Function BuildBatchUpdateSpec

pg_documentdb/src/commands/update.c:777–898

* BuildBatchUpdateSpec validates the update command BSON and builds * a BatchUpdateSpec. */

 * a BatchUpdateSpec.
 */
static BatchUpdateSpec *
BuildBatchUpdateSpec(bson_iter_t *updateCommandIter, pgbsonsequence *updateDocs,
					 Datum *databaseNameDatum)
{
	const char *collectionName = NULL;
	bool isOrdered = true;
	bool bypassDocumentValidation = false;

	bson_value_t let = { 0 };
	bson_value_t updateValue = { 0 };
	while (bson_iter_next(updateCommandIter))
	{
		const char *field = bson_iter_key(updateCommandIter);

		if (strcmp(field, "update") == 0)
		{
			if (!BSON_ITER_HOLDS_UTF8(updateCommandIter))
			{
				ereport(ERROR, (errcode(ERRCODE_DOCUMENTDB_BADVALUE),
								errmsg("collection name has invalid type %s",
									   BsonIterTypeName(updateCommandIter))));
			}

			collectionName = bson_iter_utf8(updateCommandIter, NULL);
		}
		else if (strcmp(field, "updates") == 0)
		{
			EnsureTopLevelFieldType("update.updates", updateCommandIter, BSON_TYPE_ARRAY);

			/* if both docs and spec are provided, fail */
			if (updateDocs != NULL)
			{
				ereport(ERROR, (errcode(ERRCODE_DOCUMENTDB_FAILEDTOPARSE),
								errmsg("Unexpected further updates required")));
			}

			updateValue = *bson_iter_value(updateCommandIter);
		}
		else if (strcmp(field, "ordered") == 0)
		{
			EnsureTopLevelFieldType("update.ordered", updateCommandIter, BSON_TYPE_BOOL);

			isOrdered = bson_iter_bool(updateCommandIter);
		}
		else if (strcmp(field, "bypassDocumentValidation") == 0)
		{
			/* TODO: unsupport by default */
			if (!EnableBypassDocumentValidation)
			{
				continue;
			}

			EnsureTopLevelFieldType("update.bypassDocumentValidation", updateCommandIter,
									BSON_TYPE_BOOL);

			bypassDocumentValidation = bson_iter_bool(updateCommandIter);
		}
		else if (strcmp(field, "maxTimeMS") == 0)