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Darwinism/XDRStream/EmitContexts/OrderModel.vb

123 lines
4.7 KiB

#Region "Microsoft.VisualBasic::9a4a157e09c3aeebcddba38b88055f15, XDRStream\EmitContexts\OrderModel.vb"
' Author:
'
' asuka (amethyst.asuka@gcmodeller.org)
' xie (genetics@smrucc.org)
' xieguigang (xie.guigang@live.com)
'
' Copyright (c) 2018 GPL3 Licensed
'
'
' GNU GENERAL PUBLIC LICENSE (GPL3)
'
'
' This program is free software: you can redistribute it and/or modify
' it under the terms of the GNU General Public License as published by
' the Free Software Foundation, either version 3 of the License, or
' (at your option) any later version.
'
' This program is distributed in the hope that it will be useful,
' but WITHOUT ANY WARRANTY; without even the implied warranty of
' MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
' GNU General Public License for more details.
'
' You should have received a copy of the GNU General Public License
' along with this program. If not, see <http://www.gnu.org/licenses/>.
' /********************************************************************************/
' Summaries:
' Class OrderModel
'
' Properties: Fields
'
' Function: BuildReader, BuildWriter, Create
'
' Sub: AppendField
'
'
' /********************************************************************************/
#End Region
Imports System
Imports System.Linq
Imports System.Reflection
Imports System.Collections.Generic
Imports System.Linq.Expressions
Namespace Xdr.EmitContexts
Public Class OrderModel
Private _Fields As System.Collections.Generic.List(Of Xdr.EmitContexts.FieldDesc)
Public Property Fields As List(Of FieldDesc)
Get
Return _Fields
End Get
Private Set(value As List(Of FieldDesc))
_Fields = value
End Set
End Property
Public Function BuildReader(targetType As Type) As [Delegate]
Dim pReader = Expression.Parameter(GetType(Reader))
Dim variables As List(Of ParameterExpression) = New List(Of ParameterExpression)()
Dim body As List(Of Expression) = New List(Of Expression)()
Dim resultVar = Expression.Variable(targetType, "result")
variables.Add(resultVar)
Dim assign = Expression.Assign(resultVar, Expression.[New](targetType))
body.Add(assign)
For Each fieldDesc In Fields
body.Add(fieldDesc.BuildAssign(fieldDesc.BuildRead(pReader), resultVar))
Next
body.Add(resultVar)
Dim block = Expression.Block(variables, body)
Return Expression.Lambda(CType(GetType(ReadOneDelegate(Of)).MakeGenericType(targetType), Type), CType(block, Expression), pReader).Compile()
End Function
Public Function BuildWriter(targetType As Type) As [Delegate]
Dim pWriter = Expression.Parameter(GetType(Writer))
Dim pItem = Expression.Parameter(targetType)
Dim variables As List(Of ParameterExpression) = New List(Of ParameterExpression)()
Dim body As List(Of Expression) = New List(Of Expression)()
For Each fieldDesc In Fields
body.Add(fieldDesc.BuildWrite(pWriter, pItem))
Next
Dim block = Expression.Block(variables, body)
Return Expression.Lambda(CType(GetType(WriteOneDelegate(Of)).MakeGenericType(targetType), Type), CType(block, Expression), CType(pWriter, ParameterExpression), CType(pItem, ParameterExpression)).Compile()
End Function
Public Shared Function Create(t As Type) As OrderModel
Dim fields As SortedList(Of UInteger, FieldDesc) = New SortedList(Of UInteger, FieldDesc)()
For Each f In t.GetFields().Where(Function(fi) fi.IsPublic AndAlso Not fi.IsStatic)
AppendField(fields, f)
Next
For Each p In t.GetProperties().Where(Function(pi) pi.CanWrite AndAlso pi.CanRead)
AppendField(fields, p)
Next
If fields.Count = 0 Then Return Nothing
Dim result As OrderModel = New OrderModel()
result.Fields = fields.Values.ToList()
Return result
End Function
Private Shared Sub AppendField(fields As SortedList(Of UInteger, FieldDesc), mi As MemberInfo)
Dim fAttr As OrderAttribute = mi.GetAttr(Of OrderAttribute)()
If fAttr Is Nothing Then Return
If fields.ContainsKey(fAttr.Order) Then Throw New InvalidOperationException("duplicate order " & fAttr.Order)
fields.Add(fAttr.Order, New FieldDesc(mi))
End Sub
End Class
End Namespace