v4-0003-varatt_external-varatt_external_oid-and-VARTAG_ON.patch

From 742631089dfe7f2f247ee2cd652e749081d68c47 Mon Sep 17 00:00:00 2001
From: Michael Paquier <michael@paquier.xyz>
Date: Fri, 8 Aug 2025 14:50:06 +0900
Subject: [PATCH v4 03/15] varatt_external->varatt_external_oid and
 VARTAG_ONDISK->VARTAG_ONDISK_OID

This rename is in preparation of a follow-up commit that aims at adding
support for multiple types of external on-disk TOAST pointers, where the
OID type is only one subset of them.
---
 src/include/access/detoast.h                  |  4 +--
 src/include/varatt.h                          | 34 +++++++++++--------
 src/backend/access/common/detoast.c           | 10 +++---
 src/backend/access/common/toast_compression.c |  2 +-
 src/backend/access/common/toast_internals.c   |  8 ++---
 .../replication/logical/reorderbuffer.c       |  2 +-
 src/backend/utils/adt/varlena.c               |  2 +-
 contrib/amcheck/verify_heapam.c               |  6 ++--
 8 files changed, 36 insertions(+), 32 deletions(-)

diff --git a/src/include/access/detoast.h b/src/include/access/detoast.h
index e603a2276c38..d80a62e64fd5 100644
--- a/src/include/access/detoast.h
+++ b/src/include/access/detoast.h
@@ -14,7 +14,7 @@
 
 /*
  * Macro to fetch the possibly-unaligned contents of an EXTERNAL datum
- * into a local "struct varatt_external" toast pointer.  This should be
+ * into a local "struct varatt_external_oid" toast pointer.  This should be
  * just a memcpy, but some versions of gcc seem to produce broken code
  * that assumes the datum contents are aligned.  Introducing an explicit
  * intermediate "varattrib_1b_e *" variable seems to fix it.
@@ -28,7 +28,7 @@ do { \
 } while (0)
 
 /* Size of an EXTERNAL datum that contains a standard TOAST pointer */
-#define TOAST_POINTER_SIZE (VARHDRSZ_EXTERNAL + sizeof(varatt_external))
+#define TOAST_POINTER_SIZE (VARHDRSZ_EXTERNAL + sizeof(varatt_external_oid))
 
 /* Size of an EXTERNAL datum that contains an indirection pointer */
 #define INDIRECT_POINTER_SIZE (VARHDRSZ_EXTERNAL + sizeof(varatt_indirect))
diff --git a/src/include/varatt.h b/src/include/varatt.h
index aeeabf9145b5..fcf2dffaa2fd 100644
--- a/src/include/varatt.h
+++ b/src/include/varatt.h
@@ -16,7 +16,7 @@
 #define VARATT_H
 
 /*
- * struct varatt_external is a traditional "TOAST pointer", that is, the
+ * struct varatt_external_oid is a traditional "TOAST pointer", that is, the
  * information needed to fetch a Datum stored out-of-line in a TOAST table.
  * The data is compressed if and only if the external size stored in
  * va_extinfo is less than va_rawsize - VARHDRSZ.
@@ -29,14 +29,14 @@
  * you can look at these fields!  (The reason we use memcmp is to avoid
  * having to do that just to detect equality of two TOAST pointers...)
  */
-typedef struct varatt_external
+typedef struct varatt_external_oid
 {
 	int32		va_rawsize;		/* Original data size (includes header) */
 	uint32		va_extinfo;		/* External saved size (without header) and
 								 * compression method */
 	Oid			va_valueid;		/* Unique ID of value within TOAST table */
 	Oid			va_toastrelid;	/* RelID of TOAST table containing it */
-}			varatt_external;
+}			varatt_external_oid;
 
 /*
  * These macros define the "saved size" portion of va_extinfo.  Its remaining
@@ -51,7 +51,7 @@ typedef struct varatt_external
  * The creator of such a Datum is entirely responsible that the referenced
  * storage survives for as long as referencing pointer Datums can exist.
  *
- * Note that just as for struct varatt_external, this struct is stored
+ * Note that just as for struct varatt_external_oid, this struct is stored
  * unaligned within any containing tuple.
  */
 typedef struct varatt_indirect
@@ -66,7 +66,7 @@ typedef struct varatt_indirect
  * storage.  APIs for this, in particular the definition of struct
  * ExpandedObjectHeader, are in src/include/utils/expandeddatum.h.
  *
- * Note that just as for struct varatt_external, this struct is stored
+ * Note that just as for struct varatt_external_oid, this struct is stored
  * unaligned within any containing tuple.
  */
 typedef struct ExpandedObjectHeader ExpandedObjectHeader;
@@ -78,15 +78,16 @@ typedef struct varatt_expanded
 
 /*
  * Type tag for the various sorts of "TOAST pointer" datums.  The peculiar
- * value for VARTAG_ONDISK comes from a requirement for on-disk compatibility
- * with a previous notion that the tag field was the pointer datum's length.
+ * value for VARTAG_ONDISK_OID comes from a requirement for on-disk
+ * compatibility with a previous notion that the tag field was the pointer
+ * datum's length.
  */
 typedef enum vartag_external
 {
 	VARTAG_INDIRECT = 1,
 	VARTAG_EXPANDED_RO = 2,
 	VARTAG_EXPANDED_RW = 3,
-	VARTAG_ONDISK = 18
+	VARTAG_ONDISK_OID = 18
 } vartag_external;
 
 /* Is a TOAST pointer either type of expanded-object pointer? */
@@ -105,8 +106,8 @@ VARTAG_SIZE(vartag_external tag)
 		return sizeof(varatt_indirect);
 	else if (VARTAG_IS_EXPANDED(tag))
 		return sizeof(varatt_expanded);
-	else if (tag == VARTAG_ONDISK)
-		return sizeof(varatt_external);
+	else if (tag == VARTAG_ONDISK_OID)
+		return sizeof(varatt_external_oid);
 	else
 	{
 		Assert(false);
@@ -360,7 +361,7 @@ VARATT_IS_EXTERNAL(const void *PTR)
 static inline bool
 VARATT_IS_EXTERNAL_ONDISK(const void *PTR)
 {
-	return VARATT_IS_EXTERNAL(PTR) && VARTAG_EXTERNAL(PTR) == VARTAG_ONDISK;
+	return VARATT_IS_EXTERNAL(PTR) && VARTAG_EXTERNAL(PTR) == VARTAG_ONDISK_OID;
 }
 
 /* Is varlena datum an indirect pointer? */
@@ -502,15 +503,18 @@ VARDATA_COMPRESSED_GET_COMPRESS_METHOD(const void *PTR)
 	return ((varattrib_4b *) PTR)->va_compressed.va_tcinfo >> VARLENA_EXTSIZE_BITS;
 }
 
-/* Same for external Datums; but note argument is a struct varatt_external */
+/*
+ * Same for external Datums; but note argument is a struct
+ * varatt_external_oid.
+ */
 static inline Size
-VARATT_EXTERNAL_GET_EXTSIZE(struct varatt_external toast_pointer)
+VARATT_EXTERNAL_GET_EXTSIZE(struct varatt_external_oid toast_pointer)
 {
 	return toast_pointer.va_extinfo & VARLENA_EXTSIZE_MASK;
 }
 
 static inline uint32
-VARATT_EXTERNAL_GET_COMPRESS_METHOD(struct varatt_external toast_pointer)
+VARATT_EXTERNAL_GET_COMPRESS_METHOD(struct varatt_external_oid toast_pointer)
 {
 	return toast_pointer.va_extinfo >> VARLENA_EXTSIZE_BITS;
 }
@@ -533,7 +537,7 @@ VARATT_EXTERNAL_GET_COMPRESS_METHOD(struct varatt_external toast_pointer)
  * actually saves space, so we expect either equality or less-than.
  */
 static inline bool
-VARATT_EXTERNAL_IS_COMPRESSED(struct varatt_external toast_pointer)
+VARATT_EXTERNAL_IS_COMPRESSED(struct varatt_external_oid toast_pointer)
 {
 	return VARATT_EXTERNAL_GET_EXTSIZE(toast_pointer) <
 		(Size) (toast_pointer.va_rawsize - VARHDRSZ);
diff --git a/src/backend/access/common/detoast.c b/src/backend/access/common/detoast.c
index 626517877422..04eedb474c74 100644
--- a/src/backend/access/common/detoast.c
+++ b/src/backend/access/common/detoast.c
@@ -225,7 +225,7 @@ detoast_attr_slice(struct varlena *attr,
 
 	if (VARATT_IS_EXTERNAL_ONDISK(attr))
 	{
-		struct varatt_external toast_pointer;
+		struct varatt_external_oid toast_pointer;
 
 		VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
 
@@ -344,7 +344,7 @@ toast_fetch_datum(struct varlena *attr)
 {
 	Relation	toastrel;
 	struct varlena *result;
-	struct varatt_external toast_pointer;
+	struct varatt_external_oid toast_pointer;
 	int32		attrsize;
 
 	if (!VARATT_IS_EXTERNAL_ONDISK(attr))
@@ -398,7 +398,7 @@ toast_fetch_datum_slice(struct varlena *attr, int32 sliceoffset,
 {
 	Relation	toastrel;
 	struct varlena *result;
-	struct varatt_external toast_pointer;
+	struct varatt_external_oid toast_pointer;
 	int32		attrsize;
 
 	if (!VARATT_IS_EXTERNAL_ONDISK(attr))
@@ -550,7 +550,7 @@ toast_raw_datum_size(Datum value)
 	if (VARATT_IS_EXTERNAL_ONDISK(attr))
 	{
 		/* va_rawsize is the size of the original datum -- including header */
-		struct varatt_external toast_pointer;
+		struct varatt_external_oid toast_pointer;
 
 		VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
 		result = toast_pointer.va_rawsize;
@@ -610,7 +610,7 @@ toast_datum_size(Datum value)
 		 * compressed or not.  We do not count the size of the toast pointer
 		 * ... should we?
 		 */
-		struct varatt_external toast_pointer;
+		struct varatt_external_oid toast_pointer;
 
 		VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
 		result = VARATT_EXTERNAL_GET_EXTSIZE(toast_pointer);
diff --git a/src/backend/access/common/toast_compression.c b/src/backend/access/common/toast_compression.c
index 926f1e4008ab..26aad84d367a 100644
--- a/src/backend/access/common/toast_compression.c
+++ b/src/backend/access/common/toast_compression.c
@@ -262,7 +262,7 @@ toast_get_compression_id(struct varlena *attr)
 	 */
 	if (VARATT_IS_EXTERNAL_ONDISK(attr))
 	{
-		struct varatt_external toast_pointer;
+		struct varatt_external_oid toast_pointer;
 
 		VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
 
diff --git a/src/backend/access/common/toast_internals.c b/src/backend/access/common/toast_internals.c
index 0016a16afc95..d555c02e908e 100644
--- a/src/backend/access/common/toast_internals.c
+++ b/src/backend/access/common/toast_internals.c
@@ -127,7 +127,7 @@ toast_save_datum(Relation rel, Datum value,
 	bool		t_isnull[3];
 	CommandId	mycid = GetCurrentCommandId(true);
 	struct varlena *result;
-	struct varatt_external toast_pointer;
+	struct varatt_external_oid toast_pointer;
 	union
 	{
 		struct varlena hdr;
@@ -237,7 +237,7 @@ toast_save_datum(Relation rel, Datum value,
 		toast_pointer.va_valueid = InvalidOid;
 		if (oldexternal != NULL)
 		{
-			struct varatt_external old_toast_pointer;
+			struct varatt_external_oid old_toast_pointer;
 
 			Assert(VARATT_IS_EXTERNAL_ONDISK(oldexternal));
 			/* Must copy to access aligned fields */
@@ -369,7 +369,7 @@ toast_save_datum(Relation rel, Datum value,
 	 * Create the TOAST pointer value that we'll return
 	 */
 	result = (struct varlena *) palloc(TOAST_POINTER_SIZE);
-	SET_VARTAG_EXTERNAL(result, VARTAG_ONDISK);
+	SET_VARTAG_EXTERNAL(result, VARTAG_ONDISK_OID);
 	memcpy(VARDATA_EXTERNAL(result), &toast_pointer, sizeof(toast_pointer));
 
 	return PointerGetDatum(result);
@@ -385,7 +385,7 @@ void
 toast_delete_datum(Relation rel, Datum value, bool is_speculative)
 {
 	struct varlena *attr = (struct varlena *) DatumGetPointer(value);
-	struct varatt_external toast_pointer;
+	struct varatt_external_oid toast_pointer;
 	Relation	toastrel;
 	Relation   *toastidxs;
 	ScanKeyData toastkey;
diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index 36e2a4360e18..0eb99b4f1377 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -5102,7 +5102,7 @@ ReorderBufferToastReplace(ReorderBuffer *rb, ReorderBufferTXN *txn,
 		struct varlena *varlena;
 
 		/* va_rawsize is the size of the original datum -- including header */
-		struct varatt_external toast_pointer;
+		struct varatt_external_oid toast_pointer;
 		struct varatt_indirect redirect_pointer;
 		struct varlena *new_datum = NULL;
 		struct varlena *reconstructed;
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index ffae8c23abfa..38d4e6d45f28 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -4219,7 +4219,7 @@ pg_column_toast_chunk_id(PG_FUNCTION_ARGS)
 {
 	int			typlen;
 	struct varlena *attr;
-	struct varatt_external toast_pointer;
+	struct varatt_external_oid toast_pointer;
 
 	/* On first call, get the input type's typlen, and save at *fn_extra */
 	if (fcinfo->flinfo->fn_extra == NULL)
diff --git a/contrib/amcheck/verify_heapam.c b/contrib/amcheck/verify_heapam.c
index 3b2bdced4cdc..030f9fb64b51 100644
--- a/contrib/amcheck/verify_heapam.c
+++ b/contrib/amcheck/verify_heapam.c
@@ -73,7 +73,7 @@ typedef enum SkipPages
  */
 typedef struct ToastedAttribute
 {
-	struct varatt_external toast_pointer;
+	struct varatt_external_oid toast_pointer;
 	BlockNumber blkno;			/* block in main table */
 	OffsetNumber offnum;		/* offset in main table */
 	AttrNumber	attnum;			/* attribute in main table */
@@ -1672,7 +1672,7 @@ check_tuple_attribute(HeapCheckContext *ctx)
 	uint16		infomask;
 	uint64		toast_pointer_valueid;
 	CompactAttribute *thisatt;
-	struct varatt_external toast_pointer;
+	struct varatt_external_oid toast_pointer;
 
 	infomask = ctx->tuphdr->t_infomask;
 	thisatt = TupleDescCompactAttr(RelationGetDescr(ctx->rel), ctx->attnum);
@@ -1731,7 +1731,7 @@ check_tuple_attribute(HeapCheckContext *ctx)
 	{
 		uint8		va_tag = VARTAG_EXTERNAL(tp + ctx->offset);
 
-		if (va_tag != VARTAG_ONDISK)
+		if (va_tag != VARTAG_ONDISK_OID)
 		{
 			report_corruption(ctx,
 							  psprintf("toasted attribute has unexpected TOAST tag %u",
-- 
2.50.0