Add contrib/pg_walinspect.

Provides similar functionality to pg_waldump, but from a SQL interface
rather than a separate utility.

Author: Bharath Rupireddy
Reviewed-by: Greg Stark, Kyotaro Horiguchi, Andres Freund, Ashutosh Sharma, Nitin Jadhav, RKN Sai Krishna
Discussion: https://postgr.es/m/CALj2ACUGUYXsEQdKhEdsBzhGEyF3xggvLdD8C0VT72TNEfOiog%40mail.gmail.com

5 files changed, 50 insertions, 4 deletions

diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index e302bd102cd..5e1e3446aed 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -31,7 +31,7 @@ extern XLogRecPtr XactLastRecEnd;
 extern PGDLLIMPORT XLogRecPtr XactLastCommitEnd;
 
 /* these variables are GUC parameters related to XLOG */
-extern int	wal_segment_size;
+extern PGDLLIMPORT int	wal_segment_size;
 extern int	min_wal_size_mb;
 extern int	max_wal_size_mb;
 extern int	wal_keep_size_mb;
diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h
index d9df7f295d5..750f6341205 100644
--- a/src/include/access/xlog_internal.h
+++ b/src/include/access/xlog_internal.h
@@ -320,7 +320,7 @@ typedef struct RmgrData
 							  struct XLogRecordBuffer *buf);
 } RmgrData;
 
-extern RmgrData RmgrTable[];
+extern PGDLLIMPORT RmgrData RmgrTable[];
 extern void RmgrStartup(void);
 extern void RmgrCleanup(void);
 extern void RmgrNotFound(RmgrId rmid);
@@ -350,6 +350,10 @@ extern XLogRecPtr RequestXLogSwitch(bool mark_unimportant);
 
 extern void GetOldestRestartPoint(XLogRecPtr *oldrecptr, TimeLineID *oldtli);
 
+extern void XLogRecGetBlockRefInfo(XLogReaderState *record, bool pretty,
+								   bool detailed_format, StringInfo buf,
+								   uint32 *fpi_len);
+
 /*
  * Exported for the functions in timeline.c and xlogarchive.c.  Only valid
  * in the startup process.
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index d8eb8576110..727e9fe9718 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -344,9 +344,7 @@ extern void XLogReaderSetDecodeBuffer(XLogReaderState *state,
 
 /* Position the XLogReader to given record */
 extern void XLogBeginRead(XLogReaderState *state, XLogRecPtr RecPtr);
-#ifdef FRONTEND
 extern XLogRecPtr XLogFindNextRecord(XLogReaderState *state, XLogRecPtr RecPtr);
-#endif							/* FRONTEND */
 
 /* Return values from XLogPageReadCB. */
 typedef enum XLogPageReadResult
diff --git a/src/include/access/xlogstats.h b/src/include/access/xlogstats.h
new file mode 100644
index 00000000000..453bb1f4913
--- /dev/null
+++ b/src/include/access/xlogstats.h
@@ -0,0 +1,40 @@
+/*-------------------------------------------------------------------------
+ *
+ * xlogstats.h
+ *		Definitions for WAL Statitstics
+ *
+ * Copyright (c) 2022, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *		src/include/access/xlogstats.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef XLOGSTATS_H
+#define XLOGSTATS_H
+
+#define MAX_XLINFO_TYPES 16
+
+typedef struct XLogRecStats
+{
+	uint64	count;
+	uint64	rec_len;
+	uint64	fpi_len;
+} XLogRecStats;
+
+typedef struct XLogStats
+{
+	uint64	count;
+#ifdef FRONTEND
+	XLogRecPtr	startptr;
+	XLogRecPtr	endptr;
+#endif
+	XLogRecStats    rmgr_stats[RM_MAX_ID + 1];
+	XLogRecStats    record_stats[RM_MAX_ID + 1][MAX_XLINFO_TYPES];
+} XLogStats;
+
+extern void XLogRecGetLen(XLogReaderState *record, uint32 *rec_len,
+						  uint32 *fpi_len);
+extern void XLogRecStoreStats(XLogStats *stats, XLogReaderState *record);
+
+#endif							/* XLOGSTATS_H */
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index ff40f96e423..3746e31e40f 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -93,6 +93,10 @@ extern void FreeFakeRelcacheEntry(Relation fakerel);
 extern int	read_local_xlog_page(XLogReaderState *state,
 								 XLogRecPtr targetPagePtr, int reqLen,
 								 XLogRecPtr targetRecPtr, char *cur_page);
+extern int	read_local_xlog_page_no_wait(XLogReaderState *state,
+										 XLogRecPtr targetPagePtr, int reqLen,
+										 XLogRecPtr targetRecPtr,
+										 char *cur_page);
 extern void wal_segment_open(XLogReaderState *state,
 							 XLogSegNo nextSegNo,
 							 TimeLineID *tli_p);