CODEWITHSUNDEEP
tinkerpoptinkerpop3gremlin-server
banjara
banjara

Reputation: 3890

Graph traversal name to graph name mapping

Is there any API using which I can get graphTraversalName to graphName mapping defined in the script?

I am using the below messy code but it's error-prone if both graphs are using the same underlying storage.

    Map<String, String>  graphTraversalToNameMap = new ConcurrentHashMap<String, String>();
    while(traversalSourceIterator.hasNext()){
      String traversalSource = traversalSourceIterator.next();
      String currentGraphString = ( (GraphTraversalSource) graphManager.getAsBindings().get(traversalSource)).getGraph().toString();
      graphNameTraversalMap.put(currentGraphString, traversalSource);
    }

    Iterator<String> graphNamesIterator =  graphManager.getGraphNames().iterator();
    while(graphNamesIterator.hasNext()){
      String graphName = graphNamesIterator.next();
      String currentGraphString = graphManager.getGraph(graphName).toString();
      String traversalSource = graphNameTraversalMap.get(currentGraphString);
      graphTraversalToNameMap.put(traversalSource, graphName);
    }

Does gremlinExecutor.getScriptEngineManager().getBindings().entrySet() provide order guarantee? I can iterate over this and populate my map

Upvotes: 0

Views: 54

Answers (2)

banjara
banjara

Reputation: 3890

Underlying storage details can be obtained from the configuration object and can be used for the mapping, sample code:

public class GraphTraversalMappingUtil {
  public static void populateGraphTraversalToNameMapping(GraphManager graphManager){

    if(graphTraversalToNameMap.size() != 0){
      return;
    }

    Iterator<String> traversalSourceIterator = graphManager.getTraversalSourceNames().iterator();

    Map<StorageBackendKey, String> storageKeyToTraversalMap = new HashMap<StorageBackendKey, String>();
    while(traversalSourceIterator.hasNext()){
      String traversalSource = traversalSourceIterator.next();
      StorageBackendKey key = new StorageBackendKey(
              graphManager.getTraversalSource(traversalSource).getGraph().configuration());
      storageKeyToTraversalMap.put(key, traversalSource);
    }

    Iterator<String> graphNamesIterator =  graphManager.getGraphNames().iterator();
    while(graphNamesIterator.hasNext()) {
      String graphName = graphNamesIterator.next();
      StorageBackendKey key = new StorageBackendKey(
              graphManager.getGraph(graphName).configuration());
      graphTraversalToNameMap.put(storageKeyToTraversalMap.get(key), graphName);
    }
  }
}

For full code, refer: https://pastebin.com/7m8hi53p

Upvotes: 0

stephen mallette
stephen mallette

Reputation: 46216

Is there any API using which I can get graphTraversalName to graphName mapping defined in the script?

No. They share the same namespace in Gremlin Server so the relationship gets lost programmatically. You would need to do something like what you are doing but I wouldn't rely on toString() of a Graph for equality. Perhaps use the Graph instance itself? Although that might not work either depending on your situation and what you want for equality as you could have two different Graph configurations pointed at the same data and want to resolve those as the same graph. I'm also not sure that any approach will work generally for all graph systems. Anyway, I think I'd experiment with using Map<Graph, String> graphTraversalToNameMap for your case and see how that goes.

Does gremlinExecutor.getScriptEngineManager().getBindings().entrySet() provide order guarantee?

No as it is backed by a ConcurrentHashMap. You would have to provide your own order.

Upvotes: 1

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