Function CollStatsCoordinator

pg_documentdb/src/commands/coll_stats.c:319–359

* The core logic for coll stats on the entry point function * i.e. the Coordinator of the coll stats. * This function simply calls the "worker" collstats against * all available nodes, and then aggregates/merges the results into * the necessary wire protocol format. */

 * the necessary wire protocol format.
 */
static pgbson *
CollStatsCoordinator(Datum databaseName, Datum collectionName, int scale)
{
	if (scale < 1)
	{
		ereport(ERROR, (errcode(ERRCODE_DOCUMENTDB_LOCATION51024), errmsg(
							"The BSON field 'scale' must have a value of at least 1, but the provided value is '%d'.",
							scale)));
	}

	StringInfo namespaceString = makeStringInfo();

	appendStringInfo(namespaceString, "%.*s.%.*s",
					 (int) VARSIZE_ANY_EXHDR(databaseName),
					 (char *) VARDATA_ANY(databaseName),
					 (int) VARSIZE_ANY_EXHDR(collectionName),
					 (char *) VARDATA_ANY(collectionName));

	CollStatsResult result = { 0 };
	result.ns = namespaceString->data;
	result.scaleFactor = scale;
	result.ok = 1;

	pgbson *response;
	MongoCollection *collection =
		GetMongoCollectionByNameDatum(databaseName,
									  collectionName,
									  AccessShareLock);
	if (collection == NULL)
	{
		response = BuildEmptyResponseMessage(&result);
	}
	else
	{
		BuildResultData(databaseName, collectionName, &result, collection, scale,
						CollStatsAggMode_CountAndStorage);
		response = BuildResponseMessage(&result);
	}

	return response;
}


/*