Welcome to mirror list, hosted at ThFree Co, Russian Federation.

LastAsync.cs « Observαble « Linq « Reactive « System.Reactive.Linq « Rx.NET - github.com/mono/rx.git - Unnamed repository; edit this file 'description' to name the repository.
summaryrefslogtreecommitdiff
blob: 1ecd9301b8ec5bc9e52a922766ce1e856b2a9562 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.

#if !NO_PERF
using System;

namespace System.Reactive.Linq.Observαble
{
    class LastAsync<TSource> : Producer<TSource>
    {
        private readonly IObservable<TSource> _source;
        private readonly Func<TSource, bool> _predicate;
        private readonly bool _throwOnEmpty;

        public LastAsync(IObservable<TSource> source, Func<TSource, bool> predicate, bool throwOnEmpty)
        {
            _source = source;
            _predicate = predicate;
            _throwOnEmpty = throwOnEmpty;
        }

        protected override IDisposable Run(IObserver<TSource> observer, IDisposable cancel, Action<IDisposable> setSink)
        {
            if (_predicate != null)
            {
                var sink = new π(this, observer, cancel);
                setSink(sink);
                return _source.SubscribeSafe(sink);
            }
            else
            {
                var sink = new _(this, observer, cancel);
                setSink(sink);
                return _source.SubscribeSafe(sink);
            }
        }

        class _ : Sink<TSource>, IObserver<TSource>
        {
            private readonly LastAsync<TSource> _parent;
            private TSource _value;
            private bool _seenValue;

            public _(LastAsync<TSource> parent, IObserver<TSource> observer, IDisposable cancel)
                : base(observer, cancel)
            {
                _parent = parent;

                _value = default(TSource);
                _seenValue = false;
            }

            public void OnNext(TSource value)
            {
                _value = value;
                _seenValue = true;
            }

            public void OnError(Exception error)
            {
                base._observer.OnError(error);
                base.Dispose();
            }

            public void OnCompleted()
            {
                if (!_seenValue && _parent._throwOnEmpty)
                {
                    base._observer.OnError(new InvalidOperationException(Strings_Linq.NO_ELEMENTS));
                }
                else
                {
                    base._observer.OnNext(_value);
                    base._observer.OnCompleted();
                }

                base.Dispose();
            }
        }

        class π : Sink<TSource>, IObserver<TSource>
        {
            private readonly LastAsync<TSource> _parent;
            private TSource _value;
            private bool _seenValue;

            public π(LastAsync<TSource> parent, IObserver<TSource> observer, IDisposable cancel)
                : base(observer, cancel)
            {
                _parent = parent;

                _value = default(TSource);
                _seenValue = false;
            }

            public void OnNext(TSource value)
            {
                var b = false;

                try
                {
                    b = _parent._predicate(value);
                }
                catch (Exception ex)
                {
                    base._observer.OnError(ex);
                    base.Dispose();
                    return;
                }

                if (b)
                {
                    _value = value;
                    _seenValue = true;
                }
            }

            public void OnError(Exception error)
            {
                base._observer.OnError(error);
                base.Dispose();
            }

            public void OnCompleted()
            {
                if (!_seenValue && _parent._throwOnEmpty)
                {
                    base._observer.OnError(new InvalidOperationException(Strings_Linq.NO_MATCHING_ELEMENTS));
                }
                else
                {
                    base._observer.OnNext(_value);
                    base._observer.OnCompleted();
                }

                base.Dispose();
            }
        }
    }
}
#endif