Revision history for this message
| Tim Penhey (thumper) wrote : | # |
| 1 | === modified file 'lib/lp/code/browser/decorations.py' |
| 2 | --- lib/lp/code/browser/decorations.py 2010-06-17 01:16:30 +0000 |
| 3 | +++ lib/lp/code/browser/decorations.py 2010-06-17 05:57:00 +0000 |
| 4 | @@ -21,25 +21,38 @@ |
| 5 | |
| 6 | |
| 7 | class DecoratedBug: |
| 8 | - """Provide some additional attributes to a normal bug.""" |
| 9 | + """Provide some cached attributes to a normal bug. |
| 10 | + |
| 11 | + We provide cached properties where sensible, and override default bug |
| 12 | + behaviour where the cached properties can be used to avoid extra database |
| 13 | + queries. |
| 14 | + """ |
| 15 | delegates(IBug, 'bug') |
| 16 | |
| 17 | def __init__(self, bug, branch, tasks=None): |
| 18 | self.bug = bug |
| 19 | self.branch = branch |
| 20 | - self.tasks = tasks |
| 21 | - if self.tasks is None: |
| 22 | - self.tasks = self.bug.bugtasks |
| 23 | - |
| 24 | - @property |
| 25 | - def bugtasks(self): |
| 26 | - return self.tasks |
| 27 | + if tasks is None: |
| 28 | + tasks = self.bug.bugtasks |
| 29 | + self.bugtasks = tasks |
| 30 | |
| 31 | @property |
| 32 | def default_bugtask(self): |
| 33 | - return self.tasks[0] |
| 34 | + """Use the first bugtask. |
| 35 | + |
| 36 | + Use the cached tasks as calling default_bugtask on the bug object |
| 37 | + causes a DB query. |
| 38 | + """ |
| 39 | + return self.bugtasks[0] |
| 40 | |
| 41 | def getBugTask(self, target): |
| 42 | + """Get the bugtask for a specific target. |
| 43 | + |
| 44 | + This method is overridden rather than letting it fall through to the |
| 45 | + underlying bug as the underlying implementation gets the bugtasks from |
| 46 | + self, which would in that case be the normal bug model object, which |
| 47 | + would then hit the database to get the tasks. |
| 48 | + """ |
| 49 | # Copied from Bug.getBugTarget to avoid importing. |
| 50 | for bugtask in self.bugtasks: |
| 51 | if bugtask.target == target: |
| 52 | @@ -49,6 +62,9 @@ |
| 53 | @property |
| 54 | def bugtask(self): |
| 55 | """Return the bugtask for the branch project, or the default bugtask. |
| 56 | + |
| 57 | + This method defers the identitication of the appropriate task to the |
| 58 | + branch target. |
| 59 | """ |
| 60 | return self.branch.target.getBugTask(self) |
| 61 | |
| 62 | @@ -65,6 +81,13 @@ |
| 63 | |
| 64 | @cachedproperty |
| 65 | def linked_bugs(self): |
| 66 | + """Override the default behaviour of the branch object. |
| 67 | + |
| 68 | + The default behaviour is just to get the bugs. We want to display the |
| 69 | + tasks however, and to avoid the extra database queries to get the |
| 70 | + tasks, we get them all at once, and provide decorated bugs (that have |
| 71 | + their tasks cached). |
| 72 | + """ |
| 73 | bugs = defaultdict(list) |
| 74 | for bug, task in self.branch.getLinkedBugsAndTasks(): |
| 75 | bugs[bug].append(task) |
| 76 | @@ -74,14 +97,26 @@ |
| 77 | |
| 78 | @property |
| 79 | def displayname(self): |
| 80 | + """Override the default model property. |
| 81 | + |
| 82 | + If left to the underlying model, it would call the bzr_identity on the |
| 83 | + underlying branch rather than the cached bzr_identity on the decorated |
| 84 | + branch. And that would cause two database queries. |
| 85 | + """ |
| 86 | return self.bzr_identity |
| 87 | |
| 88 | @cachedproperty |
| 89 | def bzr_identity(self): |
| 90 | + """Cache the result of the bzr identity. |
| 91 | + |
| 92 | + The property is defined in the bzrIdentityMixin class. This uses the |
| 93 | + associatedProductSeries and associatedSuiteSourcePackages methods. |
| 94 | + """ |
| 95 | return super(DecoratedBranch, self).bzr_identity |
| 96 | |
| 97 | @cachedproperty |
| 98 | def is_series_branch(self): |
| 99 | + """A simple property to see if there are any series links.""" |
| 100 | # True if linked to a product series or suite source package. |
| 101 | return ( |
| 102 | len(self.associated_product_series) > 0 or |
| 103 | @@ -97,21 +132,31 @@ |
| 104 | |
| 105 | @cachedproperty |
| 106 | def associated_product_series(self): |
| 107 | + """Cache the realized product series links.""" |
| 108 | return list(self.branch.associatedProductSeries()) |
| 109 | |
| 110 | @cachedproperty |
| 111 | def suite_source_packages(self): |
| 112 | + """Cache the realized suite source package links.""" |
| 113 | return list(self.branch.associatedSuiteSourcePackages()) |
| 114 | |
| 115 | @cachedproperty |
| 116 | def upgrade_pending(self): |
| 117 | + """Cache the result as the property hits the database.""" |
| 118 | return self.branch.upgrade_pending |
| 119 | |
| 120 | @cachedproperty |
| 121 | def subscriptions(self): |
| 122 | + """Cache the realized branch subscription objects.""" |
| 123 | return list(self.branch.subscriptions) |
| 124 | |
| 125 | def hasSubscription(self, user): |
| 126 | + """Override the default branch implementation. |
| 127 | + |
| 128 | + The default implementation hits the database. Since we have a full |
| 129 | + list of subscribers anyway, a simple check over the list is |
| 130 | + sufficient. |
| 131 | + """ |
| 132 | for sub in self.subscriptions: |
| 133 | if sub.person == user: |
| 134 | return True |
| 135 | @@ -119,6 +164,11 @@ |
| 136 | |
| 137 | @cachedproperty |
| 138 | def latest_revisions(self): |
| 139 | + """Cache the query result. |
| 140 | + |
| 141 | + When a tal:repeat is used, the method is called twice. Firstly to |
| 142 | + check that there is something to iterate over, and secondly for the |
| 143 | + actual iteration. Without the cached property, the database is hit |
| 144 | + twice. |
| 145 | + """ |
| 146 | return list(self.branch.latest_revisions()) |
| 147 | - |
| 148 | - |
On Thu, 17 Jun 2010 17:07:26 you wrote:
> Review: Approve
> I notice neither DecoratedBug nor DecoratedBranch have docstrings, nor do
> they define an interface making them inscrutable. This is particularly
> confusing for DecoratedBug which provides self.tasks, self.bugtasks,
> self.bugtask, self.getBugTask(), self.default_
> synonyms and some of them (getBugTask() and bugtask) return different
> things despite their names indicating the are synonyms.
>
> We can let this slide on this branch though since this is moving code to a
> better location, so a net win. It would be nice to merge the synonyms and
> document things though if possible.
>
> Otherwise all fine.
Thanks.
Did some docstring additions and simplified the bugtasks.
Tim