bitbake: toaster: typeaheads Add a git revisions suggestions

When we're importing a layer it's useful to suggest available git revisions of the
layers. This uses git ls-remote to fetch the revisions and then filter on this.
Caching is added for this typeahead to avoid having to fetch this
information multiple times in a single session.

[YOCTO #8429]

(Bitbake rev: a94ae3ad0cb07a52004143c6f86f371b9e330e9f)

Signed-off-by: Michael Wood <michael.g.wood@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/toaster/toastergui/typeaheads.py

@@ -16,9 +16,12 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+import subprocess
+
 from toastergui.widgets import ToasterTypeAhead
 from orm.models import Project
 from django.core.urlresolvers import reverse
+from django.core.cache import cache
 
 class LayersTypeAhead(ToasterTypeAhead):
     """ Typeahead for layers available and not added in the current project's
@@ -147,3 +150,29 @@ class ProjectsTypeAhead(ToasterTypeAhead):
             results.append(needed_fields)
 
         return results
+
+
+class GitRevisionTypeAhead(ToasterTypeAhead):
+    def apply_search(self, search_term, prj, request):
+        results = []
+        git_url = request.GET.get('git_url')
+        ls_remote = cache.get(git_url)
+
+        if ls_remote is None:
+            ls_remote = subprocess.check_output(['git', 'ls-remote', git_url],
+                                                universal_newlines=True)
+            ls_remote = ls_remote.splitlines()
+            # Avoid fetching the list of git refs on each new input
+            cache.set(git_url, ls_remote, 120)
+
+        for rev in ls_remote:
+            git_rev = str(rev).split("/")[-1:][0]
+            # "HEAD" has a special meaning in Toaster...  YOCTO #9924
+            if "HEAD" in git_rev:
+                continue
+
+            if git_rev.startswith(search_term):
+                results.append({'name': git_rev,
+                                'detail': '[ %s ]' % str(rev)})
+
+        return results

bitbake/lib/toaster/toastergui/urls.py

@@ -182,8 +182,9 @@ urlpatterns = patterns('toastergui.views',
             typeaheads.RecipesTypeAhead.as_view(), name='xhr_recipestypeahead'),
         url(r'^xhr_typeahead/projects$',
             typeaheads.ProjectsTypeAhead.as_view(), name='xhr_projectstypeahead'),
-
+        url(r'^xhr_typeahead/gitrev$',
-
+            typeaheads.GitRevisionTypeAhead.as_view(),
+            name='xhr_gitrevtypeahead'),
 
         url(r'^xhr_testreleasechange/(?P<pid>\d+)$', 'xhr_testreleasechange',
             name='xhr_testreleasechange'),