Reimplement the linked list data structure used throughout the backend.

In the past, we used a 'Lispy' linked list implementation: a "list" was
merely a pointer to the head node of the list. The problem with that
design is that it makes lappend() and length() linear time. This patch
fixes that problem (and others) by maintaining a count of the list
length and a pointer to the tail node along with each head node pointer.
A "list" is now a pointer to a structure containing some meta-data
about the list; the head and tail pointers in that structure refer
to ListCell structures that maintain the actual linked list of nodes.

The function names of the list API have also been changed to, I hope,
be more logically consistent. By default, the old function names are
still available; they will be disabled-by-default once the rest of
the tree has been updated to use the new API names.

1 files changed, 20 insertions, 20 deletions

diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 448f99e1d37..1fe8e58e585 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.119 2004/05/08 00:34:49 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.120 2004/05/26 04:41:11 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -109,7 +109,7 @@ DefineIndex(RangeVar *heapRelation,
 	/*
 	 * count attributes in index
 	 */
-	numberOfAttributes = length(attributeList);
+	numberOfAttributes = list_length(attributeList);
 	if (numberOfAttributes <= 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
@@ -165,7 +165,7 @@ DefineIndex(RangeVar *heapRelation,
 												namespaceId);
 		else
 		{
-			IndexElem  *iparam = (IndexElem *) lfirst(attributeList);
+			IndexElem  *iparam = (IndexElem *) linitial(attributeList);
 
 			indexRelationName = CreateIndexName(RelationGetRelationName(rel),
 												iparam->name,
@@ -208,7 +208,7 @@ DefineIndex(RangeVar *heapRelation,
 	 */
 	if (rangetable != NIL)
 	{
-		if (length(rangetable) != 1 || getrelid(1, rangetable) != relationId)
+		if (list_length(rangetable) != 1 || getrelid(1, rangetable) != relationId)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 					 errmsg("index expressions and predicates may refer only to the table being indexed")));
@@ -226,7 +226,7 @@ DefineIndex(RangeVar *heapRelation,
 	if (primary)
 	{
 		List	   *cmds;
-		List	   *keys;
+		ListCell   *keys;
 
 		/*
 		 * If ALTER TABLE, check that there isn't already a PRIMARY KEY.
@@ -399,7 +399,7 @@ ComputeIndexAttrs(IndexInfo *indexInfo,
 				  Oid accessMethodId,
 				  bool isconstraint)
 {
-	List	   *rest;
+	ListCell   *rest;
 	int			attn = 0;
 
 	/*
@@ -516,9 +516,9 @@ GetIndexOpClass(List *opclass, Oid attrType,
 	 * Release 7.5 removes bigbox_ops (which was dead code for a long while
 	 * anyway).  tgl 2003/11/11
 	 */
-	if (length(opclass) == 1)
+	if (list_length(opclass) == 1)
 	{
-		char	   *claname = strVal(lfirst(opclass));
+		char	   *claname = strVal(linitial(opclass));
 
 		if (strcmp(claname, "network_ops") == 0 ||
 			strcmp(claname, "timespan_ops") == 0 ||
@@ -697,8 +697,8 @@ static bool
 relationHasPrimaryKey(Relation rel)
 {
 	bool		result = false;
-	List	   *indexoidlist,
-			   *indexoidscan;
+	List	   *indexoidlist;
+	ListCell   *indexoidscan;
 
 	/*
 	 * Get the list of index OIDs for the table from the relcache, and
@@ -709,7 +709,7 @@ relationHasPrimaryKey(Relation rel)
 
 	foreach(indexoidscan, indexoidlist)
 	{
-		Oid			indexoid = lfirsto(indexoidscan);
+		Oid			indexoid = lfirst_oid(indexoidscan);
 		HeapTuple	indexTuple;
 
 		indexTuple = SearchSysCache(INDEXRELID,
@@ -723,7 +723,7 @@ relationHasPrimaryKey(Relation rel)
 			break;
 	}
 
-	freeList(indexoidlist);
+	list_free(indexoidlist);
 
 	return result;
 }
@@ -843,12 +843,13 @@ void
 ReindexDatabase(const char *dbname, bool force /* currently unused */,
 				bool all)
 {
-	Relation	relationRelation;
+	Relation	 relationRelation;
 	HeapScanDesc scan;
-	HeapTuple	tuple;
+	HeapTuple	 tuple;
 	MemoryContext private_context;
 	MemoryContext old;
-	List	   *relids = NIL;
+	List		*relids = NIL;
+	ListCell	*l;
 
 	AssertArg(dbname);
 
@@ -887,7 +888,7 @@ ReindexDatabase(const char *dbname, bool force /* currently unused */,
 	 * reindexing itself will try to update pg_class.
 	 */
 	old = MemoryContextSwitchTo(private_context);
-	relids = lappendo(relids, RelOid_pg_class);
+	relids = lappend_oid(relids, RelOid_pg_class);
 	MemoryContextSwitchTo(old);
 
 	/*
@@ -921,7 +922,7 @@ ReindexDatabase(const char *dbname, bool force /* currently unused */,
 			continue;			/* got it already */
 
 		old = MemoryContextSwitchTo(private_context);
-		relids = lappendo(relids, HeapTupleGetOid(tuple));
+		relids = lappend_oid(relids, HeapTupleGetOid(tuple));
 		MemoryContextSwitchTo(old);
 	}
 	heap_endscan(scan);
@@ -929,9 +930,9 @@ ReindexDatabase(const char *dbname, bool force /* currently unused */,
 
 	/* Now reindex each rel in a separate transaction */
 	CommitTransactionCommand();
-	while (relids)
+	foreach(l, relids)
 	{
-		Oid		relid = lfirsto(relids);
+		Oid		relid = lfirst_oid(l);
 
 		StartTransactionCommand();
 		SetQuerySnapshot();		/* might be needed for functions in
@@ -941,7 +942,6 @@ ReindexDatabase(const char *dbname, bool force /* currently unused */,
 					(errmsg("table \"%s\" was reindexed",
 							get_rel_name(relid))));
 		CommitTransactionCommand();
-		relids = lnext(relids);
 	}
 	StartTransactionCommand();