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Reimplement the linked list data structure used throughout the backend.

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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.
This commit is contained in:
Neil Conway
2004-05-26 04:41:50 +00:00
parent 18d0d10563
commit d0b4399d81
125 changed files with 3639 additions and 3038 deletions
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75
src/backend/optimizer/plan/subselect.c
View File

@@ -7,7 +7,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/optimizer/plan/subselect.c,v 1.89 2004/05/11 13:15:15 tgl Exp $
* $PostgreSQL: pgsql/src/backend/optimizer/plan/subselect.c,v 1.90 2004/05/26 04:41:24 neilc Exp $
*
*-------------------------------------------------------------------------
*/
@@ -101,7 +101,7 @@ static Param *
replace_outer_var(Var *var)
{
Param *retval;
List *ppl;
ListCell *ppl;
PlannerParamItem *pitem;
Index abslevel;
int i;
@@ -250,7 +250,6 @@ make_subplan(SubLink *slink, List *lefthand, bool isTopQual)
Plan *plan;
Bitmapset *tmpset;
int paramid;
List *lst;
Node *result;
/*
@@ -348,7 +347,7 @@ make_subplan(SubLink *slink, List *lefthand, bool isTopQual)
}
else if (node->parParam == NIL && slink->subLinkType == EXPR_SUBLINK)
{
TargetEntry *te = lfirst(plan->targetlist);
TargetEntry *te = linitial(plan->targetlist);
Param *prm;
Assert(!te->resdom->resjunk);
@@ -359,7 +358,7 @@ make_subplan(SubLink *slink, List *lefthand, bool isTopQual)
}
else if (node->parParam == NIL && slink->subLinkType == ARRAY_SUBLINK)
{
TargetEntry *te = lfirst(plan->targetlist);
TargetEntry *te = linitial(plan->targetlist);
Oid arraytype;
Param *prm;
@@ -395,11 +394,12 @@ make_subplan(SubLink *slink, List *lefthand, bool isTopQual)
result = (Node *) (node->useOr ? make_orclause(exprs) :
make_andclause(exprs));
else
result = (Node *) lfirst(exprs);
result = (Node *) linitial(exprs);
}
else
{
List *args;
ListCell *l;
/*
* We can't convert subplans of ALL_SUBLINK or ANY_SUBLINK types
@@ -471,9 +471,9 @@ make_subplan(SubLink *slink, List *lefthand, bool isTopQual)
* Make node->args from parParam.
*/
args = NIL;
foreach(lst, node->parParam)
foreach(l, node->parParam)
{
PlannerParamItem *pitem = nth(lfirsti(lst), PlannerParamList);
PlannerParamItem *pitem = nth(lfirsti(l), PlannerParamList);
/*
* The Var or Aggref has already been adjusted to have the
@@ -509,15 +509,17 @@ convert_sublink_opers(List *lefthand, List *operOids,
List **righthandIds)
{
List *result = NIL;
List *lst;
ListCell *l, *lefthand_item, *tlist_item;
*righthandIds = NIL;
lefthand_item = list_head(lefthand);
tlist_item = list_head(targetlist);
foreach(lst, operOids)
foreach(l, operOids)
{
Oid opid = lfirsto(lst);
Node *leftop = lfirst(lefthand);
TargetEntry *te = lfirst(targetlist);
Oid opid = lfirsto(l);
Node *leftop = (Node *) lfirst(lefthand_item);
TargetEntry *te = (TargetEntry *) lfirst(tlist_item);
Node *rightop;
Operator tup;
@@ -574,8 +576,8 @@ convert_sublink_opers(List *lefthand, List *operOids,
ReleaseSysCache(tup);
lefthand = lnext(lefthand);
targetlist = lnext(targetlist);
lefthand_item = lnext(lefthand_item);
tlist_item = lnext(tlist_item);
}
return result;
@@ -591,7 +593,7 @@ static bool
subplan_is_hashable(SubLink *slink, SubPlan *node)
{
double subquery_size;
List *opids;
ListCell *l;
/*
* The sublink type must be "= ANY" --- that is, an IN operator. (We
@@ -602,7 +604,7 @@ subplan_is_hashable(SubLink *slink, SubPlan *node)
if (slink->subLinkType != ANY_SUBLINK)
return false;
if (length(slink->operName) != 1 ||
strcmp(strVal(lfirst(slink->operName)), "=") != 0)
strcmp(strVal(linitial(slink->operName)), "=") != 0)
return false;
/*
@@ -636,9 +638,9 @@ subplan_is_hashable(SubLink *slink, SubPlan *node)
* different sets of operators with the hash table, but there is no
* obvious usefulness to that at present.)
*/
foreach(opids, slink->operOids)
foreach(l, slink->operOids)
{
Oid opid = lfirsto(opids);
Oid opid = lfirsto(l);
HeapTuple tup;
Form_pg_operator optup;
@@ -690,7 +692,7 @@ convert_IN_to_join(Query *parse, SubLink *sublink)
if (sublink->subLinkType != ANY_SUBLINK)
return NULL;
if (length(sublink->operName) != 1 ||
strcmp(strVal(lfirst(sublink->operName)), "=") != 0)
strcmp(strVal(linitial(sublink->operName)), "=") != 0)
return NULL;
/*
@@ -859,8 +861,8 @@ process_sublinks_mutator(Node *node, bool *isTopQual)
*/
if (and_clause(node))
{
List *newargs = NIL;
List *l;
List *newargs = NIL;
ListCell *l;
/* Still at qual top-level */
locTopQual = *isTopQual;
@@ -884,8 +886,8 @@ process_sublinks_mutator(Node *node, bool *isTopQual)
if (or_clause(node))
{
List *newargs = NIL;
List *l;
List *newargs = NIL;
ListCell *l;
foreach(l, ((BoolExpr *) node)->args)
{
@@ -918,7 +920,7 @@ SS_finalize_plan(Plan *plan, List *rtable)
Bitmapset *outer_params = NULL;
Bitmapset *valid_params = NULL;
int paramid;
List *lst;
ListCell *l;
/*
* First, scan the param list to discover the sets of params that are
@@ -926,9 +928,9 @@ SS_finalize_plan(Plan *plan, List *rtable)
* this once to save time in the per-plan recursion steps.
*/
paramid = 0;
foreach(lst, PlannerParamList)
foreach(l, PlannerParamList)
{
PlannerParamItem *pitem = (PlannerParamItem *) lfirst(lst);
PlannerParamItem *pitem = (PlannerParamItem *) lfirst(l);
if (pitem->abslevel < PlannerQueryLevel)
{
@@ -966,7 +968,6 @@ finalize_plan(Plan *plan, List *rtable,
Bitmapset *outer_params, Bitmapset *valid_params)
{
finalize_primnode_context context;
List *lst;
if (plan == NULL)
return NULL;
@@ -1033,14 +1034,18 @@ finalize_plan(Plan *plan, List *rtable,
break;
case T_Append:
foreach(lst, ((Append *) plan)->appendplans)
{
context.paramids =
bms_add_members(context.paramids,
finalize_plan((Plan *) lfirst(lst),
rtable,
outer_params,
valid_params));
ListCell *l;
foreach(l, ((Append *) plan)->appendplans)
{
context.paramids =
bms_add_members(context.paramids,
finalize_plan((Plan *) lfirst(l),
rtable,
outer_params,
valid_params));
}
}
break;