Write the machinery required to make Importer and Reimporter fully mo…

…dular.

Now there can be many loader, selectable at run time, with also
the possibility of autodetection.

cmscontrib/YamlImporter.py → cmscontrib/Importer.py

@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 
 # Programming contest management system
-# Copyright © 2010-2012 Giovanni Mascellani <[email protected]>
+# Copyright © 2010-2013 Giovanni Mascellani <[email protected]>
 # Copyright © 2010-2012 Stefano Maggiolo <[email protected]>
 # Copyright © 2010-2012 Matteo Boscariol <[email protected]>
 # Copyright © 2013 Luca Wehrstedt <[email protected]>
@@ -20,9 +20,10 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-"""This script imports a contest from disk using YamlLoader.
+"""This script imports a contest from disk using one of the available
+loaders.
 
-The data parsed by YamlLoader is used to create a new Contest in the
+The data parsed by the loader is used to create a new Contest in the
 database.
 
 """
@@ -36,30 +37,31 @@
 
 from cms import logger
 from cms.db.FileCacher import FileCacher
-from cms.db.SQLAlchemyAll import metadata, SessionGen, FSObject, User, \
+from cms.db.SQLAlchemyAll import metadata, SessionGen, User, \
     drop_everything
 
-from cmscontrib.YamlLoader import YamlLoader
+from cmscontrib.Loaders import choose_loader, build_epilog
 
 
 class Importer:
 
-    """This script imports a contest from disk using YamlLoader.
+    """This script imports a contest from disk using one of the
+    available loaders.
 
-    The data parsed by YamlLoader is used to create a new Contest in
+    The data parsed by the loader is used to create a new Contest in
     the database.
 
     """
 
-    def __init__(self, path, drop, test, zero_time, user_number):
+    def __init__(self, path, drop, test, zero_time, user_number, loader_class):
         self.drop = drop
         self.test = test
         self.zero_time = zero_time
         self.user_number = user_number
 
         self.file_cacher = FileCacher()
 
-        self.loader = YamlLoader(os.path.realpath(path), self.file_cacher)
+        self.loader = loader_class(os.path.realpath(path), self.file_cacher)
 
     def _prepare_db(self):
         logger.info("Creating database structure.")
@@ -123,29 +125,38 @@ def do_import(self):
 
 def main():
     """Parse arguments and launch process."""
+
     parser = argparse.ArgumentParser(
-        description="Import a contest from disk using YamlLoader")
+        description="Import a contest from disk",
+        epilog=build_epilog(),
+        formatter_class=argparse.RawDescriptionHelpFormatter)
     group = parser.add_mutually_exclusive_group()
     group.add_argument("-z", "--zero-time", action="store_true",
                        help="set to zero contest start and stop time")
     group.add_argument("-t", "--test", action="store_true",
                        help="setup a contest for testing "
-                       "(times: 0, 2*10^9; ips: unset, passwords: a)")
+                       "(times: 1970, 2100; ips: unset, passwords: a)")
     parser.add_argument("-d", "--drop", action="store_true",
                         help="drop everything from the database "
                         "before importing")
     parser.add_argument("-n", "--user-number", action="store", type=int,
                         help="put N random users instead of importing them")
+    parser.add_argument("-L", "--loader", action="store", default=None,
+                        help="use the specified loader (default: autodetect)")
     parser.add_argument("import_directory",
                         help="source directory from where import")
 
     args = parser.parse_args()
+    loader_class = choose_loader(args.loader,
+                                 args.import_directory,
+                                 parser.error)
 
     Importer(path=args.import_directory,
              drop=args.drop,
              test=args.test,
              zero_time=args.zero_time,
-             user_number=args.user_number).do_import()
+             user_number=args.user_number,
+             loader_class=loader_class).do_import()
 
 
 if __name__ == "__main__":

cmscontrib/Loaders.py

@@ -0,0 +1,75 @@
+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+
+# Programming contest management system
+# Copyright © 2013 Giovanni Mascellani <[email protected]>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""List of loaders known by CMS, with some support functions.
+
+"""
+
+from cmscontrib.YamlLoader import YamlLoader
+
+LOADERS = dict((loader_class.short_name(), loader_class)
+               for loader_class in [YamlLoader])
+
+
+def choose_loader(arg, path, error_callback):
+    """Decide which loader to use, depending upon the specified
+    argument and possibly performing an autodetection.
+
+    The autodetection is done by calling detect() on all the known
+    loaders and returning the only one that returns True. If no one or
+    more than one return True, then the autodetection is considered
+    failed and None is returned.
+
+    arg (string): the argument, possibly None, passed to the program
+                  as loader specification.
+    path (string): the path passed to the program from which to
+                   perform the loading.
+    error_callback (method): a method to call to report errors.
+
+    return (class): the chosen loader class.
+
+    """
+    if arg is not None:
+        try:
+            return LOADERS[arg]
+        except KeyError:
+            error_callback("Specified loader doesn't exist")
+    else:
+        res = None
+        for loader in LOADERS.itervalues():
+            if loader.detect(path):
+                if res is None:
+                    res = loader
+                else:
+                    error_callback(
+                        "Couldn't autodetect the loader, "
+                        "please specify it: more than one "
+                        "loader accepted the detection")
+        if res is None:
+            error_callback("Couldn't autodetect the loader, "
+                           "please specify it: no "
+                           "loader accepted the detection")
+        return res
+
+
+def build_epilog():
+    epilog = "The following loaders are supported:\n"
+    for short_name, loader_class in sorted(LOADERS.items()):
+        epilog += " * %s (%s)\n" % (short_name, loader_class.description())
+    return epilog

cmscontrib/YamlReimporter.py → cmscontrib/Reimporter.py

@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 
 # Programming contest management system
-# Copyright © 2010-2012 Giovanni Mascellani <[email protected]>
+# Copyright © 2010-2013 Giovanni Mascellani <[email protected]>
 # Copyright © 2010-2012 Stefano Maggiolo <[email protected]>
 # Copyright © 2010-2012 Matteo Boscariol <[email protected]>
 # Copyright © 2013 Luca Versari <[email protected]>
@@ -21,9 +21,10 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-"""This script reimports a contest from disk using YamlLoader.
+"""This script reimports a contest from disk using one of the
+available loaders.
 
-The data parsed by YamlLoader is used to update a Contest that's
+The data parsed by the loader is used to update a Contest that's
 already existing in the database.
 
 """
@@ -38,7 +39,7 @@
 from cms.db.SQLAlchemyAll import \
     SessionGen, Base, Contest, User, Task, Submission
 
-from cmscontrib.YamlLoader import YamlLoader
+from cmscontrib.Loaders import choose_loader, build_epilog
 
 
 def _is_rel(prp, attr):
@@ -48,20 +49,21 @@ def _is_rel(prp, attr):
 
 class Reimporter:
 
-    """This script reimports a contest from disk using YamlLoader
+    """This script reimports a contest from disk using the specified
+    loader.
 
-    The data parsed by YamlLoader is used to update a Contest that's
+    The data parsed by the loader is used to update a Contest that's
     already existing in the database.
 
     """
 
-    def __init__(self, path, contest_id, force):
+    def __init__(self, path, contest_id, force, loader_class):
         self.old_contest_id = contest_id
         self.force = force
 
         self.file_cacher = FileCacher()
 
-        self.loader = YamlLoader(os.path.realpath(path), self.file_cacher)
+        self.loader = loader_class(os.path.realpath(path), self.file_cacher)
 
     def _update_columns(self, old_object, new_object):
         for prp in old_object._col_props:
@@ -285,23 +287,31 @@ def do_reimport(self):
 def main():
     """Parse arguments and launch process."""
     parser = argparse.ArgumentParser(
-        description="Reimport a contest from disk using YamlLoader")
+        description="Reimport a contest from disk",
+        epilog=build_epilog(),
+        formatter_class=argparse.RawDescriptionHelpFormatter)
     parser.add_argument("-c", "--contest-id", action="store", type=int,
                         help="id of contest to overwrite")
     parser.add_argument("-f", "--force", action="store_true",
                         help="force the reimport even if some users or tasks "
                         "may get lost")
+    parser.add_argument("-L", "--loader", action="store", default=None,
+                        help="use the specified loader (default: autodetect)")
     parser.add_argument("import_directory",
                         help="source directory from where import")
 
     args = parser.parse_args()
+    loader_class = choose_loader(args.loader,
+                                 args.import_directory,
+                                 parser.error)
 
     if args.contest_id is None:
         args.contest_id = ask_for_contest()
 
     Reimporter(path=args.import_directory,
                contest_id=args.contest_id,
-               force=args.force).do_reimport()
+               force=args.force,
+               loader_class=loader_class).do_reimport()
 
 
 if __name__ == "__main__":

cmscontrib/YamlLoader.py

@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 
 # Programming contest management system
-# Copyright © 2010-2012 Giovanni Mascellani <[email protected]>
+# Copyright © 2010-2013 Giovanni Mascellani <[email protected]>
 # Copyright © 2010-2012 Stefano Maggiolo <[email protected]>
 # Copyright © 2010-2012 Matteo Boscariol <[email protected]>
 # Copyright © 2013 Luca Wehrstedt <[email protected]>
@@ -72,6 +72,34 @@ def __init__(self, path, file_cacher):
         self.path = path
         self.file_cacher = file_cacher
 
+    @classmethod
+    def short_name(cls):
+        """Short name of this loader.
+
+        """
+        return 'italy_yaml'
+
+    @classmethod
+    def description(cls):
+        """Description of this loader.
+
+        """
+        return 'Italian YAML-based format'
+
+    @classmethod
+    def detect(cls, path):
+        """Detect whether this loader is able to interpret the given
+        path.
+
+        path (string): the path to scan.
+
+        return (bool): True if the loader is able to interpret the
+                       given path.
+
+        """
+        # Not really refined...
+        return os.path.exists(os.path.join(path, "contest.yaml"))
+
     def get_contest(self):
 
         """Produce a Contest object.

setup.py

@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 
 # Programming contest management system
-# Copyright © 2010-2012 Giovanni Mascellani <[email protected]>
+# Copyright © 2010-2013 Giovanni Mascellani <[email protected]>
 # Copyright © 2010-2013 Stefano Maggiolo <[email protected]>
 # Copyright © 2010-2012 Matteo Boscariol <[email protected]>
 #
@@ -125,8 +125,8 @@ def do_setup():
                   "cmsRemoveUser=cmscontrib.RemoveUser:main",
                   "cmsRemoveTask=cmscontrib.RemoveTask:main",
                   "cmsComputeComplexity=cmscontrib.ComputeComplexity:main",
-                  "cmsYamlImporter=cmscontrib.YamlImporter:main",
-                  "cmsYamlReimporter=cmscontrib.YamlReimporter:main",
+                  "cmsImporter=cmscontrib.Importer:main",
+                  "cmsReimporter=cmscontrib.Reimporter:main",
                   "cmsSpoolExporter=cmscontrib.SpoolExporter:main",
                   "cmsContestExporter=cmscontrib.ContestExporter:main",
                   "cmsContestImporter=cmscontrib.ContestImporter:main",