1 | #Region "Microsoft.VisualBasic::0aca79be365c7d2a43e63d417c5f3757, Microsoft.VisualBasic.Core\ApplicationServices\Parallel\MMFProtocol\MapStream\MSReader.vb" |
2 | |
3 | ' Author: |
4 | ' |
5 | ' asuka (amethyst.asuka@gcmodeller.org) |
6 | ' xie (genetics@smrucc.org) |
7 | ' xieguigang (xie.guigang@live.com) |
8 | ' |
9 | ' Copyright (c) 2018 GPL3 Licensed |
10 | ' |
11 | ' |
12 | ' GNU GENERAL PUBLIC LICENSE (GPL3) |
13 | ' |
14 | ' |
15 | ' This program is free software: you can redistribute it and/or modify |
16 | ' it under the terms of the GNU General Public License as published by |
17 | ' the Free Software Foundation, either version 3 of the License, or |
18 | ' (at your option) any later version. |
19 | ' |
20 | ' This program is distributed in the hope that it will be useful, |
21 | ' but WITHOUT ANY WARRANTY; without even the implied warranty of |
22 | ' MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
23 | ' GNU General Public License for more details. |
24 | ' |
25 | ' You should have received a copy of the GNU General Public License |
26 | ' along with this program. If not, see <http://www.gnu.org/licenses/>. |
27 | |
28 | |
29 | |
30 | ' /********************************************************************************/ |
31 | |
32 | ' Summaries: |
33 | |
34 | ' Class IMapBase |
35 | ' |
36 | ' Properties: URI |
37 | ' |
38 | ' Constructor: (+1 Overloads) Sub New |
39 | ' |
40 | ' Function: Read, ToString |
41 | ' |
42 | ' Sub: (+2 Overloads) Dispose |
43 | ' |
44 | ' Class MSIOReader |
45 | ' |
46 | ' Constructor: (+1 Overloads) Sub New |
47 | ' |
48 | ' Function: ReadBadge, ToString |
49 | ' |
50 | ' Sub: __clientThreadElapsed, __threadElapsed, Update |
51 | ' |
52 | ' |
53 | ' /********************************************************************************/ |
54 | |
55 | #End Region |
56 | |
57 | Imports System.IO.MemoryMappedFiles |
58 | |
59 | Namespace Parallel.MMFProtocol.MapStream |
60 | |
61 | Public MustInherit Class IMapBase : Implements IDisposable |
62 | |
63 | Public ReadOnly Property URI As String |
64 | |
65 | Protected _chunkBuffer As Byte() |
66 | Protected _mmfileStream As MemoryMappedFile |
67 | |
68 | Sub New(uri As String, ChunkSize As Long) |
69 | Me._URI = uri |
70 | Me._chunkBuffer = New Byte(ChunkSize - 1) {} |
71 | End Sub |
72 | |
73 | Public Function Read() As MMFStream |
74 | Call _mmfileStream.CreateViewStream.Read(_chunkBuffer, Scan0, _chunkBuffer.Length) |
75 | Return New MMFStream(_chunkBuffer) |
76 | End Function |
77 | |
78 | Public Overrides Function ToString() As String |
79 | Return URI |
80 | End Function |
81 | |
82 | #Region "IDisposable Support" |
83 | Protected disposedValue As Boolean ' To detect redundant calls |
84 | |
85 | ' IDisposable |
86 | Protected Overridable Sub Dispose(disposing As Boolean) |
87 | If Not Me.disposedValue Then |
88 | If disposing Then |
89 | ' TODO: dispose managed state (managed objects). |
90 | End If |
91 | |
92 | ' TODO: free unmanaged resources (unmanaged objects) and override Finalize() below. |
93 | ' TODO: set large fields to null. |
94 | End If |
95 | Me.disposedValue = True |
96 | End Sub |
97 | |
98 | ' TODO: override Finalize() only if Dispose(disposing As Boolean) above has code to free unmanaged resources. |
99 | 'Protected Overrides Sub Finalize() |
100 | ' ' Do not change this code. Put cleanup code in Dispose(disposing As Boolean) above. |
101 | ' Dispose(False) |
102 | ' MyBase.Finalize() |
103 | 'End Sub |
104 | |
105 | ' This code added by Visual Basic to correctly implement the disposable pattern. |
106 | Public Sub Dispose() Implements IDisposable.Dispose |
107 | ' Do not change this code. Put cleanup code in Dispose(disposing As Boolean) above. |
108 | Dispose(True) |
109 | ' TODO: uncomment the following line if Finalize() is overridden above. |
110 | ' GC.SuppressFinalize(Me) |
111 | End Sub |
112 | #End Region |
113 | End Class |
114 | |
115 | Public Class MSIOReader : Inherits IMapBase |
116 | Implements IDisposable |
117 | |
118 | ''' <summary> |
119 | ''' 内存映射文件的更新标识符 |
120 | ''' </summary> |
121 | ''' <remarks></remarks> |
122 | Dim _udtBadge As Long |
123 | Dim _mappedStream As MMFStream |
124 | |
125 | ReadOnly _dataArrivals As DataArrival |
126 | |
127 | ''' <summary> |
128 | ''' |
129 | ''' </summary> |
130 | ''' <param name="uri"></param> |
131 | ''' <param name="callback"></param> |
132 | ''' <param name="ChunkSize">内存映射文件的数据块的预分配大小</param> |
133 | Sub New(uri As String, callback As DataArrival, ChunkSize As Long) |
134 | Call MyBase.New(uri, ChunkSize) |
135 | _mmfileStream = MemoryMappedFile.OpenExisting(uri) |
136 | _dataArrivals = callback |
137 | |
138 | Call Parallel.RunTask(AddressOf __threadElapsed) |
139 | End Sub |
140 | |
141 | Public Overrides Function ToString() As String |
142 | Return $"{URI} ===> {NameOf(_udtBadge)}:={_udtBadge}" |
143 | End Function |
144 | |
145 | Public Sub Update(thisUpdate As Long) |
146 | Me._udtBadge = thisUpdate |
147 | End Sub |
148 | |
149 | ''' <summary> |
150 | ''' 由于考虑到可能会传递很大的数据块,所以在这里检测数据更新的话只读取头部的8个字节的数据 |
151 | ''' </summary> |
152 | ''' <returns></returns> |
153 | Public Function ReadBadge() As Long |
154 | Dim buf As Byte() = New Byte(MMFStream.INT64 - 1) {} |
155 | Call _mmfileStream.CreateViewStream.Read(buf, Scan0, buf.Length) |
156 | Dim n As Long = BitConverter.ToInt64(buf, Scan0) |
157 | Return n |
158 | End Function |
159 | |
160 | Private Sub __threadElapsed() |
161 | Do While Not Me.disposedValue |
162 | Call __clientThreadElapsed() |
163 | Call Threading.Thread.Sleep(1) |
164 | Loop |
165 | End Sub |
166 | |
167 | Private Sub __clientThreadElapsed() |
168 | Dim flag As Long = ReadBadge() |
169 | |
170 | If flag <= Me._udtBadge Then |
171 | Return |
172 | Else ' 当从数据流中所读取到的更新标识符大于对象实例中的更新标识符的时候,认为数据发生了更新 |
173 | Me._mappedStream = Read() |
174 | Me._udtBadge = _mappedStream.udtBadge |
175 | Me._dataArrivals(_mappedStream.byteData) |
176 | End If |
177 | End Sub |
178 | End Class |
179 | End Namespace |