[Feature] Add vis backend for MLflow.

docs/en/api/visualization.rst

@@ -31,5 +31,6 @@ visualization Backend
 
    BaseVisBackend
    LocalVisBackend
+   MLflowVisBackend
    TensorboardVisBackend
    WandbVisBackend

docs/zh_cn/api/visualization.rst

@@ -31,5 +31,6 @@ visualization Backend
 
    BaseVisBackend
    LocalVisBackend
+   MLflowVisBackend
    TensorboardVisBackend
    WandbVisBackend

mmengine/hooks/logger_hook.py

@@ -288,6 +288,9 @@ def after_run(self, runner) -> None:
             runner (Runner): The runner of the training/testing/validation
                 process.
         """
+        # close the visualizer
+        runner.visualizer.close()
+
         # copy or upload logs to self.out_dir
         if self.out_dir is None:
             return

mmengine/visualization/__init__.py

@@ -1,9 +1,9 @@
 # Copyright (c) OpenMMLab. All rights reserved.
-from .vis_backend import (BaseVisBackend, LocalVisBackend,
+from .vis_backend import (BaseVisBackend, LocalVisBackend, MLflowVisBackend,
                           TensorboardVisBackend, WandbVisBackend)
 from .visualizer import Visualizer
 
 __all__ = [
     'Visualizer', 'BaseVisBackend', 'LocalVisBackend', 'WandbVisBackend',
-    'TensorboardVisBackend'
+    'TensorboardVisBackend', 'MLflowVisBackend'
 ]

mmengine/visualization/vis_backend.py

@@ -6,6 +6,7 @@
 import os.path as osp
 import warnings
 from abc import ABCMeta, abstractmethod
+from collections.abc import MutableMapping
 from typing import Any, Callable, Optional, Sequence, Union
 
 import cv2
@@ -14,8 +15,10 @@
 
 from mmengine.config import Config
 from mmengine.fileio import dump
-from mmengine.logging import print_log
+from mmengine.hooks.logger_hook import SUFFIX_TYPE
+from mmengine.logging import MMLogger, print_log
 from mmengine.registry import VISBACKENDS
+from mmengine.utils import scandir
 from mmengine.utils.dl_utils import TORCH_VERSION
 
 
@@ -613,3 +616,203 @@ def close(self):
         """close an opened tensorboard object."""
         if hasattr(self, '_tensorboard'):
             self._tensorboard.close()
+
+
+@VISBACKENDS.register_module()
+class MLflowVisBackend(BaseVisBackend):
+    """MLflow visualization backend class.
+
+    It can write images, config, scalars, etc. to a
+    mlflow file.
+
+    Examples:
+        >>> from mmengine.visualization import MLflowVisBackend
+        >>> from mmengine import Config
+        >>> import numpy as np
+        >>> vis_backend = MLflowVisBackend(save_dir='temp_dir')
+        >>> img = np.random.randint(0, 256, size=(10, 10, 3))
+        >>> vis_backend.add_image('img.png', img)
+        >>> vis_backend.add_scalar('mAP', 0.6)
+        >>> vis_backend.add_scalars({'loss': 0.1,'acc':0.8})
+        >>> cfg = Config(dict(a=1, b=dict(b1=[0, 1])))
+        >>> vis_backend.add_config(cfg)
+
+    Args:
+        save_dir (str): The root directory to save the files
+            produced by the backend.
+        exp_name (str, optional): The experiment name. Default to None.
+        run_name (str, optional): The run name. Default to None.
+        tags (dict, optional): The tags to be added to the experiment.
+            Default to None.
+        params (dict, optional): The params to be added to the experiment.
+            Default to None.
+        tracking_uri (str, optional): The tracking uri. Default to None.
+        artifact_suffix (Tuple[str] or str, optional): The artifact suffix.
+            Default to ('.json', '.log', '.py', 'yaml').
+    """
+
+    def __init__(self,
+                 save_dir: str,
+                 exp_name: Optional[str] = None,
+                 run_name: Optional[str] = None,
+                 tags: Optional[dict] = None,
+                 params: Optional[dict] = None,
+                 tracking_uri: Optional[str] = None,
+                 artifact_suffix: SUFFIX_TYPE = ('.json', '.log', '.py',
+                                                 'yaml')):
+        super().__init__(save_dir)
+        self._exp_name = exp_name
+        self._run_name = run_name
+        self._tags = tags
+        self._params = params
+        self._tracking_uri = tracking_uri
+        self._artifact_suffix = artifact_suffix
+
+    def _init_env(self):
+        """Setup env for MLflow."""
+        if not os.path.exists(self._save_dir):
+            os.makedirs(self._save_dir, exist_ok=True)  # type: ignore
+
+        try:
+            import mlflow
+        except ImportError:
+            raise ImportError(
+                'Please run "pip install mlflow" to install mlflow'
+            )  # type: ignore
+        self._mlflow = mlflow
+
+        # when mlflow is imported, a default logger is created.
+        # at this time, the default logger's stream is None
+        # so the stream is reopened only when the stream is None
+        # or the stream is closed
+        logger = MMLogger.get_current_instance()
+        for handler in logger.handlers:
+            if handler.stream is None or handler.stream.closed:
+                handler.stream = open(handler.baseFilename, 'a')
+
+        if self._tracking_uri is not None:
+            logger.warning(
+                'Please make sure that the mlflow server is running.')
+            self._mlflow.set_tracking_uri(self._tracking_uri)
+        else:
+            if os.name == 'nt':
+                file_url = f'file:\\{os.path.abspath(self._save_dir)}'
+            else:
+                file_url = f'file://{os.path.abspath(self._save_dir)}'
+            self._mlflow.set_tracking_uri(file_url)
+
+        self._exp_name = self._exp_name or 'Default'
+
+        if self._mlflow.get_experiment_by_name(self._exp_name) is None:
+            self._mlflow.create_experiment(self._exp_name)
+
+        self._mlflow.set_experiment(self._exp_name)
+
+        if self._run_name is not None:
+            self._mlflow.set_tag('mlflow.runName', self._run_name)
+        if self._tags is not None:
+            self._mlflow.set_tags(self._tags)
+        if self._params is not None:
+            self._mlflow.log_params(self._params)
+
+    @property  # type: ignore
+    @force_init_env
+    def experiment(self):
+        """Return MLflow object."""
+        return self._mlflow
+
+    @force_init_env
+    def add_config(self, config: Config, **kwargs) -> None:
+        """Record the config to mlflow.
+
+        Args:
+            config (Config): The Config object
+        """
+        self.cfg = config
+        self._mlflow.log_params(self._flatten(self.cfg))
+        self._mlflow.log_text(self.cfg.pretty_text, 'config.py')
+
+    @force_init_env
+    def add_image(self,
+                  name: str,
+                  image: np.ndarray,
+                  step: int = 0,
+                  **kwargs) -> None:
+        """Record the image to mlflow.
+
+        Args:
+            name (str): The image identifier.
+            image (np.ndarray): The image to be saved. The format
+                should be RGB.
+            step (int): Global step value to record. Default to 0.
+        """
+        self._mlflow.log_image(image, name)
+
+    @force_init_env
+    def add_scalar(self,
+                   name: str,
+                   value: Union[int, float, torch.Tensor, np.ndarray],
+                   step: int = 0,
+                   **kwargs) -> None:
+        """Record the scalar data to mlflow.
+
+        Args:
+            name (str): The scalar identifier.
+            value (int, float, torch.Tensor, np.ndarray): Value to save.
+            step (int): Global step value to record. Default to 0.
+        """
+        self._mlflow.log_metric(name, value, step)
+
+    @force_init_env
+    def add_scalars(self,
+                    scalar_dict: dict,
+                    step: int = 0,
+                    file_path: Optional[str] = None,
+                    **kwargs) -> None:
+        """Record the scalar's data to mlflow.
+
+        Args:
+            scalar_dict (dict): Key-value pair storing the tag and
+                corresponding values.
+            step (int): Global step value to record. Default to 0.
+            file_path (str, optional): Useless parameter. Just for
+                interface unification. Default to None.
+        """
+        assert isinstance(scalar_dict, dict)
+        assert 'step' not in scalar_dict, 'Please set it directly ' \
+                                          'through the step parameter'
+        self._mlflow.log_metrics(scalar_dict, step)
+
+    def close(self) -> None:
+        """Close the mlflow."""
+        file_paths = dict()
+        for filename in scandir(self.cfg.work_dir, self._artifact_suffix,
+                                True):
+            file_path = osp.join(self.cfg.work_dir, filename)
+            relative_path = os.path.relpath(file_path, self.cfg.work_dir)
+            dir_path = os.path.dirname(relative_path)
+            file_paths[file_path] = dir_path
+
+        for file_path, dir_path in file_paths.items():
+            self._mlflow.log_artifact(file_path, dir_path)
+
+        if hasattr(self, '_mlflow'):
+            self._mlflow.end_run()
+
+    def _flatten(self, d, parent_key='', sep='.') -> dict:
+        """Flatten the dict."""
+        items = dict()
+        for k, v in d.items():
+            new_key = parent_key + sep + k if parent_key else k
+            if isinstance(v, MutableMapping):
+                items.update(self._flatten(v, new_key, sep=sep))
+            elif isinstance(v, list):
+                if any(isinstance(x, dict) for x in v):
+                    for i, x in enumerate(v):
+                        items.update(
+                            self._flatten(x, new_key + sep + str(i), sep=sep))
+                else:
+                    items[new_key] = v
+            else:
+                items[new_key] = v
+        return items

requirements/tests.txt

@@ -2,5 +2,6 @@ coverage
 dadaptation
 lion-pytorch
 lmdb
+mlflow
 parameterized
 pytest

tests/test_visualizer/test_vis_backend.py

@@ -12,8 +12,8 @@
 from mmengine import Config
 from mmengine.fileio import load
 from mmengine.registry import VISBACKENDS
-from mmengine.visualization import (LocalVisBackend, TensorboardVisBackend,
-                                    WandbVisBackend)
+from mmengine.visualization import (LocalVisBackend, MLflowVisBackend,
+                                    TensorboardVisBackend, WandbVisBackend)
 
 
 class TestLocalVisBackend:
@@ -242,3 +242,46 @@ def test_close(self):
         wandb_vis_backend._init_env()
         wandb_vis_backend.close()
         shutil.rmtree('temp_dir')
+
+
+class TestMLflowVisBackend:
+
+    def test_init(self):
+        MLflowVisBackend('temp_dir')
+        VISBACKENDS.build(dict(type='MLflowVisBackend', save_dir='temp_dir'))
+
+    def test_experiment(self):
+        mlflow_vis_backend = MLflowVisBackend('temp_dir')
+        assert mlflow_vis_backend.experiment == mlflow_vis_backend._mlflow
+
+    def test_add_config(self):
+        cfg = Config(dict(a=1, b=dict(b1=[0, 1])))
+        mlflow_vis_backend = MLflowVisBackend('temp_dir')
+        mlflow_vis_backend.add_config(cfg)
+
+    def test_add_image(self):
+        image = np.random.randint(0, 256, size=(10, 10, 3)).astype(np.uint8)
+        mlflow_vis_backend = MLflowVisBackend('temp_dir')
+        mlflow_vis_backend.add_image('img.png', image)
+
+    def test_add_scalar(self):
+        mlflow_vis_backend = MLflowVisBackend('temp_dir')
+        mlflow_vis_backend.add_scalar('map', 0.9)
+        # test append mode
+        mlflow_vis_backend.add_scalar('map', 0.9)
+        mlflow_vis_backend.add_scalar('map', 0.95)
+
+    def test_add_scalars(self):
+        mlflow_vis_backend = MLflowVisBackend('temp_dir')
+        input_dict = {'map': 0.7, 'acc': 0.9}
+        mlflow_vis_backend.add_scalars(input_dict)
+        # test append mode
+        mlflow_vis_backend.add_scalars({'map': 0.8, 'acc': 0.8})
+
+    def test_close(self):
+        cfg = Config(dict(work_dir='temp_dir'))
+        mlflow_vis_backend = MLflowVisBackend('temp_dir')
+        mlflow_vis_backend._init_env()
+        mlflow_vis_backend.add_config(cfg)
+        mlflow_vis_backend.close()
+        shutil.rmtree('temp_dir')