/// <summary>
/// Gets the next available Database Triple ID if the Triple is not in the Database of the existing Database Triple ID
/// </summary>
/// <param name="t">Triple to get an ID for</param>
/// <param name="createRequired">Whether the Manager needs to create a Triple Record in the Database</param>
/// <returns></returns>
protected virtual int GetNextTripleID(Triple t, out bool createRequired)
{
int id = -1;
createRequired = false;
try
{
Monitor.Enter(this._tripleIDs);
if (this._nextTripleID == -1)
{
this.LoadTripleIDMap();
}
//Use the Triple Collection to record Triples we've requested IDs for
//This allows us to take advantage of the Triple Collections ability to detect
//when Triple Hash Codes collide and then we can use this in the next step to
//do a Database lookup if necessary
if (!this._tripleCollection.Contains(t))
{
this._tripleCollection.Add(t);
}
if (this._tripleIDs.ContainsKey(t.GetHashCode()))
{
id = this._tripleIDs[t.GetHashCode()];
if (id == -1 || t.Collides)
{
//There are multiple Triples with this Hash Code
//Lookup from Database
String s, p, o;
s = this.SaveNode(t.Subject);
p = this.SaveNode(t.Predicate);
o = this.SaveNode(t.Object);
String getTripleID = "SELECT tripleID FROM TRIPLES WHERE tripleSubject=" + s + " AND triplePredicate=" + p + " AND tripleObject=" + o;
Object tripleID = this.ExecuteScalar(getTripleID);
if (tripleID != null)
{
return Int32.Parse(tripleID.ToString());
}
else
{
id = ++this._nextTripleID;
createRequired = true;
}
}
}
else
{
id = ++this._nextTripleID;
this._tripleIDs.Add(t.GetHashCode(), id);
createRequired = true;
}
}
finally
{
Monitor.Exit(this._tripleIDs);
}
if (id != -1)
{
return id;
}
else
{
throw new RdfStorageException("Error obtaining a Triple ID");
}
}
public static void Main(string[] args)
{
StreamWriter output = new StreamWriter("HashCodeTests.txt");
Console.SetOut(output);
try
{
Console.WriteLine("## Hash Code Tests");
Console.WriteLine("Tests that Literal and URI Nodes produce different Hashes");
Console.WriteLine();
//Create the Nodes
Graph g = new Graph();
IUriNode u = g.CreateUriNode(new Uri("http://www.google.com"));
ILiteralNode l = g.CreateLiteralNode("http://www.google.com/");
Console.WriteLine("Created a URI and Literal Node both referring to 'http://www.google.com'");
Console.WriteLine("String form of URI Node is:");
Console.WriteLine(u.ToString());
Console.WriteLine("String form of Literal Node is:");
Console.WriteLine(l.ToString());
Console.WriteLine("Hash Code of URI Node is " + u.GetHashCode());
Console.WriteLine("Hash Code of Literal Node is " + l.GetHashCode());
Console.WriteLine("Hash Codes are Equal? " + u.GetHashCode().Equals(l.GetHashCode()));
Console.WriteLine("Nodes are equal? " + u.Equals(l));
//Create Triples
IBlankNode b = g.CreateBlankNode();
IUriNode type = g.CreateUriNode("rdf:type");
Triple t1, t2;
t1 = new Triple(b, type, u);
t2 = new Triple(b, type, l);
Console.WriteLine();
Console.WriteLine("Created two Triples stating a Blank Node has rdf:type of the Nodes created earlier");
Console.WriteLine("String form of Triple 1 (using URI Node) is:");
Console.WriteLine(t1.ToString());
Console.WriteLine("String form of Triple 2 (using Literal Node) is:");
Console.WriteLine(t2.ToString());
Console.WriteLine("Hash Code of Triple 1 is " + t1.GetHashCode());
Console.WriteLine("Hash Code of Triple 2 is " + t2.GetHashCode());
Console.WriteLine("Hash Codes are Equal? " + t1.GetHashCode().Equals(t2.GetHashCode()));
Console.WriteLine("Triples are Equal? " + t1.Equals(t2));
//Now going to look at the Hash Code collisions from the dotNetRDF Store
Console.WriteLine();
Console.WriteLine("Examing the Hash Code Collisions from one of our SQL Store test data sets");
// MicrosoftSqlStoreManager manager = new MicrosoftSqlStoreManager("localhost", "bbcone", "example", "password");
// DataTable collisions = manager.ExecuteQuery(@"SELECT * FROM TRIPLES WHERE tripleHash IN
// (
// SELECT tripleHash FROM TRIPLES GROUP BY tripleHash HAVING COUNT(tripleID)>1
// ) ORDER BY tripleHash");
// foreach (DataRow r in collisions.Rows)
// {
// String s, p, o;
// int hash;
// s = r["tripleSubject"].ToString();
// p = r["triplePredicate"].ToString();
// o = r["tripleObject"].ToString();
// hash = Int32.Parse(r["tripleHash"].ToString());
// INode subj = manager.LoadNode(g, s);
// INode pred = manager.LoadNode(g, p);
// INode obj = manager.LoadNode(g, o);
// Triple t = new Triple(subj, pred, obj);
// Console.WriteLine("Subject (ID " + s + "): " + subj.ToString() + " (Hash " + subj.GetHashCode() + ")");
// Console.WriteLine("Predicate (ID " + p + "): " + pred.ToString() + " (Hash " + pred.GetHashCode() + ")");
// Console.WriteLine("Object (ID " + o + "): " + obj.ToString() + " (Hash " + obj.GetHashCode() + ")");
// Console.WriteLine(t.ToString());
// Console.WriteLine("Triple Hash " + t.GetHashCode());
// Console.WriteLine("Triple Hash Code Construct " + subj.GetHashCode().ToString() + pred.GetHashCode().ToString() + obj.GetHashCode().ToString());
// Console.WriteLine("Triple Hash in Store " + hash);
// Console.WriteLine();
// }
// manager.Dispose();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
Console.WriteLine(ex.StackTrace);
}
finally
{
output.Close();
}
}
protected override string GetIndexNameForTriple(Triple t)
{
return @"index\spo\" + this.GetHash(t.GetHashCode().ToString());
}
public void NodesHashCodes()
{
Console.WriteLine("Tests that Literal and URI Nodes produce different Hashes");
Console.WriteLine();
//Create the Nodes
Graph g = new Graph();
IUriNode u = g.CreateUriNode(new Uri("http://www.google.com"));
ILiteralNode l = g.CreateLiteralNode("http://www.google.com/");
Console.WriteLine("Created a URI and Literal Node both referring to 'http://www.google.com'");
Console.WriteLine("String form of URI Node is:");
Console.WriteLine(u.ToString());
Console.WriteLine("String form of Literal Node is:");
Console.WriteLine(l.ToString());
Console.WriteLine("Hash Code of URI Node is " + u.GetHashCode());
Console.WriteLine("Hash Code of Literal Node is " + l.GetHashCode());
Console.WriteLine("Hash Codes are Equal? " + u.GetHashCode().Equals(l.GetHashCode()));
Console.WriteLine("Nodes are equal? " + u.Equals(l));
Assert.AreNotEqual(u.GetHashCode(), l.GetHashCode());
Assert.AreNotEqual(u, l);
//Create some plain and typed literals which may have colliding Hash Codes
ILiteralNode plain = g.CreateLiteralNode("test^^http://example.org/type");
ILiteralNode typed = g.CreateLiteralNode("test", new Uri("http://example.org/type"));
Console.WriteLine();
Console.WriteLine("Created a Plain and Typed Literal where the String representations are identical");
Console.WriteLine("Plain Literal String form is:");
Console.WriteLine(plain.ToString());
Console.WriteLine("Typed Literal String from is:");
Console.WriteLine(typed.ToString());
Console.WriteLine("Hash Code of Plain Literal is " + plain.GetHashCode());
Console.WriteLine("Hash Code of Typed Literal is " + typed.GetHashCode());
Console.WriteLine("Hash Codes are Equal? " + plain.GetHashCode().Equals(typed.GetHashCode()));
Console.WriteLine("Nodes are equal? " + plain.Equals(typed));
Assert.AreNotEqual(plain.GetHashCode(), typed.GetHashCode());
Assert.AreNotEqual(plain, typed);
//Create Triples
IBlankNode b = g.CreateBlankNode();
IUriNode type = g.CreateUriNode("rdf:type");
Triple t1, t2;
t1 = new Triple(b, type, u);
t2 = new Triple(b, type, l);
Console.WriteLine();
Console.WriteLine("Created two Triples stating a Blank Node has rdf:type of the URI Nodes created earlier");
Console.WriteLine("String form of Triple 1 (using URI Node) is:");
Console.WriteLine(t1.ToString());
Console.WriteLine("String form of Triple 2 (using Literal Node) is:");
Console.WriteLine(t2.ToString());
Console.WriteLine("Hash Code of Triple 1 is " + t1.GetHashCode());
Console.WriteLine("Hash Code of Triple 2 is " + t2.GetHashCode());
Console.WriteLine("Hash Codes are Equal? " + t1.GetHashCode().Equals(t2.GetHashCode()));
Console.WriteLine("Triples are Equal? " + t1.Equals(t2));
Assert.AreNotEqual(t1.GetHashCode(), t2.GetHashCode());
Assert.AreNotEqual(t1, t2);
//Create Triples from the earlier Literal Nodes
t1 = new Triple(b, type, plain);
t2 = new Triple(b, type, typed);
Console.WriteLine();
Console.WriteLine("Created two Triples stating a Blank Node has rdf:type of the Literal Nodes created earlier");
Console.WriteLine("String form of Triple 1 (using Plain Literal) is:");
Console.WriteLine(t1.ToString());
Console.WriteLine("String form of Triple 2 (using Typed Literal) is:");
Console.WriteLine(t2.ToString());
Console.WriteLine("Hash Code of Triple 1 is " + t1.GetHashCode());
Console.WriteLine("Hash Code of Triple 2 is " + t2.GetHashCode());
Console.WriteLine("Hash Codes are Equal? " + t1.GetHashCode().Equals(t2.GetHashCode()));
Console.WriteLine("Triples are Equal? " + t1.Equals(t2));
Assert.AreNotEqual(t1.GetHashCode(), t2.GetHashCode());
Assert.AreNotEqual(t1, t2);
}
/// <summary>
/// Removes a Triple from a Graphs Database record
/// </summary>
/// <param name="t">Triple to remove</param>
/// <param name="graphID">Database Graph ID</param>
public override void RemoveTriple(Triple t, string graphID)
{
//If the Triple being removed is in the Buffer to be added still remove it
lock (this._writerBuffer)
{
this._writerBuffer.Remove(new BatchTriple(t, graphID));
}
//Does the Triple have a known Database ID
if (this._tripleIDs.ContainsKey(t.GetHashCode()))
{
//Can use the existing ID
int id = this._tripleIDs[t.GetHashCode()];
String removeTriple = "DELETE FROM GRAPH_TRIPLES WHERE graphID=" + graphID + " AND tripleID=" + id;
try
{
this.Open(false);
this.ExecuteNonQuery(removeTriple);
this.Close(false);
}
catch (SqlException sqlEx)
{
this.Close(true, true);
throw new RdfStorageException("Unable to unlink a Triple record to a Graph in the Database", sqlEx);
}
}
else
{
//Get the IDs for the Nodes
String s, p, o;
s = this.SaveNode(t.Subject);
p = this.SaveNode(t.Predicate);
o = this.SaveNode(t.Object);
//Does the Triple exist in the Database
String getTriple = "SELECT tripleID FROM TRIPLES WHERE tripleHash=" + t.GetHashCode();
Object id = this.ExecuteScalar(getTriple);
if (id == null)
{
//Nothing to do since the Triple isn't in the Database and thus can't be linked to the Graph for unlinking to be needed
}
else
{
//Remove the link to the Triple
String removeTriple = "DELETE FROM GRAPH_TRIPLES WHERE graphID=" + graphID + " AND tripleID=" + id.ToString();
try
{
this.Open(false);
this.ExecuteNonQuery(removeTriple);
this.Close(false);
}
catch (SqlException sqlEx)
{
this.Close(true, true);
throw new RdfStorageException("Unable to unlink a Triple record to a Graph in the Database", sqlEx);
}
}
}
}
/// <summary>
/// Loads Triples for the Graph with the given ID into the given Graph object
/// </summary>
/// <param name="g">Graph to load into</param>
/// <param name="graphID">Database Graph ID</param>
public override void LoadTriples(IGraph g, string graphID)
{
//Build the SQL for getting the Triples
String getTriples = "SELECT * FROM GRAPH_TRIPLES G INNER JOIN TRIPLES T ON G.tripleID=T.tripleID WHERE G.graphID=" + graphID;
//Get the Data
this.Open(true);
DataTable data = this.ExecuteQuery(getTriples);
//Load the Triples
String s, p, o;
INode subj, pred, obj;
foreach (DataRow r in data.Rows)
{
//Get the IDs
s = r["tripleSubject"].ToString();
p = r["triplePredicate"].ToString();
o = r["tripleObject"].ToString();
//Get the Nodes from these IDs
subj = this.LoadNode(g, s);
pred = this.LoadNode(g, p);
obj = this.LoadNode(g, o);
Triple t = new Triple(subj, pred, obj);
g.Assert(t);
//Store ID for later
try
{
Monitor.Enter(this._tripleIDs);
if (!this._tripleIDs.ContainsKey(t.GetHashCode()))
{
int id = Int32.Parse(r["tripleID"].ToString());
this._tripleIDs.Add(t.GetHashCode(), id);
}
}
finally
{
Monitor.Exit(this._tripleIDs);
}
}
//Close the Database Connection
this.Close(true);
}
public void NongenericComparable()
{
Triple <int, OddEvenComparable, string> triple1, triple2;
triple1 = new Triple <int, OddEvenComparable, string>(4, new OddEvenComparable(7), "B");
triple2 = new Triple <int, OddEvenComparable, string>(7, new OddEvenComparable(3), "A");
Assert.IsTrue(triple1.CompareTo(triple2) < 0);
Assert.IsFalse(triple1.Equals(triple2));
Assert.IsFalse(triple1.GetHashCode() == triple2.GetHashCode());
triple1 = new Triple <int, OddEvenComparable, string>(4, new OddEvenComparable(7), "B");
triple2 = new Triple <int, OddEvenComparable, string>(4, new OddEvenComparable(2), "A");
Assert.IsTrue(triple1.CompareTo(triple2) < 0);
Assert.IsFalse(triple1.Equals(triple2));
Assert.IsFalse(triple1.GetHashCode() == triple2.GetHashCode());
triple1 = new Triple <int, OddEvenComparable, string>(4, new OddEvenComparable(7), "A");
triple2 = new Triple <int, OddEvenComparable, string>(4, new OddEvenComparable(7), "A");
Assert.IsTrue(triple1.CompareTo(triple2) == 0);
Assert.IsTrue(triple1.Equals(triple2));
Assert.IsTrue(triple1.GetHashCode() == triple2.GetHashCode());
triple1 = new Triple <int, OddEvenComparable, string>(7, new OddEvenComparable(7), "B");
triple2 = new Triple <int, OddEvenComparable, string>(4, new OddEvenComparable(2), "C");
Assert.IsTrue(triple1.CompareTo(triple2) > 0);
Assert.IsFalse(triple1.Equals(triple2));
Assert.IsFalse(triple1.GetHashCode() == triple2.GetHashCode());
triple1 = new Triple <int, OddEvenComparable, string>(0, new OddEvenComparable(8), "A");
triple2 = new Triple <int, OddEvenComparable, string>(0, new OddEvenComparable(2), "A");
Assert.IsTrue(triple1.CompareTo(triple2) > 0);
Assert.IsFalse(triple1.Equals(triple2));
Assert.IsFalse(triple1.GetHashCode() == triple2.GetHashCode());
Triple <OddEvenComparable, int, string> triple3, triple4;
triple3 = new Triple <OddEvenComparable, int, string>(new OddEvenComparable(7), 4, "A");
triple4 = new Triple <OddEvenComparable, int, string>(new OddEvenComparable(3), 7, "B");
Assert.IsTrue(triple3.CompareTo(triple4) > 0);
Assert.IsFalse(triple3.Equals(triple4));
Assert.IsFalse(triple3.GetHashCode() == triple4.GetHashCode());
triple3 = new Triple <OddEvenComparable, int, string>(new OddEvenComparable(7), 4, "B");
triple4 = new Triple <OddEvenComparable, int, string>(new OddEvenComparable(2), 4, "A");
Assert.IsTrue(triple3.CompareTo(triple4) < 0);
Assert.IsFalse(triple3.Equals(triple4));
Assert.IsFalse(triple3.GetHashCode() == triple4.GetHashCode());
triple3 = new Triple <OddEvenComparable, int, string>(new OddEvenComparable(7), 4, "C");
triple4 = new Triple <OddEvenComparable, int, string>(new OddEvenComparable(7), 4, "C");
Assert.IsTrue(triple3.CompareTo(triple4) == 0);
Assert.IsTrue(triple3.Equals(triple4));
Assert.IsTrue(triple3.GetHashCode() == triple4.GetHashCode());
triple3 = new Triple <OddEvenComparable, int, string>(new OddEvenComparable(2), 7, "A");
triple4 = new Triple <OddEvenComparable, int, string>(new OddEvenComparable(7), 4, "B");
Assert.IsTrue(triple3.CompareTo(triple4) > 0);
Assert.IsFalse(triple3.Equals(triple4));
Assert.IsFalse(triple3.GetHashCode() == triple4.GetHashCode());
triple3 = new Triple <OddEvenComparable, int, string>(new OddEvenComparable(8), 0, "A");
triple4 = new Triple <OddEvenComparable, int, string>(new OddEvenComparable(2), 0, "A");
Assert.IsTrue(triple3.CompareTo(triple4) > 0);
Assert.IsFalse(triple3.Equals(triple4));
Assert.IsFalse(triple3.GetHashCode() == triple4.GetHashCode());
triple3 = new Triple <OddEvenComparable, int, string>(new OddEvenComparable(2), 4, "A");
triple4 = new Triple <OddEvenComparable, int, string>(new OddEvenComparable(2), 3, "B");
Assert.IsTrue(triple3.CompareTo(triple4) > 0);
Assert.IsFalse(triple3.Equals(triple4));
Assert.IsFalse(triple3.GetHashCode() == triple4.GetHashCode());
Triple <int, string, OddEvenComparable> triple5, triple6;
triple5 = new Triple <int, string, OddEvenComparable>(4, "B", new OddEvenComparable(7));
triple6 = new Triple <int, string, OddEvenComparable>(7, "A", new OddEvenComparable(3));
Assert.IsTrue(triple5.CompareTo(triple6) < 0);
Assert.IsFalse(triple5.Equals(triple6));
Assert.IsFalse(triple5.GetHashCode() == triple6.GetHashCode());
triple5 = new Triple <int, string, OddEvenComparable>(4, "A", new OddEvenComparable(7));
triple6 = new Triple <int, string, OddEvenComparable>(4, "A", new OddEvenComparable(2));
Assert.IsTrue(triple5.CompareTo(triple6) < 0);
Assert.IsFalse(triple5.Equals(triple6));
Assert.IsFalse(triple5.GetHashCode() == triple6.GetHashCode());
triple5 = new Triple <int, string, OddEvenComparable>(4, "A", new OddEvenComparable(7));
triple6 = new Triple <int, string, OddEvenComparable>(4, "A", new OddEvenComparable(7));
Assert.IsTrue(triple5.CompareTo(triple6) == 0);
Assert.IsTrue(triple5.Equals(triple6));
Assert.IsTrue(triple5.GetHashCode() == triple6.GetHashCode());
triple5 = new Triple <int, string, OddEvenComparable>(7, "B", new OddEvenComparable(7));
triple6 = new Triple <int, string, OddEvenComparable>(4, "C", new OddEvenComparable(2));
Assert.IsTrue(triple5.CompareTo(triple6) > 0);
Assert.IsFalse(triple5.Equals(triple6));
Assert.IsFalse(triple5.GetHashCode() == triple6.GetHashCode());
triple5 = new Triple <int, string, OddEvenComparable>(0, "A", new OddEvenComparable(8));
triple6 = new Triple <int, string, OddEvenComparable>(0, "A", new OddEvenComparable(2));
Assert.IsTrue(triple5.CompareTo(triple6) > 0);
Assert.IsFalse(triple5.Equals(triple6));
Assert.IsFalse(triple5.GetHashCode() == triple6.GetHashCode());
}
/// <summary>
/// Returns a hash code for this instance.
/// </summary>
/// <returns>
/// A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table.
/// </returns>
public override int GetHashCode()
{
return(m_left.GetHashCode() ^ m_right.GetHashCode() ^ m_sharedItem.GetHashCode() ^ m_posLeft.GetHashCode() ^ m_posRight.GetHashCode());
}
/// <summary>
/// Hash Code for Batch Triples
/// </summary>
/// <returns></returns>
public override int GetHashCode()
{
return((_graphID + _t.GetHashCode()).GetHashCode());
}
