Ejemplo n.º 1
0
        private ObjectHandle VisitElementAt(MethodCallExpression m)
        {
            Visit(m.Arguments.First());
            object argument;

            if (!TryExtractConstantValue(m.Arguments.Last(), out argument) || argument.GetType() != typeof(int))
            {
                throw new NotSupportedException($"The method '{m.Method}' has to be invoked with a single integer constant argument or closure variable");
            }

            var index = (int)argument;

            ObjectHandle obj;

            if (OptionalSortDescriptorBuilder == null)
            {
                var objectPtr = CoreQueryHandle.FindDirect(_realm.SharedRealmHandle, (IntPtr)index);
                obj = Realm.CreateObjectHandle(objectPtr, _realm.SharedRealmHandle);
            }
            else
            {
                using (var rh = _realm.MakeResultsForQuery(CoreQueryHandle, OptionalSortDescriptorBuilder))
                {
                    var objectPtr = rh.GetObjectAtIndex(index);
                    obj = Realm.CreateObjectHandle(objectPtr, _realm.SharedRealmHandle);
                }
            }

            return(obj);
        }
        internal override Expression VisitMethodCall(MethodCallExpression m)
        {
            if (m.Method.DeclaringType == typeof(Queryable))
            {
                if (m.Method.Name == nameof(Queryable.Where))
                {
                    Visit(m.Arguments[0]);
                    var lambda = (LambdaExpression)StripQuotes(m.Arguments[1]);
                    Visit(lambda.Body);
                    return(m);
                }

                if (m.Method.Name == nameof(Queryable.OrderBy))
                {
                    Visit(m.Arguments[0]);
                    AddSort((LambdaExpression)StripQuotes(m.Arguments[1]), true, true);
                    return(m);
                }

                if (m.Method.Name == nameof(Queryable.OrderByDescending))
                {
                    Visit(m.Arguments[0]);
                    AddSort((LambdaExpression)StripQuotes(m.Arguments[1]), true, false);
                    return(m);
                }

                if (m.Method.Name == nameof(Queryable.ThenBy))
                {
                    Visit(m.Arguments[0]);
                    AddSort((LambdaExpression)StripQuotes(m.Arguments[1]), false, true);
                    return(m);
                }

                if (m.Method.Name == nameof(Queryable.ThenByDescending))
                {
                    Visit(m.Arguments[0]);
                    AddSort((LambdaExpression)StripQuotes(m.Arguments[1]), false, false);
                    return(m);
                }

                if (m.Method.Name == nameof(Queryable.Count))
                {
                    RecurseToWhereOrRunLambda(m);
                    var foundCount = CoreQueryHandle.Count();
                    return(Expression.Constant(foundCount));
                }

                if (m.Method.Name == nameof(Queryable.Any))
                {
                    RecurseToWhereOrRunLambda(m);
                    var foundAny = CoreQueryHandle.FindDirect(_realm.SharedRealmHandle) != IntPtr.Zero;
                    return(Expression.Constant(foundAny));
                }

                if (m.Method.Name.StartsWith(nameof(Queryable.First)))
                {
                    RecurseToWhereOrRunLambda(m);
                    var firstObjectPtr = IntPtr.Zero;
                    if (OptionalSortDescriptorBuilder == null)
                    {
                        firstObjectPtr = CoreQueryHandle.FindDirect(_realm.SharedRealmHandle);
                    }
                    else
                    {
                        using (ResultsHandle rh = _realm.MakeResultsForQuery(CoreQueryHandle, OptionalSortDescriptorBuilder))
                        {
                            firstObjectPtr = rh.GetObjectAtIndex(0);
                        }
                    }

                    if (firstObjectPtr != IntPtr.Zero)
                    {
                        return(Expression.Constant(_realm.MakeObject(_metadata, firstObjectPtr)));
                    }

                    if (m.Method.Name == nameof(Queryable.First))
                    {
                        throw new InvalidOperationException("Sequence contains no matching element");
                    }

                    Debug.Assert(m.Method.Name == nameof(Queryable.FirstOrDefault), $"The method {m.Method.Name}  is not supported. We expected {nameof(Queryable.FirstOrDefault)}.");
                    return(Expression.Constant(null));
                }

                /*
                 * // FIXME: See discussion in the test DefaultIfEmptyReturnsDefault
                 * // kept because it shows part of what might be a viable implementation if can work out architectural issues
                 *
                 *              if (m.Method.Name == nameof(Queryable.DefaultIfEmpty))
                 *              {
                 *                  RecurseToWhereOrRunLambda(m);
                 *                  IntPtr firstObjectPtr = _coreQueryHandle.FindDirect(IntPtr.Zero);
                 *                  if (firstObjectPtr != IntPtr.Zero)
                 *                      return m;  // as if just a "Where"
                 *                  var innerType = m.Type.GetGenericArguments()[0];
                 *                  var listType = typeof(List<>).MakeGenericType(innerType);
                 *                  var singleNullItemList = Activator.CreateInstance(listType);
                 *                  ((IList)singleNullItemList).Add(null);
                 *                  return Expression.Constant(singleNullItemList);
                 *              }
                 */
                if (m.Method.Name.StartsWith(nameof(Queryable.Single)))  // same as unsorted First with extra checks
                {
                    RecurseToWhereOrRunLambda(m);
                    var firstObjectPtr = CoreQueryHandle.FindDirect(_realm.SharedRealmHandle);
                    if (firstObjectPtr == IntPtr.Zero)
                    {
                        if (m.Method.Name == nameof(Queryable.Single))
                        {
                            throw new InvalidOperationException("Sequence contains no matching element");
                        }

                        Debug.Assert(m.Method.Name == nameof(Queryable.SingleOrDefault), $"The method {m.Method.Name}  is not supported. We expected {nameof(Queryable.SingleOrDefault)}.");
                        return(Expression.Constant(null));
                    }

                    var firstObject   = Realm.CreateObjectHandle(firstObjectPtr, _realm.SharedRealmHandle);
                    var nextObjectPtr = CoreQueryHandle.FindNext(firstObject);
                    if (nextObjectPtr != IntPtr.Zero)
                    {
                        throw new InvalidOperationException("Sequence contains more than one matching element");
                    }

                    return(Expression.Constant(_realm.MakeObject(_metadata, firstObject)));
                }

                if (m.Method.Name.StartsWith(nameof(Queryable.Last)))
                {
                    RecurseToWhereOrRunLambda(m);

                    var lastObjectPtr = IntPtr.Zero;
                    using (ResultsHandle rh = _realm.MakeResultsForQuery(CoreQueryHandle, OptionalSortDescriptorBuilder))
                    {
                        var lastIndex = rh.Count() - 1;
                        if (lastIndex >= 0)
                        {
                            lastObjectPtr = rh.GetObjectAtIndex(lastIndex);
                        }
                    }

                    if (lastObjectPtr != IntPtr.Zero)
                    {
                        return(Expression.Constant(_realm.MakeObject(_metadata, lastObjectPtr)));
                    }

                    if (m.Method.Name == nameof(Queryable.Last))
                    {
                        throw new InvalidOperationException("Sequence contains no matching element");
                    }

                    Debug.Assert(m.Method.Name == nameof(Queryable.LastOrDefault), $"The method {m.Method.Name}  is not supported. We expected {nameof(Queryable.LastOrDefault)}.");
                    return(Expression.Constant(null));
                }

                if (m.Method.Name.StartsWith(nameof(Queryable.ElementAt)))
                {
                    Visit(m.Arguments.First());
                    object argument;
                    if (!TryExtractConstantValue(m.Arguments.Last(), out argument) || argument.GetType() != typeof(int))
                    {
                        throw new NotSupportedException($"The method '{m.Method}' has to be invoked with a single integer constant argument or closure variable");
                    }

                    IntPtr objectPtr;
                    var    index = (int)argument;
                    if (OptionalSortDescriptorBuilder == null)
                    {
                        objectPtr = CoreQueryHandle.FindDirect(_realm.SharedRealmHandle, (IntPtr)index);
                    }
                    else
                    {
                        using (var rh = _realm.MakeResultsForQuery(CoreQueryHandle, OptionalSortDescriptorBuilder))
                        {
                            objectPtr = rh.GetObjectAtIndex(index);
                        }
                    }

                    if (objectPtr != IntPtr.Zero)
                    {
                        var objectHandle = Realm.CreateObjectHandle(objectPtr, _realm.SharedRealmHandle);
                        return(Expression.Constant(_realm.MakeObject(_metadata, objectHandle)));
                    }

                    if (m.Method.Name == nameof(Queryable.ElementAt))
                    {
                        throw new ArgumentOutOfRangeException();
                    }

                    Debug.Assert(m.Method.Name == nameof(Queryable.ElementAtOrDefault), $"The method {m.Method.Name}  is not supported. We expected {nameof(Queryable.ElementAtOrDefault)}.");
                    return(Expression.Constant(null));
                }
            }

            if (m.Method.DeclaringType == typeof(string) ||
                m.Method.DeclaringType == typeof(StringExtensions))
            {
                QueryHandle.Operation <string> queryMethod = null;

                // For extension methods, member should be m.Arguments[0] as MemberExpression;
                MemberExpression member = null;

                // For extension methods, that should be 1
                var stringArgumentIndex = 0;

                if (m.Method == Methods.String.Contains.Value)
                {
                    queryMethod = (q, c, v) => q.StringContains(c, v, caseSensitive: true);
                }
                else if (m.Method == Methods.String.ContainsStringComparison.Value)
                {
                    member = m.Arguments[0] as MemberExpression;
                    stringArgumentIndex = 1;
                    queryMethod         = (q, c, v) => q.StringContains(c, v, GetComparisonCaseSensitive(m));
                }
                else if (m.Method == Methods.String.StartsWith.Value)
                {
                    queryMethod = (q, c, v) => q.StringStartsWith(c, v, caseSensitive: true);
                }
                else if (m.Method == Methods.String.StartsWithStringComparison.Value)
                {
                    queryMethod = (q, c, v) => q.StringStartsWith(c, v, GetComparisonCaseSensitive(m));
                }
                else if (m.Method == Methods.String.EndsWith.Value)
                {
                    queryMethod = (q, c, v) => q.StringEndsWith(c, v, caseSensitive: true);
                }
                else if (m.Method == Methods.String.EndsWithStringComparison.Value)
                {
                    queryMethod = (q, c, v) => q.StringEndsWith(c, v, GetComparisonCaseSensitive(m));
                }
                else if (m.Method == Methods.String.IsNullOrEmpty.Value)
                {
                    member = m.Arguments.SingleOrDefault() as MemberExpression;
                    if (member == null)
                    {
                        throw new NotSupportedException($"The method '{m.Method}' has to be invoked with a RealmObject member");
                    }

                    var columnIndex = CoreQueryHandle.GetColumnIndex(member.Member.Name);

                    CoreQueryHandle.GroupBegin();
                    CoreQueryHandle.NullEqual(columnIndex);
                    CoreQueryHandle.Or();
                    CoreQueryHandle.StringEqual(columnIndex, string.Empty, caseSensitive: true);
                    CoreQueryHandle.GroupEnd();
                    return(m);
                }
                else if (m.Method == Methods.String.EqualsMethod.Value)
                {
                    queryMethod = (q, c, v) => q.StringEqual(c, v, caseSensitive: true);
                }
                else if (m.Method == Methods.String.EqualsStringComparison.Value)
                {
                    queryMethod = (q, c, v) => q.StringEqual(c, v, GetComparisonCaseSensitive(m));
                }
                else if (m.Method == Methods.String.Like.Value)
                {
                    member = m.Arguments[0] as MemberExpression;
                    stringArgumentIndex = 1;
                    object caseSensitive;
                    if (!TryExtractConstantValue(m.Arguments.Last(), out caseSensitive) || !(caseSensitive is bool))
                    {
                        throw new NotSupportedException($"The method '{m.Method}' has to be invoked with a string and boolean constant arguments.");
                    }

                    queryMethod = (q, c, v) => q.StringLike(c, v, (bool)caseSensitive);
                }

                if (queryMethod != null)
                {
                    member = member ?? m.Object as MemberExpression;

                    if (member == null)
                    {
                        throw new NotSupportedException($"The method '{m.Method}' has to be invoked on a RealmObject member");
                    }

                    var columnIndex = CoreQueryHandle.GetColumnIndex(member.Member.Name);

                    object argument;
                    if (!TryExtractConstantValue(m.Arguments[stringArgumentIndex], out argument) ||
                        (argument != null && argument.GetType() != typeof(string)))
                    {
                        throw new NotSupportedException($"The method '{m.Method}' has to be invoked with a single string constant argument or closure variable");
                    }

                    queryMethod(CoreQueryHandle, columnIndex, (string)argument);
                    return(m);
                }
            }

            throw new NotSupportedException($"The method '{m.Method.Name}' is not supported");
        }