PG-1126: Expose Percona API version

src/backend/utils/misc/Makefile

@@ -22,6 +22,7 @@ OBJS = \
 	guc_tables.o \
 	help_config.o \
 	injection_point.o \
+	percona.o \
 	pg_config.o \
 	pg_controldata.o \
 	pg_rusage.o \

src/backend/utils/misc/meson.build

@@ -7,6 +7,7 @@ backend_sources += files(
   'guc_tables.c',
   'help_config.c',
   'injection_point.c',
+  'percona.c',
   'pg_config.c',
   'pg_controldata.c',
   'pg_rusage.c',

src/backend/utils/misc/percona.c

@@ -0,0 +1,15 @@
+/*-------------------------------------------------------------------------
+ *
+ * percona.c
+ *      Percona specific functions
+ *
+ * IDENTIFICATION
+ *    src/backend/utils/misc/percona.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "utils/percona.h"
+
+const int percona_api_version = PERCONA_API_VERSION;

src/include/pg_config_manual.h

@@ -383,3 +383,5 @@
  * Enable tracing of syncscan operations (see also the trace_syncscan GUC var).
  */
 /* #define TRACE_SYNCSCAN */
+
+#define PERCONA_API_VERSION 1

src/include/utils/percona.h

@@ -0,0 +1,28 @@
+/*-------------------------------------------------------------------------
+ *
+ * percona.h
+ *      Percona specific functions
+ *
+ * IDENTIFICATION
+ *    src/include/utils/percona.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef PERCONA__H__
+#define PERCONA__H__
+
+extern const PGDLLIMPORT int percona_api_version;
+
+static inline bool check_percona_api_version(void)
+{
+    if (PERCONA_API_VERSION != percona_api_version)
+    {
+        elog(FATAL, "Percona API version mismatch, the extension was built againts a different PostgreSQL version!");
+        return false;
+    }
+
+    return true;
+}
+
+#endif // PERCONA__H__