Added global configuration mechanism and defaultStream support

lib/defines.h

@@ -133,6 +133,7 @@ static inline void show_stackframe(){}
 #define SHM_STREAM_INDEX "MstSTRM%s" //%s stream name
 #define SHM_STREAM_STATE "MstSTATE%s" //%s stream name
 #define SHM_STREAM_CONF "MstSCnf%s" //%s stream name
+#define SHM_GLOBAL_CONF "MstGlobalConfig"
 #define STRMSTAT_OFF 0
 #define STRMSTAT_INIT 1
 #define STRMSTAT_BOOT 2

lib/stream.cpp

@@ -205,12 +205,44 @@ JSON::Value Util::getStreamConfig(const std::string &streamname){
   Util::DTSCShmReader rStrmConf(tmpBuf);
   DTSC::Scan stream_cfg = rStrmConf.getScan();
   if (!stream_cfg){
-    WARN_MSG("Could not get stream '%s' config!", smp.c_str());
+    if (!Util::getGlobalConfig("defaultStream")){
+      WARN_MSG("Could not get stream '%s' config!", smp.c_str());
+    }else{
+      INFO_MSG("Could not get stream '%s' config, not emitting WARN message because fallback is configured", smp.c_str());
+    }
     return result;
   }
   return stream_cfg.asJSON();
 }
 
+JSON::Value Util::getGlobalConfig(const std::string &optionName){
+  IPC::sharedPage globCfg(SHM_GLOBAL_CONF);
+  if (!globCfg.mapped){
+    FAIL_MSG("Could not open global configuration options to read setting for '%s'", optionName.c_str());
+    return JSON::Value();
+  }
+  Util::RelAccX cfgData(globCfg.mapped);
+  if (!cfgData.isReady()){
+    FAIL_MSG("Global configuration options not ready; cannot read setting for '%s'", optionName.c_str());
+    return JSON::Value();
+  }
+  Util::RelAccXFieldData dataField = cfgData.getFieldData(optionName);
+  switch (dataField.type & 0xF0){
+    case RAX_INT:
+    case RAX_UINT:
+      //Integer types, return JSON::Value integer
+      return JSON::Value(cfgData.getInt(dataField));
+    case RAX_RAW:
+    case RAX_STRING:
+      //String types, return JSON::Value string
+      return JSON::Value(std::string(cfgData.getPointer(dataField), cfgData.getSize(optionName)));
+    default:
+      //Unimplemented types
+      FAIL_MSG("Global configuration setting for '%s' is not an implemented datatype!", optionName.c_str());
+      return JSON::Value();
+  }
+}
+
 DTSC::Meta Util::getStreamMeta(const std::string &streamname){
   DTSC::Meta ret;
   char pageId[NAME_BUFFER_SIZE];

lib/stream.h

@@ -17,6 +17,7 @@ namespace Util {
   bool startInput(std::string streamname, std::string filename = "", bool forkFirst = true, bool isProvider = false, const std::map<std::string, std::string> & overrides = std::map<std::string, std::string>(), pid_t * spawn_pid = NULL);
   int startPush(const std::string & streamname, std::string & target);
   JSON::Value getStreamConfig(const std::string & streamname);
+  JSON::Value getGlobalConfig(const std::string & optionName);
   JSON::Value getInputBySource(const std::string & filename, bool isProvider = false);
   DTSC::Meta getStreamMeta(const std::string & streamname);
   uint8_t getStreamStatus(const std::string & streamname);

src/controller/controller_api.cpp

@@ -494,6 +494,9 @@ void Controller::handleAPICommands(JSON::Value & Request, JSON::Value & Response
       out["prometheus"] = in["prometheus"];
       Controller::prometheus = out["prometheus"].asStringRef();
     }
+    if (in.isMember("defaultStream")){
+      out["defaultStream"] = in["defaultStream"];
+    }
   }
   if (Request.isMember("bandwidth")){
     if (Request["bandwidth"].isObject()){

src/controller/controller_capabilities.cpp

@@ -160,6 +160,13 @@ namespace Controller {
     trgs["LIVE_BANDWIDTH"]["response"] = "always";
     trgs["LIVE_BANDWIDTH"]["response_action"] = "If false, shuts down the stream buffer.";
     trgs["LIVE_BANDWIDTH"]["argument"] = "Triggers only if current bytes per second exceeds this amount (integer)";
+
+    trgs["DEFAULT_STREAM"]["when"] = "When any user attempts to open a stream that cannot be opened (because it is either offline or not configured), allows rewriting the stream to a different one as fallback. Supports variable substitution.";
+    trgs["DEFAULT_STREAM"]["stream_specific"] = true;
+    trgs["DEFAULT_STREAM"]["payload"] = "current defaultStream setting (string)\nrequested stream name (string)\nviewer host (string)\noutput type (string)\nfull request URL (string, may be blank for non-URL-based requests!)";
+    trgs["DEFAULT_STREAM"]["response"] = "always";
+    trgs["DEFAULT_STREAM"]["response_action"] = "Overrides the default stream setting (for this view) to the response value. If empty, fails loading the stream and returns an error to the viewer/user.";
+
   }
   
   ///Aquire list of available protocols, storing in global 'capabilities' JSON::Value.

src/controller/controller_storage.cpp

@@ -334,6 +334,27 @@ namespace Controller{
       writeStream(it.key(), *it);
     }
 
+    {
+      //Global configuration options, if any
+      IPC::sharedPage globCfg;
+      globCfg.init(SHM_GLOBAL_CONF, 4096, false, false);
+      if (!globCfg.mapped){
+        globCfg.init(SHM_GLOBAL_CONF, 4096, true, false);
+      }
+      if (globCfg.mapped){
+        Util::RelAccX globAccX(globCfg.mapped, false);
+        if (!globAccX.isReady()){
+          globAccX.addField("defaultStream", RAX_128STRING);
+          globAccX.setRCount(1);
+          globAccX.setEndPos(1);
+          globAccX.setReady();
+        }
+        globAccX.setString("defaultStream", Storage["config"]["defaultStream"].asStringRef());
+        globCfg.master = false;//leave the page after closing
+      }
+    }
+
+
     /*LTS-START*/
     static std::map<std::string, IPC::sharedPage> pageForType; // should contain one page for every trigger type
     static JSON::Value writtenTrigs;

src/output/output.cpp

@@ -372,8 +372,31 @@ namespace Mist{
       }
     }else{
       if (!Util::startInput(streamName, "", true, isPushing())){
-        onFail("Stream open failed", true);
+        JSON::Value defStrmJson = Util::getGlobalConfig("defaultStream");
-        return;
+        std::string defStrm = defStrmJson.asString();
+        if(Triggers::shouldTrigger("DEFAULT_STREAM", streamName)){
+          std::string payload = defStrm+"\n"+streamName+"\n" + getConnectedHost() +"\n"+capa["name"].asStringRef()+"\n"+reqUrl;
+          //The return value is ignored, because the response (defStrm in this case) tells us what to do next, if anything.
+          Triggers::doTrigger("DEFAULT_STREAM", payload, streamName, false, defStrm);
+        }
+        if (!defStrm.size()){
+          onFail("Stream open failed", true);
+          return;
+        }
+        std::string newStrm = defStrm;
+        Util::streamVariables(newStrm, streamName, "");
+        if (streamName == newStrm){
+          onFail("Stream open failed; nothing to fall back to ("+defStrm+" == "+newStrm+")", true);
+          return;
+        }
+        INFO_MSG("Stream open failed; falling back to default stream '%s' -> '%s'", defStrm.c_str(), newStrm.c_str());
+        std::string origStream = streamName;
+        streamName = newStrm;
+        Util::Config::streamName = streamName;
+        if (!Util::startInput(streamName, "", true, isPushing())){
+          onFail("Stream open failed (fallback stream for '"+origStream+"')", true);
+          return;
+        }
       }
     }
     disconnect();

src/output/output_http_internal.cpp

@@ -6,6 +6,7 @@
 #include "flashPlayer.h"
 #include "oldFlashPlayer.h"
 #include <mist/websocket.h>
+#include <mist/triggers.h>
 
 namespace Mist {
   /// Helper function to find the protocol entry for a given port number
@@ -358,8 +359,36 @@ namespace Mist {
     if (config->getString("nostreamtext") != ""){
       json_resp["on_error"] = config->getString("nostreamtext");
     }
+    //Make note of any defaultStream-based redirection
+    if (origStreamName.size() && origStreamName != streamName){
+      json_resp["redirected"].append(origStreamName);
+      json_resp["redirected"].append(streamName);
+    }
     uint8_t streamStatus = Util::getStreamStatus(streamName);
     if (streamStatus != STRMSTAT_READY){
+      //If we haven't rewritten the stream name yet to a fallback, attempt to do so
+      if (origStreamName == streamName){
+        JSON::Value defStrmJson = Util::getGlobalConfig("defaultStream");
+        std::string defStrm = defStrmJson.asString();
+        if(Triggers::shouldTrigger("DEFAULT_STREAM", streamName)){
+          std::string payload = defStrm+"\n"+streamName+"\n" + getConnectedHost() +"\n"+capa["name"].asStringRef()+"\n"+reqUrl;
+          //The return value is ignored, because the response (defStrm in this case) tells us what to do next, if anything.
+          Triggers::doTrigger("DEFAULT_STREAM", payload, streamName, false, defStrm);
+        }
+        if (defStrm.size()){
+          std::string newStrm = defStrm;
+          Util::streamVariables(newStrm, streamName, "");
+          if (streamName != newStrm){
+            INFO_MSG("Falling back to default stream '%s' -> '%s'", defStrm.c_str(), newStrm.c_str());
+            origStreamName = streamName;
+            streamName = newStrm;
+            Util::Config::streamName = streamName;
+            reconnect();
+            return getStatusJSON(reqHost, useragent);
+          }
+        }
+        origStreamName.clear();//no fallback, don't check again
+      }
       switch (streamStatus){
         case STRMSTAT_OFF:
           json_resp["error"] = "Stream is offline";
@@ -504,6 +533,7 @@ namespace Mist {
   }
 
   void OutHTTP::onHTTP(){
+    origStreamName = streamName;
     std::string method = H.method;
 
     //Handle certbot validations
@@ -907,6 +937,8 @@ namespace Mist {
     Util::startInput(streamName, "", true, false);
 
     char pageName[NAME_BUFFER_SIZE];
+    std::string currStreamName;
+    currStreamName = streamName;
     snprintf(pageName, NAME_BUFFER_SIZE, SHM_STREAM_STATE, streamName.c_str());
     IPC::sharedPage streamStatus(pageName, 1, false, false);
     uint8_t prevState, newState, metaCounter;
@@ -925,6 +957,11 @@ namespace Mist {
           disconnect();
         }
         JSON::Value resp = getStatusJSON(reqHost, useragent);
+        if (currStreamName != streamName){
+          currStreamName = streamName;
+          snprintf(pageName, NAME_BUFFER_SIZE, SHM_STREAM_STATE, streamName.c_str());
+          streamStatus.close();
+        }
         ws.sendFrame(resp.toString());
         prevState = newState;
       }else{

src/output/output_http_internal.h

@@ -20,6 +20,8 @@ namespace Mist {
       virtual bool onFinish(){
         return stayConnected;
       }
+    private:
+      std::string origStreamName;
   };
 }