Changeset 9726 for main/waeup.kofa/trunk/src/waeup/kofa/utils/batching.py

Timestamp:

26 Nov 2012, 23:27:46 (12 years ago)

Author:

uli

Message:

Add VirtualExportJobContainers? for storing export jobs in a central exports container.

File:

• main/waeup.kofa/trunk/src/waeup/kofa/utils/batching.py (modified) (3 diffs)

main/waeup.kofa/trunk/src/waeup/kofa/utils/batching.py

@@ -32 +32 @@
 from zope.component import createObject, getUtility
 from zope.component.hooks import setSite
-from zope.interface import Interface
+from zope.interface import Interface, implementer
 from zope.schema import getFields
 from zope.event import notify
@@ -39 +39 @@
     IBatchProcessor, FatalCSVError, IObjectConverter, IJobManager,
     ICSVExporter, IGNORE_MARKER, DuplicationError, JOB_STATUS_MAP,
-    IExportJobContainer, IExportJob)
+    IExportJobContainer, IExportJob, IExportContainerFinder)
 
 class BatchProcessor(grok.GlobalUtility):
@@ -672 +672 @@
                 return entry
         return None
+
+class VirtualExportJobContainer(ExportJobContainer):
+    """A virtual export job container.
+
+    Virtual ExportJobContainers can be used as a mixin just like real
+    ExportJobContainer.
+
+    They retrieve and store data in the site-wide ExportJobContainer.
+
+    Functionality is currently entirely as for regular
+    ExportJobContainers, except that data is stored elsewhere.
+
+    VirtualExportJobContainers need a registered
+    IExportContainerFinder utility to find a suitable container for
+    storing data.
+    """
+    grok.implements(IExportJobContainer)
+
+    @property
+    def _site_container(self):
+        return getUtility(IExportContainerFinder)()
+
+    # The following is a simple trick. While ExportJobContainers store
+    # only one attribute in ZODB, it is sufficient to replace this
+    # attribute `running_exports` with a suitable manager to make the
+    # whole virtual container work like the original but with the data
+    # stored in the site-wide exports container. This way, virtual
+    # export containers provide the whole functionality of a regular
+    # exports container but store no data at all with themselves.
+    @property
+    def running_exports(self):
+        """Exports stored in the site-wide exports container.
+        """
+        return self._site_container.running_exports
+
+    @running_exports.setter
+    def running_exports(self, value):
+        self._site_container.running_exports = value
+
+    @running_exports.deleter
+    def running_exports(self):
+        del self._site_container.running_exports
+
+
+@implementer(IExportContainerFinder)
+class ExportContainerFinder(grok.GlobalUtility):
+    """Finder for local (site-wide) export container.
+    """
+
+    def __call__(self):
+        """Get the local export container-
+
+        If no site can be determined or the site provides no export
+        container, None is returned.
+        """
+        site = grok.getSite()
+        if site is None:
+            return None
+        return site.get('datacenter', None)