在前两讲《初探.Net Remoting服务端 Loading Remtoing配置内容的过程 》《初探.Net Remoting客户端 Loading Remtoing配置内容的过程 》中,我已经分析了Remoting 的Sink机制,接下来,就提供一个具体的范例:CompressionSink(原始SourceCode源于Advanced .Net Remoting 1StED)。 CompressionSink通过在客户端和服务端各自插入一个数据压缩-解压缩的Sink。目的是希望减少大数据量传递对网络带宽的占用,提高传输效率。下载SourceCode ,BTW,这个压缩Sink相对比较稳定,大家可以在各自的项目中放心使用。:-)
详细设计:
提供一个Assembly: CompressionSink.dll
它包括:
客户端:
CompressionSink.CompressionClientSinkProvider类和CompressionSink.CompressionClientSink类
服务端:
CompressionSink.CompressionServerSinkProvider类和CompressionSink.CompressionServerSink类
压缩类:CompressionHelper
压缩内核:NZipLib库。
客户端的配置文件 :
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.runtime.remoting>
<application>
<channels>
<channel ref="http">
<clientProviders>
<formatter ref="soap" />
<provider type="CompressionSink.CompressionClientSinkProvider, CompressionSink" />
</clientProviders>
</channel>
</channels>
<client>
<wellknown type="Service.SomeSAO, Service" url="http://localhost:5555/SomeSAO.soap" />
</client>
</application>
</system.runtime.remoting>
</configuration>
服务端的配置文件 :
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.runtime.remoting>
<application>
<channels>
<channel ref="http" port="5555">
<serverProviders>
<provider type="CompressionSink.CompressionServerSinkProvider, CompressionSink" />
<formatter ref="soap"/>
</serverProviders>
</channel>
</channels>
<service>
<wellknown mode="Singleton" type="Service.SomeSAO, Service" objectUri="SomeSAO.soap" />
</service>
</application>
</system.runtime.remoting>
</configuration>
{
private IClientChannelSinkProvider _nextProvider;
public CompressionClientSinkProvider(IDictionary properties, ICollection providerData)
{
// not yet needed
}
public IClientChannelSinkProvider Next
{
get {
return _nextProvider;
}
set {
_nextProvider = value;
}
}
public IClientChannelSink CreateSink(IChannelSender channel, string url, object remoteChannelData)
{
// create other sinks in the chain
IClientChannelSink next = _nextProvider.CreateSink(channel,
url,
remoteChannelData);
// put our sink on top of the chain and return it
return new CompressionClientSink(next);
}
}
2 IClientChannelSink
3 {
4 private IClientChannelSink _nextSink;
5
6 public CompressionClientSink(IClientChannelSink next)
7 {
8 _nextSink = next;
9 }
10
11 public IClientChannelSink NextChannelSink
12 {
13 get {
14 return _nextSink;
15 }
16 }
17
18
19 public void AsyncProcessRequest(IClientChannelSinkStack sinkStack,
20 IMessage msg,
21 ITransportHeaders headers,
22 Stream stream)
23 {
24
25
26 // generate a compressed stream using NZipLib
27 stream = CompressionHelper.getCompressedStreamCopy(stream);
28
29 // push onto stack and forward the request
30 sinkStack.Push(this,null);
31 _nextSink.AsyncProcessRequest(sinkStack,msg,headers,stream);
32 }
33
34
35 public void AsyncProcessResponse(IClientResponseChannelSinkStack sinkStack,
36 object state,
37 ITransportHeaders headers,
38 Stream stream)
39 {
40
41 // deflate the response
42 stream =
43 CompressionHelper.getUncompressedStreamCopy(stream);
44
45 // forward the request
46 sinkStack.AsyncProcessResponse(headers,stream);
47 }
48
49
50 public Stream GetRequestStream(IMessage msg,
51 ITransportHeaders headers)
52 {
53 return _nextSink.GetRequestStream(msg, headers);
54 }
55
56
57 public void ProcessMessage(IMessage msg,
58 ITransportHeaders requestHeaders,
59 Stream requestStream,
60 out ITransportHeaders responseHeaders,
61 out Stream responseStream)
62 {
63 // generate a compressed stream using NZipLib
64
65 Stream localrequestStream =
66 CompressionHelper.getCompressedStreamCopy(requestStream);
67
68 Stream localresponseStream;
69 // forward the call to the next sink
70 _nextSink.ProcessMessage(msg,
71 requestHeaders,
72 localrequestStream,
73 out responseHeaders,
74 out localresponseStream);
75
76 // deflate the response
77 responseStream =
78 CompressionHelper.getUncompressedStreamCopy(localresponseStream);
79
80 }
81 }
2 {
3 private IServerChannelSinkProvider _nextProvider;
4
5 public CompressionServerSinkProvider(IDictionary properties, ICollection providerData)
6 {
7 // not yet needed
8 }
9
10 public IServerChannelSinkProvider Next
11 {
12 get {
13 return<