MT#56321 DSM: Introduce helper functions related to DSM processing

We have to optimize our code:
- substitute all repeating (DSM related) code with a helper static functions
- remove all excessive stuff, which plays no role

Change-Id: I27170509d84a634dc4a9a865ea8395e4e8cc2f3d

apps/sbc/CallLeg.cpp

@@ -184,6 +184,12 @@ static bool isHoldRequest(AmSdp &sdp, HoldMethod &method)
   return true; // no active stream was found
 }
 
+static bool isDSMEarlyAnnounceForced(const std::string &hdrs)
+{
+  string announce = getHeader(hdrs, SIP_HDR_P_DSM_APP);
+  string p_dsm_app_param = get_header_param(announce, DSM_PARAM_EARLY_AN);
+  return p_dsm_app_param == DSM_VALUE_FORCE;
+}
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -554,9 +560,7 @@ void CallLeg::onInitialReply(B2BSipReplyEvent *e)
 {
   /* 100-199 */
   if (e->reply.code < 200) {
-    string announce = getHeader(e->reply.hdrs, SIP_HDR_P_DSM_APP);
-    string p_dsm_app_param = get_header_param(announce, DSM_PARAM_EARLY_AN);
-    dlg->setForcedEarlyAnnounce(p_dsm_app_param == DSM_VALUE_FORCE);
+    dlg->setForcedEarlyAnnounce(isDSMEarlyAnnounceForced(e->reply.hdrs));
 
     /* exceptionally treat 183 with the 'P-DSM-App: <app-name>;early-announce=force',
        similarly to the 200OK response, this will properly update the caller
@@ -568,7 +572,7 @@ void CallLeg::onInitialReply(B2BSipReplyEvent *e)
        - pre-announce
        - play-last-caller
        - office-hours */
-    if (e->reply.code == 183 && !announce.empty() && dlg->getForcedEarlyAnnounce()) {
+    if (e->reply.code == 183 && dlg->getForcedEarlyAnnounce()) {
       b2bInitial2xx(e->reply, e->forward);
     } else {
       b2bInitial1xx(e->reply, e->forward);

core/AmB2BSession.cpp

@@ -62,6 +62,23 @@ static void errCode2RelayedReply(AmSipReply &reply, int err_code, unsigned defau
   }
 }
 
+static bool isDSMEarlyAnnounceForced(const std::string &hdrs)
+{
+    string announce = getHeader(hdrs, SIP_HDR_P_DSM_APP);
+    string p_dsm_app_param = get_header_param(announce, DSM_PARAM_EARLY_AN);
+    return p_dsm_app_param == DSM_VALUE_FORCE;
+}
+
+static bool isDSMPlaybackFinished(const std::string &hdrs)
+{
+  /** TODO: for the future, we might also want to check
+   *  particular DSM applications, for now plays no role.
+   */
+  string p_dsm_app = getHeader(hdrs, SIP_HDR_P_DSM_APP, true);
+  string p_dsm_app_param = get_header_param(p_dsm_app, DSM_PARAM_PLAYBACK);
+  return p_dsm_app_param == DSM_VALUE_FINISHED;
+}
+
 //
 // AmB2BSession methods
 //
@@ -296,9 +313,7 @@ void AmB2BSession::onB2BEvent(B2BEvent* ev)
 
         /* ensure that 'P-DSM-App: <app-name>;early-announce=force' is not present */
         if (reply_ev->reply.code == 183 && !dlg->getForcedEarlyAnnounce()) {
-          string announce = getHeader(reply_ev->reply.hdrs, SIP_HDR_P_DSM_APP);
-          string p_dsm_app_param = get_header_param(announce, DSM_PARAM_EARLY_AN);
-          dlg->setForcedEarlyAnnounce(p_dsm_app_param == DSM_VALUE_FORCE);
+          dlg->setForcedEarlyAnnounce(isDSMEarlyAnnounceForced(reply_ev->reply.hdrs));
         }
 
         /* don't forget to reset the force_early_announce, if 200 OK in the same leg received */
@@ -353,24 +368,14 @@ void AmB2BSession::onB2BEvent(B2BEvent* ev)
         /* 480 - processing of the playback completion from DSM applications */
         } else if (reply_ev->reply.code == 480 && dlg->getStatus() == AmSipDialog::Connected) {
 
-          string p_dsm_app = getHeader(reply_ev->reply.hdrs, SIP_HDR_P_DSM_APP, true);
-
           /* TT#188800, if this is a completion of the playback of one of the DSM applications,
             (office hours, play last caller, pre announce, early dbprompt)
             in the session, which has had AA or a transfer before going to this DSM application,
             then a caller is now likely in the connected state, and requires BYE, not 480 */
-          if (p_dsm_app.find(DSM_APP_OH) != std::string::npos ||
-              p_dsm_app.find(DSM_APP_PRE_AN) != std::string::npos ||
-              p_dsm_app.find(DSM_APP_EARLYDB_PR) != std::string::npos ||
-              p_dsm_app.find(DSM_APP_P_L_CALLER) != std::string::npos) {
-
-            /* check the ;playback= parameter */
-            string p_dsm_app_param = get_header_param(p_dsm_app, DSM_PARAM_PLAYBACK);
-            if (p_dsm_app_param == DSM_VALUE_FINISHED) {
-              DBG("This is the end of DSM playback, the caller is in the connected state.\n");
-              DBG("Terminating the original leg with BYE, instead of 480.\n");
-              terminateLeg();
-            }
+          if (isDSMPlaybackFinished(reply_ev->reply.hdrs)) {
+            DBG("This is the end of DSM playback, the caller is in the connected state.\n");
+            DBG("Terminating the original leg with BYE, instead of 480.\n");
+            terminateLeg();
           }
         }
       }

core/AmSipDialog.cpp

@@ -41,6 +41,10 @@
 
 #include "global_defs.h"
 
+//
+// helper functions
+//
+
 static void addTranscoderStats(string &hdrs)
 {
   // add transcoder statistics into request/reply headers
@@ -62,6 +66,13 @@ static void addTranscoderStats(string &hdrs)
   }
 }
 
+static bool isDSMEarlyAnnounceForced(const std::string &hdrs)
+{
+    string announce = getHeader(hdrs, SIP_HDR_P_DSM_APP);
+    string p_dsm_app_param = get_header_param(announce, DSM_PARAM_EARLY_AN);
+    return p_dsm_app_param == DSM_VALUE_FORCE;
+}
+
 AmSipDialog::AmSipDialog(AmSipDialogEventHandler* h)
   : AmBasicSipDialog(h),oa(this),rel100(this,h),
     offeranswer_enabled(true),
@@ -409,9 +420,7 @@ bool AmSipDialog::onRxReplyStatus(const AmSipReply& reply)
         /* 100-199 */
         if (reply.code < 200) {
 
-          string announce = getHeader(reply.hdrs, SIP_HDR_P_DSM_APP, true);
-          string p_dsm_app_param = get_header_param(announce, DSM_PARAM_EARLY_AN);
-          setForcedEarlyAnnounce(p_dsm_app_param == DSM_VALUE_FORCE);
+          setForcedEarlyAnnounce(isDSMEarlyAnnounceForced(reply.hdrs));
 
           /* we should always keep Route set for this leg updated in case
              the provisional response updates the list of routes for any reason */
@@ -429,10 +438,11 @@ bool AmSipDialog::onRxReplyStatus(const AmSipReply& reply)
              And furthermore will give the possibility to receive and forward BYE.
 
              DSM applications using it:
-             - early-dbprompt (early_announce)
+             - early-dbprompt
              - pre-announce
+             - play-last-caller
              - office-hours */
-          if (reply.code == 183 && !announce.empty() && getForcedEarlyAnnounce()) {
+          if (reply.code == 183 && getForcedEarlyAnnounce()) {
             DBG("This is 183 with <;%s=%s>, treated exceptionally as 200OK.\n", DSM_PARAM_EARLY_AN, DSM_VALUE_FORCE);
 
             setStatus(Connected);