add buffer size as abstract collectorstorage method

src/evidently/collector/config.py

@@ -62,9 +62,10 @@ def is_ready(self, config: "CollectorConfig", storage: "CollectorStorage") -> bo
         print("---")
         print("RowsCountTrigger")
         print(f"rows_count: {self.rows_count}")
-        print(f"buffer length:{len(storage._buffers[config.id])}")
-        if len(storage._buffers[config.id]) > 0: 
-            if len(storage._buffers[config.id]) % self.rows_count == 0:
+        buffer_size = storage.get_buffer_size(config.id)
+        print(f"buffer length:{buffer_size}")
+        if buffer_size > 0: 
+            if buffer_size % self.rows_count == 0:
                 print("Creating snapshot")
                 return True
         print("Not creating snapshot")

src/evidently/collector/storage.py

@@ -34,6 +34,10 @@ def init_all(self, config):
     @abc.abstractmethod
     def append(self, id: str, data: Any):
         raise NotImplementedError
+
+    @abc.abstractmethod
+    def get_buffer_size(self, id: str):
+        raise NotImplementedError
 
     @abc.abstractmethod
     def get_and_flush(self, id: str):
@@ -62,6 +66,9 @@ def init(self, id: str):
     def append(self, id: str, data: Any):
         self._buffers[id].append(data)
 
+    def get_buffer_size(self, id: str):
+        return len(self._buffers[id])
+
     def get_and_flush(self, id: str):
         if id not in self._buffers or len(self._buffers[id]) == 0:
             return None