Improve handling of CustomPath/CustomPlan(State) children.

Allow CustomPath to have a list of paths, CustomPlan a list of plans,
and CustomPlanState a list of planstates known to the core system, so
that custom path/plan providers can more reasonably use this
infrastructure for nodes with multiple children.

KaiGai Kohei, per a design suggestion from Tom Lane, with some
further kibitzing by me.
This commit is contained in:
Robert Haas 2015-06-26 09:40:47 -04:00
parent 4b8e24b9ad
commit 5ca611841b
8 changed files with 77 additions and 7 deletions

View File

@ -60,6 +60,7 @@ typedef struct CustomPath
{
Path path;
uint32 flags;
List *custom_paths;
List *custom_private;
const CustomPathMethods *methods;
} CustomPath;
@ -73,6 +74,9 @@ typedef struct CustomPath
<literal>CUSTOMPATH_SUPPORT_BACKWARD_SCAN</> if the custom path can support
a backward scan and <literal>CUSTOMPATH_SUPPORT_MARK_RESTORE</> if it
can support mark and restore. Both capabilities are optional.
An optional <structfield>custom_paths</> is a list of <structname>Path</>
nodes used by this custom-path node; these will be transformed into
<structname>Plan</> nodes by planner.
<structfield>custom_private</> can be used to store the custom path's
private data. Private data should be stored in a form that can be handled
by <literal>nodeToString</>, so that debugging routines that attempt to
@ -112,7 +116,8 @@ Plan *(*PlanCustomPath) (PlannerInfo *root,
RelOptInfo *rel,
CustomPath *best_path,
List *tlist,
List *clauses);
List *clauses,
List *custom_plans);
</programlisting>
Convert a custom path to a finished plan. The return value will generally
be a <literal>CustomScan</> object, which the callback must allocate and
@ -145,6 +150,7 @@ typedef struct CustomScan
{
Scan scan;
uint32 flags;
List *custom_plans;
List *custom_exprs;
List *custom_private;
List *custom_scan_tlist;
@ -159,6 +165,8 @@ typedef struct CustomScan
estimated costs, target lists, qualifications, and so on.
<structfield>flags</> is a bitmask with the same meaning as in
<structname>CustomPath</>.
<structfield>custom_plans</> can be used to store child
<structname>Plan</> nodes.
<structfield>custom_exprs</> should be used to
store expression trees that will need to be fixed up by
<filename>setrefs.c</> and <filename>subselect.c</>, while

View File

@ -115,6 +115,8 @@ static void ExplainMemberNodes(List *plans, PlanState **planstates,
List *ancestors, ExplainState *es);
static void ExplainSubPlans(List *plans, List *ancestors,
const char *relationship, ExplainState *es);
static void ExplainCustomChildren(CustomScanState *css,
List *ancestors, ExplainState *es);
static void ExplainProperty(const char *qlabel, const char *value,
bool numeric, ExplainState *es);
static void ExplainOpenGroup(const char *objtype, const char *labelname,
@ -1624,6 +1626,8 @@ ExplainNode(PlanState *planstate, List *ancestors,
IsA(plan, BitmapAnd) ||
IsA(plan, BitmapOr) ||
IsA(plan, SubqueryScan) ||
(IsA(planstate, CustomScanState) &&
((CustomScanState *) planstate)->custom_ps != NIL) ||
planstate->subPlan;
if (haschildren)
{
@ -1678,6 +1682,10 @@ ExplainNode(PlanState *planstate, List *ancestors,
ExplainNode(((SubqueryScanState *) planstate)->subplan, ancestors,
"Subquery", NULL, es);
break;
case T_CustomScan:
ExplainCustomChildren((CustomScanState *) planstate,
ancestors, es);
break;
default:
break;
}
@ -2647,6 +2655,20 @@ ExplainSubPlans(List *plans, List *ancestors,
}
}
/*
* Explain a list of children of a CustomScan.
*/
static void
ExplainCustomChildren(CustomScanState *css, List *ancestors, ExplainState *es)
{
ListCell *cell;
const char *label =
(list_length(css->custom_ps) != 1 ? "children" : "child");
foreach (cell, css->custom_ps)
ExplainNode((PlanState *) lfirst(cell), ancestors, label, NULL, es);
}
/*
* Explain a property, such as sort keys or targets, that takes the form of
* a list of unlabeled items. "data" is a list of C strings.

View File

@ -2157,6 +2157,16 @@ create_customscan_plan(PlannerInfo *root, CustomPath *best_path,
{
CustomScan *cplan;
RelOptInfo *rel = best_path->path.parent;
List *custom_plans = NIL;
ListCell *lc;
/* Recursively transform child paths. */
foreach (lc, best_path->custom_paths)
{
Plan *plan = create_plan_recurse(root, (Path *) lfirst(lc));
custom_plans = lappend(custom_plans, plan);
}
/*
* Sort clauses into the best execution order, although custom-scan
@ -2172,7 +2182,8 @@ create_customscan_plan(PlannerInfo *root, CustomPath *best_path,
rel,
best_path,
tlist,
scan_clauses);
scan_clauses,
custom_plans);
Assert(IsA(cplan, CustomScan));
/*

View File

@ -1151,6 +1151,8 @@ set_customscan_references(PlannerInfo *root,
CustomScan *cscan,
int rtoffset)
{
ListCell *lc;
/* Adjust scanrelid if it's valid */
if (cscan->scan.scanrelid > 0)
cscan->scan.scanrelid += rtoffset;
@ -1194,6 +1196,12 @@ set_customscan_references(PlannerInfo *root,
fix_scan_list(root, cscan->custom_exprs, rtoffset);
}
/* Adjust child plan-nodes recursively, if needed */
foreach (lc, cscan->custom_plans)
{
lfirst(lc) = set_plan_refs(root, (Plan *) lfirst(lc), rtoffset);
}
/* Adjust custom_relids if needed */
if (rtoffset > 0)
{

View File

@ -2373,10 +2373,27 @@ finalize_plan(PlannerInfo *root, Plan *plan, Bitmapset *valid_params,
break;
case T_CustomScan:
finalize_primnode((Node *) ((CustomScan *) plan)->custom_exprs,
&context);
/* We assume custom_scan_tlist cannot contain Params */
context.paramids = bms_add_members(context.paramids, scan_params);
{
CustomScan *cscan = (CustomScan *) plan;
ListCell *lc;
finalize_primnode((Node *) cscan->custom_exprs,
&context);
/* We assume custom_scan_tlist cannot contain Params */
context.paramids =
bms_add_members(context.paramids, scan_params);
/* child nodes if any */
foreach (lc, cscan->custom_plans)
{
context.paramids =
bms_add_members(context.paramids,
finalize_plan(root,
(Plan *) lfirst(lc),
valid_params,
scan_params));
}
}
break;
case T_ModifyTable:

View File

@ -1616,6 +1616,7 @@ typedef struct CustomScanState
{
ScanState ss;
uint32 flags; /* mask of CUSTOMPATH_* flags, see relation.h */
List *custom_ps; /* list of child PlanState nodes, if any */
const CustomExecMethods *methods;
} CustomScanState;

View File

@ -550,6 +550,7 @@ typedef struct CustomScan
{
Scan scan;
uint32 flags; /* mask of CUSTOMPATH_* flags, see relation.h */
List *custom_plans; /* list of Plan nodes, if any */
List *custom_exprs; /* expressions that custom code may evaluate */
List *custom_private; /* private data for custom code */
List *custom_scan_tlist; /* optional tlist describing scan

View File

@ -929,7 +929,8 @@ typedef struct CustomPathMethods
RelOptInfo *rel,
struct CustomPath *best_path,
List *tlist,
List *clauses);
List *clauses,
List *custom_plans);
/* Optional: print additional fields besides "private" */
void (*TextOutCustomPath) (StringInfo str,
const struct CustomPath *node);
@ -939,6 +940,7 @@ typedef struct CustomPath
{
Path path;
uint32 flags; /* mask of CUSTOMPATH_* flags, see above */
List *custom_paths; /* list of child Path nodes, if any */
List *custom_private;
const CustomPathMethods *methods;
} CustomPath;