Merge lp:~lifeless/launchpad/registry-packagings into lp:launchpad

[Robert Collins]

Change listified packagings into DecoratedResultSets to allow count() without deserialising thousands of objects.

Help address a high frequency timeout, bug 612358.

This probably is RC, as IIRC its an edge specific issue at the moment.

[Curtis Hovey (sinzui)]

Thanks for working this issue out with me. This looks good to land.

review: Approve

[Robert Collins (lifeless)]

Using my own rc stamp after discussion with Curtis.

review: Approve (release-critical)

=== modified file 'lib/lp/registry/browser/distroseries.py'
--- lib/lp/registry/browser/distroseries.py	2010-08-06 12:49:27 +0000
+++ lib/lp/registry/browser/distroseries.py	2010-08-10 03:04:59 +0000
@@ -317,7 +317,7 @@
     @cachedproperty
     def num_linked_packages(self):
         """The number of linked packagings for this distroseries."""
-        return len(self.context.packagings)
+        return self.context.packagings.count()
 
     @property
     def num_unlinked_packages(self):

=== modified file 'lib/lp/registry/doc/distroseries.txt'
--- lib/lp/registry/doc/distroseries.txt	2010-07-28 02:02:25 +0000
+++ lib/lp/registry/doc/distroseries.txt	2010-08-10 03:04:59 +0000
@@ -479,7 +479,7 @@
     >>> distribution = factory.makeDistribution()
     >>> distroseries = factory.makeDistroRelease(distribution=distribution)
     >>> pkgs = distroseries.getMostRecentlyLinkedPackagings()
-    >>> print len(pkgs)
+    >>> print pkgs.count()
     0
 
     >>> for name in ['aaron', 'bjorn', 'chex', 'deryck', 'edwin', 'francis']:

=== modified file 'lib/lp/registry/model/distroseries.py'
--- lib/lp/registry/model/distroseries.py	2010-08-02 02:13:52 +0000
+++ lib/lp/registry/model/distroseries.py	2010-08-10 03:04:59 +0000
@@ -286,10 +286,20 @@
 
     @cachedproperty
     def _all_packagings(self):
-        """Get an unordered list of all packagings."""
+        """Get an unordered list of all packagings.
+        
+        :return: A ResultSet which can be decorated or tuned further. Use
+            DistroSeries._packaging_row_to_packaging to extract the
+            packaging objects out.
+        """
         # We join to SourcePackageName, ProductSeries, and Product to cache
         # the objects that are implicitly needed to work with a
         # Packaging object.
+        # NB: precaching objects like this method tries to do has a very poor
+        # hit rate with storm - many queries will still be executed; consider
+        # ripping this out and instead allowing explicit inclusion of things 
+        # like Person._all_members does - returning a cached object graph.
+        # -- RBC 20100810
         # Avoid circular import failures.
         from lp.registry.model.product import Product
         from lp.registry.model.productseries import ProductSeries
@@ -309,14 +319,19 @@
         results = IStore(self).using(*origin).find(find_spec, condition)
         return results
 
+    @staticmethod
+    def _packaging_row_to_packaging(row):
+        # each row has:
+        #  (packaging, spn, product_series, product)
+        return row[0]
+
     @property
     def packagings(self):
         """See `IDistroSeries`."""
         results = self._all_packagings
         results = results.order_by(SourcePackageName.name)
-        return [
-            packaging
-            for (packaging, spn, product_series, product) in results]
+        return DecoratedResultSet(results,
+            DistroSeries._packaging_row_to_packaging)
 
     def getPrioritizedUnlinkedSourcePackages(self):
         """See `IDistroSeries`.
@@ -454,9 +469,8 @@
         # identical creation dates.
         results = results.order_by(Desc(Packaging.datecreated),
                                    SourcePackageName.name)[:5]
-        return [
-            packaging
-            for (packaging, spn, product_series, product) in results]
+        return DecoratedResultSet(results,
+            DistroSeries._packaging_row_to_packaging)
 
     @property
     def supported(self):