SOAP通信の拡張（圧縮）

概要

SOAP通信の拡張を行うことで、SOAPの圧縮等が可能となります。
以下のコードは圧縮を実装したコードになります。

クライアントRequestを圧縮します。
Responseを解凍します。

コード

Client.vb

Imports System.IO.Compression
Imports System.Web.Services.Protocols

Public Class CompressSoapExtension
    Inherits SoapExtension
    Private oldStream As Stream
    Private newStream As Stream
    Public Overrides Function ChainStream(ByVal stream As Stream) As Stream
        'oldStreamは通信に使うためのストリーム
        oldStream = stream
        'newStreamはクライアント内でデータを処理するためのストリーム
        newStream = New MemoryStream()
        Return newStream
    End Function
    Public Overloads Overrides Function GetInitializer(ByVal methodInfo As LogicalMethodInfo, _
                                                    ByVal attribute As SoapExtensionAttribute) As Object
        Return Nothing
    End Function
    Public Overloads Overrides Function GetInitializer(ByVal webserviceType As Type) As Object
        Return Nothing
    End Function
    Public Overrides Sub Initialize(ByVal initializer As Object)
    End Sub
    Public Overrides Sub ProcessMessage(ByVal message As SoapMessage)
        Select Case message.Stage
            Case SoapMessageStage.BeforeSerialize
            Case SoapMessageStage.AfterSerialize
                'シリアライズ後の処理・データの圧縮を行う
                newStream.Position = 0
                Dim compressedStream As MemoryStream = Compress(newStream)
                '圧縮されたデータをoldStreamに書き込む
                compressedStream.Position = 0
                Dim readByte As Integer = compressedStream.ReadByte()
                While readByte > -1
                    oldStream.WriteByte(readByte)
                    oldStream.Flush()
                    readByte = compressedStream.ReadByte()
                End While
                oldStream.Flush()
            Case SoapMessageStage.BeforeDeserialize
                'デシリアライズの前処理・データの解凍を行う
                Dim DecompressedStream As MemoryStream = Decompress(oldStream)
                DecompressedStream.Position = 0
                Dim reader As StreamReader = New StreamReader(DecompressedStream)
                Dim rpcMessage As String = reader.ReadToEnd()
                '解凍されたデータをnewStreamに書き込む
                Dim writer As StreamWriter = New StreamWriter(newStream)
                writer.Write(rpcMessage)
                writer.Flush()
                newStream.Position = 0
        End Select
    End Sub
    Protected Function Compress(ByVal outputStream As Stream) As MemoryStream
        '圧縮処理を実装する
        Dim num As Integer
        Dim buff(1024) As Byte
        Dim memStream As New MemoryStream
        '' GZipStreamのインスタンスを作成（出力先:memStream、閉じたときにmemStreamを閉じない）
        Dim CompStream As New GZipStream(memStream, CompressionMode.Compress, True)
        Do
            '1kbずつ圧縮する
            num = outputStream.Read(buff, 0, buff.Length)
            If num <= 0 Then Exit Do
            CompStream.Write(buff, 0, num)
        Loop
        CompStream.Flush()
        CompStream.Close()
        memStream.Position = 0
        Return memStream
    End Function
    Protected Function Decompress(ByVal inputStream As Stream) As MemoryStream
        '解凍処理を実装する
        Dim num As Integer
        Dim buff(1024) As Byte
        Dim memStream As New MemoryStream
        Dim CompStream As New GZipStream(inputStream, CompressionMode.Decompress)
        Do
            ''1kbずつ解凍する
            num = CompStream.Read(buff, 0, buff.Length)
            If num <= 0 Then Exit Do
            memStream.Write(buff, 0, num)
        Loop
        CompStream.Close()
        memStream.Position = 0
        Return memStream
    End Function
End Class

サーバーでRequestを解凍します。
Reqponseを圧縮します。

Server.vb

Public Class CompressSoapExtension
    Inherits SoapExtension
    Private oldStream As Stream
    Private newStream As Stream
    Public Overrides Function ChainStream(ByVal stream As Stream) As Stream
        'oldStreamは通信に使うためのストリーム
        oldStream = stream
        'newStreamはクライアント内でデータを処理するためのストリーム
        newStream = New MemoryStream()
        Return newStream
    End Function
    Public Overloads Overrides Function GetInitializer(ByVal methodInfo As LogicalMethodInfo, _
                                                    ByVal attribute As SoapExtensionAttribute) As Object
        Return Nothing
    End Function
    Public Overloads Overrides Function GetInitializer(ByVal webserviceType As Type) As Object
        Return Nothing
    End Function
    Public Overrides Sub Initialize(ByVal initializer As Object)
    End Sub
    Public Overrides Sub ProcessMessage(ByVal message As SoapMessage)
        Select Case message.Stage
            Case SoapMessageStage.BeforeSerialize
                'message.ContentEncoding = "gzip"
            Case SoapMessageStage.AfterSerialize
                'シリアライズ後の処理・データの圧縮を行う
                newStream.Position = 0
                Dim compressedStream As MemoryStream = Compress(newStream)
                '圧縮されたデータをoldStreamに書き込む
                compressedStream.Position = 0
                Dim readByte As Integer = compressedStream.ReadByte()
                While readByte > -1
                    oldStream.WriteByte(readByte)
                    oldStream.Flush()
                    readByte = compressedStream.ReadByte()
                End While
                oldStream.Flush()
            Case SoapMessageStage.BeforeDeserialize
                'デシリアライズの前処理・データの解凍を行う
                oldStream.Position = 0
                Dim DecompressedStream As MemoryStream = Decompress(oldStream)
                DecompressedStream.Position = 0
                Dim reader As StreamReader = New StreamReader(DecompressedStream)
                Dim rpcMessage As String = reader.ReadToEnd()

                '解凍されたデータをnewStreamに書き込む
                Dim writer As StreamWriter = New StreamWriter(newStream)
                writer.Write(rpcMessage)
                writer.Flush()
                newStream.Position = 0
        End Select
    End Sub
    Protected Function Compress(ByVal outputStream As Stream) As MemoryStream
        '圧縮処理を実装する
        Dim num As Integer
        Dim buff(1024) As Byte
        Dim memStream As New MemoryStream
        Dim CompStream As New GZipStream(memStream, CompressionMode.Compress, True)
        Do
            num = outputStream.Read(buff, 0, buff.Length)
            If num <= 0 Then Exit Do
            CompStream.Write(buff, 0, num)
        Loop
        CompStream.Flush()
        CompStream.Close()
        memStream.Position = 0
        Return memStream
    End Function
    Protected Function Decompress(ByVal inputStream As Stream) As MemoryStream
        '解凍処理を実装する
        Dim num As Integer
        Dim buff(1024) As Byte
        Dim memStream As New MemoryStream
        Dim CompStream As New GZipStream(inputStream, CompressionMode.Decompress)
        Do
            num = CompStream.Read(buff, 0, buff.Length)
            If num <= 0 Then Exit Do
            memStream.Write(buff, 0, num)
        Loop
        CompStream.Close()
        memStream.Position = 0
        Return memStream
    End Function
End Class