Removing link duplicates

tangos/scripts/manager.py

@@ -168,8 +168,11 @@ def flag_duplicates_deprecated(opts):
 
     session = db.core.get_default_session()
 
-    print("unmark all:",session.execute("update haloproperties set deprecated=0").rowcount)
-    print("      mark:",session.execute("update haloproperties set deprecated=1 where id in (SELECT min(id) FROM haloproperties GROUP BY halo_id, name_id HAVING COUNT(*)>1 ORDER BY halo_id, name_id)").rowcount)
+    print("unmark all properties:", session.execute("update haloproperties set deprecated=0").rowcount)
+    print("duplicate properties marked:", session.execute("update haloproperties set deprecated=1 where id in (SELECT min(id) FROM haloproperties GROUP BY halo_id, name_id HAVING COUNT(*)>1 ORDER BY halo_id, name_id)").rowcount)
+
+    print("unmark all links:", session.execute("update halolink set deprecated=0").rowcount)
+    print("duplicate links marked:", session.execute("update halolink set deprecated=1 where id in (SELECT min(id) FROM halolink GROUP BY halo_from_id, halo_to_id, relation_id HAVING COUNT(*)>1 ORDER BY halo_from_id, halo_to_id, weight)").rowcount)
 
     session.commit()
 
@@ -204,9 +207,21 @@ def remove_duplicates(options):
         )
     """)).rowcount
 
+    count_links = session.execute(dedent("""
+        DELETE FROM halolink
+        WHERE id NOT IN (
+            SELECT * FROM (
+                SELECT MAX(id)
+                FROM halolink
+                GROUP BY halo_from_id, halo_to_id, relation_id
+            ) as t
+        )
+    """)).rowcount
+
     if dialect == 'mysql':
         session.execute("SET @@SESSION.optimizer_switch = @__optimizations")
     print("Deleted %d rows" % count)
+    print("Deleted %d links" % count_links)
     session.commit()
 
 
@@ -522,10 +537,10 @@ def get_argument_parser_and_subparsers():
 
 
     subparse_deprecate = subparse.add_parser("flag-duplicates",
-                                             help="Flag old copies of properties (if they are present)")
+                                             help="Flag old copies of properties and duplicate links (if they are present)")
     subparse_deprecate.set_defaults(func=flag_duplicates_deprecated)
     subparse_deprecate = subparse.add_parser("remove-duplicates",
-                                             help="Remove old copies of properties (if they are present)")
+                                             help="Remove old copies of properties and duplicate links (if they are present)")
     subparse_deprecate.set_defaults(func=remove_duplicates)
 
     subparse_rollback = subparse.add_parser("rollback", help="Remove database updates")

tests/test_remove_duplicate.py

@@ -1,6 +1,9 @@
+import numpy as np
+
 import tangos
 from tangos import core, testing
 from tangos.cached_writer import create_property
+from tangos.core.halo_data import link
 from tangos.scripts.manager import remove_duplicates
 from tangos.testing.simulation_generator import SimulationGeneratorForTests
 
@@ -23,6 +26,33 @@ def setup_module():
     session.add(px, session)
     session.commit()
 
+    # Also create links between halos, including duplicates
+    halo2 = tangos.get_halo(2)
+    halo3 = tangos.get_halo(3)
+    halo9 = tangos.get_halo(9)
+
+    # two links between halo 1 to halo 2 with the same weight and name (maximal duplicate)
+    d_test = tangos.core.get_or_create_dictionary_item(session, "test")
+    l_obj = link.HaloLink(halo, halo2, d_test, 1.0)
+    session.add(l_obj)
+    l_obj = link.HaloLink(halo, halo2, d_test, 1.0)
+    session.add(l_obj)
+    # and another time but with same weight but different name (not a duplicate)
+    diff_name = tangos.core.get_or_create_dictionary_item(session, "other_test")
+    l_obj = link.HaloLink(halo, halo2, diff_name, 1.0)
+    session.add(l_obj)
+    # and another time, with same name but different weight
+    # (this is a non-maximal duplicate, oldest addition gets deleted and we keep the most recent link)
+    l_obj = link.HaloLink(halo, halo2, d_test, 0.5)
+    session.add(l_obj)
+    # and another time, with same weight and name as previous but linking to a different halo (not a duplicate)
+    l_obj = link.HaloLink(halo, halo3, d_test, 1.0)
+    session.add(l_obj)
+
+    # and now a completely independent link between halo 2 to halo 9
+    l_obj = link.HaloLink(halo2, halo9, d_test, 1.0)
+    session.add(l_obj)
+
 
 def teardown_module():
     core.close_db()
@@ -37,6 +67,16 @@ def test():
         halo = tangos.get_halo(ihalo)
         assert halo["Mvir"] == ihalo
 
+    # We also have five links for halo 1 and one for halo 2
+    assert tangos.get_halo(1).links.count() == 5
+    assert tangos.get_halo(2).links.count() == 1
+    # Only 4 links in halo 1 are maximally unique
+    quads = [[l.halo_from.id, l.halo_to.id, l.weight, l.relation_id] for l in tangos.get_halo(1).all_links]
+    assert len(np.unique(quads, axis=0)) == 4
+    # And 3 links are unique by name, halo from and to
+    triplets = [[l.halo_from.id, l.halo_to.id, l.relation_id] for l in tangos.get_halo(1).all_links]
+    assert len(np.unique(triplets, axis=0)) == 3
+
     # Let's cleanup
     remove_duplicates(None)
 
@@ -46,3 +86,21 @@ def test():
     for ihalo in range(2, 10):
         halo = tangos.get_halo(ihalo)
         assert halo["Mvir"] == ihalo
+
+    # Now halo 1 should have two less links
+    assert tangos.get_halo(1).links.count() == 3
+    # which are all unique according to name, halo from and to
+    triplets = [[l.halo_from.id, l.halo_to.id, l.relation_id] for l in tangos.get_halo(1).all_links]
+    assert len(np.unique(triplets, axis=0)) == tangos.get_halo(1).links.count()
+
+    # When deleting non-maximal duplicate (link index 1),
+    # we have kept the latest addition to the database with weight 0.5
+    test_link = tangos.get_halo(1).all_links[1]
+    assert test_link.halo_from.id == 1
+    assert test_link.halo_to.id == 2
+    assert test_link.weight == 0.5
+
+    # And links of halo 2 should not have changed
+    assert tangos.get_halo(2).links.count() == 1
+    assert tangos.get_halo(2).all_links[0].halo_from.id == 2
+    assert tangos.get_halo(2).all_links[0].halo_to.id == 9