Rationalize handling of VacuumParams

This commit refactors the vacuum routines that rely on VacuumParams,
adding const markers where necessary to force a new policy in the code.
This structure should not use a pointer as it may be used across
multiple relations, and its contents should never be updated.
vacuum_rel() stands as an exception as it touches the "index_cleanup"
and "truncate" options.

VacuumParams has been introduced in 0d831389749a, and 661643dedad9 has
fixed a bug impacting VACUUM operating on multiple relations.  The
changes done in tableam.h break ABI compatibility, so this commit can
only happen on HEAD.

Author: Shihao Zhong <zhong950419@gmail.com>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://postgr.es/m/CAGRkXqTo+aK=GTy5pSc-9cy8H2F2TJvcrZ-zXEiNJj93np1UUw@mail.gmail.com

3 files changed, 8 insertions, 8 deletions

diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 3a9424c19c9..a2bd5a897f8 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -21,6 +21,7 @@
 #include "access/skey.h"
 #include "access/table.h"		/* for backward compatibility */
 #include "access/tableam.h"
+#include "commands/vacuum.h"
 #include "nodes/lockoptions.h"
 #include "nodes/primnodes.h"
 #include "storage/bufpage.h"
@@ -396,9 +397,8 @@ extern void log_heap_prune_and_freeze(Relation relation, Buffer buffer,
 									  OffsetNumber *unused, int nunused);
 
 /* in heap/vacuumlazy.c */
-struct VacuumParams;
 extern void heap_vacuum_rel(Relation rel,
-							struct VacuumParams *params, BufferAccessStrategy bstrategy);
+							const VacuumParams params, BufferAccessStrategy bstrategy);
 
 /* in heap/heapam_visibility.c */
 extern bool HeapTupleSatisfiesVisibility(HeapTuple htup, Snapshot snapshot,
diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h
index 8713e12cbfb..1c9e802a6b1 100644
--- a/src/include/access/tableam.h
+++ b/src/include/access/tableam.h
@@ -20,6 +20,7 @@
 #include "access/relscan.h"
 #include "access/sdir.h"
 #include "access/xact.h"
+#include "commands/vacuum.h"
 #include "executor/tuptable.h"
 #include "storage/read_stream.h"
 #include "utils/rel.h"
@@ -36,7 +37,6 @@ extern PGDLLIMPORT bool synchronize_seqscans;
 struct BulkInsertStateData;
 struct IndexInfo;
 struct SampleScanState;
-struct VacuumParams;
 struct ValidateIndexState;
 
 /*
@@ -645,7 +645,7 @@ typedef struct TableAmRoutine
 	 * integrate with autovacuum's scheduling.
 	 */
 	void		(*relation_vacuum) (Relation rel,
-									struct VacuumParams *params,
+									const VacuumParams params,
 									BufferAccessStrategy bstrategy);
 
 	/*
@@ -1664,7 +1664,7 @@ table_relation_copy_for_cluster(Relation OldTable, Relation NewTable,
  * routine, even if (for ANALYZE) it is part of the same VACUUM command.
  */
 static inline void
-table_relation_vacuum(Relation rel, struct VacuumParams *params,
+table_relation_vacuum(Relation rel, const VacuumParams params,
 					  BufferAccessStrategy bstrategy)
 {
 	rel->rd_tableam->relation_vacuum(rel, params, bstrategy);
diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h
index bc37a80dc74..14eeccbd718 100644
--- a/src/include/commands/vacuum.h
+++ b/src/include/commands/vacuum.h
@@ -336,7 +336,7 @@ extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns;
 
 /* in commands/vacuum.c */
 extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel);
-extern void vacuum(List *relations, VacuumParams *params,
+extern void vacuum(List *relations, const VacuumParams params,
 				   BufferAccessStrategy bstrategy, MemoryContext vac_context,
 				   bool isTopLevel);
 extern void vac_open_indexes(Relation relation, LOCKMODE lockmode,
@@ -357,7 +357,7 @@ extern void vac_update_relstats(Relation relation,
 								bool *frozenxid_updated,
 								bool *minmulti_updated,
 								bool in_outer_xact);
-extern bool vacuum_get_cutoffs(Relation rel, const VacuumParams *params,
+extern bool vacuum_get_cutoffs(Relation rel, const VacuumParams params,
 							   struct VacuumCutoffs *cutoffs);
 extern bool vacuum_xid_failsafe_check(const struct VacuumCutoffs *cutoffs);
 extern void vac_update_datfrozenxid(void);
@@ -398,7 +398,7 @@ extern void parallel_vacuum_main(dsm_segment *seg, shm_toc *toc);
 
 /* in commands/analyze.c */
 extern void analyze_rel(Oid relid, RangeVar *relation,
-						VacuumParams *params, List *va_cols, bool in_outer_xact,
+						const VacuumParams params, List *va_cols, bool in_outer_xact,
 						BufferAccessStrategy bstrategy);
 extern bool std_typanalyze(VacAttrStats *stats);