Change internal RelFileNode references to RelFileNumber or RelFileLocator.

We have been using the term RelFileNode to refer to either (1) the
integer that is used to name the sequence of files for a certain relation
within the directory set aside for that tablespace/database combination;
or (2) that value plus the OIDs of the tablespace and database; or
occasionally (3) the whole series of files created for a relation
based on those values. Using the same name for more than one thing is
confusing.

Replace RelFileNode with RelFileNumber when we're talking about just the
single number, i.e. (1) from above, and with RelFileLocator when we're
talking about all the things that are needed to locate a relation's files
on disk, i.e. (2) from above. In the places where we refer to (3) as
a relfilenode, instead refer to "relation storage".

Since there is a ton of SQL code in the world that knows about
pg_class.relfilenode, don't change the name of that column, or of other
SQL-facing things that derive their name from it.

On the other hand, do adjust closely-related internal terminology. For
example, the structure member names dbNode and spcNode appear to be
derived from the fact that the structure itself was called RelFileNode,
so change those to dbOid and spcOid. Likewise, various variables with
names like rnode and relnode get renamed appropriately, according to
how they're being used in context.

Hopefully, this is clearer than before. It is also preparation for
future patches that intend to widen the relfilenumber fields from its
current width of 32 bits. Variables that store a relfilenumber are now
declared as type RelFileNumber rather than type Oid; right now, these
are the same, but that can now more easily be changed.

Dilip Kumar, per an idea from me. Reviewed also by Andres Freund.
I fixed some whitespace issues, changed a couple of words in a
comment, and made one other minor correction.

Discussion: http://postgr.es/m/CA+TgmoamOtXbVAQf9hWFzonUo6bhhjS6toZQd7HZ-pmojtAmag@mail.gmail.com
Discussion: http://postgr.es/m/CA+Tgmobp7+7kmi4gkq7Y+4AM9fTvL+O1oQ4-5gFTT+6Ng-dQ=g@mail.gmail.com
Discussion: http://postgr.es/m/CAFiTN-vTe79M8uDH1yprOU64MNFE+R3ODRuA+JWf27JbhY4hJw@mail.gmail.com

1 files changed, 19 insertions, 19 deletions

diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c
index 2ce9be2cc76..f3c29fa9091 100644
--- a/src/backend/access/transam/xloginsert.c
+++ b/src/backend/access/transam/xloginsert.c
@@ -70,7 +70,7 @@ typedef struct
 {
 	bool		in_use;			/* is this slot in use? */
 	uint8		flags;			/* REGBUF_* flags */
-	RelFileNode rnode;			/* identifies the relation and block */
+	RelFileLocator rlocator;	/* identifies the relation and block */
 	ForkNumber	forkno;
 	BlockNumber block;
 	Page		page;			/* page content */
@@ -257,7 +257,7 @@ XLogRegisterBuffer(uint8 block_id, Buffer buffer, uint8 flags)
 
 	regbuf = &registered_buffers[block_id];
 
-	BufferGetTag(buffer, &regbuf->rnode, &regbuf->forkno, &regbuf->block);
+	BufferGetTag(buffer, &regbuf->rlocator, &regbuf->forkno, &regbuf->block);
 	regbuf->page = BufferGetPage(buffer);
 	regbuf->flags = flags;
 	regbuf->rdata_tail = (XLogRecData *) &regbuf->rdata_head;
@@ -278,7 +278,7 @@ XLogRegisterBuffer(uint8 block_id, Buffer buffer, uint8 flags)
 			if (i == block_id || !regbuf_old->in_use)
 				continue;
 
-			Assert(!RelFileNodeEquals(regbuf_old->rnode, regbuf->rnode) ||
+			Assert(!RelFileLocatorEquals(regbuf_old->rlocator, regbuf->rlocator) ||
 				   regbuf_old->forkno != regbuf->forkno ||
 				   regbuf_old->block != regbuf->block);
 		}
@@ -293,7 +293,7 @@ XLogRegisterBuffer(uint8 block_id, Buffer buffer, uint8 flags)
  * shared buffer pool (i.e. when you don't have a Buffer for it).
  */
 void
-XLogRegisterBlock(uint8 block_id, RelFileNode *rnode, ForkNumber forknum,
+XLogRegisterBlock(uint8 block_id, RelFileLocator *rlocator, ForkNumber forknum,
 				  BlockNumber blknum, Page page, uint8 flags)
 {
 	registered_buffer *regbuf;
@@ -308,7 +308,7 @@ XLogRegisterBlock(uint8 block_id, RelFileNode *rnode, ForkNumber forknum,
 
 	regbuf = &registered_buffers[block_id];
 
-	regbuf->rnode = *rnode;
+	regbuf->rlocator = *rlocator;
 	regbuf->forkno = forknum;
 	regbuf->block = blknum;
 	regbuf->page = page;
@@ -331,7 +331,7 @@ XLogRegisterBlock(uint8 block_id, RelFileNode *rnode, ForkNumber forknum,
 			if (i == block_id || !regbuf_old->in_use)
 				continue;
 
-			Assert(!RelFileNodeEquals(regbuf_old->rnode, regbuf->rnode) ||
+			Assert(!RelFileLocatorEquals(regbuf_old->rlocator, regbuf->rlocator) ||
 				   regbuf_old->forkno != regbuf->forkno ||
 				   regbuf_old->block != regbuf->block);
 		}
@@ -768,7 +768,7 @@ XLogRecordAssemble(RmgrId rmid, uint8 info,
 			rdt_datas_last = regbuf->rdata_tail;
 		}
 
-		if (prev_regbuf && RelFileNodeEquals(regbuf->rnode, prev_regbuf->rnode))
+		if (prev_regbuf && RelFileLocatorEquals(regbuf->rlocator, prev_regbuf->rlocator))
 		{
 			samerel = true;
 			bkpb.fork_flags |= BKPBLOCK_SAME_REL;
@@ -793,8 +793,8 @@ XLogRecordAssemble(RmgrId rmid, uint8 info,
 		}
 		if (!samerel)
 		{
-			memcpy(scratch, &regbuf->rnode, sizeof(RelFileNode));
-			scratch += sizeof(RelFileNode);
+			memcpy(scratch, &regbuf->rlocator, sizeof(RelFileLocator));
+			scratch += sizeof(RelFileLocator);
 		}
 		memcpy(scratch, &regbuf->block, sizeof(BlockNumber));
 		scratch += sizeof(BlockNumber);
@@ -1031,7 +1031,7 @@ XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
 		int			flags = 0;
 		PGAlignedBlock copied_buffer;
 		char	   *origdata = (char *) BufferGetBlock(buffer);
-		RelFileNode rnode;
+		RelFileLocator rlocator;
 		ForkNumber	forkno;
 		BlockNumber blkno;
 
@@ -1058,8 +1058,8 @@ XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
 		if (buffer_std)
 			flags |= REGBUF_STANDARD;
 
-		BufferGetTag(buffer, &rnode, &forkno, &blkno);
-		XLogRegisterBlock(0, &rnode, forkno, blkno, copied_buffer.data, flags);
+		BufferGetTag(buffer, &rlocator, &forkno, &blkno);
+		XLogRegisterBlock(0, &rlocator, forkno, blkno, copied_buffer.data, flags);
 
 		recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI_FOR_HINT);
 	}
@@ -1080,7 +1080,7 @@ XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
  * the unused space to be left out from the WAL record, making it smaller.
  */
 XLogRecPtr
-log_newpage(RelFileNode *rnode, ForkNumber forkNum, BlockNumber blkno,
+log_newpage(RelFileLocator *rlocator, ForkNumber forkNum, BlockNumber blkno,
 			Page page, bool page_std)
 {
 	int			flags;
@@ -1091,7 +1091,7 @@ log_newpage(RelFileNode *rnode, ForkNumber forkNum, BlockNumber blkno,
 		flags |= REGBUF_STANDARD;
 
 	XLogBeginInsert();
-	XLogRegisterBlock(0, rnode, forkNum, blkno, page, flags);
+	XLogRegisterBlock(0, rlocator, forkNum, blkno, page, flags);
 	recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI);
 
 	/*
@@ -1112,7 +1112,7 @@ log_newpage(RelFileNode *rnode, ForkNumber forkNum, BlockNumber blkno,
  * because we can write multiple pages in a single WAL record.
  */
 void
-log_newpages(RelFileNode *rnode, ForkNumber forkNum, int num_pages,
+log_newpages(RelFileLocator *rlocator, ForkNumber forkNum, int num_pages,
 			 BlockNumber *blknos, Page *pages, bool page_std)
 {
 	int			flags;
@@ -1142,7 +1142,7 @@ log_newpages(RelFileNode *rnode, ForkNumber forkNum, int num_pages,
 		nbatch = 0;
 		while (nbatch < XLR_MAX_BLOCK_ID && i < num_pages)
 		{
-			XLogRegisterBlock(nbatch, rnode, forkNum, blknos[i], pages[i], flags);
+			XLogRegisterBlock(nbatch, rlocator, forkNum, blknos[i], pages[i], flags);
 			i++;
 			nbatch++;
 		}
@@ -1177,16 +1177,16 @@ XLogRecPtr
 log_newpage_buffer(Buffer buffer, bool page_std)
 {
 	Page		page = BufferGetPage(buffer);
-	RelFileNode rnode;
+	RelFileLocator rlocator;
 	ForkNumber	forkNum;
 	BlockNumber blkno;
 
 	/* Shared buffers should be modified in a critical section. */
 	Assert(CritSectionCount > 0);
 
-	BufferGetTag(buffer, &rnode, &forkNum, &blkno);
+	BufferGetTag(buffer, &rlocator, &forkNum, &blkno);
 
-	return log_newpage(&rnode, forkNum, blkno, page, page_std);
+	return log_newpage(&rlocator, forkNum, blkno, page, page_std);
 }
 
 /*