public void Assert(JsonLdTriple triple)
{
lock (this)
{
AssertNoLock(triple);
}
}
/// <summary>
/// Return the entity from the graph
/// </summary>
/// <param name="entity"></param>
/// <returns></returns>
private JToken GetEntityFromGraph(Uri entity)
{
JToken token = null;
JsonLdTripleCollection triples = null;
DataTraceSources.Verbose("[EntityCache] GetEntity {0}", entity.AbsoluteUri);
// make sure everything added at this point has gone into the master graph
WaitForTasks();
lock (this)
{
// find the best JToken for this subject that we have
triples = _masterGraph.SelectSubject(entity);
// update the last access time for these pages
foreach (var page in triples.Select(t => t.Page).Distinct())
{
page.UpdateLastUsed();
}
}
// find the best jtoken for the subject
JsonLdTriple triple = triples.Where(n => n.JsonNode != null).OrderByDescending(t => t.HasIdMatchingUrl ? 1 : 0).FirstOrDefault();
if (triple != null)
{
token = triple.JsonNode;
}
return(token);
}
private void AssertNoLock(JsonLdTriple triple)
{
string subject = triple.Subject.GetValue();
string predicate = triple.Predicate.GetValue();
string obj = triple.Object.GetValue();
Dictionary <string, List <JsonLdTriple> > inner = null;
if (_subjectIndex.TryGetValue(subject, out inner))
{
List <JsonLdTriple> objs = null;
if (inner.TryGetValue(predicate, out objs))
{
JsonLdTriple existingTriple = objs.Where(t => t.Object.IsValue(obj)).FirstOrDefault();
if (existingTriple != null)
{
// move the existing one to the alts if we have a better one now
if (IsBetter(triple, existingTriple))
{
objs.Remove(existingTriple);
objs.Add(triple);
}
}
else
{
// normal add
objs.Add(triple);
}
}
else
{
inner.Add(predicate, new List <JsonLdTriple>()
{
triple
});
}
}
else
{
// completely new
inner = new Dictionary <string, List <JsonLdTriple> >();
_subjectIndex.Add(subject, inner);
inner.Add(predicate, new List <JsonLdTriple>()
{
triple
});
}
}
/// <summary>
/// True if A is better
/// </summary>
public static bool IsBetter(JsonLdTriple a, JsonLdTriple b)
{
if (a == b)
{
return(false);
}
if (a.JsonNode != null && b.JsonNode == null)
{
return(true);
}
if (a.HasIdMatchingUrl && !b.HasIdMatchingUrl)
{
return(true);
}
if (a.JsonNode != null && b.JsonNode != null)
{
return(a.JsonNode.Descendants().Count() > a.JsonNode.Descendants().Count());
}
return(false);
}
/// <summary>
/// True if the Page uri and JToken reference are also equal.
/// </summary>
public bool IsExactSame(JsonLdTriple other)
{
return(JsonNode.Equals(other.JsonNode) && Page.Equals(other.Page) && base.Equals(other));
}
/// <summary>
/// Load a compacted json object into a JsonLdGraph
/// </summary>
public static JsonLdGraph Load(JObject compacted, JsonLdPage page)
{
Dictionary <int, JObject> nodes = new Dictionary <int, JObject>();
int marker = 0;
// Mark each node with a serial number
Action <JObject> addSerial = (node) =>
{
if (!Utility.IsInContext(node))
{
int serial = marker++;
node[Constants.CacheNode] = serial;
nodes.Add(serial, node);
}
};
// add serials
Utility.JsonEntityVisitor(compacted, addSerial);
// create graph without JTokens
var basicGraph = Utility.GetGraphFromCompacted(compacted);
// split out the cache triples
List <Triple> normalTriples = new List <Triple>();
Dictionary <string, JObject> cacheTriples = new Dictionary <string, JObject>();
foreach (var triple in basicGraph.Triples)
{
// cache node predicates represent the mapping between the subject and token serial
if (triple.Predicate.IsValue(Constants.CacheNode))
{
string subject = triple.Subject.GetValue();
int serial;
Int32.TryParse(triple.Object.GetValue(), out serial);
// Remove the serial we added
JObject jObject = nodes[serial];
jObject.Remove(Constants.CacheNode);
// there should not be any duplicates here
cacheTriples.Add(subject, jObject);
}
else
{
// store this to go into the graph
normalTriples.Add(triple);
}
}
// create the real graph
JsonLdGraph jsonGraph = new JsonLdGraph();
// merge the graph data with the compacted json tokens
foreach (var triple in normalTriples)
{
string subject = triple.Subject.GetValue();
JObject jObject = null;
cacheTriples.TryGetValue(subject, out jObject);
var jsonTriple = new JsonLdTriple(page, jObject, triple.Subject, triple.Predicate, triple.Object);
jsonGraph.Assert(jsonTriple);
}
return(jsonGraph);
}
