Flexible options for BASE_BACKUP.

Previously, BASE_BACKUP used an entirely hard-coded syntax, but that's
hard to extend. Instead, adopt the same kind of syntax we've used for
SQL commands such as VACUUM, ANALYZE, COPY, and EXPLAIN, where it's
not necessary for all of the option names to be parser keywords.

In the new syntax, most of the options now take an optional Boolean
argument. To match our practice in other in places, the options which
the old syntax called NOWAIT and NOVERIFY_CHECKSUMS options are in the
new syntax called WAIT and VERIFY_CHECKUMS, and the default value is
false. In the new syntax, the FAST option has been replaced by a
CHECKSUM option whose value may be 'fast' or 'spread'.

This commit does not remove support for the old syntax. It just adds
the new one as an additional option, and makes pg_basebackup prefer
the new syntax when the server is new enough to support it.

Patch by me, reviewed and tested by Fabien Coelho, Sergei Kornilov,
Fujii Masao, and Tushar Ahuja.

Discussion: http://postgr.es/m/CA+TgmobAczXDRO_Gr2euo_TxgzaH1JxbNxvFx=HYvBinefNH8Q@mail.gmail.com
Discussion: http://postgr.es/m/CA+TgmoZGwR=ZVWFeecncubEyPdwghnvfkkdBe9BLccLSiqdf9Q@mail.gmail.com

2 files changed, 116 insertions, 32 deletions

diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c
index e09108d0ece..4c97ab7b5a7 100644
--- a/src/backend/replication/basebackup.c
+++ b/src/backend/replication/basebackup.c
@@ -19,6 +19,7 @@
 #include "access/xlog_internal.h"	/* for pg_start/stop_backup */
 #include "catalog/pg_type.h"
 #include "common/file_perm.h"
+#include "commands/defrem.h"
 #include "commands/progress.h"
 #include "lib/stringinfo.h"
 #include "libpq/libpq.h"
@@ -764,7 +765,7 @@ parse_basebackup_options(List *options, basebackup_options *opt)
 	ListCell   *lopt;
 	bool		o_label = false;
 	bool		o_progress = false;
-	bool		o_fast = false;
+	bool		o_checkpoint = false;
 	bool		o_nowait = false;
 	bool		o_wal = false;
 	bool		o_maxrate = false;
@@ -787,7 +788,7 @@ parse_basebackup_options(List *options, basebackup_options *opt)
 				ereport(ERROR,
 						(errcode(ERRCODE_SYNTAX_ERROR),
 						 errmsg("duplicate option \"%s\"", defel->defname)));
-			opt->label = strVal(defel->arg);
+			opt->label = defGetString(defel);
 			o_label = true;
 		}
 		else if (strcmp(defel->defname, "progress") == 0)
@@ -796,25 +797,35 @@ parse_basebackup_options(List *options, basebackup_options *opt)
 				ereport(ERROR,
 						(errcode(ERRCODE_SYNTAX_ERROR),
 						 errmsg("duplicate option \"%s\"", defel->defname)));
-			opt->progress = true;
+			opt->progress = defGetBoolean(defel);
 			o_progress = true;
 		}
-		else if (strcmp(defel->defname, "fast") == 0)
+		else if (strcmp(defel->defname, "checkpoint") == 0)
 		{
-			if (o_fast)
+			char	   *optval = defGetString(defel);
+
+			if (o_checkpoint)
 				ereport(ERROR,
 						(errcode(ERRCODE_SYNTAX_ERROR),
 						 errmsg("duplicate option \"%s\"", defel->defname)));
-			opt->fastcheckpoint = true;
-			o_fast = true;
+			if (pg_strcasecmp(optval, "fast") == 0)
+				opt->fastcheckpoint = true;
+			else if (pg_strcasecmp(optval, "spread") == 0)
+				opt->fastcheckpoint = false;
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("unrecognized checkpoint type: \"%s\"",
+								optval)));
+			o_checkpoint = true;
 		}
-		else if (strcmp(defel->defname, "nowait") == 0)
+		else if (strcmp(defel->defname, "wait") == 0)
 		{
 			if (o_nowait)
 				ereport(ERROR,
 						(errcode(ERRCODE_SYNTAX_ERROR),
 						 errmsg("duplicate option \"%s\"", defel->defname)));
-			opt->nowait = true;
+			opt->nowait = !defGetBoolean(defel);
 			o_nowait = true;
 		}
 		else if (strcmp(defel->defname, "wal") == 0)
@@ -823,19 +834,19 @@ parse_basebackup_options(List *options, basebackup_options *opt)
 				ereport(ERROR,
 						(errcode(ERRCODE_SYNTAX_ERROR),
 						 errmsg("duplicate option \"%s\"", defel->defname)));
-			opt->includewal = true;
+			opt->includewal = defGetBoolean(defel);
 			o_wal = true;
 		}
 		else if (strcmp(defel->defname, "max_rate") == 0)
 		{
-			long		maxrate;
+			int64		maxrate;
 
 			if (o_maxrate)
 				ereport(ERROR,
 						(errcode(ERRCODE_SYNTAX_ERROR),
 						 errmsg("duplicate option \"%s\"", defel->defname)));
 
-			maxrate = intVal(defel->arg);
+			maxrate = defGetInt64(defel);
 			if (maxrate < MAX_RATE_LOWER || maxrate > MAX_RATE_UPPER)
 				ereport(ERROR,
 						(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
@@ -851,21 +862,21 @@ parse_basebackup_options(List *options, basebackup_options *opt)
 				ereport(ERROR,
 						(errcode(ERRCODE_SYNTAX_ERROR),
 						 errmsg("duplicate option \"%s\"", defel->defname)));
-			opt->sendtblspcmapfile = true;
+			opt->sendtblspcmapfile = defGetBoolean(defel);
 			o_tablespace_map = true;
 		}
-		else if (strcmp(defel->defname, "noverify_checksums") == 0)
+		else if (strcmp(defel->defname, "verify_checksums") == 0)
 		{
 			if (o_noverify_checksums)
 				ereport(ERROR,
 						(errcode(ERRCODE_SYNTAX_ERROR),
 						 errmsg("duplicate option \"%s\"", defel->defname)));
-			noverify_checksums = true;
+			noverify_checksums = !defGetBoolean(defel);
 			o_noverify_checksums = true;
 		}
 		else if (strcmp(defel->defname, "manifest") == 0)
 		{
-			char	   *optval = strVal(defel->arg);
+			char	   *optval = defGetString(defel);
 			bool		manifest_bool;
 
 			if (o_manifest)
@@ -890,7 +901,7 @@ parse_basebackup_options(List *options, basebackup_options *opt)
 		}
 		else if (strcmp(defel->defname, "manifest_checksums") == 0)
 		{
-			char	   *optval = strVal(defel->arg);
+			char	   *optval = defGetString(defel);
 
 			if (o_manifest_checksums)
 				ereport(ERROR,
@@ -905,8 +916,10 @@ parse_basebackup_options(List *options, basebackup_options *opt)
 			o_manifest_checksums = true;
 		}
 		else
-			elog(ERROR, "option \"%s\" not recognized",
-				 defel->defname);
+			ereport(ERROR,
+					errcode(ERRCODE_SYNTAX_ERROR),
+					errmsg("option \"%s\" not recognized",
+						   defel->defname));
 	}
 	if (opt->label == NULL)
 		opt->label = "base backup";
diff --git a/src/backend/replication/repl_gram.y b/src/backend/replication/repl_gram.y
index e1e8ec29cc4..3b59d62ed86 100644
--- a/src/backend/replication/repl_gram.y
+++ b/src/backend/replication/repl_gram.y
@@ -95,13 +95,13 @@ static SQLCmd *make_sqlcmd(void);
 %type <node>	base_backup start_replication start_logical_replication
 				create_replication_slot drop_replication_slot identify_system
 				timeline_history show sql_cmd
-%type <list>	base_backup_opt_list
-%type <defelt>	base_backup_opt
+%type <list>	base_backup_legacy_opt_list generic_option_list
+%type <defelt>	base_backup_legacy_opt generic_option
 %type <uintval>	opt_timeline
 %type <list>	plugin_options plugin_opt_list
 %type <defelt>	plugin_opt_elem
 %type <node>	plugin_opt_arg
-%type <str>		opt_slot var_name
+%type <str>		opt_slot var_name ident_or_keyword
 %type <boolval>	opt_temporary
 %type <list>	create_slot_opt_list
 %type <defelt>	create_slot_opt
@@ -157,12 +157,24 @@ var_name:	IDENT	{ $$ = $1; }
 		;
 
 /*
+ * BASE_BACKUP ( option [ 'value' ] [, ...] )
+ *
+ * We also still support the legacy syntax:
+ *
  * BASE_BACKUP [LABEL '<label>'] [PROGRESS] [FAST] [WAL] [NOWAIT]
  * [MAX_RATE %d] [TABLESPACE_MAP] [NOVERIFY_CHECKSUMS]
  * [MANIFEST %s] [MANIFEST_CHECKSUMS %s]
+ *
+ * Future options should be supported only using the new syntax.
  */
 base_backup:
-			K_BASE_BACKUP base_backup_opt_list
+			K_BASE_BACKUP '(' generic_option_list ')'
+				{
+					BaseBackupCmd *cmd = makeNode(BaseBackupCmd);
+					cmd->options = $3;
+					$$ = (Node *) cmd;
+				}
+			| K_BASE_BACKUP base_backup_legacy_opt_list
 				{
 					BaseBackupCmd *cmd = makeNode(BaseBackupCmd);
 					cmd->options = $2;
@@ -170,14 +182,14 @@ base_backup:
 				}
 			;
 
-base_backup_opt_list:
-			base_backup_opt_list base_backup_opt
+base_backup_legacy_opt_list:
+			base_backup_legacy_opt_list base_backup_legacy_opt
 				{ $$ = lappend($1, $2); }
 			| /* EMPTY */
 				{ $$ = NIL; }
 			;
 
-base_backup_opt:
+base_backup_legacy_opt:
 			K_LABEL SCONST
 				{
 				  $$ = makeDefElem("label",
@@ -190,8 +202,8 @@ base_backup_opt:
 				}
 			| K_FAST
 				{
-				  $$ = makeDefElem("fast",
-								   (Node *)makeInteger(true), -1);
+				  $$ = makeDefElem("checkpoint",
+								   (Node *)makeString("fast"), -1);
 				}
 			| K_WAL
 				{
@@ -200,8 +212,8 @@ base_backup_opt:
 				}
 			| K_NOWAIT
 				{
-				  $$ = makeDefElem("nowait",
-								   (Node *)makeInteger(true), -1);
+				  $$ = makeDefElem("wait",
+								   (Node *)makeInteger(false), -1);
 				}
 			| K_MAX_RATE UCONST
 				{
@@ -215,8 +227,8 @@ base_backup_opt:
 				}
 			| K_NOVERIFY_CHECKSUMS
 				{
-				  $$ = makeDefElem("noverify_checksums",
-								   (Node *)makeInteger(true), -1);
+				  $$ = makeDefElem("verify_checksums",
+								   (Node *)makeInteger(false), -1);
 				}
 			| K_MANIFEST SCONST
 				{
@@ -422,6 +434,65 @@ plugin_opt_arg:
 sql_cmd:
 			IDENT							{ $$ = (Node *) make_sqlcmd(); }
 		;
+
+generic_option_list:
+			generic_option_list ',' generic_option
+				{ $$ = lappend($1, $3); }
+			| generic_option
+				{ $$ = list_make1($1); }
+			;
+
+generic_option:
+			ident_or_keyword
+				{
+					$$ = makeDefElem($1, NULL, -1);
+				}
+			| ident_or_keyword IDENT
+				{
+					$$ = makeDefElem($1, (Node *) makeString($2), -1);
+				}
+			| ident_or_keyword SCONST
+				{
+					$$ = makeDefElem($1, (Node *) makeString($2), -1);
+				}
+			| ident_or_keyword UCONST
+				{
+					$$ = makeDefElem($1, (Node *) makeInteger($2), -1);
+				}
+			;
+
+ident_or_keyword:
+			IDENT							{ $$ = $1; }
+			| K_BASE_BACKUP					{ $$ = "base_backup"; }
+			| K_IDENTIFY_SYSTEM				{ $$ = "identify_system"; }
+			| K_SHOW						{ $$ = "show"; }
+			| K_START_REPLICATION			{ $$ = "start_replication"; }
+			| K_CREATE_REPLICATION_SLOT	{ $$ = "create_replication_slot"; }
+			| K_DROP_REPLICATION_SLOT		{ $$ = "drop_replication_slot"; }
+			| K_TIMELINE_HISTORY			{ $$ = "timeline_history"; }
+			| K_LABEL						{ $$ = "label"; }
+			| K_PROGRESS					{ $$ = "progress"; }
+			| K_FAST						{ $$ = "fast"; }
+			| K_WAIT						{ $$ = "wait"; }
+			| K_NOWAIT						{ $$ = "nowait"; }
+			| K_MAX_RATE					{ $$ = "max_rate"; }
+			| K_WAL							{ $$ = "wal"; }
+			| K_TABLESPACE_MAP				{ $$ = "tablespace_map"; }
+			| K_NOVERIFY_CHECKSUMS			{ $$ = "noverify_checksums"; }
+			| K_TIMELINE					{ $$ = "timeline"; }
+			| K_PHYSICAL					{ $$ = "physical"; }
+			| K_LOGICAL						{ $$ = "logical"; }
+			| K_SLOT						{ $$ = "slot"; }
+			| K_RESERVE_WAL					{ $$ = "reserve_wal"; }
+			| K_TEMPORARY					{ $$ = "temporary"; }
+			| K_TWO_PHASE					{ $$ = "two_phase"; }
+			| K_EXPORT_SNAPSHOT				{ $$ = "export_snapshot"; }
+			| K_NOEXPORT_SNAPSHOT			{ $$ = "noexport_snapshot"; }
+			| K_USE_SNAPSHOT				{ $$ = "use_snapshot"; }
+			| K_MANIFEST					{ $$ = "manifest"; }
+			| K_MANIFEST_CHECKSUMS			{ $$ = "manifest_checksums"; }
+		;
+
 %%
 
 static SQLCmd *