v2-0001-Add-support-for-command-line-option-to-pass-LSN.patch

From 7cc2fb70188676406ca883055467aff602438fcd Mon Sep 17 00:00:00 2001
From: Jeevan Chalke <jeevan.chalke@enterprisedb.com>
Date: Mon, 9 Sep 2019 10:38:01 +0530
Subject: [PATCH v2 1/4] Add support for command line option to pass LSN.

This adds [ LSN 'lsn' ] to BASE_BACKUP command and --lsn=LSN to
the pg_basebackup binary.

Also, add small tests.
---
 src/backend/replication/basebackup.c         | 20 ++++++++++++++++++++
 src/backend/replication/repl_gram.y          |  6 ++++++
 src/backend/replication/repl_scanner.l       |  1 +
 src/bin/pg_basebackup/pg_basebackup.c        | 15 +++++++++++++--
 src/bin/pg_basebackup/t/010_pg_basebackup.pl | 12 +++++++++++-
 5 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c
index 6aab8d7..e72bf8e 100644
--- a/src/backend/replication/basebackup.c
+++ b/src/backend/replication/basebackup.c
@@ -38,6 +38,7 @@
 #include "storage/ipc.h"
 #include "storage/reinit.h"
 #include "utils/builtins.h"
+#include "utils/pg_lsn.h"
 #include "utils/ps_status.h"
 #include "utils/relcache.h"
 #include "utils/timestamp.h"
@@ -52,6 +53,7 @@ typedef struct
 	bool		includewal;
 	uint32		maxrate;
 	bool		sendtblspcmapfile;
+	XLogRecPtr 	lsn;
 } basebackup_options;
 
 
@@ -652,6 +654,7 @@ parse_basebackup_options(List *options, basebackup_options *opt)
 	bool		o_maxrate = false;
 	bool		o_tablespace_map = false;
 	bool		o_noverify_checksums = false;
+	bool		o_lsn = false;
 
 	MemSet(opt, 0, sizeof(*opt));
 	foreach(lopt, options)
@@ -740,6 +743,23 @@ parse_basebackup_options(List *options, basebackup_options *opt)
 			noverify_checksums = true;
 			o_noverify_checksums = true;
 		}
+		else if (strcmp(defel->defname, "lsn") == 0)
+		{
+			bool		have_error = false;
+
+			if (o_lsn)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("duplicate option \"%s\"", defel->defname)));
+			o_lsn = true;
+
+			/* Validate given LSN and convert it into XLogRecPtr. */
+			opt->lsn = pg_lsn_in_internal(strVal(defel->arg), &have_error);
+			if (XLogRecPtrIsInvalid(opt->lsn))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+						 errmsg("invalid value for LSN")));
+		}
 		else
 			elog(ERROR, "option \"%s\" not recognized",
 				 defel->defname);
diff --git a/src/backend/replication/repl_gram.y b/src/backend/replication/repl_gram.y
index c4e11cc..c24d319 100644
--- a/src/backend/replication/repl_gram.y
+++ b/src/backend/replication/repl_gram.y
@@ -87,6 +87,7 @@ static SQLCmd *make_sqlcmd(void);
 %token K_EXPORT_SNAPSHOT
 %token K_NOEXPORT_SNAPSHOT
 %token K_USE_SNAPSHOT
+%token K_LSN
 
 %type <node>	command
 %type <node>	base_backup start_replication start_logical_replication
@@ -214,6 +215,11 @@ base_backup_opt:
 				  $$ = makeDefElem("noverify_checksums",
 								   (Node *)makeInteger(true), -1);
 				}
+			| K_LSN SCONST
+				{
+				  $$ = makeDefElem("lsn",
+								   (Node *)makeString($2), -1);
+				}
 			;
 
 create_replication_slot:
diff --git a/src/backend/replication/repl_scanner.l b/src/backend/replication/repl_scanner.l
index 380faeb..77b5af4 100644
--- a/src/backend/replication/repl_scanner.l
+++ b/src/backend/replication/repl_scanner.l
@@ -107,6 +107,7 @@ EXPORT_SNAPSHOT		{ return K_EXPORT_SNAPSHOT; }
 NOEXPORT_SNAPSHOT	{ return K_NOEXPORT_SNAPSHOT; }
 USE_SNAPSHOT		{ return K_USE_SNAPSHOT; }
 WAIT				{ return K_WAIT; }
+LSN					{ return K_LSN; }
 
 ","				{ return ','; }
 ";"				{ return ';'; }
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 7986872..1791853 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -105,6 +105,7 @@ static bool temp_replication_slot = true;
 static bool create_slot = false;
 static bool no_slot = false;
 static bool verify_checksums = true;
+static char *lsn = NULL;
 
 static bool success = false;
 static bool made_new_pgdata = false;
@@ -341,6 +342,7 @@ usage(void)
 			 "                         include required WAL files with specified method\n"));
 	printf(_("  -z, --gzip             compress tar output\n"));
 	printf(_("  -Z, --compress=0-9     compress tar output with given compression level\n"));
+	printf(_("      --lsn=LSN          incremental backup, using LSN as threshold\n"));
 	printf(_("\nGeneral options:\n"));
 	printf(_("  -c, --checkpoint=fast|spread\n"
 			 "                         set fast or spread checkpointing\n"));
@@ -1805,6 +1807,7 @@ BaseBackup(void)
 				maxServerMajor;
 	int			serverVersion,
 				serverMajor;
+	char	   *lsn_clause = NULL;
 
 	Assert(conn != NULL);
 
@@ -1871,8 +1874,11 @@ BaseBackup(void)
 			fprintf(stderr, "\n");
 	}
 
+	if (lsn)
+		lsn_clause = psprintf("LSN '%s'", lsn);
+
 	basebkp =
-		psprintf("BASE_BACKUP LABEL '%s' %s %s %s %s %s %s %s",
+		psprintf("BASE_BACKUP LABEL '%s' %s %s %s %s %s %s %s %s",
 				 escaped_label,
 				 showprogress ? "PROGRESS" : "",
 				 includewal == FETCH_WAL ? "WAL" : "",
@@ -1880,7 +1886,8 @@ BaseBackup(void)
 				 includewal == NO_WAL ? "" : "NOWAIT",
 				 maxrate_clause ? maxrate_clause : "",
 				 format == 't' ? "TABLESPACE_MAP" : "",
-				 verify_checksums ? "" : "NOVERIFY_CHECKSUMS");
+				 verify_checksums ? "" : "NOVERIFY_CHECKSUMS",
+				 lsn_clause ? lsn_clause : "");
 
 	if (PQsendQuery(conn, basebkp) == 0)
 	{
@@ -2199,6 +2206,7 @@ main(int argc, char **argv)
 		{"waldir", required_argument, NULL, 1},
 		{"no-slot", no_argument, NULL, 2},
 		{"no-verify-checksums", no_argument, NULL, 3},
+		{"lsn", required_argument, NULL, 4},
 		{NULL, 0, NULL, 0}
 	};
 	int			c;
@@ -2367,6 +2375,9 @@ main(int argc, char **argv)
 			case 3:
 				verify_checksums = false;
 				break;
+			case 4:
+				lsn = pg_strdup(optarg);
+				break;
 			default:
 
 				/*
diff --git a/src/bin/pg_basebackup/t/010_pg_basebackup.pl b/src/bin/pg_basebackup/t/010_pg_basebackup.pl
index b7d36b6..fd8e187 100644
--- a/src/bin/pg_basebackup/t/010_pg_basebackup.pl
+++ b/src/bin/pg_basebackup/t/010_pg_basebackup.pl
@@ -6,7 +6,7 @@ use File::Basename qw(basename dirname);
 use File::Path qw(rmtree);
 use PostgresNode;
 use TestLib;
-use Test::More tests => 106;
+use Test::More tests => 108;
 
 program_help_ok('pg_basebackup');
 program_version_ok('pg_basebackup');
@@ -556,5 +556,15 @@ $node->command_ok(
 	'pg_basebackup with -k does not report checksum mismatch');
 rmtree("$tempdir/backup_corrupt4");
 
+# check LSN
+$node->command_fails(
+	[ 'pg_basebackup', '-D', "$tempdir/lsn_test", '--lsn', "0/INVALID" ],
+	'pg_basebackup with invalid LSN fails');
+$node->command_ok(
+	[ 'pg_basebackup', '-D', "$tempdir/lsn_test", '--lsn', "0/ABCDEF01", '--no-verify-checksums' ],
+	'pg_basebackup with valid LSN');
+rmtree("$tempdir/lsn_test");
+
+
 $node->safe_psql('postgres', "DROP TABLE corrupt1;");
 $node->safe_psql('postgres', "DROP TABLE corrupt2;");
-- 
1.8.3.1