Rework some code handling pg_subscription data in psql and pg_dump

This commit fixes some inconsistencies found in the frontend code when
dealing with subscription catalog data.

The following changes are done:
- pg_subscription.h gains a EXPOSE_TO_CLIENT_CODE, so as more content
defined in pg_subscription.h becomes available in pg_subscription_d.h
for the frontend.
- In psql's describe.c, substream can be switched to use CppAsString2()
with its three LOGICALREP_STREAM_* values, with pg_subscription_d.h
included.
- pg_dump.c included pg_subscription.h, which is a header that should
only be used in the backend code.  The code is updated to use
pg_subscription_d.h instead.
- pg_dump stored all the data from pg_subscription in SubscriptionInfo
with only strings, and a good chunk of them are boolean and char values.
Using strings is not necessary, complicates the code (see for example
two_phase_disabled[] removed here), and is inconsistent with the way
other catalogs' data is handled.  The fields of SubscriptionInfo are
reordered to match with the order in its catalog, while on it.

Reviewed-by: Hayato Kuroda
Discussion: https://postgr.es/m/Z0lB2kp0ksHgmVuk@paquier.xyz

src/bin/pg_dump/pg_dump.c

@@ -50,7 +50,7 @@
 #include "catalog/pg_default_acl_d.h"
 #include "catalog/pg_largeobject_d.h"
 #include "catalog/pg_proc_d.h"
-#include "catalog/pg_subscription.h"
+#include "catalog/pg_subscription_d.h"
 #include "catalog/pg_type_d.h"
 #include "common/connect.h"
 #include "common/int.h"
@@ -4968,20 +4968,20 @@ getSubscriptions(Archive *fout)
 	i_oid = PQfnumber(res, "oid");
 	i_subname = PQfnumber(res, "subname");
 	i_subowner = PQfnumber(res, "subowner");
+	i_subenabled = PQfnumber(res, "subenabled");
 	i_subbinary = PQfnumber(res, "subbinary");
 	i_substream = PQfnumber(res, "substream");
 	i_subtwophasestate = PQfnumber(res, "subtwophasestate");
 	i_subdisableonerr = PQfnumber(res, "subdisableonerr");
 	i_subpasswordrequired = PQfnumber(res, "subpasswordrequired");
 	i_subrunasowner = PQfnumber(res, "subrunasowner");
+	i_subfailover = PQfnumber(res, "subfailover");
 	i_subconninfo = PQfnumber(res, "subconninfo");
 	i_subslotname = PQfnumber(res, "subslotname");
 	i_subsynccommit = PQfnumber(res, "subsynccommit");
 	i_subpublications = PQfnumber(res, "subpublications");
 	i_suborigin = PQfnumber(res, "suborigin");
 	i_suboriginremotelsn = PQfnumber(res, "suboriginremotelsn");
-	i_subenabled = PQfnumber(res, "subenabled");
-	i_subfailover = PQfnumber(res, "subfailover");
 
 	subinfo = pg_malloc(ntups * sizeof(SubscriptionInfo));
 
@@ -4995,18 +4995,20 @@ getSubscriptions(Archive *fout)
 		subinfo[i].dobj.name = pg_strdup(PQgetvalue(res, i, i_subname));
 		subinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_subowner));
 
+		subinfo[i].subenabled =
+			(strcmp(PQgetvalue(res, i, i_subenabled), "t") == 0);
 		subinfo[i].subbinary =
-			pg_strdup(PQgetvalue(res, i, i_subbinary));
-		subinfo[i].substream =
-			pg_strdup(PQgetvalue(res, i, i_substream));
-		subinfo[i].subtwophasestate =
-			pg_strdup(PQgetvalue(res, i, i_subtwophasestate));
+			(strcmp(PQgetvalue(res, i, i_subbinary), "t") == 0);
+		subinfo[i].substream = *(PQgetvalue(res, i, i_substream));
+		subinfo[i].subtwophasestate = *(PQgetvalue(res, i, i_subtwophasestate));
 		subinfo[i].subdisableonerr =
-			pg_strdup(PQgetvalue(res, i, i_subdisableonerr));
+			(strcmp(PQgetvalue(res, i, i_subdisableonerr), "t") == 0);
 		subinfo[i].subpasswordrequired =
-			pg_strdup(PQgetvalue(res, i, i_subpasswordrequired));
+			(strcmp(PQgetvalue(res, i, i_subpasswordrequired), "t") == 0);
 		subinfo[i].subrunasowner =
-			pg_strdup(PQgetvalue(res, i, i_subrunasowner));
+			(strcmp(PQgetvalue(res, i, i_subrunasowner), "t") == 0);
+		subinfo[i].subfailover =
+			(strcmp(PQgetvalue(res, i, i_subfailover), "t") == 0);
 		subinfo[i].subconninfo =
 			pg_strdup(PQgetvalue(res, i, i_subconninfo));
 		if (PQgetisnull(res, i, i_subslotname))
@@ -5024,10 +5026,6 @@ getSubscriptions(Archive *fout)
 		else
 			subinfo[i].suboriginremotelsn =
 				pg_strdup(PQgetvalue(res, i, i_suboriginremotelsn));
-		subinfo[i].subenabled =
-			pg_strdup(PQgetvalue(res, i, i_subenabled));
-		subinfo[i].subfailover =
-			pg_strdup(PQgetvalue(res, i, i_subfailover));
 
 		/* Decide whether we want to dump it */
 		selectDumpableObject(&(subinfo[i].dobj), fout);
@@ -5208,7 +5206,6 @@ dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo)
 	char	  **pubnames = NULL;
 	int			npubnames = 0;
 	int			i;
-	char		two_phase_disabled[] = {LOGICALREP_TWOPHASE_STATE_DISABLED, '\0'};
 
 	/* Do nothing if not dumping schema */
 	if (!dopt->dumpSchema)
@@ -5245,29 +5242,29 @@ dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo)
 	else
 		appendPQExpBufferStr(query, "NONE");
 
-	if (strcmp(subinfo->subbinary, "t") == 0)
+	if (subinfo->subbinary)
 		appendPQExpBufferStr(query, ", binary = true");
 
-	if (strcmp(subinfo->substream, "t") == 0)
+	if (subinfo->substream == LOGICALREP_STREAM_ON)
 		appendPQExpBufferStr(query, ", streaming = on");
-	else if (strcmp(subinfo->substream, "p") == 0)
+	else if (subinfo->substream == LOGICALREP_STREAM_PARALLEL)
 		appendPQExpBufferStr(query, ", streaming = parallel");
 	else
 		appendPQExpBufferStr(query, ", streaming = off");
 
-	if (strcmp(subinfo->subtwophasestate, two_phase_disabled) != 0)
+	if (subinfo->subtwophasestate != LOGICALREP_TWOPHASE_STATE_DISABLED)
 		appendPQExpBufferStr(query, ", two_phase = on");
 
-	if (strcmp(subinfo->subdisableonerr, "t") == 0)
+	if (subinfo->subdisableonerr)
 		appendPQExpBufferStr(query, ", disable_on_error = true");
 
-	if (strcmp(subinfo->subpasswordrequired, "t") != 0)
+	if (!subinfo->subpasswordrequired)
 		appendPQExpBuffer(query, ", password_required = false");
 
-	if (strcmp(subinfo->subrunasowner, "t") == 0)
+	if (subinfo->subrunasowner)
 		appendPQExpBufferStr(query, ", run_as_owner = true");
 
-	if (strcmp(subinfo->subfailover, "t") == 0)
+	if (subinfo->subfailover)
 		appendPQExpBufferStr(query, ", failover = true");
 
 	if (strcmp(subinfo->subsynccommit, "off") != 0)
@@ -5303,7 +5300,7 @@ dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo)
 			appendPQExpBuffer(query, ", '%s');\n", subinfo->suboriginremotelsn);
 		}
 
-		if (strcmp(subinfo->subenabled, "t") == 0)
+		if (subinfo->subenabled)
 		{
 			/*
 			 * Enable the subscription to allow the replication to continue

src/bin/pg_dump/pg_dump.h

@@ -664,20 +664,20 @@ typedef struct _SubscriptionInfo
 {
 	DumpableObject dobj;
 	const char *rolname;
-	char	   *subenabled;
-	char	   *subbinary;
-	char	   *substream;
-	char	   *subtwophasestate;
-	char	   *subdisableonerr;
-	char	   *subpasswordrequired;
-	char	   *subrunasowner;
+	bool		subenabled;
+	bool		subbinary;
+	char		substream;
+	char		subtwophasestate;
+	bool		subdisableonerr;
+	bool		subpasswordrequired;
+	bool		subrunasowner;
+	bool		subfailover;
 	char	   *subconninfo;
 	char	   *subslotname;
 	char	   *subsynccommit;
 	char	   *subpublications;
 	char	   *suborigin;
 	char	   *suboriginremotelsn;
-	char	   *subfailover;
 } SubscriptionInfo;
 
 /*

src/bin/psql/describe.c

@@ -25,6 +25,7 @@
 #include "catalog/pg_default_acl_d.h"
 #include "catalog/pg_proc_d.h"
 #include "catalog/pg_statistic_ext_d.h"
+#include "catalog/pg_subscription_d.h"
 #include "catalog/pg_type_d.h"
 #include "common.h"
 #include "common/logging.h"
@@ -6679,9 +6680,9 @@ describeSubscriptions(const char *pattern, bool verbose)
 			if (pset.sversion >= 160000)
 				appendPQExpBuffer(&buf,
 								  ", (CASE substream\n"
-								  "    WHEN 'f' THEN 'off'\n"
-								  "    WHEN 't' THEN 'on'\n"
-								  "    WHEN 'p' THEN 'parallel'\n"
+								  "    WHEN " CppAsString2(LOGICALREP_STREAM_OFF) " THEN 'off'\n"
+								  "    WHEN " CppAsString2(LOGICALREP_STREAM_ON) " THEN 'on'\n"
+								  "    WHEN " CppAsString2(LOGICALREP_STREAM_PARALLEL) " THEN 'parallel'\n"
 								  "   END) AS \"%s\"\n",
 								  gettext_noop("Streaming"));
 			else

src/include/catalog/pg_subscription.h

@@ -23,26 +23,6 @@
 #include "lib/stringinfo.h"
 #include "nodes/pg_list.h"
 
-/*
- * two_phase tri-state values. See comments atop worker.c to know more about
- * these states.
- */
-#define LOGICALREP_TWOPHASE_STATE_DISABLED 'd'
-#define LOGICALREP_TWOPHASE_STATE_PENDING 'p'
-#define LOGICALREP_TWOPHASE_STATE_ENABLED 'e'
-
-/*
- * The subscription will request the publisher to only send changes that do not
- * have any origin.
- */
-#define LOGICALREP_ORIGIN_NONE "none"
-
-/*
- * The subscription will request the publisher to send changes regardless
- * of their origin.
- */
-#define LOGICALREP_ORIGIN_ANY "any"
-
 /* ----------------
  *		pg_subscription definition. cpp turns this into
  *		typedef struct FormData_pg_subscription
@@ -159,6 +139,28 @@ typedef struct Subscription
 								 * specified origin */
 } Subscription;
 
+#ifdef EXPOSE_TO_CLIENT_CODE
+
+/*
+ * two_phase tri-state values. See comments atop worker.c to know more about
+ * these states.
+ */
+#define LOGICALREP_TWOPHASE_STATE_DISABLED 'd'
+#define LOGICALREP_TWOPHASE_STATE_PENDING 'p'
+#define LOGICALREP_TWOPHASE_STATE_ENABLED 'e'
+
+/*
+ * The subscription will request the publisher to only send changes that do not
+ * have any origin.
+ */
+#define LOGICALREP_ORIGIN_NONE "none"
+
+/*
+ * The subscription will request the publisher to send changes regardless
+ * of their origin.
+ */
+#define LOGICALREP_ORIGIN_ANY "any"
+
 /* Disallow streaming in-progress transactions. */
 #define LOGICALREP_STREAM_OFF 'f'
 
@@ -174,6 +176,8 @@ typedef struct Subscription
  */
 #define LOGICALREP_STREAM_PARALLEL 'p'
 
+#endif							/* EXPOSE_TO_CLIENT_CODE */
+
 extern Subscription *GetSubscription(Oid subid, bool missing_ok);
 extern void FreeSubscription(Subscription *sub);
 extern void DisableSubscription(Oid subid);