From c98d525d4b5cd968fec1b260b2539bb10ff8b0c1 Mon Sep 17 00:00:00 2001
From: Christophe Bedard <fixed-term.christophe.bourquebedard@de.bosch.com>
Date: Fri, 7 Jun 2019 10:57:28 +0200
Subject: [PATCH] Extract EventHandler class

---
 tracetools_analysis/analysis/handler.py       | 42 +++++++++++++++++++
 tracetools_analysis/analysis/ros_processor.py | 28 ++-----------
 2 files changed, 45 insertions(+), 25 deletions(-)
 create mode 100644 tracetools_analysis/analysis/handler.py

diff --git a/tracetools_analysis/analysis/handler.py b/tracetools_analysis/analysis/handler.py
new file mode 100644
index 0000000..4b5412d
--- /dev/null
+++ b/tracetools_analysis/analysis/handler.py
@@ -0,0 +1,42 @@
+# Event handler
+
+import sys
+from . import lttng_models
+
+
+class EventHandler():
+    """Base event handling class."""
+
+    def __init__(self, handler_map):
+        """
+        Constructor.
+
+        :param handler_map (map(str: function)): the mapping from event name to handling method
+        """
+        self._handler_map = handler_map
+
+    def process_events(self, events):
+        """
+        Process events by calling their handlers.
+
+        :param events (list(dict(str:str))): the events to process
+        """
+        for event in events:
+            self._handle(event)
+
+    def _handle(self, event):
+        event_name = lttng_models.get_name(event)
+        handler_function = self._handler_map.get(event_name, None)
+        if handler_function is not None:
+            pid = lttng_models.get_field(event,
+                                         'vpid',
+                                         default=lttng_models.get_field(event, 'pid'))
+            tid = lttng_models.get_field(event,
+                                         'vtid',
+                                         default=lttng_models.get_field(event, 'tid'))
+            timestamp = lttng_models.get_field(event, '_timestamp')
+            procname = lttng_models.get_field(event, 'procname')
+            metadata = lttng_models.EventMetadata(event_name, pid, tid, timestamp, procname)
+            handler_function(event, metadata)
+        else:
+            print(f'unhandled event name: {event_name}', file=sys.stderr)
diff --git a/tracetools_analysis/analysis/ros_processor.py b/tracetools_analysis/analysis/ros_processor.py
index 601b2da..abfe5bc 100644
--- a/tracetools_analysis/analysis/ros_processor.py
+++ b/tracetools_analysis/analysis/ros_processor.py
@@ -1,8 +1,8 @@
 # Process trace events and create ROS model
 
 import sys
-from .lttng_models import EventMetadata, get_field, get_name
-
+from .lttng_models import get_field
+from .handler import EventHandler
 
 def ros_process(events):
     """
@@ -16,7 +16,7 @@ def ros_process(events):
     return processor
 
 
-class RosProcessor():
+class RosProcessor(EventHandler):
     """
     ROS-aware event processing/handling class.
 
@@ -38,28 +38,6 @@ class RosProcessor():
             'ros2:rclcpp_subscription_callback_end': self._handle_subscription_callback_end,
         }
 
-    def process_events(self, events):
-        """
-        Process events.
-
-        :param events (list(dict(str:str))): the events to process
-        """
-        for event in events:
-            self._handle(event)
-
-    def _handle(self, event):
-        event_name = get_name(event)
-        handler_function = self._handler_map.get(event_name, None)
-        if handler_function is not None:
-            pid = get_field(event, 'vpid', default=get_field(event, 'pid'))
-            tid = get_field(event, 'vtid', default=get_field(event, 'tid'))
-            timestamp = get_field(event, '_timestamp')
-            procname = get_field(event, 'procname')
-            metadata = EventMetadata(event_name, pid, tid, timestamp, procname)
-            handler_function(event, metadata)
-        else:
-            print(f'unhandled event name: {event_name}', file=sys.stderr)
-
     def _handle_subscription_init(self, event, metadata):
         # TODO
         pass