/*
* bool DownloadPage(DownloadMessage msg)
* {
* var origmsg = msg;
* var tcs = new TaskCompletionSource<GotContentMessage>();
* var gotMsg = new GotContentMessage(msg);
* Client.GetAsync(msg.DownloadUri,HttpCompletionOption.ResponseContentRead)
* .ContinueWith((response, origmsg2) => { response.Result.Content.ReadAsStringAsync();
* return tcs.Task;
* })
* .ContinueWith(t2=> DoResponse(t2))
* .PipeTo(Self);
* return true; // show ActorSystem we handled message [expect next one immediately!]
* }
*/
/// <summary>
/// process incoming DownloadMessage
/// </summary>
/// <param name="msg">incoming msg<see cref="DownloadMessage"/></param>
/// <returns>true to state that message has been accepted</returns>
internal bool DownloadPage(DownloadMessage msg)
{
var uri = msg.DownloadUri;
SysDiag.Debug.Assert(uri.IsAbsoluteUri, $"DownloadActor.DownloadPage({uri}) called with non-absolute Url");
var fs = msg.TargetPath;
var fi = new FileInfo(fs);
var dn = fi.DirectoryName; // string representing the directory's full path
if (Directory.Exists(dn))
{
if (msg.EnumDisposition == DownloadMessage.E_FileDisposition.LeaveIfExists &&
File.Exists(fs))
{
var failmsg = new DownloadedMessage(msg, fs, HttpStatusCode.NotModified);
Sender.Tell(failmsg);
}
}
else
{
_Log.Info("DownloadPage creating directory {0} for {1}.{2}", dn, fi.Name, fi.Extension);
Directory.CreateDirectory(dn);
}
// preserve volatile state now (before t1 that starts hot) for use by subsequent completion
var ctx1 = new Context1(Sender, msg);
var t1 = Client.GetAsync(uri, HttpCompletionOption.ResponseHeadersRead); // returns Task<HttpResponseMessage>
var t2A = t1.ContinueWith((req, state) =>
{
var ctx1A = state as Context1; // recover entry context
var dlmsg = ctx1A.DownloadMessage;
var status = req.Result.StatusCode;
if (req.IsFaulted)
{
var s = "";
Console.WriteLine();
PostBack(dlmsg, ctx1A, status, req.Exception);
}
else
{
var hrm = req.Result;
try
{
hrm.EnsureSuccessStatusCode(); // throw if !IsSuccessStatusCode
// TODO: refine the destination filename.extn from the response
// TODO: decide if file already exists and if overwrite/transform
#pragma warning disable GCop302 // Since '{0}' implements IDisposable, wrap it in a using() statement
var outfs = new FileStream(fs, FileMode.Create); // open stream to write file. Disposed later !
#pragma warning restore GCop302 // Since '{0}' implements IDisposable, wrap it in a using() statement
_Log.Info($"DownloadActor.DownloadPage({msg.Url} => {fs}) started");
}
catch (Exception excp1)
{
PostBack(dlmsg, ctx1A, status, excp1);
}
}
}, ctx1);
var t2 = t1.ContinueWith(GetStuff,
ctx1,
TaskContinuationOptions.OnlyOnRanToCompletion); // happy path (no cancel/fault)
var t2F = t1.ContinueWith((req2, state) =>
{
var ctx1f = (Context1)state;
},
TaskContinuationOptions.NotOnRanToCompletion);
var t3 = t2.ContinueWith(t_gotContent)
.PipeTo(Self); // Task
return(true); // show ActorSystem we handled message [expect next one immediately!]
}
/// <summary>
/// The PostBack
/// </summary>
/// <param name="dlmsg">The dlmsg<see cref="DownloadMessage"/></param>
/// <param name="ctx1A">The ctx1A<see cref="Context1"/></param>
/// <param name="status">The status<see cref="HttpStatusCode"/></param>
/// <param name="excp1">The excp1<see cref="Exception"/></param>
private static void PostBack(DownloadMessage dlmsg, Context1 ctx1A, HttpStatusCode status, Exception excp1)
{
var failmsg = new DownloadedMessage(dlmsg, ctx1A.DownloadMessage.TargetPath, status, excp1);
ctx1A.OrigSender.Tell(failmsg);
}