koji-gc: use history to query trashcan contents

as a side effect, we get the hub to apply our grace period for us

util/koji-gc

@@ -664,11 +664,19 @@ def handle_delete(just_salvage=False):
     """
     print("Getting list of builds in trash...")
     trashcan_tag = options.trashcan_tag
-    trash = sorted([(b['nvr'], b) for b in session.listTagged(trashcan_tag)])
-    print("...got %i builds" % len(trash))
-    # XXX - it would be better if there were more appropriate server calls for this
     grace_period = options.grace_period
-    import time
+    # using history makes for a smaller query that listTagged
+    history = session.queryHistory(tables=['tag_listing'],
+                                   tag=trashcan_tag,
+                                   active=True,
+                                   before=time.time()-grace_period)
+    # simulate needed binfo fields
+    binfos = history['tag_listing']
+    for binfo in binfos:
+        binfo['nvr'] = '%(name)s-%(version)s-%(release)s' % binfo
+        binfo['id'] = binfo['build_id']
+    trash = sorted([(b['nvr'], b) for b in binfos])
+    print("...got %i builds" % len(trash))
 
     print("1st pass: blacklist")
     continuing = []
@@ -709,30 +717,7 @@ def handle_delete(just_salvage=False):
             continue
         continuing.append((nvr, binfo))
 
-    print("4th pass: history")
-    continuing, trash = [], continuing
-    for nvr, binfo in trash:
-        # determine how long this build has been in the trashcan
-        mcall.queryHistory(build=binfo['id'], tag=trashcan_tag)
-
-    for (nvr, binfo), [history] in zip(trash, mcall.call_all()):
-        current = [x for x in history['tag_listing'] if x['active']]
-        if not current:
-            # untagged just now?
-            print("Warning: history missing for %s" % nvr)
-            pprint.pprint(binfo)
-            pprint.pprint(history)
-            continue
-        assert len(current) == 1  # see db constraint
-        current = current[0]
-        age = time.time() - current['create_ts']
-        if age < grace_period:
-            if options.debug:
-                print("Skipping build %s, age=%i" % (nvr, age))
-            continue
-        continuing.append(binfo)
-
-    print("5th pass: deletion")
+    print("4th pass: deletion")
     for binfo in continuing:
         # go ahead and delete
         if options.test: