Adding asynchronous data reading feature.

1 files changed, 52 insertions, 3 deletions

diff --git a/src/argaze/TobiiGlassesPro2/TobiiData.py b/src/argaze/TobiiGlassesPro2/TobiiData.py
index ed570c9..0e28054 100644
--- a/src/argaze/TobiiGlassesPro2/TobiiData.py
+++ b/src/argaze/TobiiGlassesPro2/TobiiData.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 
-from typing import Tuple
+from typing import Tuple, TypeVar
 from dataclasses import dataclass
 import threading
 import uuid
@@ -16,6 +16,9 @@ from argaze.utils import MiscFeatures
 
 import numpy
 
+TobiiDataObjectType = TypeVar('TobiiDataObjectType', bound="TobiiDataObjectType")
+# Type definition for type annotation convenience
+
 @dataclass
 class DirSig():
     """Define dir sig data (dir sig)."""
@@ -318,7 +321,7 @@ class TobiiDataStream():
         self.__json_data_parser = TobiiJsonDataParser()
         self.__first_ts = 0
 
-        # Data subscription
+        # Sync reading data subscription
         self.reading_callbacks = []
         self.__subcription_lock = threading.Lock() 
 
@@ -412,7 +415,7 @@ class TobiiDataStream():
             # lock data subcription
             self.__subcription_lock.acquire()
 
-            # share incoming data to all subcribers
+            # share incoming data to all subscribers
             for callback in self.reading_callbacks:
 
                 callback(data_ts, data_object, data_object_type)
@@ -514,3 +517,49 @@ class TobiiDataStream():
 
         # Unsubscribe to tobii data stream
         self.unsubscribe(self.__capture_callback)
+
+    def __buffer_callback(self, data_ts, data_object, data_object_type):
+
+        # Lock data queue access
+        self.__queue_lock.acquire()
+
+        # Put data into the queue
+        self.__data_queue.put((data_ts, data_object, data_object_type))
+
+        # Unlock data queue access
+        self.__queue_lock.release()
+
+    def read(self) -> Tuple[int, TobiiDataObjectType, str]:
+        """Iterate over incoming data buffer asynchronously."""
+
+        # Setup data buffering
+        self.__data_queue = queue.Queue()
+        self.__queue_lock = threading.Lock()
+
+        # Subscribe to tobii data stream
+        self.subscribe(self.__buffer_callback)
+
+        return self.__iter__()
+
+    def __iter__(self):
+
+        return self
+
+    def __next__(self):
+
+        # Wait for data
+        while self.__data_queue.empty():
+
+            time.sleep(0.0001)
+            continue
+
+        # Lock data queue access
+        self.__queue_lock.acquire()
+
+        # Get data from the queue
+        data_ts, data_object, data_object_type = self.__data_queue.get()
+
+        # Unlock data queue access
+        self.__queue_lock.release()
+            
+        return data_ts, data_object, data_object_type