save and print diff config

Summary:
Pull Request resolved: https://github.com/facebookresearch/d2go/pull/202

This diff print the diff between the default config and the full config at the start of the run

Reviewed By: wat3rBro

Differential Revision: D35346096

fbshipit-source-id: 1ce9b58a8d613d1dd572358ce1e51462c90cb337

d2go/config/utils.py

@@ -135,3 +135,55 @@ def get_cfg_diff_table(cfg, original_cfg):
         headers=["config key", "old value", "new value"],
     )
     return table
+
+
+def get_diff_cfg(old_cfg, new_cfg):
+    """
+    outputs a CfgNode containing keys, values appearing in new_cfg and not in old_cfg.
+    If `new_allowed` is not set, then new keys will throw a KeyError
+    old_cfg: CfgNode, the original config, usually the dafulat
+    new_cfg: CfgNode, the full config being passed by the user
+
+    if new allowed is not set on new_cfg, key error is raised
+    returns: CfgNode, a config containing only key, value changes between old_cfg and new_cfg
+
+    example:
+        Cfg1:
+            SYSTEM:
+                NUM_GPUS: 2
+            TRAIN:
+                SCALES: (1, 2)
+            DATASETS:
+                train_2017:
+                    17: 1
+                    18: 1
+        Cfg2:
+            SYSTEM:
+                NUM_GPUS: 2
+            TRAIN:
+                SCALES: (4, 5, 8)
+            DATASETS:
+                train_2017:
+                    17: 1
+                    18: 1
+
+        get_diff_cfg(Cfg1, Cfg2) gives:
+            TRAIN:
+                SCALES: (8, 16, 32)
+    """
+
+    def get_diff_cfg_rec(old_cfg, new_cfg, out):
+        for key in new_cfg.keys():
+            if key not in old_cfg.keys() and old_cfg.is_new_allowed():
+                out[key] = new_cfg[key]
+            elif old_cfg[key] != new_cfg[key]:
+                if type(new_cfg[key]) is type(out):
+                    out[key] = out.__class__()
+                    out[key] = get_diff_cfg_rec(old_cfg[key], new_cfg[key], out[key])
+                else:
+
+                    out[key] = new_cfg[key]
+        return out
+
+    out = new_cfg.__class__()
+    return get_diff_cfg_rec(old_cfg, new_cfg, out)

d2go/setup.py

@@ -15,6 +15,7 @@ from d2go.config import (
     reroute_config_path,
     temp_defrost,
 )
+from d2go.config.utils import get_diff_cfg
 from d2go.distributed import get_local_rank, get_num_processes_per_machine
 from d2go.runner import create_runner, GeneralizedRCNNRunner
 from d2go.utils.helper import run_once
@@ -25,7 +26,6 @@ from detectron2.utils.logger import setup_logger
 from detectron2.utils.serialize import PicklableWrapper
 from mobile_cv.common.misc.py import FolderLock, MultiprocessingPdb, post_mortem_if_fail
 
-
 logger = logging.getLogger(__name__)
 
 
@@ -209,7 +209,10 @@ def setup_after_launch(cfg: CN, output_dir: str, runner):
     runner = initialize_runner(runner, cfg)
 
     log_info(cfg, runner)
-
+    dump_cfg(
+        get_diff_cfg(runner.get_default_cfg(), cfg),
+        os.path.join(output_dir, "diff_config.yaml"),
+    )
     auto_scale_world_size(cfg, new_world_size=comm.get_world_size())
 
 

tests/misc/test_config.py

@@ -10,6 +10,7 @@ import unittest
 from d2go.config import CfgNode
 from d2go.config import auto_scale_world_size, reroute_config_path
 from d2go.config.utils import (
+    get_diff_cfg,
     config_dict_to_list_str,
     flatten_config_dict,
     get_cfg_diff_table,
@@ -148,6 +149,48 @@ class TestConfigUtils(unittest.TestCase):
             get_from_flattened_config_dict(d, "MODEL.MODEL.INPUT_SIZE"), None
         )  # non-exist
 
+    def test_get_diff_cfg(self):
+        """check config that is diff from default config, no new keys"""
+        # create base config
+        cfg1 = CfgNode()
+        cfg1.A = CfgNode()
+        cfg1.A.Y = 2
+        # case 1: new allowed not set, new config has only old keys
+        cfg2 = cfg1.clone()
+        cfg2.set_new_allowed(False)
+        cfg2.A.Y = 3
+        gt = CfgNode()
+        gt.A = CfgNode()
+        gt.A.Y = 3
+        self.assertEqual(gt, get_diff_cfg(cfg1, cfg2))
+
+    def test_diff_cfg_no_new_allowed(self):
+        """check that if new_allowed is False, new keys cause key error"""
+        # create base config
+        cfg1 = CfgNode()
+        cfg1.A = CfgNode()
+        cfg1.A.set_new_allowed(False)
+        cfg1.A.Y = 2
+        # case 2: new allowed not set, new config has new keys
+        cfg2 = cfg1.clone()
+        cfg2.A.X = 2
+        self.assertRaises(KeyError, get_diff_cfg, cfg1, cfg2)
+
+    def test_diff_cfg_with_new_allowed(self):
+        """diff config with new keys and new_allowed set to True"""
+        # create base config
+        cfg1 = CfgNode()
+        cfg1.A = CfgNode()
+        cfg1.A.set_new_allowed(True)
+        cfg1.A.Y = 2
+        # case 3: new allowed set, new config has new keys
+        cfg2 = cfg1.clone()
+        cfg2.A.X = 2
+        gt = CfgNode()
+        gt.A = CfgNode()
+        gt.A.X = 2
+        self.assertEqual(gt, get_diff_cfg(cfg1, cfg2))
+
     def test_get_cfg_diff_table(self):
         """Check compare two dicts"""
         d1 = {"a0": "a1", "b0": {"b1": "b2"}, "c0": {"c1": {"c2": 3}}}