fix the bug of pytts in linux

voice/pytts/pytts_voice.py

@@ -2,8 +2,9 @@
 pytts voice service (offline)
 """
 
+import os
+import sys
 import time
-
 import pyttsx3
 
 from bridge.reply import Reply, ReplyType
@@ -11,7 +12,6 @@ from common.log import logger
 from common.tmp_dir import TmpDir
 from voice.voice import Voice
 
-
 class PyttsVoice(Voice):
     engine = pyttsx3.init()
 
@@ -20,19 +20,42 @@ class PyttsVoice(Voice):
         self.engine.setProperty("rate", 125)
         # 音量
         self.engine.setProperty("volume", 1.0)
-        for voice in self.engine.getProperty("voices"):
-            if "Chinese" in voice.name:
-                self.engine.setProperty("voice", voice.id)
+        if sys.platform == 'win32':
+            for voice in self.engine.getProperty("voices"):
+                if "Chinese" in voice.name:
+                    self.engine.setProperty("voice", voice.id)
+        else:
+            self.engine.setProperty("voice", "zh")
+            # If the problem of espeak is fixed, using runAndWait() and remove this startLoop()
+            # TODO: check if this is work on win32
+            self.engine.startLoop(useDriverLoop=False)
 
     def textToVoice(self, text):
         try:
-            wavFile = TmpDir().path() + "reply-" + str(int(time.time())) + ".wav"
+            # avoid the same filename
+            wavFileName = "reply-" + str(int(time.time())) + "-" + str(hash(text) & 0x7fffffff) + ".wav"
+            wavFile = TmpDir().path() + wavFileName
+            logger.info("[Pytts] textToVoice text={} voice file name={}".format(text, wavFile))
+
             self.engine.save_to_file(text, wavFile)
-            self.engine.runAndWait()
-            logger.info(
-                "[Pytts] textToVoice text={} voice file name={}".format(text, wavFile)
-            )
+
+            if sys.platform == 'win32':
+                self.engine.runAndWait()
+            else:
+                # In ubuntu, runAndWait do not really wait until the file created. 
+                # It will return once the task queue is empty, but the task is still running in coroutine.
+                # And if you call runAndWait() and time.sleep() twice, it will stuck, so do not use this.
+                # If you want to fix this, add self._proxy.setBusy(True) in line 127 in espeak.py, at the beginning of the function save_to_file.
+                # self.engine.runAndWait()
+
+                # Before espeak fix this problem, we iterate the generator and control the waiting by ourself.
+                # But this is not the canonical way to use it, for example if the file already exists it also cannot wait. 
+                self.engine.iterate()
+                while self.engine.isBusy() or wavFileName not in os.listdir(TmpDir().path()):
+                    time.sleep(0.1)
+
             reply = Reply(ReplyType.VOICE, wavFile)
+
         except Exception as e:
             reply = Reply(ReplyType.ERROR, str(e))
         finally: