Ejemplo n.º 1
0
		private bool Query(int groupindex, BindingSet bindings, SelectableSource targetModel) {
			QueryStatement[] group = statements[groupindex];
			
			QueryStatement qs = group[0];
			
			int numMultiplyBound = IsMultiplyBound(qs.Subject, bindings)
				+ IsMultiplyBound(qs.Predicate, bindings)
				+ IsMultiplyBound(qs.Object, bindings);
			
			if (numMultiplyBound >= 1) {
				// If there is one or more multiply-bound variable,
				// then we need to iterate through the permutations
				// of the variables in the statement.
				
				Debug(qs.ToString() + " Something Multiply Bound");
				
				MemoryStore matches = new MemoryStore();
				targetModel.Select(
					new SelectFilter(
						(Entity[])qs.Subject.GetValues(bindings.Union, true),
						(Entity[])qs.Predicate.GetValues(bindings.Union, true),
						qs.Object.GetValues(bindings.Union, false),
						QueryMeta == null ? null : new Entity[] { QueryMeta }
						),
					new ClearMetaDupCheck(matches));
				
				Debug("\t" + matches.StatementCount + " Matches");
				
				if (matches.StatementCount == 0) {
					// This statement doesn't match any of
					// the existing bindings.  If this was
					// optional, preserve the bindings.
					return qs.Optional;
				}
				
				// We need to preserve the pairings of
				// the multiply bound variable with the matching
				// statements.
				
				ArrayList newbindings = new ArrayList();
				
				if (!qs.Optional) bindings.Union.Clear(qs);
				
				foreach (QueryResult binding in bindings.Results) {
					// Break apart the permutations in this binding.
					BindingEnumerator enumer2 = new BindingEnumerator(qs, binding);
					Entity s, p;
					Resource o;
					while (enumer2.MoveNext(out s, out p, out o)) {
						// Get the matching statements from the union query
						Statement bs = new Statement(s, p, o);
						MemoryStore innermatches = matches.Select(bs).Load();
						
						// If no matches, the binding didn't match the filter.
						if (innermatches.StatementCount == 0) {
							if (qs.Optional) {
								// Preserve the binding.
								QueryResult bc = binding.Clone();
								bc.Set(qs, bs);
								newbindings.Add(bc);
								continue;
							} else {
								// Toss out the binding.
								continue;
							}
						}
						
						for (int si = 0; si < innermatches.StatementCount; si++) {
							Statement m = innermatches[si];
							if (!MatchesFilters(m, qs, targetModel)) {
								if (qs.Optional) {
									QueryResult bc = binding.Clone();
									bc.Set(qs, bs);
									newbindings.Add(bc);
								}
								continue;
							}
							bindings.Union.Add(qs, m);
							
							QueryResult r = binding.Clone();
							r.Set(qs, m);
							r.StatementMatched[groupindex] = true;
							newbindings.Add(r);
						}
					}
				}
				
				bindings.Results = newbindings;
				
			} else {
				// There are no multiply bound variables, but if
				// there are more than two unbound variables,
				// we need to be sure to preserve the pairings
				// of the matching values.
			
				int numUnbound = IsUnbound(qs.Subject, bindings)
					+ IsUnbound(qs.Predicate, bindings)
					+ IsUnbound(qs.Object, bindings);
					
				bool sunbound = IsUnbound(qs.Subject, bindings) == 1;
				bool punbound = IsUnbound(qs.Predicate, bindings) == 1;
				bool ounbound = IsUnbound(qs.Object, bindings) == 1;
				
				Statement s = GetStatement(qs, bindings);
				
				// If we couldn't get a statement out of this,
				// then if this was not an optional filter,
				// fail.  If this was optional, don't change
				// the bindings any. 
				if (s == StatementFailed) return qs.Optional;
				
				if (numUnbound == 0) {
					Debug(qs.ToString() + " All bound");
					
					// All variables are singly bound already.
					// We can just test if the statement exists.
					if (targetModel.Contains(s)) {
						// Mark each binding that it matched this statement.
						foreach (QueryResult r in bindings.Results)
							r.StatementMatched[groupindex] = true;
					} else {
						return qs.Optional;
					}
				
				} else if (numUnbound == 1) {
					Debug(qs.ToString() + " 1 Unbound");
				
					// There is just one unbound variable.  The others
					// are not multiply bound, so they must be uniquely
					// bound (but they may not be bound in all results).
					// Run a combined select to find all possible values
					// of the unbound variable at once, and set these to
					// be the values of the variable for matching results.
					
					ResSet values = new ResSet();
					MemoryStore ms = new MemoryStore();
					targetModel.Select(s, ms);
					for (int si = 0; si < ms.StatementCount; si++) {
						Statement match = ms[si];
						if (!MatchesFilters(match, qs, targetModel)) continue;
						if (sunbound) values.Add(match.Subject);
						if (punbound) values.Add(match.Predicate);
						if (ounbound) values.Add(match.Object);
					}
					
					Debug("\t" + values.Count + " matches");
					
					if (values.Count == 0)
						return qs.Optional;
						
					int varIndex = -1;
					if (sunbound) varIndex = qs.Subject.VarIndex;
					if (punbound) varIndex = qs.Predicate.VarIndex;
					if (ounbound) varIndex = qs.Object.VarIndex;
					
					if (bindings.Results.Count == 0)
						bindings.Results.Add(new QueryResult(this));
					
					bindings.Union.Bindings[varIndex] = new ResSet();
					foreach (Resource r in values)
						bindings.Union.Bindings[varIndex].Add(r);
						
					foreach (QueryResult r in bindings.Results) {
						// Check that the bound variables are bound in this result.
						// If it is bound, it will be bound to the correct resource,
						// but it might not be bound at all if an optional statement
						// failed to match -- in which case, don't modify the binding.
						if (qs.Subject.IsVariable && !sunbound && r.Bindings[qs.Subject.VarIndex] == null) continue;
						if (qs.Predicate.IsVariable && !punbound && r.Bindings[qs.Predicate.VarIndex] == null) continue;
						if (qs.Object.IsVariable && !ounbound && r.Bindings[qs.Object.VarIndex] == null) continue;
					
						r.Bindings[varIndex] = values;
						r.StatementMatched[groupindex] = true;
					}
					
				} else {
					// There are two or more unbound variables, the
					// third variable being uniquely bound, if bound.
					// Keep track of the pairing of unbound variables.
					
					if (numUnbound == 3)
						throw new QueryExecutionException("Query would select all statements in the store.");
					
					Debug(qs.ToString() + " 2 or 3 Unbound");
				
					if (bindings.Results.Count == 0)
						bindings.Results.Add(new QueryResult(this));
						
					ArrayList newbindings = new ArrayList();
					MemoryStore ms = new MemoryStore();
					targetModel.Select(s, ms);
					for (int si = 0; si < ms.StatementCount; si++) {
						Statement match = ms[si];
						if (!MatchesFilters(match, qs, targetModel)) continue;
						bindings.Union.Add(qs, match);
						foreach (QueryResult r in bindings.Results) {
							if (numUnbound == 2) {
								// Check that the bound variable is bound in this result.
								// If it is bound, it will be bound to the correct resource,
								// but it might not be bound at all if an optional statement
								// failed to match -- in which case, preserve the binding if
								// this was an optional statement.
								bool matches = true;
								if (qs.Subject.IsVariable && !sunbound && r.Bindings[qs.Subject.VarIndex] == null) matches = false;
								if (qs.Predicate.IsVariable && !punbound && r.Bindings[qs.Predicate.VarIndex] == null) matches = false;
								if (qs.Object.IsVariable && !ounbound && r.Bindings[qs.Object.VarIndex] == null) matches = false;
								if (!matches) {
									if (qs.Optional)
										newbindings.Add(r);
									continue;
								}
							}
						
							QueryResult r2 = r.Clone();
							r2.Add(qs, match);
							r2.StatementMatched[groupindex] = true;
							newbindings.Add(r2);
						}
					}
					if (newbindings.Count == 0)
						return qs.Optional; // don't clear out bindings if this was optional and it failed
					bindings.Results = newbindings;
				}
			}
			
			return true;
		}
Ejemplo n.º 2
0
        private bool Query(int groupindex, BindingSet bindings, SelectableSource targetModel)
        {
            QueryStatement[] group = statements[groupindex];

            QueryStatement qs = group[0];

            int numMultiplyBound = IsMultiplyBound(qs.Subject, bindings)
                                   + IsMultiplyBound(qs.Predicate, bindings)
                                   + IsMultiplyBound(qs.Object, bindings);

            if (numMultiplyBound >= 1)
            {
                // If there is one or more multiply-bound variable,
                // then we need to iterate through the permutations
                // of the variables in the statement.

                Debug(qs.ToString() + " Something Multiply Bound");

                MemoryStore matches = new MemoryStore();
                targetModel.Select(
                    new SelectFilter(
                        (Entity[])qs.Subject.GetValues(bindings.Union, true),
                        (Entity[])qs.Predicate.GetValues(bindings.Union, true),
                        qs.Object.GetValues(bindings.Union, false),
                        QueryMeta == null ? null : new Entity[] { QueryMeta }
                        ),
                    new ClearMetaDupCheck(matches));

                Debug("\t" + matches.StatementCount + " Matches");

                if (matches.StatementCount == 0)
                {
                    // This statement doesn't match any of
                    // the existing bindings.  If this was
                    // optional, preserve the bindings.
                    return(qs.Optional);
                }

                // We need to preserve the pairings of
                // the multiply bound variable with the matching
                // statements.

                ArrayList newbindings = new ArrayList();

                if (!qs.Optional)
                {
                    bindings.Union.Clear(qs);
                }

                foreach (QueryResult binding in bindings.Results)
                {
                    // Break apart the permutations in this binding.
                    BindingEnumerator enumer2 = new BindingEnumerator(qs, binding);
                    Entity            s, p;
                    Resource          o;
                    while (enumer2.MoveNext(out s, out p, out o))
                    {
                        // Get the matching statements from the union query
                        Statement   bs           = new Statement(s, p, o);
                        MemoryStore innermatches = matches.Select(bs).Load();

                        // If no matches, the binding didn't match the filter.
                        if (innermatches.StatementCount == 0)
                        {
                            if (qs.Optional)
                            {
                                // Preserve the binding.
                                QueryResult bc = binding.Clone();
                                bc.Set(qs, bs);
                                newbindings.Add(bc);
                                continue;
                            }
                            else
                            {
                                // Toss out the binding.
                                continue;
                            }
                        }

                        for (int si = 0; si < innermatches.StatementCount; si++)
                        {
                            Statement m = innermatches[si];
                            if (!MatchesFilters(m, qs, targetModel))
                            {
                                if (qs.Optional)
                                {
                                    QueryResult bc = binding.Clone();
                                    bc.Set(qs, bs);
                                    newbindings.Add(bc);
                                }
                                continue;
                            }
                            bindings.Union.Add(qs, m);

                            QueryResult r = binding.Clone();
                            r.Set(qs, m);
                            r.StatementMatched[groupindex] = true;
                            newbindings.Add(r);
                        }
                    }
                }

                bindings.Results = newbindings;
            }
            else
            {
                // There are no multiply bound variables, but if
                // there are more than two unbound variables,
                // we need to be sure to preserve the pairings
                // of the matching values.

                int numUnbound = IsUnbound(qs.Subject, bindings)
                                 + IsUnbound(qs.Predicate, bindings)
                                 + IsUnbound(qs.Object, bindings);

                bool sunbound = IsUnbound(qs.Subject, bindings) == 1;
                bool punbound = IsUnbound(qs.Predicate, bindings) == 1;
                bool ounbound = IsUnbound(qs.Object, bindings) == 1;

                Statement s = GetStatement(qs, bindings);

                // If we couldn't get a statement out of this,
                // then if this was not an optional filter,
                // fail.  If this was optional, don't change
                // the bindings any.
                if (s == StatementFailed)
                {
                    return(qs.Optional);
                }

                if (numUnbound == 0)
                {
                    Debug(qs.ToString() + " All bound");

                    // All variables are singly bound already.
                    // We can just test if the statement exists.
                    if (targetModel.Contains(s))
                    {
                        // Mark each binding that it matched this statement.
                        foreach (QueryResult r in bindings.Results)
                        {
                            r.StatementMatched[groupindex] = true;
                        }
                    }
                    else
                    {
                        return(qs.Optional);
                    }
                }
                else if (numUnbound == 1)
                {
                    Debug(qs.ToString() + " 1 Unbound");

                    // There is just one unbound variable.  The others
                    // are not multiply bound, so they must be uniquely
                    // bound (but they may not be bound in all results).
                    // Run a combined select to find all possible values
                    // of the unbound variable at once, and set these to
                    // be the values of the variable for matching results.

                    ResSet      values = new ResSet();
                    MemoryStore ms     = new MemoryStore();
                    targetModel.Select(s, ms);
                    for (int si = 0; si < ms.StatementCount; si++)
                    {
                        Statement match = ms[si];
                        if (!MatchesFilters(match, qs, targetModel))
                        {
                            continue;
                        }
                        if (sunbound)
                        {
                            values.Add(match.Subject);
                        }
                        if (punbound)
                        {
                            values.Add(match.Predicate);
                        }
                        if (ounbound)
                        {
                            values.Add(match.Object);
                        }
                    }

                    Debug("\t" + values.Count + " matches");

                    if (values.Count == 0)
                    {
                        return(qs.Optional);
                    }

                    int varIndex = -1;
                    if (sunbound)
                    {
                        varIndex = qs.Subject.VarIndex;
                    }
                    if (punbound)
                    {
                        varIndex = qs.Predicate.VarIndex;
                    }
                    if (ounbound)
                    {
                        varIndex = qs.Object.VarIndex;
                    }

                    if (bindings.Results.Count == 0)
                    {
                        bindings.Results.Add(new QueryResult(this));
                    }

                    bindings.Union.Bindings[varIndex] = new ResSet();
                    foreach (Resource r in values)
                    {
                        bindings.Union.Bindings[varIndex].Add(r);
                    }

                    foreach (QueryResult r in bindings.Results)
                    {
                        // Check that the bound variables are bound in this result.
                        // If it is bound, it will be bound to the correct resource,
                        // but it might not be bound at all if an optional statement
                        // failed to match -- in which case, don't modify the binding.
                        if (qs.Subject.IsVariable && !sunbound && r.Bindings[qs.Subject.VarIndex] == null)
                        {
                            continue;
                        }
                        if (qs.Predicate.IsVariable && !punbound && r.Bindings[qs.Predicate.VarIndex] == null)
                        {
                            continue;
                        }
                        if (qs.Object.IsVariable && !ounbound && r.Bindings[qs.Object.VarIndex] == null)
                        {
                            continue;
                        }

                        r.Bindings[varIndex]           = values;
                        r.StatementMatched[groupindex] = true;
                    }
                }
                else
                {
                    // There are two or more unbound variables, the
                    // third variable being uniquely bound, if bound.
                    // Keep track of the pairing of unbound variables.

                    if (numUnbound == 3)
                    {
                        throw new QueryExecutionException("Query would select all statements in the store.");
                    }

                    Debug(qs.ToString() + " 2 or 3 Unbound");

                    if (bindings.Results.Count == 0)
                    {
                        bindings.Results.Add(new QueryResult(this));
                    }

                    ArrayList   newbindings = new ArrayList();
                    MemoryStore ms          = new MemoryStore();
                    targetModel.Select(s, ms);
                    for (int si = 0; si < ms.StatementCount; si++)
                    {
                        Statement match = ms[si];
                        if (!MatchesFilters(match, qs, targetModel))
                        {
                            continue;
                        }
                        bindings.Union.Add(qs, match);
                        foreach (QueryResult r in bindings.Results)
                        {
                            if (numUnbound == 2)
                            {
                                // Check that the bound variable is bound in this result.
                                // If it is bound, it will be bound to the correct resource,
                                // but it might not be bound at all if an optional statement
                                // failed to match -- in which case, preserve the binding if
                                // this was an optional statement.
                                bool matches = true;
                                if (qs.Subject.IsVariable && !sunbound && r.Bindings[qs.Subject.VarIndex] == null)
                                {
                                    matches = false;
                                }
                                if (qs.Predicate.IsVariable && !punbound && r.Bindings[qs.Predicate.VarIndex] == null)
                                {
                                    matches = false;
                                }
                                if (qs.Object.IsVariable && !ounbound && r.Bindings[qs.Object.VarIndex] == null)
                                {
                                    matches = false;
                                }
                                if (!matches)
                                {
                                    if (qs.Optional)
                                    {
                                        newbindings.Add(r);
                                    }
                                    continue;
                                }
                            }

                            QueryResult r2 = r.Clone();
                            r2.Add(qs, match);
                            r2.StatementMatched[groupindex] = true;
                            newbindings.Add(r2);
                        }
                    }
                    if (newbindings.Count == 0)
                    {
                        return(qs.Optional);                        // don't clear out bindings if this was optional and it failed
                    }
                    bindings.Results = newbindings;
                }
            }

            return(true);
        }