From 2486e124c1985a5a70bd63590da61a73a5a2e715 Mon Sep 17 00:00:00 2001
From: Sergey Linev <S.Linev@gsi.de>
Date: Tue, 18 Apr 2017 15:05:37 +0200
Subject: [PATCH] http: provide lonpoll handler similar to websocket
It uses open requests to send data directly from server.
For the moment buffers queue depth=1, but can be easily improved
---
net/http/inc/THttpEngine.h | 4 ++-
net/http/src/THttpEngine.cxx | 17 +++++-----
net/http/src/THttpServer.cxx | 65 +++++++++++++++++++++++++++++++-----
3 files changed, 68 insertions(+), 18 deletions(-)
diff --git a/net/http/inc/THttpEngine.h b/net/http/inc/THttpEngine.h
index 3afaa668217..efeecb1f034 100644
--- a/net/http/inc/THttpEngine.h
+++ b/net/http/inc/THttpEngine.h
@@ -68,10 +68,12 @@ public:
virtual void SendCharStar(const char *str);
- virtual void ProcessData(THttpCallArg *arg);
+ virtual Bool_t PreviewData(THttpCallArg *) { return kTRUE; }
// --------- method to work with Canvas (temporary solution)
+ virtual void ProcessData(THttpCallArg *arg);
+
virtual void AssignCanvas(TCanvas *canv);
virtual void CanvasModified();
diff --git a/net/http/src/THttpEngine.cxx b/net/http/src/THttpEngine.cxx
index 7dc6901cd98..d0a637afe9e 100644
--- a/net/http/src/THttpEngine.cxx
+++ b/net/http/src/THttpEngine.cxx
@@ -66,6 +66,15 @@ THttpWSEngine::~THttpWSEngine()
AssignCanvas(0);
}
+////////////////////////////////////////////////////////////////////////////////
+/// Envelope for sending string via the websocket
+
+void THttpWSEngine::SendCharStar(const char *str)
+{
+ if (str) Send(str, strlen(str));
+}
+
+
////////////////////////////////////////////////////////////////////////////////
/// react on canvas modifications
@@ -190,14 +199,6 @@ void THttpWSEngine::ProcessData(THttpCallArg *arg)
}
}
-////////////////////////////////////////////////////////////////////////////////
-/// Envelope for sending string via the websocket
-
-void THttpWSEngine::SendCharStar(const char *str)
-{
- if (str) Send(str, strlen(str));
-}
-
////////////////////////////////////////////////////////////////////////////////
/// assign canvas to the web socket
/// connects with CanvasModified signal
diff --git a/net/http/src/THttpServer.cxx b/net/http/src/THttpServer.cxx
index b355af83fa5..20d090425cc 100644
--- a/net/http/src/THttpServer.cxx
+++ b/net/http/src/THttpServer.cxx
@@ -70,11 +70,12 @@ public:
class TLongPollEngine : public THttpWSEngine {
protected:
- THttpCallArg *fPoll; ///< polling connection, which can be used for the sending next operation
+ THttpCallArg *fPoll; ///< polling request, which can be used for the next sending
+ TString fBuf; ///< single entry to keep data which is not yet send to the client
public:
TLongPollEngine(const char *name, const char *title)
- : THttpWSEngine(name, title), fPoll(0)
+ : THttpWSEngine(name, title), fPoll(0), fBuf()
{
}
@@ -82,14 +83,53 @@ public:
virtual UInt_t GetId() const { return TString::Hash((void *)this, sizeof(void *)); }
- virtual void ClearHandle() { fPoll = 0; }
+ virtual void ClearHandle()
+ {
+ if (fPoll) { fPoll->Set404(); fPoll->NotifyCondition(); fPoll = 0; }
+ }
- virtual void Send(const void *buf, int len)
+ virtual void Send(const void * /*buf*/, int /*len*/)
{
+ Error("TLongPollEngine::Send", "Should never be called, only text is supported");
}
virtual void SendCharStar(const char *buf)
{
+ if (fPoll) {
+ fPoll->SetContentType("text/plain");
+ fPoll->SetContent(buf);
+ fPoll->NotifyCondition();
+ fPoll = 0;
+ } else
+ if (fBuf.Length() == 0) {
+ fBuf = buf;
+ } else {
+ Error("TLongPollEngine::SendCharStar", "Too many send operations, use TList object instead");
+ }
+ }
+
+ virtual Bool_t PreviewData(THttpCallArg *arg)
+ {
+ // function called in the user code before processing correspondent websocket data
+
+ if (fPoll) {
+ // if there are pending request, reply it immediately
+ fPoll->SetContentType("text/plain");
+ fPoll->SetContent("");
+ fPoll->NotifyCondition();
+ fPoll = 0;
+ }
+
+ if (fBuf.Length() > 0) {
+ arg->SetContentType("text/plain");
+ arg->SetContent(fBuf.Data());
+ fBuf = "";
+ } else {
+ arg->SetPostponed();
+ fPoll = arg;
+ }
+
+ return kTRUE;
}
};
@@ -518,7 +558,7 @@ void THttpServer::ProcessRequests()
fSniffer->SetCurrentCallArg(0);
}
- arg->fCond.notify_one();
+ arg->NotifyCondition();
}
// regularly call Process() method of engine to let perform actions in ROOT context
@@ -722,7 +762,7 @@ void THttpServer::ProcessRequest(THttpCallArg *arg)
// try to emulate websocket connect
// if accepted, reply with connection id, which must be used in the following communications
arg->SetMethod("WS_CONNECT");
- if (canv->GetCanvasImp()->ProcessWSRequest(arg) && !arg->Is404()) {
+ if (canv->GetCanvasImp()->ProcessWSRequest(arg)) {
arg->SetMethod("WS_READY");
TLongPollEngine* handle = new TLongPollEngine("longpoll", arg->fPathName.Data());
@@ -730,19 +770,26 @@ void THttpServer::ProcessRequest(THttpCallArg *arg)
arg->SetWSId(handle->GetId());
arg->SetWSHandle(handle);
- if (canv->GetCanvasImp()->ProcessWSRequest(arg) && !arg->Is404())
+ if (canv->GetCanvasImp()->ProcessWSRequest(arg)) {
arg->SetContent(TString::Format("%u",arg->GetWSId()));
+ arg->SetContentType("text/plain");
+ }
}
+ if (!arg->IsContentType("text/plain"))
+ arg->Set404();
} else {
TUrl url;
url.SetOptions(arg->fQuery);
url.ParseOptions();
Int_t connid = url.GetIntValueFromOptions("connection");
arg->SetWSId((UInt_t)connid);
- if (url.HasOption("close"))
+ if (url.HasOption("close")) {
arg->SetMethod("WS_CLOSE");
- else
+ arg->SetContent("OK");
+ arg->SetContentType("text/plain");
+ } else {
arg->SetMethod("WS_DATA");
+ }
if (!canv->GetCanvasImp()->ProcessWSRequest(arg)) arg->Set404();
}
return;
--
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