From 7f7c26e982cd8f0e1eb3be635d2f76ad3249d93b Mon Sep 17 00:00:00 2001
From: Dave Horton <daveh@beachdognet.com>
Date: Wed, 25 Sep 2024 20:13:56 -0400
Subject: [PATCH] fix for
 https://github.com/jambonz/freeswitch-modules/issues/117 (#912)

---
 lib/session/call-session.js |  9 ---------
 lib/tasks/tts-task.js       | 15 +++++++++++++--
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/lib/session/call-session.js b/lib/session/call-session.js
index 1da224dc..e1b8d905 100644
--- a/lib/session/call-session.js
+++ b/lib/session/call-session.js
@@ -520,15 +520,6 @@ class CallSession extends Emitter {
     this._actionHookDelayRetries = e;
   }
 
-  // Getter/setter for current tts vendor
-  get currentTtsVendor() {
-    return this._currentTtsVendor;
-  }
-
-  set currentTtsVendor(vendor) {
-    this._currentTtsVendor = vendor;
-  }
-
   get actionHookDelayProcessor() {
     return this._actionHookDelayProcessor;
   }
diff --git a/lib/tasks/tts-task.js b/lib/tasks/tts-task.js
index 583b522d..be085841 100644
--- a/lib/tasks/tts-task.js
+++ b/lib/tasks/tts-task.js
@@ -95,14 +95,25 @@ class TtsTask extends Task {
       credentials.voice_engine = this.options.voice_engine || credentials.voice_engine;
     }
 
+    /**
+     * note on cache_speech_handles.  This was found to be risky.
+     * It can cause a crash in the following sequence on a single call:
+     * 1. Stream tts on vendor A with cache_speech_handles=1, then
+     * 2. Stream tts on vendor B with cache_speech_handles=1
+     *
+     * we previously tried to track when vendors were switched and manage the flag accordingly,
+     * but it difficult to track all the scenarios and the benefit (slightly faster start to tts playout)
+     * is probably minimal.  DH.
+     */
     ep.set({
       tts_engine: vendor.startsWith('custom:') ? 'custom' : vendor,
       tts_voice: voice,
-      cache_speech_handles: !cs.currentTtsVendor || cs.currentTtsVendor === vendor ? 1 : 0,
+      //cache_speech_handles: !cs.currentTtsVendor || cs.currentTtsVendor === vendor ? 1 : 0,
+      cache_speech_handles: 0,
     }).catch((err) => this.logger.info({err}, 'Error setting tts_engine on endpoint'));
     // set the current vendor on the call session
     // If vendor is changed from the previous one, then reset the cache_speech_handles flag
-    cs.currentTtsVendor = vendor;
+    //cs.currentTtsVendor = vendor;
 
     if (!preCache && !this._disableTracing) this.logger.info({vendor, language, voice, model}, 'TaskSay:exec');
     try {