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, 32 insertions, 32 deletions

diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index b4a2c8d2197..34efa121b40 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -27,7 +27,7 @@
 #include "utils/builtins.h"
 #include "utils/numeric.h"
 #include "utils/rel.h"
-#include "utils/relfilenodemap.h"
+#include "utils/relfilenumbermap.h"
 #include "utils/relmapper.h"
 #include "utils/syscache.h"
 
@@ -292,7 +292,7 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
  * is no check here or at the call sites for that.
  */
 static int64
-calculate_relation_size(RelFileNode *rfn, BackendId backend, ForkNumber forknum)
+calculate_relation_size(RelFileLocator *rfn, BackendId backend, ForkNumber forknum)
 {
 	int64		totalsize = 0;
 	char	   *relationpath;
@@ -349,7 +349,7 @@ pg_relation_size(PG_FUNCTION_ARGS)
 	if (rel == NULL)
 		PG_RETURN_NULL();
 
-	size = calculate_relation_size(&(rel->rd_node), rel->rd_backend,
+	size = calculate_relation_size(&(rel->rd_locator), rel->rd_backend,
 								   forkname_to_number(text_to_cstring(forkName)));
 
 	relation_close(rel, AccessShareLock);
@@ -374,7 +374,7 @@ calculate_toast_table_size(Oid toastrelid)
 
 	/* toast heap size, including FSM and VM size */
 	for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
-		size += calculate_relation_size(&(toastRel->rd_node),
+		size += calculate_relation_size(&(toastRel->rd_locator),
 										toastRel->rd_backend, forkNum);
 
 	/* toast index size, including FSM and VM size */
@@ -388,7 +388,7 @@ calculate_toast_table_size(Oid toastrelid)
 		toastIdxRel = relation_open(lfirst_oid(lc),
 									AccessShareLock);
 		for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
-			size += calculate_relation_size(&(toastIdxRel->rd_node),
+			size += calculate_relation_size(&(toastIdxRel->rd_locator),
 											toastIdxRel->rd_backend, forkNum);
 
 		relation_close(toastIdxRel, AccessShareLock);
@@ -417,7 +417,7 @@ calculate_table_size(Relation rel)
 	 * heap size, including FSM and VM
 	 */
 	for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
-		size += calculate_relation_size(&(rel->rd_node), rel->rd_backend,
+		size += calculate_relation_size(&(rel->rd_locator), rel->rd_backend,
 										forkNum);
 
 	/*
@@ -456,7 +456,7 @@ calculate_indexes_size(Relation rel)
 			idxRel = relation_open(idxOid, AccessShareLock);
 
 			for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
-				size += calculate_relation_size(&(idxRel->rd_node),
+				size += calculate_relation_size(&(idxRel->rd_locator),
 												idxRel->rd_backend,
 												forkNum);
 
@@ -850,7 +850,7 @@ Datum
 pg_relation_filenode(PG_FUNCTION_ARGS)
 {
 	Oid			relid = PG_GETARG_OID(0);
-	Oid			result;
+	RelFileNumber result;
 	HeapTuple	tuple;
 	Form_pg_class relform;
 
@@ -864,29 +864,29 @@ pg_relation_filenode(PG_FUNCTION_ARGS)
 		if (relform->relfilenode)
 			result = relform->relfilenode;
 		else					/* Consult the relation mapper */
-			result = RelationMapOidToFilenode(relid,
-											  relform->relisshared);
+			result = RelationMapOidToFilenumber(relid,
+												relform->relisshared);
 	}
 	else
 	{
 		/* no storage, return NULL */
-		result = InvalidOid;
+		result = InvalidRelFileNumber;
 	}
 
 	ReleaseSysCache(tuple);
 
-	if (!OidIsValid(result))
+	if (!RelFileNumberIsValid(result))
 		PG_RETURN_NULL();
 
 	PG_RETURN_OID(result);
 }
 
 /*
- * Get the relation via (reltablespace, relfilenode)
+ * Get the relation via (reltablespace, relfilenumber)
  *
  * This is expected to be used when somebody wants to match an individual file
  * on the filesystem back to its table. That's not trivially possible via
- * pg_class, because that doesn't contain the relfilenodes of shared and nailed
+ * pg_class, because that doesn't contain the relfilenumbers of shared and nailed
  * tables.
  *
  * We don't fail but return NULL if we cannot find a mapping.
@@ -898,14 +898,14 @@ Datum
 pg_filenode_relation(PG_FUNCTION_ARGS)
 {
 	Oid			reltablespace = PG_GETARG_OID(0);
-	Oid			relfilenode = PG_GETARG_OID(1);
+	RelFileNumber relfilenumber = PG_GETARG_OID(1);
 	Oid			heaprel;
 
-	/* test needed so RelidByRelfilenode doesn't misbehave */
-	if (!OidIsValid(relfilenode))
+	/* test needed so RelidByRelfilenumber doesn't misbehave */
+	if (!RelFileNumberIsValid(relfilenumber))
 		PG_RETURN_NULL();
 
-	heaprel = RelidByRelfilenode(reltablespace, relfilenode);
+	heaprel = RelidByRelfilenumber(reltablespace, relfilenumber);
 
 	if (!OidIsValid(heaprel))
 		PG_RETURN_NULL();
@@ -924,7 +924,7 @@ pg_relation_filepath(PG_FUNCTION_ARGS)
 	Oid			relid = PG_GETARG_OID(0);
 	HeapTuple	tuple;
 	Form_pg_class relform;
-	RelFileNode rnode;
+	RelFileLocator rlocator;
 	BackendId	backend;
 	char	   *path;
 
@@ -937,29 +937,29 @@ pg_relation_filepath(PG_FUNCTION_ARGS)
 	{
 		/* This logic should match RelationInitPhysicalAddr */
 		if (relform->reltablespace)
-			rnode.spcNode = relform->reltablespace;
+			rlocator.spcOid = relform->reltablespace;
 		else
-			rnode.spcNode = MyDatabaseTableSpace;
-		if (rnode.spcNode == GLOBALTABLESPACE_OID)
-			rnode.dbNode = InvalidOid;
+			rlocator.spcOid = MyDatabaseTableSpace;
+		if (rlocator.spcOid == GLOBALTABLESPACE_OID)
+			rlocator.dbOid = InvalidOid;
 		else
-			rnode.dbNode = MyDatabaseId;
+			rlocator.dbOid = MyDatabaseId;
 		if (relform->relfilenode)
-			rnode.relNode = relform->relfilenode;
+			rlocator.relNumber = relform->relfilenode;
 		else					/* Consult the relation mapper */
-			rnode.relNode = RelationMapOidToFilenode(relid,
-													 relform->relisshared);
+			rlocator.relNumber = RelationMapOidToFilenumber(relid,
+															relform->relisshared);
 	}
 	else
 	{
 		/* no storage, return NULL */
-		rnode.relNode = InvalidOid;
+		rlocator.relNumber = InvalidRelFileNumber;
 		/* some compilers generate warnings without these next two lines */
-		rnode.dbNode = InvalidOid;
-		rnode.spcNode = InvalidOid;
+		rlocator.dbOid = InvalidOid;
+		rlocator.spcOid = InvalidOid;
 	}
 
-	if (!OidIsValid(rnode.relNode))
+	if (!RelFileNumberIsValid(rlocator.relNumber))
 	{
 		ReleaseSysCache(tuple);
 		PG_RETURN_NULL();
@@ -990,7 +990,7 @@ pg_relation_filepath(PG_FUNCTION_ARGS)
 
 	ReleaseSysCache(tuple);
 
-	path = relpathbackend(rnode, backend, MAIN_FORKNUM);
+	path = relpathbackend(rlocator, backend, MAIN_FORKNUM);
 
 	PG_RETURN_TEXT_P(cstring_to_text(path));
 }