From 5adbae33557a48164c110a2ca4037b6529d98f0b Mon Sep 17 00:00:00 2001
From: Pierre-Yves Chibon <pingou@pingoured.fr>
Date: Apr 26 2016 09:25:42 +0000
Subject: Add a script to remove the cache of one or more widgets as needed


---

diff --git a/smart_cache_invalidator.py b/smart_cache_invalidator.py
new file mode 100755
index 0000000..b1b32c5
--- /dev/null
+++ b/smart_cache_invalidator.py
@@ -0,0 +1,119 @@
+#!/usr/bin/env python
+
+"""
+Small script to remove the cache of one or more widgets while keeping the
+other ones un-touched.
+
+This is really useful for development purposes as it allow seeing changes
+made to a widget without dropping the entire cache database.
+"""
+
+
+import argparse
+import os
+
+import anydbm
+import fedmsg.config
+import fedmsg.meta
+
+import hubs.models
+
+# get the DB session
+fedmsg_config = fedmsg.config.load_config()
+fedmsg.meta.make_processors(**fedmsg_config)
+
+session = hubs.models.init(fedmsg_config['hubs.sqlalchemy.uri'])
+
+
+def do_list(args):
+    ''' List the different widget for which there is data cached. '''
+    db = anydbm.open(args.cache_db)
+    for key in db.keys():
+        widget_id = key.split('|')[0]
+        widget = hubs.models.Widget.get(session, widget_id)
+        if widget:
+            print '- Widget cached %s (#%s) in %s' % (
+                widget.hub_id, widget_id, widget.plugin)
+    db.close()
+
+
+def do_clean(args):
+    ''' Clean the widget for which there is data cached. '''
+    for ext in ['.dogpile.lock', '.rw.lock']:
+        filename = args.cache_db + ext
+        if os.path.exists(filename):
+            os.unlink(filename)
+
+    db = anydbm.open(args.cache_db, 'w')
+    for key in db.keys():
+        widget_id = key.split('|')[0]
+        widget = hubs.models.Widget.get(session, widget_id)
+        if args.widget in [widget.plugin if widget else '', widget_id]:
+            del(db[key])
+            break
+    db.close()
+
+
+def setup_parser():
+    '''
+    Set the main arguments.
+    '''
+    parser = argparse.ArgumentParser(prog="smart_cache_invalidator")
+    # General connection options
+    parser.add_argument('--cache-db', dest="cache_db",
+                        default='/var/tmp/fedora-hubs-cache.db',
+                        help="The Fedora-hubs cache database")
+
+    subparsers = parser.add_subparsers(title='actions')
+
+    # List
+    parser_list = subparsers.add_parser(
+        'list',
+        help='List the different widgets for which there is cached data')
+    parser_list.set_defaults(func=do_list)
+
+    # Clean
+    parser_clean = subparsers.add_parser(
+        'clean', help='Clean the specified widget')
+    parser_clean.add_argument(
+        'widget', help="Identifier or name of the widget to clean")
+    parser_clean.set_defaults(func=do_clean)
+
+    return parser
+
+
+def main():
+    ''' Main function '''
+    return_code = 0
+
+    # Set up parser for global args
+    parser = setup_parser()
+
+    # Parse the commandline
+    try:
+        arg = parser.parse_args()
+    except argparse.ArgumentTypeError as err:
+        print("\nError: {0}".format(err))
+        return 1
+
+    if not os.path.exists(arg.cache_db):
+        print('No cache DB found')
+        return 2
+
+    try:
+        arg.func(arg)
+    except KeyboardInterrupt:
+        print("\nInterrupted by user.")
+        return_code = 3
+    except argparse.ArgumentError as err:
+        print('{0}'.format(err.message))
+        return_code = 4
+    except Exception as err:
+        print('Error: {0}'.format(err))
+        return_code = 5
+
+    return return_code
+
+
+if __name__ == '__main__':
+    main()