BufferedStream 类
定义
重要
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添加缓冲层以在另一个流上读取和写入操作。 无法继承此类。
public ref class BufferedStream sealed : System::IO::Streampublic sealed class BufferedStream : System.IO.Stream[System.Runtime.InteropServices.ComVisible(true)]
public sealed class BufferedStream : System.IO.Streamtype BufferedStream = class
inherit Stream[<System.Runtime.InteropServices.ComVisible(true)>]
type BufferedStream = class
inherit StreamPublic NotInheritable Class BufferedStream
Inherits Stream- 继承
- 继承
- 属性
示例
下面的代码示例演示如何在 NetworkStream 类上使用 BufferedStream 类来提高某些 I/O 操作的性能。 在启动客户端之前，在远程计算机上启动服务器。 启动客户端时，将远程计算机名称指定为命令行参数。 根据 dataArraySize 和 streamBufferSize 常量来查看它们对性能的影响。
第一个示例显示客户端上运行的代码，第二个示例显示服务器上运行的代码。
示例 1：在客户端 上运行的代码
#using <system.dll>
using namespace System;
using namespace System::IO;
using namespace System::Globalization;
using namespace System::Net;
using namespace System::Net::Sockets;
static const int streamBufferSize = 1000;
public ref class Client
{
private:
literal int dataArraySize = 100;
literal int numberOfLoops = 10000;
Client(){}
public:
static void ReceiveData( Stream^ netStream, Stream^ bufStream )
{
DateTime startTime;
Double networkTime;
Double bufferedTime = 0;
int bytesReceived = 0;
array<Byte>^receivedData = gcnew array<Byte>(dataArraySize);
// Receive data using the NetworkStream.
Console::WriteLine( "Receiving data using NetworkStream." );
startTime = DateTime::Now;
while ( bytesReceived < numberOfLoops * receivedData->Length )
{
bytesReceived += netStream->Read( receivedData, 0, receivedData->Length );
}
networkTime = (DateTime::Now - startTime).TotalSeconds;
Console::WriteLine( "{0} bytes received in {1} seconds.\n", bytesReceived.ToString(), networkTime.ToString( "F1" ) );
// Receive data using the BufferedStream.
Console::WriteLine( "Receiving data using BufferedStream." );
bytesReceived = 0;
startTime = DateTime::Now;
while ( bytesReceived < numberOfLoops * receivedData->Length )
{
bytesReceived += bufStream->Read( receivedData, 0, receivedData->Length );
}
bufferedTime = (DateTime::Now - startTime).TotalSeconds;
Console::WriteLine( "{0} bytes received in {1} seconds.\n", bytesReceived.ToString(), bufferedTime.ToString( "F1" ) );
// Print the ratio of read times.
Console::WriteLine( "Receiving data using the buffered "
"network stream was {0} {1} than using the network "
"stream alone.", (networkTime / bufferedTime).ToString( "P0" ), bufferedTime < networkTime ? (String^)"faster" : "slower" );
}
static void SendData( Stream^ netStream, Stream^ bufStream )
{
DateTime startTime;
Double networkTime;
Double bufferedTime;
// Create random data to send to the server.
array<Byte>^dataToSend = gcnew array<Byte>(dataArraySize);
(gcnew Random)->NextBytes( dataToSend );
// Send the data using the NetworkStream.
Console::WriteLine( "Sending data using NetworkStream." );
startTime = DateTime::Now;
for ( int i = 0; i < numberOfLoops; i++ )
{
netStream->Write( dataToSend, 0, dataToSend->Length );
}
networkTime = (DateTime::Now - startTime).TotalSeconds;
Console::WriteLine( "{0} bytes sent in {1} seconds.\n", (numberOfLoops * dataToSend->Length).ToString(), networkTime.ToString( "F1" ) );
// Send the data using the BufferedStream.
Console::WriteLine( "Sending data using BufferedStream." );
startTime = DateTime::Now;
for ( int i = 0; i < numberOfLoops; i++ )
{
bufStream->Write( dataToSend, 0, dataToSend->Length );
}
bufStream->Flush();
bufferedTime = (DateTime::Now - startTime).TotalSeconds;
Console::WriteLine( "{0} bytes sent in {1} seconds.\n", (numberOfLoops * dataToSend->Length).ToString(), bufferedTime.ToString( "F1" ) );
// Print the ratio of write times.
Console::WriteLine( "Sending data using the buffered "
"network stream was {0} {1} than using the network "
"stream alone.\n", (networkTime / bufferedTime).ToString( "P0" ), bufferedTime < networkTime ? (String^)"faster" : "slower" );
}
};
int main( int argc, char *argv[] )
{
// Check that an argument was specified when the
// program was invoked.
if ( argc == 1 )
{
Console::WriteLine( "Error: The name of the host computer"
" must be specified when the program is invoked." );
return -1;
}
String^ remoteName = gcnew String( argv[ 1 ] );
// Create the underlying socket and connect to the server.
Socket^ clientSocket = gcnew Socket( AddressFamily::InterNetwork,SocketType::Stream,ProtocolType::Tcp );
clientSocket->Connect( gcnew IPEndPoint( Dns::Resolve( remoteName )->AddressList[ 0 ],1800 ) );
Console::WriteLine( "Client is connected.\n" );
// Create a NetworkStream that owns clientSocket and
// then create a BufferedStream on top of the NetworkStream.
NetworkStream^ netStream = gcnew NetworkStream( clientSocket,true );
BufferedStream^ bufStream = gcnew BufferedStream( netStream,streamBufferSize );
try
{
// Check whether the underlying stream supports seeking.
Console::WriteLine( "NetworkStream {0} seeking.\n", bufStream->CanSeek ? (String^)"supports" : "does not support" );
// Send and receive data.
if ( bufStream->CanWrite )
{
Client::SendData( netStream, bufStream );
}
if ( bufStream->CanRead )
{
Client::ReceiveData( netStream, bufStream );
}
}
finally
{
// When bufStream is closed, netStream is in turn closed,
// which in turn shuts down the connection and closes
// clientSocket.
Console::WriteLine( "\nShutting down connection." );
bufStream->Close();
}
}
using System;
using System.IO;
using System.Globalization;
using System.Net;
using System.Net.Sockets;
public class Client
{
const int dataArraySize = 100;
const int streamBufferSize = 1000;
const int numberOfLoops = 10000;
static void Main(string[] args)
{
// Check that an argument was specified when the
// program was invoked.
if(args.Length == 0)
{
Console.WriteLine("Error: The name of the host computer" +
" must be specified when the program is invoked.");
return;
}
string remoteName = args[0];
// Create the underlying socket and connect to the server.
Socket clientSocket = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
clientSocket.Connect(new IPEndPoint(
Dns.Resolve(remoteName).AddressList[0], 1800));
Console.WriteLine("Client is connected.\n");
// Create a NetworkStream that owns clientSocket and
// then create a BufferedStream on top of the NetworkStream.
// Both streams are disposed when execution exits the
// using statement.
using(Stream
netStream = new NetworkStream(clientSocket, true),
bufStream =
new BufferedStream(netStream, streamBufferSize))
{
// Check whether the underlying stream supports seeking.
Console.WriteLine("NetworkStream {0} seeking.\n",
bufStream.CanSeek ? "supports" : "does not support");
// Send and receive data.
if(bufStream.CanWrite)
{
SendData(netStream, bufStream);
}
if(bufStream.CanRead)
{
ReceiveData(netStream, bufStream);
}
// When bufStream is closed, netStream is in turn
// closed, which in turn shuts down the connection
// and closes clientSocket.
Console.WriteLine("\nShutting down the connection.");
bufStream.Close();
}
}
static void SendData(Stream netStream, Stream bufStream)
{
DateTime startTime;
double networkTime, bufferedTime;
// Create random data to send to the server.
byte[] dataToSend = new byte[dataArraySize];
new Random().NextBytes(dataToSend);
// Send the data using the NetworkStream.
Console.WriteLine("Sending data using NetworkStream.");
startTime = DateTime.Now;
for(int i = 0; i < numberOfLoops; i++)
{
netStream.Write(dataToSend, 0, dataToSend.Length);
}
networkTime = (DateTime.Now - startTime).TotalSeconds;
Console.WriteLine("{0} bytes sent in {1} seconds.\n",
numberOfLoops * dataToSend.Length,
networkTime.ToString("F1"));
// Send the data using the BufferedStream.
Console.WriteLine("Sending data using BufferedStream.");
startTime = DateTime.Now;
for(int i = 0; i < numberOfLoops; i++)
{
bufStream.Write(dataToSend, 0, dataToSend.Length);
}
bufStream.Flush();
bufferedTime = (DateTime.Now - startTime).TotalSeconds;
Console.WriteLine("{0} bytes sent in {1} seconds.\n",
numberOfLoops * dataToSend.Length,
bufferedTime.ToString("F1"));
// Print the ratio of write times.
Console.WriteLine("Sending data using the buffered " +
"network stream was {0} {1} than using the network " +
"stream alone.\n",
(networkTime/bufferedTime).ToString("P0"),
bufferedTime < networkTime ? "faster" : "slower");
}
static void ReceiveData(Stream netStream, Stream bufStream)
{
DateTime startTime;
double networkTime, bufferedTime = 0;
int bytesReceived = 0;
byte[] receivedData = new byte[dataArraySize];
// Receive data using the NetworkStream.
Console.WriteLine("Receiving data using NetworkStream.");
startTime = DateTime.Now;
while(bytesReceived < numberOfLoops * receivedData.Length)
{
bytesReceived += netStream.Read(
receivedData, 0, receivedData.Length);
}
networkTime = (DateTime.Now - startTime).TotalSeconds;
Console.WriteLine("{0} bytes received in {1} seconds.\n",
bytesReceived.ToString(),
networkTime.ToString("F1"));
// Receive data using the BufferedStream.
Console.WriteLine("Receiving data using BufferedStream.");
bytesReceived = 0;
startTime = DateTime.Now;
int numBytesToRead = receivedData.Length;
while (numBytesToRead > 0)
{
// Read may return anything from 0 to numBytesToRead.
int n = bufStream.Read(receivedData,0, receivedData.Length);
// The end of the file is reached.
if (n == 0)
break;
bytesReceived += n;
numBytesToRead -= n;
}
bufferedTime = (DateTime.Now - startTime).TotalSeconds;
Console.WriteLine("{0} bytes received in {1} seconds.\n",
bytesReceived.ToString(),
bufferedTime.ToString("F1"));
// Print the ratio of read times.
Console.WriteLine("Receiving data using the buffered network" +
" stream was {0} {1} than using the network stream alone.",
(networkTime/bufferedTime).ToString("P0"),
bufferedTime < networkTime ? "faster" : "slower");
}
}
module Client
open System
open System.IO
open System.Net
open System.Net.Sockets
let dataArraySize = 100
let streamBufferSize = 1000
let numberOfLoops = 10000
let sendData (netStream: Stream) (bufStream: Stream) =
// Create random data to send to the server.
let dataToSend = Array.zeroCreate dataArraySize
Random().NextBytes dataToSend
// Send the data using the NetworkStream.
printfn "Sending data using NetworkStream."
let startTime = DateTime.Now
for _ = 0 to numberOfLoops - 1 do
netStream.Write(dataToSend, 0, dataToSend.Length)
let networkTime = (DateTime.Now - startTime).TotalSeconds
printfn $"{numberOfLoops * dataToSend.Length} bytes sent in {networkTime:F1} seconds.\n"
// Send the data using the BufferedStream.
printfn "Sending data using BufferedStream."
let startTime = DateTime.Now
for _ = 0 to numberOfLoops - 1 do
bufStream.Write(dataToSend, 0, dataToSend.Length)
bufStream.Flush()
let bufferedTime = (DateTime.Now - startTime).TotalSeconds
printfn $"{numberOfLoops * dataToSend.Length} bytes sent in {bufferedTime:F1} seconds.\n"
// Print the ratio of write times.
printfn $"""Sending data using the buffered network stream was {networkTime / bufferedTime:P0} {if bufferedTime < networkTime then "faster" else "slower"} than using the network stream alone."""
printfn ""
let receiveData (netStream: Stream) (bufStream: Stream) =
let mutable bytesReceived = 0
let receivedData = Array.zeroCreate dataArraySize
// Receive data using the NetworkStream.
printfn "Receiving data using NetworkStream."
let startTime = DateTime.Now
while bytesReceived < numberOfLoops * receivedData.Length do
bytesReceived <- bytesReceived + netStream.Read(receivedData, 0, receivedData.Length)
let networkTime = (DateTime.Now - startTime).TotalSeconds
printfn $"{bytesReceived} bytes received in {networkTime:F1} seconds.\n"
// Receive data using the BufferedStream.
printfn "Receiving data using BufferedStream."
bytesReceived <- 0
let startTime = DateTime.Now
let mutable numBytesToRead = receivedData.Length
let mutable broken = false
while not broken && numBytesToRead > 0 do
// Read may return anything from 0 to numBytesToRead.
let n = bufStream.Read(receivedData,0, receivedData.Length)
// The end of the file is reached.
if n = 0 then
broken <- true
else
bytesReceived <- bytesReceived + n
numBytesToRead <- numBytesToRead - n
let bufferedTime = (DateTime.Now - startTime).TotalSeconds
printfn $"{bytesReceived} bytes received in {bufferedTime:F1} seconds.\n"
// Print the ratio of read times.
printfn $"""Receiving data using the buffered network stream was {networkTime / bufferedTime:P0} {if bufferedTime < networkTime then "faster" else "slower"} than using the network stream alone."""
[<EntryPoint>]
let main args =
// Check that an argument was specified when the
// program was invoked.
if args.Length = 0 then
printfn "Error: The name of the host computer must be specified when the program is invoked."
else
let remoteName = args[0]
// Create the underlying socket and connect to the server.
let clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
clientSocket.Connect(IPEndPoint(Dns.GetHostEntry(remoteName).AddressList[0], 1800))
printfn "Client is connected.\n"
// Create a NetworkStream that owns clientSocket and
// then create a BufferedStream on top of the NetworkStream.
// Both streams are disposed when execution exits the
// using statement.
use netStream = new NetworkStream(clientSocket, true)
use bufStream = new BufferedStream(netStream, streamBufferSize)
// Check whether the underlying stream supports seeking.
printfn $"""NetworkStream {if bufStream.CanSeek then "supports" else "does not support"} seeking.\n"""
// Send and receive data.
if bufStream.CanWrite then
sendData netStream bufStream
if bufStream.CanRead then
receiveData netStream bufStream
// When bufStream is closed, netStream is in turn
// closed, which in turn shuts down the connection
// and closes clientSocket.
printfn "\nShutting down the connection."
bufStream.Close()
0
' Compile using /r:System.dll.
Imports System.IO
Imports System.Globalization
Imports System.Net
Imports System.Net.Sockets
Public Class Client
Const dataArraySize As Integer = 100
Const streamBufferSize As Integer = 1000
Const numberOfLoops As Integer = 10000
Shared Sub Main(args As String())
' Check that an argument was specified when the
' program was invoked.
If args.Length = 0 Then
Console.WriteLine("Error: The name of the host " & _
"computer must be specified when the program " & _
"is invoked.")
Return
End If
Dim remoteName As String = args(0)
' Create the underlying socket and connect to the server.
Dim clientSocket As New Socket(AddressFamily.InterNetwork, _
SocketType.Stream, ProtocolType.Tcp)
clientSocket.Connect(New IPEndPoint( _
Dns.Resolve(remoteName).AddressList(0), 1800))
Console.WriteLine("Client is connected." & vbCrLf)
' Create a NetworkStream that owns clientSocket and then
' create a BufferedStream on top of the NetworkStream.
Dim netStream As New NetworkStream(clientSocket, True)
Dim bufStream As New _
BufferedStream(netStream, streamBufferSize)
Try
' Check whether the underlying stream supports seeking.
If bufStream.CanSeek Then
Console.WriteLine("NetworkStream supports" & _
"seeking." & vbCrLf)
Else
Console.WriteLine("NetworkStream does not " & _
"support seeking." & vbCrLf)
End If
' Send and receive data.
If bufStream.CanWrite Then
SendData(netStream, bufStream)
End If
If bufStream.CanRead Then
ReceiveData(netStream, bufStream)
End If
Finally
' When bufStream is closed, netStream is in turn
' closed, which in turn shuts down the connection
' and closes clientSocket.
Console.WriteLine(vbCrLf & "Shutting down the connection.")
bufStream.Close()
End Try
End Sub
Shared Sub SendData(netStream As Stream, bufStream As Stream)
Dim startTime As DateTime
Dim networkTime As Double, bufferedTime As Double
' Create random data to send to the server.
Dim dataToSend(dataArraySize - 1) As Byte
Dim randomGenerator As New Random()
randomGenerator.NextBytes(dataToSend)
' Send the data using the NetworkStream.
Console.WriteLine("Sending data using NetworkStream.")
startTime = DateTime.Now
For i As Integer = 1 To numberOfLoops
netStream.Write(dataToSend, 0, dataToSend.Length)
Next i
networkTime = DateTime.Now.Subtract(startTime).TotalSeconds
Console.WriteLine("{0} bytes sent in {1} seconds." & vbCrLf, _
numberOfLoops * dataToSend.Length, _
networkTime.ToString("F1"))
' Send the data using the BufferedStream.
Console.WriteLine("Sending data using BufferedStream.")
startTime = DateTime.Now
For i As Integer = 1 To numberOfLoops
bufStream.Write(dataToSend, 0, dataToSend.Length)
Next i
bufStream.Flush()
bufferedTime = DateTime.Now.Subtract(startTime).TotalSeconds
Console.WriteLine("{0} bytes sent In {1} seconds." & vbCrLf, _
numberOfLoops * dataToSend.Length, _
bufferedTime.ToString("F1"))
' Print the ratio of write times.
Console.Write("Sending data using the buffered " & _
"network stream was {0}", _
(networkTime/bufferedTime).ToString("P0"))
If bufferedTime < networkTime Then
Console.Write(" faster")
Else
Console.Write(" slower")
End If
Console.WriteLine(" than using the network stream alone.")
End Sub
Shared Sub ReceiveData(netStream As Stream, bufStream As Stream)
Dim startTime As DateTime
Dim networkTime As Double, bufferedTime As Double = 0
Dim bytesReceived As Integer = 0
Dim receivedData(dataArraySize - 1) As Byte
' Receive data using the NetworkStream.
Console.WriteLine("Receiving data using NetworkStream.")
startTime = DateTime.Now
While bytesReceived < numberOfLoops * receivedData.Length
bytesReceived += netStream.Read( _
receivedData, 0, receivedData.Length)
End While
networkTime = DateTime.Now.Subtract(startTime).TotalSeconds
Console.WriteLine("{0} bytes received in {1} " & _
"seconds." & vbCrLf, _
bytesReceived.ToString(), _
networkTime.ToString("F1"))
' Receive data using the BufferedStream.
Console.WriteLine("Receiving data using BufferedStream.")
bytesReceived = 0
startTime = DateTime.Now
Dim numBytesToRead As Integer = receivedData.Length
Dim n As Integer
Do While numBytesToRead > 0
'Read my return anything from 0 to numBytesToRead
n = bufStream.Read(receivedData, 0, receivedData.Length)
'The end of the file is reached.
If n = 0 Then
Exit Do
End If
bytesReceived += n
numBytesToRead -= n
Loop
bufferedTime = DateTime.Now.Subtract(startTime).TotalSeconds
Console.WriteLine("{0} bytes received in {1} " & _
"seconds." & vbCrLf, _
bytesReceived.ToString(), _
bufferedTime.ToString("F1"))
' Print the ratio of read times.
Console.Write("Receiving data using the buffered " & _
"network stream was {0}", _
(networkTime/bufferedTime).ToString("P0"))
If bufferedTime < networkTime Then
Console.Write(" faster")
Else
Console.Write(" slower")
End If
Console.WriteLine(" than using the network stream alone.")
End Sub
End Class
示例 2：在服务器上运行的代码
#using <system.dll>
using namespace System;
using namespace System::Net;
using namespace System::Net::Sockets;
int main()
{
// This is a Windows Sockets 2 error code.
const int WSAETIMEDOUT = 10060;
Socket^ serverSocket;
int bytesReceived;
int totalReceived = 0;
array<Byte>^receivedData = gcnew array<Byte>(2000000);
// Create random data to send to the client.
array<Byte>^dataToSend = gcnew array<Byte>(2000000);
(gcnew Random)->NextBytes( dataToSend );
IPAddress^ ipAddress = Dns::Resolve( Dns::GetHostName() )->AddressList[ 0 ];
IPEndPoint^ ipEndpoint = gcnew IPEndPoint( ipAddress,1800 );
// Create a socket and listen for incoming connections.
Socket^ listenSocket = gcnew Socket( AddressFamily::InterNetwork,SocketType::Stream,ProtocolType::Tcp );
try
{
listenSocket->Bind( ipEndpoint );
listenSocket->Listen( 1 );
// Accept a connection and create a socket to handle it.
serverSocket = listenSocket->Accept();
Console::WriteLine( "Server is connected.\n" );
}
finally
{
listenSocket->Close();
}
try
{
// Send data to the client.
Console::Write( "Sending data ... " );
int bytesSent = serverSocket->Send( dataToSend, 0, dataToSend->Length, SocketFlags::None );
Console::WriteLine( "{0} bytes sent.\n", bytesSent.ToString() );
// Set the timeout for receiving data to 2 seconds.
serverSocket->SetSocketOption( SocketOptionLevel::Socket, SocketOptionName::ReceiveTimeout, 2000 );
// Receive data from the client.
Console::Write( "Receiving data ... " );
try
{
do
{
bytesReceived = serverSocket->Receive( receivedData, 0, receivedData->Length, SocketFlags::None );
totalReceived += bytesReceived;
}
while ( bytesReceived != 0 );
}
catch ( SocketException^ e )
{
if ( e->ErrorCode == WSAETIMEDOUT )
{
// Data was not received within the given time.
// Assume that the transmission has ended.
}
else
{
Console::WriteLine( "{0}: {1}\n", e->GetType()->Name, e->Message );
}
}
finally
{
Console::WriteLine( "{0} bytes received.\n", totalReceived.ToString() );
}
}
finally
{
serverSocket->Shutdown( SocketShutdown::Both );
Console::WriteLine( "Connection shut down." );
serverSocket->Close();
}
}
using System;
using System.Net;
using System.Net.Sockets;
public class Server
{
static void Main()
{
// This is a Windows Sockets 2 error code.
const int WSAETIMEDOUT = 10060;
Socket serverSocket;
int bytesReceived, totalReceived = 0;
byte[] receivedData = new byte[2000000];
// Create random data to send to the client.
byte[] dataToSend = new byte[2000000];
new Random().NextBytes(dataToSend);
IPAddress ipAddress =
Dns.Resolve(Dns.GetHostName()).AddressList[0];
IPEndPoint ipEndpoint = new IPEndPoint(ipAddress, 1800);
// Create a socket and listen for incoming connections.
using(Socket listenSocket = new Socket(
AddressFamily.InterNetwork, SocketType.Stream,
ProtocolType.Tcp))
{
listenSocket.Bind(ipEndpoint);
listenSocket.Listen(1);
// Accept a connection and create a socket to handle it.
serverSocket = listenSocket.Accept();
Console.WriteLine("Server is connected.\n");
}
try
{
// Send data to the client.
Console.Write("Sending data ... ");
int bytesSent = serverSocket.Send(
dataToSend, 0, dataToSend.Length, SocketFlags.None);
Console.WriteLine("{0} bytes sent.\n",
bytesSent.ToString());
// Set the timeout for receiving data to 2 seconds.
serverSocket.SetSocketOption(SocketOptionLevel.Socket,
SocketOptionName.ReceiveTimeout, 2000);
// Receive data from the client.
Console.Write("Receiving data ... ");
try
{
do
{
bytesReceived = serverSocket.Receive(receivedData,
0, receivedData.Length, SocketFlags.None);
totalReceived += bytesReceived;
}
while(bytesReceived != 0);
}
catch(SocketException e)
{
if(e.ErrorCode == WSAETIMEDOUT)
{
// Data was not received within the given time.
// Assume that the transmission has ended.
}
else
{
Console.WriteLine("{0}: {1}\n",
e.GetType().Name, e.Message);
}
}
finally
{
Console.WriteLine("{0} bytes received.\n",
totalReceived.ToString());
}
}
finally
{
serverSocket.Shutdown(SocketShutdown.Both);
Console.WriteLine("Connection shut down.");
serverSocket.Close();
}
}
}
module Server
open System
open System.Net
open System.Net.Sockets
// This is a Windows Sockets 2 error code.
let WSAETIMEDOUT = 10060
let mutable bytesReceived = -1
let mutable totalReceived = 0
let receivedData = Array.zeroCreate 2000000
// Create random data to send to the client.
let dataToSend = Array.zeroCreate 2000000
Random().NextBytes dataToSend
let ipAddress = Dns.GetHostEntry(Dns.GetHostName()).AddressList[0]
let ipEndpoint = IPEndPoint(ipAddress, 1800)
// Create a socket and listen for incoming connections.
let serverSocket =
use listenSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
listenSocket.Bind ipEndpoint
listenSocket.Listen 1
// Accept a connection and create a socket to handle it.
listenSocket.Accept()
printfn "Server is connected.\n"
try
// Send data to the client.
printf "Sending data ... "
let bytesSent = serverSocket.Send(dataToSend, 0, dataToSend.Length, SocketFlags.None)
printfn $"{bytesSent} bytes sent.\n"
// Set the timeout for receiving data to 2 seconds.
serverSocket.SetSocketOption(SocketOptionLevel.Socket,
SocketOptionName.ReceiveTimeout, 2000)
// Receive data from the client.
printf "Receiving data ... "
try
try
while bytesReceived <> 0 do
bytesReceived <- serverSocket.Receive(receivedData, 0, receivedData.Length, SocketFlags.None)
totalReceived <- totalReceived + bytesReceived
with :? SocketException as e ->
if e.ErrorCode = WSAETIMEDOUT then
// Data was not received within the given time.
// Assume that the transmission has ended.
()
else
printfn $"{e.GetType().Name}: {e.Message}\n"
finally
printfn $"{totalReceived} bytes received.\n"
finally
serverSocket.Shutdown SocketShutdown.Both
printfn "Connection shut down."
serverSocket.Close()
' Compile using /r:System.dll.
Imports System.Net
Imports System.Net.Sockets
Public Class Server
Shared Sub Main()
' This is a Windows Sockets 2 error code.
Const WSAETIMEDOUT As Integer = 10060
Dim serverSocket As Socket
Dim bytesReceived As Integer
Dim totalReceived As Integer = 0
Dim receivedData(2000000-1) As Byte
' Create random data to send to the client.
Dim dataToSend(2000000-1) As Byte
Dim randomGenerator As New Random()
randomGenerator.NextBytes(dataToSend)
Dim ipAddress As IPAddress = _
Dns.Resolve(Dns.GetHostName()).AddressList(0)
Dim ipEndpoint As New IPEndPoint(ipAddress, 1800)
' Create a socket and listen for incoming connections.
Dim listenSocket As New Socket(AddressFamily.InterNetwork, _
SocketType.Stream, ProtocolType.Tcp)
Try
listenSocket.Bind(ipEndpoint)
listenSocket.Listen(1)
' Accept a connection and create a socket to handle it.
serverSocket = listenSocket.Accept()
Console.WriteLine("Server is connected." & vbCrLf)
Finally
listenSocket.Close()
End Try
Try
' Send data to the client.
Console.Write("Sending data ... ")
Dim bytesSent As Integer = serverSocket.Send( _
dataToSend, 0, dataToSend.Length, SocketFlags.None)
Console.WriteLine("{0} bytes sent." & vbCrLf, _
bytesSent.ToString())
' Set the timeout for receiving data to 2 seconds.
serverSocket.SetSocketOption(SocketOptionLevel.Socket, _
SocketOptionName.ReceiveTimeout, 2000)
' Receive data from the client.
Console.Write("Receiving data ... ")
Try
Do
bytesReceived = serverSocket.Receive( _
receivedData, 0, receivedData.Length, _
SocketFlags.None)
totalReceived += bytesReceived
Loop While bytesReceived <> 0
Catch e As SocketException
If(e.ErrorCode = WSAETIMEDOUT)
' Data was not received within the given time.
' Assume that the transmission has ended.
Else
Console.WriteLine("{0}: {1}" & vbCrLf, _
e.GetType().Name, e.Message)
End If
Finally
Console.WriteLine("{0} bytes received." & vbCrLf, _
totalReceived.ToString())
End Try
Finally
serverSocket.Shutdown(SocketShutdown.Both)
Console.WriteLine("Connection shut down.")
serverSocket.Close()
End Try
End Sub
End Class
注解
缓冲区是内存中用于缓存数据的字节块，从而减少对操作系统的调用数。 缓冲区可提高读取和写入性能。 缓冲区可用于读取或写入，但绝不同时使用两者。
BufferedStream 的 Read 和 Write 方法会自动维护缓冲区。
重要
此类型实现 IDisposable 接口。 使用完该类型后，应直接或间接释放它。 若要直接释放类型，请在 try/catch 块中调用其 Dispose 方法。 若要间接处理它，请使用语言构造（如 using（在 C# 中）或 Using（在 Visual Basic 中）。 有关详细信息，请参阅 IDisposable 接口主题中的“使用实现 IDisposable 的对象”部分。
BufferedStream 可以围绕某些类型的流组成。 它提供用于读取和写入基础数据源或存储库的字节的实现。 使用 BinaryReader 和 BinaryWriter 读取和写入其他数据类型。
BufferedStream 旨在防止缓冲区在不需要缓冲区时减慢输入和输出速度。 如果始终读取和写入大于内部缓冲区大小的大小，则 BufferedStream 甚至可能不会分配内部缓冲区。
BufferedStream 还缓冲共享缓冲区中的读取和写入。 假设你几乎总是执行一系列读取或写入操作，但很少在两个读取或写入之间交替。
构造函数
| BufferedStream(Stream) |
使用默认缓冲区大小为 4096 字节初始化 BufferedStream 类的新实例。 |
| BufferedStream(Stream, Int32) |
使用指定的缓冲区大小初始化 BufferedStream 类的新实例。 |
属性
| BufferSize |
获取此缓冲流的缓冲区大小（以字节为单位）。 |
| CanRead |
获取一个值，该值指示当前流是否支持读取。 |
| CanSeek |
获取一个值，该值指示当前流是否支持查找。 |
| CanTimeout |
获取一个值，该值确定当前流是否可以超时。 (继承自 Stream) |
| CanWrite |
获取一个值，该值指示当前流是否支持写入。 |
| Length |
获取流长度（以字节为单位）。 |
| Position |
获取当前流中的位置。 |
| ReadTimeout |
获取或设置一个值（以毫秒为单位），该值确定流在超时前尝试读取的时间。 (继承自 Stream) |
| UnderlyingStream |
获取此缓冲流的基础 Stream 实例。 |
| WriteTimeout |
获取或设置一个值（以毫秒为单位），该值确定流在超时之前尝试写入的时间。 (继承自 Stream) |
方法
显式接口实现
| IDisposable.Dispose() |
释放 Stream使用的所有资源。 (继承自 Stream) |
扩展方法
| CopyToAsync(Stream, PipeWriter, CancellationToken) |
使用取消令牌从 Stream 异步读取字节并将其写入指定的 PipeWriter。 |
| ConfigureAwait(IAsyncDisposable, Boolean) |
配置如何执行从异步可释放项返回的任务的 await。 |
