core: provide package_list() and utilize in issue-diff.py.

issue-diff.py

@@ -21,6 +21,7 @@ import osc.conf
 import osc.core
 
 from osclib.cache import Cache
+from osclib.core import package_list
 
 # Issue summary can contain unicode characters and therefore a string containing
 # either summary or one in which ISSUE_SUMMARY is then placed must be unicode.
@@ -204,16 +205,6 @@ def issues_get(apiurl, project, package, trackers, db):
 
     return issues
 
-def package_list(apiurl, project):
-    url = osc.core.makeurl(apiurl, ['source', project], { 'expand': 1 })
-    root = ET.parse(osc.core.http_GET(url)).getroot()
-
-    packages = []
-    for package in root.findall('entry'):
-        packages.append(package.get('name'))
-
-    return sorted(packages)
-
 def git_clone(url, directory):
     return_code = subprocess.call(['git', 'clone', url, directory])
     if return_code != 0:

osclib/core.py

@@ -0,0 +1,17 @@
+from xml.etree import cElementTree as ET
+
+from osc.core import http_GET
+from osc.core import makeurl
+
+from osclib.memoize import memoize
+
+@memoize(session=True)
+def package_list(apiurl, project):
+    url = makeurl(apiurl, ['source', project], { 'expand': 1 })
+    root = ET.parse(http_GET(url)).getroot()
+
+    packages = []
+    for package in root.findall('entry'):
+        packages.append(package.get('name'))
+
+    return sorted(packages)