Updated generic HTTP output to support websockets. Added basic websocket JSON push support.

src/output/output_http.cpp

@@ -8,11 +8,21 @@
 
 namespace Mist {
   HTTPOutput::HTTPOutput(Socket::Connection & conn) : Output(conn) {
+    webSock = 0;
+    idleInterval = 0;
+    idleLast = 0;
     if (config->getString("ip").size()){
       myConn.setHost(config->getString("ip"));
     }
     config->activate();
   }
+
+  HTTPOutput::~HTTPOutput() {
+    if (webSock){
+      delete webSock;
+      webSock = 0;
+    }
+  }
   
   void HTTPOutput::init(Util::Config * cfg){
     Output::init(cfg);
@@ -152,6 +162,21 @@ namespace Mist {
   }
   
   void HTTPOutput::requestHandler(){
+    if (idleInterval && (Util::bootMS() > idleLast + idleInterval)){
+      onIdle();
+      idleLast = Util::bootMS();
+    }
+    if (webSock){
+      if (webSock->readFrame()){
+        onWebsocketFrame();
+        idleLast = Util::bootMS();
+      }else{
+        if (!isBlocking && !parseData){
+          Util::sleep(100);
+        }
+      }
+      return;
+    }
     if (myConn.Received().size() && myConn.spool()){
       DEBUG_MSG(DLVL_DONTEVEN, "onRequest");
       onRequest();
@@ -199,12 +224,14 @@ namespace Mist {
             onRequest();
           }
           if (!myConn.Received().size()){
-            Util::sleep(500);
+            if (!isBlocking && !parseData){
+              Util::sleep(100);
+            }
           }
         }
       }else{
         if (!isBlocking && !parseData){
-          Util::sleep(500);
+          Util::sleep(100);
         }
       }
     }
@@ -232,8 +259,23 @@ namespace Mist {
       if (H.GetVar("audio") != ""){targetParams["audio"] = H.GetVar("audio");}
       if (H.GetVar("video") != ""){targetParams["video"] = H.GetVar("video");}
       if (H.GetVar("subtitle") != ""){targetParams["subtitle"] = H.GetVar("subtitle");}
+      //Handle upgrade to websocket if the output supports it
+      if (doesWebsockets() && H.GetHeader("Upgrade") == "websocket"){
+        INFO_MSG("Switching to Websocket mode");
+        preWebsocketConnect();
+        webSock = new HTTP::Websocket(myConn, H);
+        if (!(*webSock)){
+          delete webSock;
+          webSock = 0;
+          return;
+        }
+        onWebsocketConnect();
+        H.Clean();
+        return;
+      }
       preHTTP();
       onHTTP();
+      idleLast = Util::bootMS();
       if (!H.bufferChunks){
         H.Clean();
       }

src/output/output_http.h

@@ -1,6 +1,7 @@
 #pragma once
 #include <mist/defines.h>
 #include <mist/http_parser.h>
+#include <mist/websocket.h>
 #include "output.h"
 
 namespace Mist {
@@ -8,19 +9,27 @@ namespace Mist {
   class HTTPOutput : public Output {
     public:
       HTTPOutput(Socket::Connection & conn);
-      virtual ~HTTPOutput(){};
+      virtual ~HTTPOutput();
       static void init(Util::Config * cfg);
       void onRequest();
       virtual void onFail();
       virtual void onHTTP(){};
+      virtual void onIdle(){};
+      virtual void onWebsocketFrame(){};
+      virtual void onWebsocketConnect(){};
+      virtual void preWebsocketConnect(){};
       virtual void requestHandler();
       virtual void preHTTP();
       static bool listenMode(){return false;}
+      virtual bool doesWebsockets(){return false;}
       void reConnector(std::string & connector);
       std::string getHandler();
       bool parseRange(uint64_t & byteStart, uint64_t & byteEnd);
   protected:
       HTTP::Parser H;
+      HTTP::Websocket * webSock;
+      uint32_t idleInterval;
+      uint64_t idleLast;
       std::string getConnectedHost();//LTS
       std::string getConnectedBinHost();//LTS
       bool isTrustedProxy(const std::string & ip);//LTS

src/output/output_json.cpp

@@ -4,18 +4,13 @@
 
 namespace Mist {
   OutJSON::OutJSON(Socket::Connection & conn) : HTTPOutput(conn){
-    ws = 0;
     realTime = 0;
+    bootMsOffset = 0;
     keepReselecting = false;
     dupcheck = false;
+    noReceive = false;
   }
-  OutJSON::~OutJSON() {
+
-    if (ws){
-      delete ws;
-      ws = 0;
-    }
-  }
-  
   void OutJSON::init(Util::Config * cfg){
     HTTPOutput::init(cfg);
     capa["name"] = "JSON";
@@ -31,7 +26,7 @@ namespace Mist {
     capa["methods"][1u]["priority"] = 0ll;
     capa["methods"][1u]["url_rel"] = "/$.json";
   }
-  
+
   void OutJSON::sendNext(){
     JSON::Value jPack = thisPacket.toJSON();
     if (dupcheck){
@@ -40,8 +35,8 @@ namespace Mist {
       }
       lastVal = jPack;
     }
-    if (ws){
+    if (webSock){
-      ws->sendFrame(jPack.toString());
+      webSock->sendFrame(jPack.toString());
       return;
     }
     if (!jsonp.size()){
@@ -83,7 +78,7 @@ namespace Mist {
     static bool recursive = false;
     if (recursive){return true;}
     recursive = true;
-    if (keepReselecting){
+    if (keepReselecting && !isPushing()){
       uint64_t maxTimer = 7200;
       while (--maxTimer && nProxy.userClient.isAlive() && keepGoing()){
         Util::wait(500);
@@ -99,18 +94,23 @@ namespace Mist {
         }
       }
       recursive = false;
-      return false;
     }
     if (!jsonp.size() && !first){
-      myConn.SendNow("]);\n\n", 5);
+      myConn.SendNow("]\n", 2);
     }
     myConn.close();
     return false;
   }
 
-  void OutJSON::onHTTP(){
+  void OutJSON::onWebsocketConnect(){
-    std::string method = H.method;
+    sentHeader = true;
-    jsonp = "";
+    parseData = !noReceive;
+  }
+
+  void OutJSON::preWebsocketConnect(){
+    if (H.GetVar("password") != ""){pushPass = H.GetVar("password");}
+    if (H.GetVar("password").size() || H.GetVar("push").size()){noReceive = true;}
+  
     if (H.GetVar("persist") != ""){keepReselecting = true;}
     if (H.GetVar("dedupe") != ""){
       dupcheck = true;
@@ -126,22 +126,84 @@ namespace Mist {
         }
       }
     }
+  }
+
+  void OutJSON::onWebsocketFrame(){
+    if (!isPushing()){
+      if (!allowPush(pushPass)){
+        onFinish();
+        return;
+      }
+    }
+    if (!bootMsOffset){
+      if (myMeta.bootMsOffset){
+        bootMsOffset = myMeta.bootMsOffset;
+      }else{
+        bootMsOffset = Util::bootMS();
+      }
+    }
+    //We now know we're allowed to push. Read a JSON object.
+    JSON::Value inJSON = JSON::fromString(webSock->data, webSock->data.size());
+    if (!inJSON || !inJSON.isObject()){
+      //Ignore empty and/or non-parsable JSON packets
+      MEDIUM_MSG("Ignoring non-JSON object: %s", webSock->data);
+      return;
+    }
+    //Let's create a new track for pushing purposes, if needed
+    if (!pushTrack){
+      pushTrack = 1;
+      while (myMeta.tracks.count(pushTrack)){
+        ++pushTrack;
+      }
+    }
+    myMeta.tracks[pushTrack].type = "meta";
+    myMeta.tracks[pushTrack].codec = "JSON";
+    //We have a track set correctly. Let's attempt to buffer a frame.
+    inJSON["trackid"] = (long long)pushTrack;
+    inJSON["datatype"] = "meta";
+    lastSendTime = Util::bootMS();
+    if (!inJSON.isMember("unix")){
+      //Base timestamp on arrival time
+      inJSON["time"] = (long long)(lastSendTime - bootMsOffset);
+    }else{
+      //Base timestamp on unix time
+      inJSON["time"] = (long long)((lastSendTime - bootMsOffset) + (Util::epoch() - Util::bootSecs()) * 1000);
+    }
+    inJSON["bmo"] = (long long)bootMsOffset;
+    lastVal = inJSON;
+    std::string packedJson = inJSON.toNetPacked();
+    DTSC::Packet newPack(packedJson.data(), packedJson.size(), true);
+    bufferLivePacket(newPack);
+    if (!idleInterval){idleInterval = 100;}
+    if (isBlocking){setBlocking(false);}
+  }
+
+  /// Repeats last JSON packet every 5 seconds to keep stream alive.
+  void OutJSON::onIdle(){
+    if (nProxy.trackState[pushTrack] != FILL_ACC){
+      continueNegotiate(pushTrack);
+      if (nProxy.trackState[pushTrack] == FILL_ACC){
+        idleInterval = 5000;
+      }
+      return;
+    }
+    lastVal["time"] = (long long)(lastVal["time"].asInt() + (Util::bootMS() - lastSendTime));
+    lastSendTime = Util::bootMS();
+    lastVal.netPrepare();
+    std::string packedJson = lastVal.toNetPacked();
+    DTSC::Packet newPack(packedJson.data(), packedJson.size(), true);
+    myMeta.tracks[pushTrack].type = "meta";
+    myMeta.tracks[pushTrack].codec = "JSON";
+    bufferLivePacket(newPack);
+  }
+
+  void OutJSON::onHTTP(){
+    std::string method = H.method;
+    preWebsocketConnect();//Not actually a websocket, but we need to do the same checks
+    jsonp = "";
     if (H.GetVar("callback") != ""){jsonp = H.GetVar("callback");}
     if (H.GetVar("jsonp") != ""){jsonp = H.GetVar("jsonp");}
     
-    if (H.GetHeader("Upgrade") == "websocket"){
-      ws = new HTTP::Websocket(myConn, H);
-      if (!(*ws)){
-        delete ws;
-        ws = 0;
-        return;
-      }
-      sentHeader = true;
-      parseData = true;
-      wantRequest = false;
-      return;
-    }
-
     H.Clean();
     H.setCORSHeaders();
     if(method == "OPTIONS" || method == "HEAD"){

src/output/output_json.h

@@ -5,21 +5,29 @@ namespace Mist {
   class OutJSON : public HTTPOutput {
     public:
       OutJSON(Socket::Connection & conn);
-      ~OutJSON();
       static void init(Util::Config * cfg);
       void onHTTP();
+      void onIdle();
+      virtual void onWebsocketFrame();
+      virtual void onWebsocketConnect();
+      virtual void preWebsocketConnect();
       bool onFinish();
       void onFail();
       void sendNext();
       void sendHeader();
+      bool doesWebsockets(){return true;}
     protected:
       JSON::Value lastVal;
+      uint64_t lastSendTime;
       bool keepReselecting;
       std::string jsonp;
+      std::string pushPass;
+      uint64_t pushTrack;
+      int64_t bootMsOffset;
       bool dupcheck;
       std::set<std::string> nodup;
       bool first;
-      HTTP::Websocket * ws;
+      bool noReceive;
   };
 }