erts: Refactor ETS compressed encoding of local node

Instead of INTERNAL_CREATION (255), use empty atom for node name
to mean the local node (regardless of node name or creation).

The purpose is to get rid of special value 255, for future expansion
of creation to 32-bit.

2 files changed, 21 insertions, 23 deletions

diff --git a/erts/emulator/beam/erl_vm.h b/erts/emulator/beam/erl_vm.h
index 98f27a1725..357094633e 100644
--- a/erts/emulator/beam/erl_vm.h
+++ b/erts/emulator/beam/erl_vm.h
@@ -165,7 +165,6 @@ extern int erts_atom_table_size;/* Atom table size */
 extern int erts_pd_initial_size;/* Initial Process dictionary table size */
 
 #define ORIG_CREATION 0
-#define INTERNAL_CREATION 255
 
 /* macros for extracting bytes from uint16's */
 
diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
index 10f03636ec..de0c155fc0 100644
--- a/erts/emulator/beam/external.c
+++ b/erts/emulator/beam/external.c
@@ -51,7 +51,7 @@
 
 #define MAX_STRING_LEN 0xffff
 
-#define is_valid_creation(Cre) ((unsigned)(Cre) < MAX_CREATION || (Cre) == INTERNAL_CREATION)
+#define is_valid_creation(Cre) ((unsigned)(Cre) < MAX_CREATION)
 
 #undef ERTS_DEBUG_USE_DIST_SEP
 #ifdef DEBUG
@@ -2152,12 +2152,12 @@ static byte*
 enc_pid(ErtsAtomCacheMap *acmp, Eterm pid, byte* ep, Uint32 dflags)
 {
     Uint on, os;
+    Eterm sysname = ((is_internal_pid(pid) && (dflags & DFLAG_INTERNAL_TAGS))
+		      ? am_Empty : pid_node_name(pid));
 
     *ep++ = PID_EXT;
     /* insert  atom here containing host and sysname  */
-    ep = enc_atom(acmp, pid_node_name(pid), ep, dflags);
-
-    /* two bytes for each number and serial */
+    ep = enc_atom(acmp, sysname, ep, dflags);
 
     on = pid_number(pid);
     os = pid_serial(pid);
@@ -2166,8 +2166,7 @@ enc_pid(ErtsAtomCacheMap *acmp, Eterm pid, byte* ep, Uint32 dflags)
     ep += 4;
     put_int32(os, ep);
     ep += 4;
-    *ep++ = (is_internal_pid(pid) && (dflags & DFLAG_INTERNAL_TAGS)) ?
-	INTERNAL_CREATION : pid_creation(pid);
+    *ep++ = pid_creation(pid);
     return ep;
 }
 
@@ -2249,14 +2248,13 @@ dec_atom(ErtsDistExternal *edep, byte* ep, Eterm* objp)
 
 static ERTS_INLINE ErlNode* dec_get_node(Eterm sysname, Uint creation)
 {
-    switch (creation) {
-    case INTERNAL_CREATION:
+    if (sysname == am_Empty)  /* && DFLAG_INTERNAL_TAGS */
 	return erts_this_node;
-    case ORIG_CREATION:
-	if (sysname == erts_this_node->sysname) {
-	    creation = erts_this_node->creation;
-	}
-    }
+
+    if (sysname == erts_this_node->sysname
+	&& (creation == erts_this_node->creation || creation == ORIG_CREATION))
+	return erts_this_node;
+
     return erts_find_or_insert_node(sysname,creation);
 }
 
@@ -2528,6 +2526,8 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
 	case REF_DEF:
 	case EXTERNAL_REF_DEF: {
 	    Uint32 *ref_num;
+	    Eterm sysname = (((dflags & DFLAG_INTERNAL_TAGS) && is_internal_ref(obj))
+			     ? am_Empty : ref_node_name(obj));
 
 	    ASSERT(dflags & DFLAG_EXTENDED_REFERENCES);
 
@@ -2535,9 +2535,8 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
 	    i = ref_no_of_numbers(obj);
 	    put_int16(i, ep);
 	    ep += 2;
-	    ep = enc_atom(acmp,ref_node_name(obj),ep,dflags);
-	    *ep++ = ((dflags & DFLAG_INTERNAL_TAGS) && is_internal_ref(obj)) ?
-		INTERNAL_CREATION : ref_creation(obj);
+	    ep = enc_atom(acmp, sysname, ep, dflags);
+	    *ep++ = ref_creation(obj);
 	    ref_num = ref_numbers(obj);
 	    for (j = 0; j < i; j++) {
 		put_int32(ref_num[j], ep);
@@ -2546,17 +2545,17 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
 	    break;
 	}
 	case PORT_DEF:
-	case EXTERNAL_PORT_DEF:
-
+	case EXTERNAL_PORT_DEF: {
+	    Eterm sysname = (((dflags & DFLAG_INTERNAL_TAGS) && is_internal_port(obj))
+			     ? am_Empty : port_node_name(obj));
 	    *ep++ = PORT_EXT;
-	    ep = enc_atom(acmp,port_node_name(obj),ep,dflags);
+	    ep = enc_atom(acmp, sysname, ep, dflags);
 	    j = port_number(obj);
 	    put_int32(j, ep);
 	    ep += 4;
-	    *ep++ = ((dflags & DFLAG_INTERNAL_TAGS) && is_internal_port(obj)) ?
-		INTERNAL_CREATION : port_creation(obj);
+	    *ep++ = port_creation(obj);
 	    break;
-
+	}
 	case LIST_DEF:
 	    {
 		int is_str;