added filters.py ToggleFilter functionality, and its test file

1 files changed, 86 insertions, 0 deletions

diff --git a/scripts/automation/trex_control_plane/common/filters.py b/scripts/automation/trex_control_plane/common/filters.py
new file mode 100644
index 00000000..3a05f4d1
--- /dev/null
+++ b/scripts/automation/trex_control_plane/common/filters.py
@@ -0,0 +1,86 @@
+
+def shallow_copy(x):
+    return type(x)(x)
+
+
+class ToggleFilter(object):
+    """
+    This class provides a "sticky" filter, that works by "toggling" items of the original database on and off.
+    """
+    def __init__(self, db_ref, show_by_default=True):
+        self._data = db_ref
+        self._toggle_db = set()
+        self._filter_method = filter
+        self.__set_initial_state(show_by_default)
+
+    def toggle_item(self, item_key):
+        if item_key in self._toggle_db:
+            self._toggle_db.remove(item_key)
+            return False
+        elif item_key in self._data:
+            self._toggle_db.add(item_key)
+            return True
+        else:
+            raise KeyError("Provided item key isn't a key of the referenced data structure.")
+
+    def filter_items(self):
+        """
+        Filters the pointed database by showing only the items mapped at toggle_db set.
+
+        :returns:
+            Filtered data of the original object.
+
+        """
+        return self._filter_method(self.__toggle_filter, self._data)
+
+    # private methods
+
+    def __set_initial_state(self, show_by_default):
+        try:
+            _ = (x for x in self._data)
+            if isinstance(self._data, dict):
+                self._filter_method = ToggleFilter.dict_filter
+                if show_by_default:
+                    self._toggle_db = self._data.keys()
+                return
+            elif isinstance(self._data, list):
+                self._filter_method = ToggleFilter.list_filter
+            elif isinstance(self._data, set):
+                self._filter_method = ToggleFilter.set_filter
+            elif isinstance(self._data, tuple):
+                self._filter_method = ToggleFilter.tuple_filter
+            if show_by_default:
+                self._toggle_db = set(shallow_copy(self._data))  # assuming all relevant data with unique identifier
+            return
+        except TypeError:
+            raise TypeError("provided data object is not iterable")
+
+    def __toggle_filter(self, x):
+        return (x in self._toggle_db)
+
+    # static utility methods
+
+    @staticmethod
+    def dict_filter(function, iterable):
+        assert isinstance(iterable, dict)
+        return {k: v
+                for k,v in iterable.iteritems()
+                if function(k, v)}
+
+    @staticmethod
+    def list_filter(function, iterable):
+        return filter(function, iterable)
+
+    @staticmethod
+    def set_filter(function, iterable):
+        return {x
+                for x in iterable
+                if function(x)}
+
+    @staticmethod
+    def tuple_filter(function, iterable):
+        return tuple(filter(function, iterable))
+
+
+if __name__ == "__main__":
+    pass