Base structure of workbench manager

mediagoblin/process_media/workbench.py

@@ -0,0 +1,73 @@
+# GNU MediaGoblin -- federated, autonomous media hosting
+# Copyright (C) 2011 Free Software Foundation, Inc
+#
+# 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/>.
+
+import tempfile
+
+
+class WorkbenchOutsideScope(Exception):
+    """
+    Raised when a workbench is outside a WorkbenchManager scope.
+    """
+    pass
+
+
+# TODO: This doesn't seem like it'd work with Windows
+DEFAULT_WORKBENCH_DIR = u'/tmp/workbench/'
+
+
+class WorkbenchManager(object):
+    """
+    A system for generating and destroying workbenches.
+
+    Workbenches are actually just subdirectories of a temporary storage space
+    for during the processing stage.
+    """
+
+    def __init__(self, base_workbench_dir):
+        self.base_workbench_dir = base_workbench_dir
+        
+    def create_workbench(self):
+        """
+        Create and return the path to a new workbench (directory).
+        """
+        pass
+
+    def destroy_workbench(self, workbench):
+        """
+        Destroy this workbench!  Deletes the directory and all its contents!
+
+        Makes sure the workbench actually belongs to this manager though.
+        """
+        pass
+
+    def possibly_localize_file(self, workbench, storage, filepath):
+        """
+        Possibly localize the file from this storage system (for read-only
+        purposes, modifications should be written to a new file.).
+
+        If the file is already local, just return the absolute filename of that
+        local file.  Otherwise, copy the file locally to the workbench, and
+        return the absolute path of the new file.
+
+        Also returns whether or not it copied the file locally.
+
+        Returns:
+          (localized_filename, copied_locally)
+          The first of these bieng the absolute filename as described above as a
+          unicode string, the second being a boolean stating whether or not we
+          had to copy the file locally.
+        """
+        pass