improve on check precache

lib/config.js

@@ -1,6 +1,7 @@
 const JAMBONES_TTS_TRIM_SILENCE = process.env.JAMBONES_TTS_TRIM_SILENCE;
 const JAMBONES_DISABLE_TTS_STREAMING = process.env.JAMBONES_DISABLE_TTS_STREAMING;
 const JAMBONES_DISABLE_AZURE_TTS_STREAMING = process.env.JAMBONES_DISABLE_AZURE_TTS_STREAMING;
+const JAMBONES_EAGERLY_PRE_CACHE_AUDIO = process.env.JAMBONES_EAGERLY_PRE_CACHE_AUDIO;
 
 const JAMBONES_HTTP_PROXY_IP = process.env.JAMBONES_HTTP_PROXY_IP;
 const JAMBONES_HTTP_PROXY_PORT = process.env.JAMBONES_HTTP_PROXY_PORT;
@@ -18,6 +19,7 @@ module.exports = {
   JAMBONES_HTTP_PROXY_IP,
   JAMBONES_HTTP_PROXY_PORT,
   JAMBONES_TTS_CACHE_DURATION_MINS,
+  JAMBONES_EAGERLY_PRE_CACHE_AUDIO,
   TMP_FOLDER,
   HTTP_TIMEOUT
 };

lib/synth-audio.js

@@ -44,6 +44,7 @@ const {
   JAMBONES_HTTP_PROXY_IP,
   JAMBONES_HTTP_PROXY_PORT,
   JAMBONES_TTS_CACHE_DURATION_MINS,
+  JAMBONES_EAGERLY_PRE_CACHE_AUDIO,
 } = require('./config');
 const EXPIRES = JAMBONES_TTS_CACHE_DURATION_MINS;
 const OpenAI = require('openai');
@@ -158,16 +159,6 @@ async function synthAudio(client, createHash, retrieveHash, logger, stats, { acc
 
   }
 
-  const preCachekey = makeSynthKey({
-    account_sid,
-    vendor,
-    language: language || '',
-    voice: voice || deploymentId,
-    engine,
-    text,
-    renderForCaching: true
-  });
-
   const key = makeSynthKey({
     account_sid,
     vendor,
@@ -182,14 +173,22 @@ async function synthAudio(client, createHash, retrieveHash, logger, stats, { acc
   debug(`synth key is ${key}`);
   let cached;
   if (!disableTtsCache) {
-    // 1. check if precache audio
-    // 2. if there is no precache, check key
-    cached = await client.get(preCachekey);
-    if (cached) {
-      // Precache audio is available update filpath with precache file extension.
-      filePath = makeFilePath({vendor, key, salt, renderForCaching: true});
-    } else {
-      cached = await client.get(key);
+    cached = await client.get(key);
+    if (!cached && JAMBONES_EAGERLY_PRE_CACHE_AUDIO) {
+      const preCachekey = makeSynthKey({
+        account_sid,
+        vendor,
+        language: language || '',
+        voice: voice || deploymentId,
+        engine,
+        text,
+        renderForCaching: true
+      });
+      cached = await client.get(preCachekey);
+      if (cached) {
+        // Precache audio is available update filpath with precache file extension.
+        filePath = makeFilePath({vendor, key, salt, renderForCaching: true});
+      }
     }
   }
   if (cached) {