Refactor the request LSNs to a separate struct (#7708)

We had a lot of code that passed around the two LSNs that are
associated with each GetPage request. Introduce a new struct to
encapsulate them. I'm about to add a third LSN to the struct in the
next commit, this is a mechanical refactoring in preparation for that.

pgxn/neon/pagestore_client.h

@@ -237,18 +237,38 @@ extern void neon_zeroextend(SMgrRelation reln, ForkNumber forknum,
 extern bool neon_prefetch(SMgrRelation reln, ForkNumber forknum,
 						  BlockNumber blocknum);
 
+/*
+ * LSN values associated with each request to the pageserver
+ */
+typedef struct
+{
+	/*
+	 * 'request_lsn' is the main value that determines which page version to
+	 * fetch.
+	 */
+	XLogRecPtr request_lsn;
+
+	/*
+	 * A hint to the pageserver that the requested page hasn't been modified
+	 * between this LSN and 'request_lsn'. That allows the pageserver to
+	 * return the page faster, without waiting for 'request_lsn' to arrive in
+	 * the pageserver, as long as 'not_modified_since' has arrived.
+	 */
+	XLogRecPtr not_modified_since;
+} neon_request_lsns;
+
 #if PG_MAJORVERSION_NUM < 16
 extern void neon_read(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
 					  char *buffer);
 extern PGDLLEXPORT void neon_read_at_lsn(NRelFileInfo rnode, ForkNumber forkNum, BlockNumber blkno,
-										 XLogRecPtr request_lsn, XLogRecPtr not_modified_since, char *buffer);
+										 neon_request_lsns request_lsns, char *buffer);
 extern void neon_write(SMgrRelation reln, ForkNumber forknum,
 					   BlockNumber blocknum, char *buffer, bool skipFsync);
 #else
 extern void neon_read(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
 					  void *buffer);
 extern PGDLLEXPORT void neon_read_at_lsn(NRelFileInfo rnode, ForkNumber forkNum, BlockNumber blkno,
-										 XLogRecPtr request_lsn, XLogRecPtr not_modified_since, void *buffer);
+										 neon_request_lsns request_lsns, void *buffer);
 extern void neon_write(SMgrRelation reln, ForkNumber forknum,
 					   BlockNumber blocknum, const void *buffer, bool skipFsync);
 #endif

pgxn/neon/pagestore_smgr.c

@@ -168,8 +168,7 @@ typedef enum PrefetchStatus
 typedef struct PrefetchRequest
 {
 	BufferTag	buftag;			/* must be first entry in the struct */
-	XLogRecPtr	request_lsn;
-	XLogRecPtr	not_modified_since;
+	neon_request_lsns request_lsns;
 	NeonResponse *response;		/* may be null */
 	PrefetchStatus status;
 	shardno_t   shard_no;
@@ -271,16 +270,15 @@ static PrefetchState *MyPState;
 
 static bool compact_prefetch_buffers(void);
 static void consume_prefetch_responses(void);
-static uint64 prefetch_register_buffer(BufferTag tag, XLogRecPtr *force_request_lsn, XLogRecPtr *force_not_modified_since);
+static uint64 prefetch_register_buffer(BufferTag tag, neon_request_lsns *force_request_lsns);
 static bool prefetch_read(PrefetchRequest *slot);
-static void prefetch_do_request(PrefetchRequest *slot, XLogRecPtr *force_request_lsn, XLogRecPtr *force_not_modified_since);
+static void prefetch_do_request(PrefetchRequest *slot, neon_request_lsns *force_request_lsns);
 static bool prefetch_wait_for(uint64 ring_index);
 static void prefetch_cleanup_trailing_unused(void);
 static inline void prefetch_set_unused(uint64 ring_index);
 
-static void neon_get_request_lsn(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
-								 XLogRecPtr *request_lsn, XLogRecPtr *not_modified_since);
-static bool neon_prefetch_response_usable(XLogRecPtr request_lsn, XLogRecPtr not_modified_since,
+static neon_request_lsns neon_get_request_lsns(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno);
+static bool neon_prefetch_response_usable(neon_request_lsns request_lsns,
 										  PrefetchRequest *slot);
 
 static bool
@@ -338,8 +336,7 @@ compact_prefetch_buffers(void)
 		target_slot->shard_no = source_slot->shard_no;
 		target_slot->status = source_slot->status;
 		target_slot->response = source_slot->response;
-		target_slot->request_lsn = source_slot->request_lsn;
-		target_slot->not_modified_since = source_slot->not_modified_since;
+		target_slot->request_lsns = source_slot->request_lsns;
 		target_slot->my_ring_index = empty_ring_index;
 
 		prfh_delete(MyPState->prf_hash, source_slot);
@@ -358,8 +355,9 @@ compact_prefetch_buffers(void)
 		};
 		source_slot->response = NULL;
 		source_slot->my_ring_index = 0;
-		source_slot->request_lsn = InvalidXLogRecPtr;
-		source_slot->not_modified_since = InvalidXLogRecPtr;
+		source_slot->request_lsns = (neon_request_lsns) {
+			InvalidXLogRecPtr, InvalidXLogRecPtr
+		};
 
 		/* update bookkeeping */
 		n_moved++;
@@ -689,7 +687,7 @@ prefetch_set_unused(uint64 ring_index)
  * prefetch_wait_for().
  */
 static void
-prefetch_do_request(PrefetchRequest *slot, XLogRecPtr *force_request_lsn, XLogRecPtr *force_not_modified_since)
+prefetch_do_request(PrefetchRequest *slot, neon_request_lsns *force_request_lsns)
 {
 	bool		found;
 	NeonGetPageRequest request = {
@@ -700,23 +698,14 @@ prefetch_do_request(PrefetchRequest *slot, XLogRecPtr *force_request_lsn, XLogRe
 		.blkno = slot->buftag.blockNum,
 	};
 
-	Assert(((force_request_lsn != NULL) == (force_not_modified_since != NULL)));
-
-	if (force_request_lsn)
-	{
-		request.req.lsn = *force_request_lsn;
-		request.req.not_modified_since = *force_not_modified_since;
-	}
+	if (force_request_lsns)
+		slot->request_lsns = *force_request_lsns;
 	else
-	{
-		neon_get_request_lsn(BufTagGetNRelFileInfo(slot->buftag),
-							 slot->buftag.forkNum,
-							 slot->buftag.blockNum,
-							 &request.req.lsn,
-							 &request.req.not_modified_since);
-	}
-	slot->request_lsn = request.req.lsn;
-	slot->not_modified_since = request.req.not_modified_since;
+		slot->request_lsns = neon_get_request_lsns(BufTagGetNRelFileInfo(slot->buftag),
+												   slot->buftag.forkNum,
+												   slot->buftag.blockNum);
+	request.req.lsn = slot->request_lsns.request_lsn;
+	request.req.not_modified_since = slot->request_lsns.not_modified_since;
 
 	Assert(slot->response == NULL);
 	Assert(slot->my_ring_index == MyPState->ring_unused);
@@ -742,25 +731,22 @@ prefetch_do_request(PrefetchRequest *slot, XLogRecPtr *force_request_lsn, XLogRe
  *
  * Register that we may want the contents of BufferTag in the near future.
  *
- * If force_request_lsn and force_not_modified_since are not NULL, those
- * values are sent to the pageserver. If they are NULL, we utilize the
- * lastWrittenLsn -infrastructure to fill them in.
+ * If force_request_lsns is not NULL, those values are sent to the
+ * pageserver. If NULL, we utilize the lastWrittenLsn -infrastructure
+ * to calculate the LSNs to send.
  *
  * NOTE: this function may indirectly update MyPState->pfs_hash; which
  * invalidates any active pointers into the hash table.
  */
 
 static uint64
-prefetch_register_buffer(BufferTag tag, XLogRecPtr *force_request_lsn,
-						 XLogRecPtr *force_not_modified_since)
+prefetch_register_buffer(BufferTag tag, neon_request_lsns *force_request_lsns)
 {
 	uint64		ring_index;
 	PrefetchRequest req;
 	PrefetchRequest *slot;
 	PrfHashEntry *entry;
 
-	Assert(((force_request_lsn != NULL) == (force_not_modified_since != NULL)));
-
 	/* use an intermediate PrefetchRequest struct to ensure correct alignment */
 	req.buftag = tag;
 Retry:
@@ -781,10 +767,9 @@ Retry:
 		 * If the caller specified a request LSN to use, only accept prefetch
 		 * responses that satisfy that request.
 		 */
-		if (force_request_lsn)
+		if (force_request_lsns)
 		{
-			if (!neon_prefetch_response_usable(*force_request_lsn,
-											   *force_not_modified_since, slot))
+			if (!neon_prefetch_response_usable(*force_request_lsns, slot))
 			{
 				/* Wait for the old request to finish and discard it */
 				if (!prefetch_wait_for(ring_index))
@@ -886,7 +871,7 @@ Retry:
 	slot->shard_no = get_shard_number(&tag);
 	slot->my_ring_index = ring_index;
 
-	prefetch_do_request(slot, force_request_lsn, force_not_modified_since);
+	prefetch_do_request(slot, force_request_lsns);
 	Assert(slot->status == PRFS_REQUESTED);
 	Assert(MyPState->ring_last <= ring_index &&
 		   ring_index < MyPState->ring_unused);
@@ -1529,11 +1514,11 @@ nm_adjust_lsn(XLogRecPtr lsn)
 /*
  * Return LSN for requesting pages and number of blocks from page server
  */
-static void
-neon_get_request_lsn(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
-					 XLogRecPtr *request_lsn, XLogRecPtr *not_modified_since)
+static neon_request_lsns
+neon_get_request_lsns(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno)
 {
 	XLogRecPtr	last_written_lsn;
+	neon_request_lsns result;
 
 	last_written_lsn = GetLastWrittenLSN(rinfo, forknum, blkno);
 	last_written_lsn = nm_adjust_lsn(last_written_lsn);
@@ -1542,12 +1527,12 @@ neon_get_request_lsn(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
 	if (RecoveryInProgress())
 	{
 		/* Request the page at the last replayed LSN. */
-		*request_lsn = GetXLogReplayRecPtr(NULL);
-		*not_modified_since = last_written_lsn;
-		Assert(last_written_lsn <= *request_lsn);
+		result.request_lsn = GetXLogReplayRecPtr(NULL);
+		result.not_modified_since = last_written_lsn;
+		Assert(last_written_lsn <= result.request_lsn);
 
-		neon_log(DEBUG1, "neon_get_request_lsn request lsn %X/%X, not_modified_since %X/%X",
-				 LSN_FORMAT_ARGS(*request_lsn), LSN_FORMAT_ARGS(*not_modified_since));
+		neon_log(DEBUG1, "neon_get_request_lsns request lsn %X/%X, not_modified_since %X/%X",
+				 LSN_FORMAT_ARGS(result.request_lsn), LSN_FORMAT_ARGS(result.not_modified_since));
 	}
 	else
 	{
@@ -1559,7 +1544,7 @@ neon_get_request_lsn(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
 		 * must still in the buffer cache, so our request cannot concern
 		 * those.
 		 */
-		neon_log(DEBUG1, "neon_get_request_lsn GetLastWrittenLSN lsn %X/%X ",
+		neon_log(DEBUG1, "neon_get_request_lsns GetLastWrittenLSN lsn %X/%X",
 				 LSN_FORMAT_ARGS(last_written_lsn));
 
 		/*
@@ -1592,9 +1577,11 @@ neon_get_request_lsn(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
 		 * flush, it should still be in the buffer cache, and we wouldn't be
 		 * requesting it.
 		 */
-		*request_lsn = flushlsn;
-		*not_modified_since = last_written_lsn;
+		result.request_lsn = flushlsn;
+		result.not_modified_since = last_written_lsn;
 	}
+
+	return result;
 }
 
 /*
@@ -1604,12 +1591,12 @@ neon_get_request_lsn(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
  * satisfy a page read now.
  */
 static bool
-neon_prefetch_response_usable(XLogRecPtr request_lsn, XLogRecPtr not_modified_since,
+neon_prefetch_response_usable(neon_request_lsns request_lsns,
 							  PrefetchRequest *slot)
 {
 	/* sanity check the LSN's on the old and the new request */
-	Assert(request_lsn >= not_modified_since);
-	Assert(slot->request_lsn >= slot->not_modified_since);
+	Assert(request_lsns.request_lsn >= request_lsns.not_modified_since);
+	Assert(slot->request_lsns.request_lsn >= slot->request_lsns.not_modified_since);
 	Assert(slot->status != PRFS_UNUSED);
 
 	/*
@@ -1627,14 +1614,15 @@ neon_prefetch_response_usable(XLogRecPtr request_lsn, XLogRecPtr not_modified_si
 	 * calculate LSNs "out of order" with each other, but the prefetch queue
 	 * is backend-private at the moment.)
 	 */
-	if (request_lsn < slot->request_lsn || not_modified_since < slot->not_modified_since)
+	if (request_lsns.request_lsn < slot->request_lsns.request_lsn ||
+		request_lsns.not_modified_since < slot->request_lsns.not_modified_since)
 	{
 		ereport(LOG,
 				(errcode(ERRCODE_IO_ERROR),
 				 errmsg(NEON_TAG "request with unexpected LSN after prefetch"),
 				 errdetail("Request %X/%X not_modified_since %X/%X, prefetch %X/%X not_modified_since %X/%X)",
-						   LSN_FORMAT_ARGS(request_lsn), LSN_FORMAT_ARGS(not_modified_since),
-						   LSN_FORMAT_ARGS(slot->request_lsn), LSN_FORMAT_ARGS(slot->not_modified_since))));
+						   LSN_FORMAT_ARGS(request_lsns.request_lsn), LSN_FORMAT_ARGS(request_lsns.not_modified_since),
+						   LSN_FORMAT_ARGS(slot->request_lsns.request_lsn), LSN_FORMAT_ARGS(slot->request_lsns.not_modified_since))));
 		return false;
 	}
 
@@ -1675,9 +1663,9 @@ neon_prefetch_response_usable(XLogRecPtr request_lsn, XLogRecPtr not_modified_si
 	 */
 
 	/* this follows from the checks above */
-	Assert(request_lsn >= slot->not_modified_since);
+	Assert(request_lsns.request_lsn >= slot->request_lsns.not_modified_since);
 
-	return not_modified_since <= slot->request_lsn;
+	return request_lsns.not_modified_since <= slot->request_lsns.request_lsn;
 }
 
 /*
@@ -1689,8 +1677,7 @@ neon_exists(SMgrRelation reln, ForkNumber forkNum)
 	bool		exists;
 	NeonResponse *resp;
 	BlockNumber n_blocks;
-	XLogRecPtr	request_lsn;
-	XLogRecPtr	not_modified_since;
+	neon_request_lsns request_lsns;
 
 	switch (reln->smgr_relpersistence)
 	{
@@ -1745,15 +1732,15 @@ neon_exists(SMgrRelation reln, ForkNumber forkNum)
 		return false;
 	}
 
-	neon_get_request_lsn(InfoFromSMgrRel(reln), forkNum, REL_METADATA_PSEUDO_BLOCKNO,
-						 &request_lsn, &not_modified_since);
+	request_lsns = neon_get_request_lsns(InfoFromSMgrRel(reln), forkNum, REL_METADATA_PSEUDO_BLOCKNO);
 	{
 		NeonExistsRequest request = {
 			.req.tag = T_NeonExistsRequest,
-			.req.lsn = request_lsn,
-			.req.not_modified_since = not_modified_since,
+			.req.lsn = request_lsns.request_lsn,
+			.req.not_modified_since = request_lsns.not_modified_since,
 			.rinfo = InfoFromSMgrRel(reln),
-		.forknum = forkNum};
+			.forknum = forkNum
+		};
 
 		resp = page_server_request(&request);
 	}
@@ -1770,7 +1757,7 @@ neon_exists(SMgrRelation reln, ForkNumber forkNum)
 					 errmsg(NEON_TAG "could not read relation existence of rel %u/%u/%u.%u from page server at lsn %X/%08X",
 							RelFileInfoFmt(InfoFromSMgrRel(reln)),
 							forkNum,
-							(uint32) (request_lsn >> 32), (uint32) request_lsn),
+							LSN_FORMAT_ARGS(request_lsns.request_lsn)),
 					 errdetail("page server returned error: %s",
 							   ((NeonErrorResponse *) resp)->message)));
 			break;
@@ -2135,7 +2122,7 @@ neon_prefetch(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum)
 
 	CopyNRelFileInfoToBufTag(tag, InfoFromSMgrRel(reln));
 
-	ring_index = prefetch_register_buffer(tag, NULL, NULL);
+	ring_index = prefetch_register_buffer(tag, NULL);
 
 	Assert(ring_index < MyPState->ring_unused &&
 		   MyPState->ring_last <= ring_index);
@@ -2188,10 +2175,10 @@ neon_writeback(SMgrRelation reln, ForkNumber forknum,
 void
 #if PG_MAJORVERSION_NUM < 16
 neon_read_at_lsn(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
-				 XLogRecPtr request_lsn, XLogRecPtr not_modified_since, char *buffer)
+				 neon_request_lsns request_lsns, char *buffer)
 #else
 neon_read_at_lsn(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
-				 XLogRecPtr request_lsn, XLogRecPtr not_modified_since, void *buffer)
+				 neon_request_lsns request_lsns, void *buffer)
 #endif
 {
 	NeonResponse *resp;
@@ -2223,7 +2210,7 @@ neon_read_at_lsn(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
 	 * value of the LwLsn cache when the entry is not found.
 	 */
 	if (RecoveryInProgress() && !(MyBackendType == B_STARTUP))
-		XLogWaitForReplayOf(request_lsn);
+		XLogWaitForReplayOf(request_lsns.request_lsn);
 
 	/*
 	 * Try to find prefetched page in the list of received pages.
@@ -2234,7 +2221,7 @@ neon_read_at_lsn(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
 	if (entry != NULL)
 	{
 		slot = entry->slot;
-		if (neon_prefetch_response_usable(request_lsn, not_modified_since, slot))
+		if (neon_prefetch_response_usable(request_lsns, slot))
 		{
 			ring_index = slot->my_ring_index;
 			pgBufferUsage.prefetch.hits += 1;
@@ -2268,8 +2255,7 @@ neon_read_at_lsn(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
 		{
 			pgBufferUsage.prefetch.misses += 1;
 
-			ring_index = prefetch_register_buffer(buftag, &request_lsn,
-												  &not_modified_since);
+			ring_index = prefetch_register_buffer(buftag, &request_lsns);
 			slot = GetPrfSlot(ring_index);
 		}
 		else
@@ -2310,7 +2296,7 @@ neon_read_at_lsn(NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
 							slot->shard_no, blkno,
 							RelFileInfoFmt(rinfo),
 							forkNum,
-							(uint32) (request_lsn >> 32), (uint32) request_lsn),
+							LSN_FORMAT_ARGS(request_lsns.request_lsn)),
 					 errdetail("page server returned error: %s",
 							   ((NeonErrorResponse *) resp)->message)));
 			break;
@@ -2333,8 +2319,7 @@ neon_read(SMgrRelation reln, ForkNumber forkNum, BlockNumber blkno, char *buffer
 neon_read(SMgrRelation reln, ForkNumber forkNum, BlockNumber blkno, void *buffer)
 #endif
 {
-	XLogRecPtr	request_lsn;
-	XLogRecPtr	not_modified_since;
+	neon_request_lsns request_lsns;
 
 	switch (reln->smgr_relpersistence)
 	{
@@ -2359,9 +2344,8 @@ neon_read(SMgrRelation reln, ForkNumber forkNum, BlockNumber blkno, void *buffer
 		return;
 	}
 
-	neon_get_request_lsn(InfoFromSMgrRel(reln), forkNum, blkno,
-						 &request_lsn, &not_modified_since);
-	neon_read_at_lsn(InfoFromSMgrRel(reln), forkNum, blkno, request_lsn, not_modified_since, buffer);
+	request_lsns = neon_get_request_lsns(InfoFromSMgrRel(reln), forkNum, blkno);
+	neon_read_at_lsn(InfoFromSMgrRel(reln), forkNum, blkno, request_lsns, buffer);
 
 #ifdef DEBUG_COMPARE_LOCAL
 	if (forkNum == MAIN_FORKNUM && IS_LOCAL_REL(reln))
@@ -2530,8 +2514,7 @@ neon_nblocks(SMgrRelation reln, ForkNumber forknum)
 {
 	NeonResponse *resp;
 	BlockNumber n_blocks;
-	XLogRecPtr	request_lsn;
-	XLogRecPtr	not_modified_since;
+	neon_request_lsns request_lsns;
 
 	switch (reln->smgr_relpersistence)
 	{
@@ -2558,13 +2541,12 @@ neon_nblocks(SMgrRelation reln, ForkNumber forknum)
 		return n_blocks;
 	}
 
-	neon_get_request_lsn(InfoFromSMgrRel(reln), forknum, REL_METADATA_PSEUDO_BLOCKNO,
-						 &request_lsn, &not_modified_since);
+	request_lsns = neon_get_request_lsns(InfoFromSMgrRel(reln), forknum, REL_METADATA_PSEUDO_BLOCKNO);
 	{
 		NeonNblocksRequest request = {
 			.req.tag = T_NeonNblocksRequest,
-			.req.lsn = request_lsn,
-			.req.not_modified_since = not_modified_since,
+			.req.lsn = request_lsns.request_lsn,
+			.req.not_modified_since = request_lsns.not_modified_since,
 			.rinfo = InfoFromSMgrRel(reln),
 			.forknum = forknum,
 		};
@@ -2584,7 +2566,7 @@ neon_nblocks(SMgrRelation reln, ForkNumber forknum)
 					 errmsg(NEON_TAG "could not read relation size of rel %u/%u/%u.%u from page server at lsn %X/%08X",
 							RelFileInfoFmt(InfoFromSMgrRel(reln)),
 							forknum,
-							(uint32) (request_lsn >> 32), (uint32) request_lsn),
+							LSN_FORMAT_ARGS(request_lsns.request_lsn)),
 					 errdetail("page server returned error: %s",
 							   ((NeonErrorResponse *) resp)->message)));
 			break;
@@ -2595,10 +2577,10 @@ neon_nblocks(SMgrRelation reln, ForkNumber forknum)
 	update_cached_relsize(InfoFromSMgrRel(reln), forknum, n_blocks);
 
 	neon_log(SmgrTrace, "neon_nblocks: rel %u/%u/%u fork %u (request LSN %X/%08X): %u blocks",
-		 RelFileInfoFmt(InfoFromSMgrRel(reln)),
-		 forknum,
-		 (uint32) (request_lsn >> 32), (uint32) request_lsn,
-		 n_blocks);
+			 RelFileInfoFmt(InfoFromSMgrRel(reln)),
+			 forknum,
+			 LSN_FORMAT_ARGS(request_lsns.request_lsn),
+			 n_blocks);
 
 	pfree(resp);
 	return n_blocks;
@@ -2612,17 +2594,15 @@ neon_dbsize(Oid dbNode)
 {
 	NeonResponse *resp;
 	int64		db_size;
-	XLogRecPtr	request_lsn,
-				not_modified_since;
+	neon_request_lsns request_lsns;
 	NRelFileInfo dummy_node = {0};
 
-	neon_get_request_lsn(dummy_node, MAIN_FORKNUM, REL_METADATA_PSEUDO_BLOCKNO,
-						 &request_lsn, &not_modified_since);
+	request_lsns = neon_get_request_lsns(dummy_node, MAIN_FORKNUM, REL_METADATA_PSEUDO_BLOCKNO);
 	{
 		NeonDbSizeRequest request = {
 			.req.tag = T_NeonDbSizeRequest,
-			.req.lsn = request_lsn,
-			.req.not_modified_since = not_modified_since,
+			.req.lsn = request_lsns.request_lsn,
+			.req.not_modified_since = request_lsns.not_modified_since,
 			.dbNode = dbNode,
 		};
 
@@ -2639,8 +2619,7 @@ neon_dbsize(Oid dbNode)
 			ereport(ERROR,
 					(errcode(ERRCODE_IO_ERROR),
 					 errmsg(NEON_TAG "could not read db size of db %u from page server at lsn %X/%08X",
-							dbNode,
-							(uint32) (request_lsn >> 32), (uint32) request_lsn),
+							dbNode, LSN_FORMAT_ARGS(request_lsns.request_lsn)),
 					 errdetail("page server returned error: %s",
 							   ((NeonErrorResponse *) resp)->message)));
 			break;
@@ -2650,9 +2629,7 @@ neon_dbsize(Oid dbNode)
 	}
 
 	neon_log(SmgrTrace, "neon_dbsize: db %u (request LSN %X/%08X): %ld bytes",
-		 dbNode,
-		 (uint32) (request_lsn >> 32), (uint32) request_lsn,
-		 db_size);
+			 dbNode, LSN_FORMAT_ARGS(request_lsns.request_lsn), db_size);
 
 	pfree(resp);
 	return db_size;

pgxn/neon_test_utils/neontest.c

@@ -48,10 +48,10 @@ PG_FUNCTION_INFO_V1(neon_xlogflush);
  */
 #if PG_MAJORVERSION_NUM < 16
 typedef void (*neon_read_at_lsn_type) (NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
-									   XLogRecPtr request_lsn, XLogRecPtr not_modified_since, char *buffer);
+									   neon_request_lsns request_lsns, char *buffer);
 #else
 typedef void (*neon_read_at_lsn_type) (NRelFileInfo rinfo, ForkNumber forkNum, BlockNumber blkno,
-									   XLogRecPtr request_lsn, XLogRecPtr not_modified_since, void *buffer);
+									   neon_request_lsns request_lsns, void *buffer);
 #endif
 
 static neon_read_at_lsn_type neon_read_at_lsn_ptr;
@@ -298,9 +298,7 @@ get_raw_page_at_lsn(PG_FUNCTION_ARGS)
 	text	   *relname;
 	text	   *forkname;
 	uint32		blkno;
-
-	XLogRecPtr	request_lsn;
-	XLogRecPtr	not_modified_since;
+	neon_request_lsns	request_lsns;
 
 	if (PG_NARGS() != 5)
 		elog(ERROR, "unexpected number of arguments in SQL function signature");
@@ -312,8 +310,8 @@ get_raw_page_at_lsn(PG_FUNCTION_ARGS)
 	forkname = PG_GETARG_TEXT_PP(1);
 	blkno = PG_GETARG_UINT32(2);
 
-	request_lsn = PG_ARGISNULL(3) ? GetXLogInsertRecPtr() : PG_GETARG_LSN(3);
-	not_modified_since = PG_ARGISNULL(4) ? request_lsn : PG_GETARG_LSN(4);
+	request_lsns.request_lsn = PG_ARGISNULL(3) ? GetXLogInsertRecPtr() : PG_GETARG_LSN(3);
+	request_lsns.not_modified_since = PG_ARGISNULL(4) ? request_lsns.request_lsn : PG_GETARG_LSN(4);
 
 	if (!superuser())
 		ereport(ERROR,
@@ -367,7 +365,8 @@ get_raw_page_at_lsn(PG_FUNCTION_ARGS)
 	SET_VARSIZE(raw_page, BLCKSZ + VARHDRSZ);
 	raw_page_data = VARDATA(raw_page);
 
-	neon_read_at_lsn(InfoFromRelation(rel), forknum, blkno, request_lsn, not_modified_since, raw_page_data);
+	neon_read_at_lsn(InfoFromRelation(rel), forknum, blkno, request_lsns,
+					 raw_page_data);
 
 	relation_close(rel, AccessShareLock);
 
@@ -413,19 +412,18 @@ get_raw_page_at_lsn_ex(PG_FUNCTION_ARGS)
 
 		ForkNumber	forknum = PG_GETARG_UINT32(3);
 		uint32		blkno = PG_GETARG_UINT32(4);
-		XLogRecPtr	request_lsn;
-		XLogRecPtr	not_modified_since;
+		neon_request_lsns	request_lsns;
 
 		/* Initialize buffer to copy to */
 		bytea	   *raw_page = (bytea *) palloc(BLCKSZ + VARHDRSZ);
 
-		request_lsn = PG_ARGISNULL(5) ? GetXLogInsertRecPtr() : PG_GETARG_LSN(5);
-		not_modified_since = PG_ARGISNULL(6) ? request_lsn : PG_GETARG_LSN(6);
+		request_lsns.request_lsn = PG_ARGISNULL(5) ? GetXLogInsertRecPtr() : PG_GETARG_LSN(5);
+		request_lsns.not_modified_since = PG_ARGISNULL(6) ? request_lsns.request_lsn : PG_GETARG_LSN(6);
 
 		SET_VARSIZE(raw_page, BLCKSZ + VARHDRSZ);
 		raw_page_data = VARDATA(raw_page);
 
-		neon_read_at_lsn(rinfo, forknum, blkno, request_lsn, not_modified_since, raw_page_data);
+		neon_read_at_lsn(rinfo, forknum, blkno, request_lsns, raw_page_data);
 		PG_RETURN_BYTEA_P(raw_page);
 	}
 }