Async iterator pattern using CCR

[NewsBot]

Here is a chunky version of a large file copy using all async calls and CCr.* Can be modifed to any in or out stream type. Note we don't ever expect to see same number of bytes each read - so this pattern works with network streams too that often return less then number of bytes we request per read.*

******* private void button11_Click(object sender, EventArgs e)

******* {

*********** DispatcherQueue dq = new DispatcherQueue();

*********** Arbiter.Activate(dq,

*************** Arbiter.FromIteratorHandler(()=> CcrCopyFile(@"c:\temp\file1.exe", @"c:\temp\file2.exe")));

******* }

******* ///

******* /// Use CCR to copy file async in 8K chunks using iterator method.

******* ///

******* IEnumerator CcrCopyFile(string inPath, string outPath)

******* {

*********** var resultPort = new Port();

*********** long totCopied = 0;

*********** using (FileStream fsIn = new FileStream(inPath, FileMode.Open, FileAccess.Read, FileShare.Read, 8192, true))

*********** using (FileStream fsOut = new FileStream(outPath, FileMode.Create, FileAccess.Write, FileShare.None, 8192, true))

*********** {

*************** byte[] buf = new byte[8192];

*************** int bytesRead = 0;

*************** do

*************** {

******************* // Read.

******************* IAsyncResult ar = null;

******************* fsIn.BeginRead(buf, 0, buf.Length - 1, resultPort.Post, null);

******************* yield return Arbiter.Receive(false, resultPort, (IAsyncResult ar2) => ar = ar2);

******************* bytesRead = fsIn.EndRead(ar);

******************* // Write.

******************* fsOut.BeginWrite(buf, 0, bytesRead, resultPort.Post, null);

******************* yield return Arbiter.Receive(false, resultPort, (IAsyncResult ar2) => ar = ar2);

******************* fsOut.EndWrite(ar);

******************* totCopied += bytesRead;

*************** } while (bytesRead > 0);

*********** }

*********** Console.WriteLine("Total bytes copied:{0}\nIn:{1}\nOut:{2}", totCopied, inPath, outPath);

******* }

 

 

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