Function WritePlanState

pg_documentdb/src/explain/documentdb_explain.c:1196–1307

static void
WritePlanState(pgbson_writer *writer, const char *stageName, QueryDesc *queryDesc,
			   PlanState *planState)
{
	WriteMongoNamespaceName(writer, queryDesc, planState);

	PgbsonWriterAppendDouble(writer, "startupCost", -1, planState->plan->startup_cost);
	PgbsonWriterAppendDouble(writer, "totalCost", -1, planState->plan->total_cost);

	if (strcmp(stageName, "EOF") != 0)
	{
		/* For EOF stage, rows is always 0 and doesn't represent actual estimated rows, so we skip it to avoid confusion. */
		PgbsonWriterAppendDouble(writer, "estimatedTotalKeysExamined", -1,
								 planState->plan->plan_rows);
	}

	if (planState->plan->qual != NIL)
	{
		pgbson_writer qualWriter;
		PgbsonWriterStartDocument(writer, "filter", -1, &qualWriter);
		WriteQuals(&qualWriter, planState->plan->qual);
		PgbsonWriterEndDocument(writer, &qualWriter);
	}

	WriteProjectionState(planState, writer);

	/* per stage type planner output */
	switch (nodeTag(planState->plan))
	{
		case T_Limit:
		{
			LimitState *limitState = (LimitState *) planState;
			Limit *limitPlan = (Limit *) limitState->ps.plan;
			if (limitPlan->limitOffset != NULL &&
				IsA(limitPlan->limitOffset, Const))
			{
				Const *offsetConst = (Const *) limitPlan->limitOffset;
				PgbsonWriterAppendDouble(writer, "skipAmount", -1, DatumGetInt64(
											 offsetConst->constvalue));
			}

			if (limitPlan->limitCount != NULL &&
				IsA(limitPlan->limitCount, Const))
			{
				Const *countConst = (Const *) limitPlan->limitCount;
				PgbsonWriterAppendDouble(writer, "limitAmount", -1, DatumGetInt64(
											 countConst->constvalue));
			}

			break;
		}

		case T_IndexScan:
		{
			IndexScanState *indexScanState = (IndexScanState *) planState;
			IndexScan *plan = (IndexScan *) indexScanState->ss.ps.plan;

			LogIndexScanDetails(writer, plan->indexid, plan->indexorderdir,