fix #713, refine source to avoid critical fetch and create. 2.0.222

@@ -344,6 +344,7 @@ Remark:
 
 ## History
 
+* v2.0, 2016-12-13, fix #713, refine source to avoid critical fetch and create. 2.0.222
 * <strong>v2.0, 2016-11-09, [2.0 beta2(2.0.221)][r2.0b2] released. 86691 lines.</strong>
 * v2.0, 2016-11-05, fix #654, crash when source cleanup for edge. 2.0.221
 * v2.0, 2016-10-26, fix #666, crash when source cleanup for http-flv. 2.0.220

@@ -1228,11 +1228,9 @@ int SrsHttpStreamServer::hijack(ISrsHttpMessage* request, ISrsHttpHandler** ph)
         }
     }
 
-    SrsSource* s = SrsSource::fetch(r);
-    if (!s) {
-        if ((ret = SrsSource::create(r, server, server, &s)) != ERROR_SUCCESS) {
-            return ret;
-        }
+    SrsSource* s = NULL;
+    if ((ret = SrsSource::fetch_or_create(r, server, server, &s)) != ERROR_SUCCESS) {
+        return ret;
     }
     srs_assert(s != NULL);
 

@@ -486,11 +486,9 @@ int SrsRtmpConn::stream_service_cycle()
     rtmp->set_send_timeout(SRS_CONSTS_RTMP_SEND_TIMEOUT_US);
     
     // find a source to serve.
-    SrsSource* source = SrsSource::fetch(req);
-    if (!source) {
-        if ((ret = SrsSource::create(req, server, server, &source)) != ERROR_SUCCESS) {
-            return ret;
-        }
+    SrsSource* source = NULL;
+    if ((ret = SrsSource::fetch_or_create(req, server, server, &source)) != ERROR_SUCCESS) {
+        return ret;
     }
     srs_assert(source != NULL);
     

@@ -731,17 +731,23 @@ ISrsSourceHandler::~ISrsSourceHandler()
 
 std::map<std::string, SrsSource*> SrsSource::pool;
 
-int SrsSource::create(SrsRequest* r, ISrsSourceHandler* h, ISrsHlsHandler* hh, SrsSource** pps)
+int SrsSource::fetch_or_create(SrsRequest* r, ISrsSourceHandler* h, ISrsHlsHandler* hh, SrsSource** pps)
 {
     int ret = ERROR_SUCCESS;
     
+    SrsSource* source = NULL;
+    if ((source = fetch(r)) != NULL) {
+        *pps = source;
+        return ret;
+    }
+    
     string stream_url = r->get_stream_url();
     string vhost = r->vhost;
     
     // should always not exists for create a source.
     srs_assert (pool.find(stream_url) == pool.end());
 
-    SrsSource* source = new SrsSource();
+    source = new SrsSource();
     if ((ret = source->initialize(r, h, hh)) != ERROR_SUCCESS) {
         srs_freep(source);
         return ret;
@@ -774,20 +780,6 @@ SrsSource* SrsSource::fetch(SrsRequest* r)
     return source;
 }
 
-SrsSource* SrsSource::fetch(std::string vhost, std::string app, std::string stream)
-{
-    SrsSource* source = NULL;
-    string stream_url = srs_generate_stream_url(vhost, app, stream);
-    
-    if (pool.find(stream_url) == pool.end()) {
-        return NULL;
-    }
-
-    source = pool[stream_url];
-
-    return source;
-}
-
 void SrsSource::dispose_all()
 {
     std::map<std::string, SrsSource*>::iterator it;

@@ -418,22 +418,20 @@ private:
     static std::map<std::string, SrsSource*> pool;
 public:
     /**
-    * find stream by vhost/app/stream.
+    *  create source when fetch from cache failed.
     * @param r the client request.
     * @param h the event handler for source.
     * @param hh the event handler for hls.
     * @param pps the matched source, if success never be NULL.
     */
-    static int create(SrsRequest* r, ISrsSourceHandler* h, ISrsHlsHandler* hh, SrsSource** pps);
+    static int fetch_or_create(SrsRequest* r, ISrsSourceHandler* h, ISrsHlsHandler* hh, SrsSource** pps);
+private:
     /**
     * get the exists source, NULL when not exists.
     * update the request and return the exists source.
     */
     static SrsSource* fetch(SrsRequest* r);
-    /**
-    * get the exists source by stream info(vhost, app, stream), NULL when not exists.
-    */
-    static SrsSource* fetch(std::string vhost, std::string app, std::string stream);
+public:
     /**
      * dispose and cycle all sources.
      */