Function BuildResultData

pg_documentdb/src/commands/db_stats.c:272–324

* Helper method on the coordinator that populates the * DbStatsResult with the merged worker statistics (along with any * additional statistics that may be needed from the coordinator). */

 * additional statistics that may be needed from the coordinator).
 */
static void
BuildResultData(Datum databaseName, DbStatsResult *result, int32 scale)
{
	int64 numViews = 0;
	List *collectionIdsList = GetAllCollectionIdsInDb(databaseName, &numViews);
	int64 numCollections = list_length(collectionIdsList);

	result->collections = numCollections;
	result->views = numViews;

	if (numCollections == 0)
	{
		/* When no collections, skip gathering data from workers */
		return;
	}

	Datum *collectionIdDatums = palloc0(sizeof(Datum) * numCollections);

	int64 i = 0;
	uint64 collectionId;
	ListCell *cell;
	foreach(cell, collectionIdsList)
	{
		CHECK_FOR_INTERRUPTS();
		collectionId = *(uint64 *) lfirst(cell);
		collectionIdDatums[i] = Int64GetDatum(collectionId);
		i++;
	}

	ArrayType *collectionIdArray = construct_array(collectionIdDatums, numCollections,
												   INT8OID,
												   sizeof(uint64), true,
												   TYPALIGN_INT);

	List *workerBsons;
	int numValues = 1;
	Datum values[1] = { PointerGetDatum(collectionIdArray) };
	Oid types[1] = { INT8ARRAYOID };

	workerBsons = RunQueryOnAllServerNodes("DbStats", values, types, numValues,
										   command_db_stats_worker,
										   ApiInternalSchemaName,
										   "db_stats_worker");

	/* Now that we have the worker BSON results, merge them to the final one */
	MergeWorkerResults(result, workerBsons, scale);

	/* Get the count of Indexes for all the collections in array.
	 * Querying index metadata needs to happen on the coordinator since
	 * the index metadata is only present at coordinator
	 */
	result->indexes = CollectionIdsGetIndexCount(collectionIdArray);
}


/*