engineeringsoftware/ogo

Object Graph Programming

OGO

Object Graph Programming (OGO) enables reading and modifying an object graph (i.e., the entire state of the JVM heap) via declarative Cypher queries.

Examples

1. Searching an ArrayList for a given element.

   ArrayList<Long> lst = new ArrayList<Long>();
   lst.add(10L);
   lst.add(20L);
   lst.add(30L);
   query("MATCH ({$1})-[:elementData]->()-[]->({value : 20}) RETURN TRUE");

   In this example, we use imperative code to instantiate and add elements to an ArrayList and then use Cypher query through OGO to query lst to check if it contains element 20.

2. Implementing the containsKey method of java.util.HashMap class.

   public boolean containsKeyOgoImpl(HashMap map, object key){
      queryBool("MATCH ({$1})-[:table]->()-[]->()-[:key]->(n)"
               +"MATCH (m {$2})"
               +"WHERE n.`equals`(m)"
               +"RETURN COUNT(n) <> 0", map, key);
   }

   In this example, the first MATCH clause matches a pattern that collects all the objects corresponding to the key field of HashMap's inner class Node into the variable n. The second MATCH clause collects the given key object into the variable m. The WHERE clause filters the elements of n based on the output of the java.lang.Object class's equals method evaluating to true for pairwise inputs from n and m. This predicate is expected to filter number of elements of n to 1 if the given key is present in the map and to 0 if absent. Finally, we use the RETURN clause to return the value of the expression that compares equality of number of elements of n to 0. The query is hence expected to return true iff the number of elements in n is non-zero which is true only if the given key is contained in map.

Coming Soon!

1. OGO Code base
2. ICSE 2024 OGO evaluation datasets

Citation

If you use OGO in your research, please cite our ICSE'24 paper. The paper can be found here.

@inproceedings{ThimmaiahETAL24OGO,
  author    = {Thimmaiah, Aditya and Lampropoulos, Leonidas and Rossbach, Christopher and Gligoric, Milos},
  title     = {Object Graph Programming},
  year      = {2024},
  doi       = {10.1145/3597503.3623319},
  booktitle = {Proceedings of the IEEE/ACM 46th International Conference on Software Engineering},
  pages     = {1--13},
}