1 files changed, 64 insertions, 0 deletions
diff --git a/src/bin/pg_waldump/compat.c b/src/bin/pg_waldump/compat.c
new file mode 100644
index 0000000..6a3386e
--- /dev/null
+++ b/src/bin/pg_waldump/compat.c
@@ -0,0 +1,64 @@
+/*-------------------------------------------------------------------------
+ *
+ * compat.c
+ *		Reimplementations of various backend functions.
+ *
+ * Portions Copyright (c) 2013-2022, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *		src/bin/pg_waldump/compat.c
+ *
+ * This file contains client-side implementations for various backend
+ * functions that the rm_desc functions in *desc.c files rely on.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/* ugly hack, same as in e.g pg_controldata */
+#define FRONTEND 1
+#include "postgres.h"
+
+#include <time.h>
+
+#include "utils/datetime.h"
+
+/* copied from timestamp.c */
+pg_time_t
+timestamptz_to_time_t(TimestampTz t)
+{
+	pg_time_t	result;
+
+	result = (pg_time_t) (t / USECS_PER_SEC +
+						  ((POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY));
+	return result;
+}
+
+/*
+ * Stopgap implementation of timestamptz_to_str that doesn't depend on backend
+ * infrastructure.  This will work for timestamps that are within the range
+ * of the platform time_t type.  (pg_time_t is compatible except for possibly
+ * being wider.)
+ *
+ * XXX the return value points to a static buffer, so beware of using more
+ * than one result value concurrently.
+ *
+ * XXX: The backend timestamp infrastructure should instead be split out and
+ * moved into src/common.  That's a large project though.
+ */
+const char *
+timestamptz_to_str(TimestampTz dt)
+{
+	static char buf[MAXDATELEN + 1];
+	char		ts[MAXDATELEN + 1];
+	char		zone[MAXDATELEN + 1];
+	time_t		result = (time_t) timestamptz_to_time_t(dt);
+	struct tm  *ltime = localtime(&result);
+
+	strftime(ts, sizeof(ts), "%Y-%m-%d %H:%M:%S", ltime);
+	strftime(zone, sizeof(zone), "%Z", ltime);
+
+	snprintf(buf, sizeof(buf), "%s.%06d %s",
+			 ts, (int) (dt % USECS_PER_SEC), zone);
+
+	return buf;
+}