             return lstring.luaS_eqlngstr(t1.tsvalue(), t2.tsvalue()) ? 1 : 0;
         }
-        case CT.LUA_TLIGHTUSERDATA:
         case CT.LUA_TUSERDATA:
         case CT.LUA_TTABLE:
             if (t1.value === t2.value) return 1;
             else if (L === null) return 0;
 
-            // TODO: fasttm ?
-            tm = ltm.luaT_gettmbyobj(L, t1, ltm.TMS.TM_EQ);
-            if (tm.ttisnil())
-                tm = ltm.luaT_gettmbyobj(L, t2, ltm.TMS.TM_EQ);
+            tm = ltm.fasttm(L, t1.value.metatable, ltm.TMS.TM_EQ);
+            if (tm === null)
+                tm = ltm.fasttm(L, t2.value.metatable, ltm.TMS.TM_EQ);
             break;
         default:
             return t1.value === t2.value ? 1 : 0;
     }
 
-    if (!tm || tm.ttisnil())
+    if (tm === null) /* no TM? */
         return 0;
 
     ltm.luaT_callTM(L, tm, t1, t2, L.top, 1);
@@ -911,9 +910,10 @@ const luaV_objlen = function(L, ra, rb) {
     let tm;
     switch(rb.ttype()) {
         case CT.LUA_TTABLE: {
-            tm = ltm.luaT_gettmbyobj(L, rb, ltm.TMS.TM_LEN);
-            if (!tm.ttisnil()) break;
-            L.stack[ra] = new lobject.TValue(CT.LUA_TNUMINT, ltable.luaH_getn(rb.value));
+            let h = rb.value;
+            tm = ltm.fasttm(L, h.metatable, ltm.TMS.TM_LEN);
+            if (tm !== null) break; /* metamethod? break switch to call it */
+            L.stack[ra] = new lobject.TValue(CT.LUA_TNUMINT, ltable.luaH_getn(h)); /* else primitive len */
             return;
         }
         case CT.LUA_TSHRSTR:
@@ -1031,8 +1031,8 @@ const gettable = function(L, t, key, ra) {
                 L.stack[ra] = new lobject.TValue(slot.type, slot.value);
                 return;
             } else { /* 't' is a table */
-                tm = ltm.luaT_gettmbyobj(L, t, ltm.TMS.TM_INDEX);  /* table's metamethod */
-                if (tm.ttisnil()) { /* no metamethod? */
+                tm = ltm.fasttm(L, t.value.metatable, ltm.TMS.TM_INDEX);  /* table's metamethod */
+                if (tm === null) { /* no metamethod? */
                     L.stack[ra] = new lobject.TValue(CT.LUA_TNIL, null); /* result is nil */
                     return;
                 }
@@ -1055,11 +1055,12 @@ const settable = function(L, t, key, val) {
         if (t.ttistable()) {
             let h = t.value; /* save 't' table */
             let slot = ltable.luaH_set(h, key);
-            if (!slot.ttisnil() || (tm = ltm.luaT_gettmbyobj(L, t, ltm.TMS.TM_NEWINDEX)).ttisnil()) {
+            if (!slot.ttisnil() || (tm = ltm.fasttm(L, h.metatable, ltm.TMS.TM_NEWINDEX)) === null) {
                 if (val.ttisnil())
                     ltable.luaH_delete(h, key);
                 else
                     slot.setfrom(val);
+                ltable.invalidateTMcache(h);
                 return;
             }
             /* else will try the metamethod */