Function BsonRepathAndBuildCore

pg_documentdb_core/src/io/bson_io.c:405–574

* bson_repath_and_build take an array of paths and an array of bsons and constructs a bson where * the root paths of each bson become the corresponding text in the array of paths and are merged into one object * ["l1", "l2"] [{"":x}, {"":y}] becomes {"l1":x, "l2":y} * * If the value is an empty document, it is treated as an EOD value and is not written. For example: * ["l1", "l2"] [{"":x}, {}

 * ["l1", "l2"] [{"":x}, {}] becomes {"l1":x}
 */
static Datum
BsonRepathAndBuildCore(PG_FUNCTION_ARGS, bool isBuildDocument)
{
	Datum *args;
	bool *nulls;
	Oid *types;

	/* fetch argument values to build the object */
	int nargs = extract_variadic_args(fcinfo, 0, false, &args, &types, &nulls);
	if (nargs < 0)
	{
		PG_RETURN_NULL();
	}
	if (nargs % 2 != 0)
	{
		ereport(ERROR,
				(errcode(ERRCODE_DOCUMENTDB_BADVALUE),
				 errmsg("argument list must have an even number of elements"),
				 errdetail(
					 "The arguments of bson_repath_and_build() must consist of alternating keys and values.")));
	}

	pgbson_writer writer;
	PgbsonWriterInit(&writer);
	for (int i = 0; i < nargs; i += 2)
	{
		if (nulls[i])
		{
			ereport(ERROR,
					(errcode(ERRCODE_DOCUMENTDB_BADVALUE),
					 errmsg("The specified argument %d must not be null", i + 1),
					 errdetail("Object keys should be text.")));
		}

		char *path;
		int len;
		if (types[i] != TEXTOID)
		{
			if (isBuildDocument)
			{
				Oid outputFunction;
				bool isVarlena;
				getTypeOutputInfo(types[i], &outputFunction, &isVarlena);

				FmgrInfo info;
				LOCAL_FCINFO(innerFcinfo, 1);
				fmgr_info(outputFunction, &info);

				InitFunctionCallInfoData(*innerFcinfo, &info, 1, fcinfo->fncollation,
										 fcinfo->context, fcinfo->resultinfo);
				innerFcinfo->args->value = args[i];
				innerFcinfo->args->isnull = nulls[i];

				Datum result = FunctionCallInvoke(innerFcinfo);
				if (innerFcinfo->isnull)
				{
					ereport(ERROR,
							(errcode(ERRCODE_DOCUMENTDB_BADVALUE),