DBZ-486 Replication message provides info about optionality

Author: jpechane

proto/pg_logicaldec.proto

@@ -32,6 +32,7 @@ message DatumMessage {
 
 message TypeInfo {
     required string modifier = 1;
+    required bool value_optional = 2;
 }
 
 message RowMessage {

src/decoderbufs.c

@@ -640,6 +640,7 @@ static void add_metadata_to_msg(Decoderbufs__TypeInfo **tmsg,
     Form_pg_attribute attr;
     char *typ_mod;
     Decoderbufs__TypeInfo typeinfo = DECODERBUFS__TYPE_INFO__INIT;
+    bool not_null;
 
     attr = tupdesc->attrs[natt];
 
@@ -649,10 +650,12 @@ static void add_metadata_to_msg(Decoderbufs__TypeInfo **tmsg,
       continue;
     }
 
+    not_null = attr->attnotnull;
     typ_mod = TextDatumGetCString(DirectFunctionCall2(format_type, attr->atttypid, attr->atttypmod));
-    elog(DEBUG1, "Adding typemodifier '%s' for column %d", typ_mod, natt);
+    elog(DEBUG1, "Adding typemodifier '%s' for column %d, optional %s", typ_mod, natt, !not_null ? "true" : "false");
 
     typeinfo.modifier = typ_mod;
+    typeinfo.value_optional = !not_null;
     tmsg[valid_attr_cnt] = palloc(sizeof(typeinfo));
     memcpy(tmsg[valid_attr_cnt], &typeinfo, sizeof(typeinfo));
 

src/proto/pg_logicaldec.pb-c.c

@@ -385,7 +385,7 @@ const ProtobufCMessageDescriptor decoderbufs__datum_message__descriptor =
   (ProtobufCMessageInit) decoderbufs__datum_message__init,
   NULL,NULL,NULL    /* reserved[123] */
 };
-static const ProtobufCFieldDescriptor decoderbufs__type_info__field_descriptors[1] =
+static const ProtobufCFieldDescriptor decoderbufs__type_info__field_descriptors[2] =
 {
   {
     "modifier",
@@ -399,14 +399,27 @@ static const ProtobufCFieldDescriptor decoderbufs__type_info__field_descriptors[
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
   },
+  {
+    "value_optional",
+    2,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_BOOL,
+    0,   /* quantifier_offset */
+    offsetof(Decoderbufs__TypeInfo, value_optional),
+    NULL,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
 };
 static const unsigned decoderbufs__type_info__field_indices_by_name[] = {
   0,   /* field[0] = modifier */
+  1,   /* field[1] = value_optional */
 };
 static const ProtobufCIntRange decoderbufs__type_info__number_ranges[1 + 1] =
 {
   { 1, 0 },
-  { 0, 1 }
+  { 0, 2 }
 };
 const ProtobufCMessageDescriptor decoderbufs__type_info__descriptor =
 {
@@ -416,7 +429,7 @@ const ProtobufCMessageDescriptor decoderbufs__type_info__descriptor =
   "Decoderbufs__TypeInfo",
   "decoderbufs",
   sizeof(Decoderbufs__TypeInfo),
-  1,
+  2,
   decoderbufs__type_info__field_descriptors,
   decoderbufs__type_info__field_indices_by_name,
   1,  decoderbufs__type_info__number_ranges,