Initial commit

Houdini/Events/HandlerFileEvent.py

@@ -0,0 +1,79 @@
+import sys
+import importlib
+from watchdog.events import FileSystemEventHandler
+
+from Houdini.Handlers import listeners_from_module
+from Houdini.Events import evaluate_handler_file_event, remove_handlers_by_module
+
+
+class HandlerFileEventHandler(FileSystemEventHandler):
+
+    def __init__(self, server):
+        self.logger = server.logger
+        self.server = server
+
+    def on_created(self, event):
+        handler_module_details = evaluate_handler_file_event(event)
+
+        if not handler_module_details:
+            return
+
+        handler_module_path, handler_module = handler_module_details
+
+        if "__init__.py" in handler_module_path:
+            return
+
+        self.logger.debug("New handler module detected %s", handler_module)
+
+        try:
+            module = importlib.import_module(handler_module)
+            listeners_from_module(self.server.xt_listeners, self.server.xml_listeners, module)
+        except Exception as import_error:
+            self.logger.error("%s detected in %s, not importing.", import_error.__class__.__name__, handler_module)
+
+    def on_deleted(self, event):
+        handler_module_details = evaluate_handler_file_event(event)
+
+        if not handler_module_details:
+            return
+
+        handler_module_path, handler_module = handler_module_details
+
+        if handler_module not in sys.modules:
+            return
+
+        self.logger.debug("Deleting listeners registered by %s..", handler_module)
+
+        remove_handlers_by_module(self.server.xt_listeners, self.server.xml_listeners, handler_module_path)
+
+    def on_modified(self, event):
+        handler_module_details = evaluate_handler_file_event(event)
+
+        if not handler_module_details:
+            return
+
+        handler_module_path, handler_module = handler_module_details
+
+        if handler_module not in sys.modules:
+            return False
+
+        self.logger.info("Reloading %s", handler_module)
+
+        xt_listeners, xml_listeners = remove_handlers_by_module(self.server.xt_listeners, self.server.xml_listeners,
+                                                                handler_module_path)
+
+        handler_module_object = sys.modules[handler_module]
+
+        try:
+            module = importlib.reload(handler_module_object)
+            listeners_from_module(self.server.xt_listeners, self.server.xml_listeners, module)
+
+            self.logger.info("Successfully reloaded %s!", handler_module)
+        except Exception as rebuild_error:
+            self.logger.error("%s detected in %s, not reloading.", rebuild_error.__class__.__name__, handler_module)
+            self.logger.info("Restoring handler references...")
+
+            self.server.xt_listeners = xt_listeners
+            self.server.xml_listeners = xml_listeners
+
+            self.logger.info("Handler references restored. Phew!")

Houdini/Events/__init__.py

@@ -0,0 +1,54 @@
+import os
+import copy
+
+
+def evaluate_handler_file_event(handler_file_event):
+    # Ignore all directory events
+    if handler_file_event.is_directory:
+        return False
+
+    handler_module_path = handler_file_event.src_path[2:]
+
+    # Ignore non-Python files
+    if handler_module_path[-3:] != ".py":
+        return False
+
+    handler_module = handler_module_path.replace(os.path.sep, ".")[:-3]
+
+    return handler_module_path, handler_module
+
+
+def evaluate_plugin_file_event(plugin_file_event):
+    # Ignore all directory events
+    if plugin_file_event.is_directory:
+        return False
+
+    handler_module_path = plugin_file_event.src_path[2:]
+
+    # Ignore non-Python files
+    if handler_module_path[-3:] != ".py":
+        return False
+
+    # Remove file extension and replace path separator with dots. Then make like a banana.. and split.
+    handler_module_tokens = handler_module_path.replace(os.path.sep, ".")[:-3].split(".")
+
+    if handler_module_tokens.pop() == "__init__":
+        return handler_module_path, ".".join(handler_module_tokens)
+
+    return False
+
+
+def remove_handlers_by_module(xt_listeners, xml_listeners, handler_module_path):
+    def remove_handlers(remove_handler_items):
+        for handler_id, handler_listeners in remove_handler_items:
+            for handler_listener in handler_listeners:
+                if handler_listener.handler_file == handler_module_path:
+                    handler_listeners.remove(handler_listener)
+
+    xt_handler_collection = copy.copy(xt_listeners)
+    remove_handlers(xt_listeners.items())
+
+    xml_handler_collection = copy.copy(xml_listeners)
+    remove_handlers(xml_listeners.items())
+
+    return xt_handler_collection, xml_handler_collection