Optimize space usage of ExplorationReport before saving (#279)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
- Added `no_candidate()` method across multiple exploration report
classes to check candidate availability.
- Enhanced `get_candidate_ids()` method with optional `clear` parameter
for memory management.

- **Improvements**
	- Optimized ratio calculations in exploration report classes.
- Introduced more efficient state tracking for candidate configurations.

- **Technical Updates**
- Updated method signatures in exploration report classes to include new
parameters.
	- Refined candidate selection and reporting mechanisms.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Signed-off-by: zjgemi <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

dpgen2/exploration/report/report.py

@@ -60,9 +60,10 @@ def converged(
         """
         pass
 
+    @abstractmethod
     def no_candidate(self) -> bool:
         r"""If no candidate configuration is found"""
-        return all([len(ii) == 0 for ii in self.get_candidate_ids()])
+        pass
 
     @abstractmethod
     def get_candidate_ids(

dpgen2/exploration/report/report_adaptive_lower.py

@@ -127,6 +127,10 @@ def __init__(
         self.fmt_str = " ".join([f"%{ii}s" for ii in spaces])
         self.fmt_flt = "%.4f"
         self.header_str = "#" + self.fmt_str % print_tuple
+        self._no_candidate = False
+        self._failed_ratio = None
+        self._accurate_ratio = None
+        self._candidate_ratio = None
 
     @staticmethod
     def doc() -> str:
@@ -274,6 +278,10 @@ def record(
         # accurate set is substracted by the candidate set
         self.accur = self.accur - self.candi
         self.model_devi = model_devi
+        self._no_candidate = len(self.candi) == 0
+        self._failed_ratio = float(len(self.failed)) / float(self.nframes)
+        self._accurate_ratio = float(len(self.accur)) / float(self.nframes)
+        self._candidate_ratio = float(len(self.candi)) / float(self.nframes)
 
     def _record_one_traj(
         self,
@@ -346,29 +354,36 @@ def failed_ratio(
         self,
         tag=None,
     ):
-        return float(len(self.failed)) / float(self.nframes)
+        return self._failed_ratio
 
     def accurate_ratio(
         self,
         tag=None,
     ):
-        return float(len(self.accur)) / float(self.nframes)
+        return self._accurate_ratio
 
     def candidate_ratio(
         self,
         tag=None,
     ):
-        return float(len(self.candi)) / float(self.nframes)
+        return self._candidate_ratio
+
+    def no_candidate(self) -> bool:
+        return self._no_candidate
 
     def get_candidate_ids(
         self,
         max_nframes: Optional[int] = None,
+        clear: bool = True,
     ) -> List[List[int]]:
         ntraj = self.ntraj
         id_cand = self._get_candidates(max_nframes)
         id_cand_list = [[] for ii in range(ntraj)]
         for ii in id_cand:
             id_cand_list[ii[0]].append(ii[1])
+        # free the memory, this method should only be called once
+        if clear:
+            self.clear()
         return id_cand_list
 
     def _get_candidates(

dpgen2/exploration/report/report_trust_levels_base.py

@@ -64,6 +64,10 @@ def __init__(
         self.fmt_str = " ".join([f"%{ii}s" for ii in spaces])
         self.fmt_flt = "%.4f"
         self.header_str = "#" + self.fmt_str % print_tuple
+        self._no_candidate = False
+        self._failed_ratio = None
+        self._accurate_ratio = None
+        self._candidate_ratio = None
 
     @staticmethod
     def args() -> List[Argument]:
@@ -133,6 +137,16 @@ def record(
         assert len(self.traj_accu) == ntraj
         assert len(self.traj_fail) == ntraj
         self.model_devi = model_devi
+        self._no_candidate = sum([len(ii) for ii in self.traj_cand]) == 0
+        self._failed_ratio = float(sum([len(ii) for ii in self.traj_fail])) / float(
+            sum(self.traj_nframes)
+        )
+        self._accurate_ratio = float(sum([len(ii) for ii in self.traj_accu])) / float(
+            sum(self.traj_nframes)
+        )
+        self._candidate_ratio = float(sum([len(ii) for ii in self.traj_cand])) / float(
+            sum(self.traj_nframes)
+        )
 
     def _get_indexes(
         self,
@@ -205,22 +219,22 @@ def failed_ratio(
         self,
         tag=None,
     ):
-        traj_nf = [len(ii) for ii in self.traj_fail]
-        return float(sum(traj_nf)) / float(sum(self.traj_nframes))
+        return self._failed_ratio
 
     def accurate_ratio(
         self,
         tag=None,
     ):
-        traj_nf = [len(ii) for ii in self.traj_accu]
-        return float(sum(traj_nf)) / float(sum(self.traj_nframes))
+        return self._accurate_ratio
 
     def candidate_ratio(
         self,
         tag=None,
     ):
-        traj_nf = [len(ii) for ii in self.traj_cand]
-        return float(sum(traj_nf)) / float(sum(self.traj_nframes))
+        return self._candidate_ratio
+
+    def no_candidate(self) -> bool:
+        return self._no_candidate
 
     @abstractmethod
     def get_candidate_ids(

dpgen2/exploration/report/report_trust_levels_max.py

@@ -41,17 +41,23 @@ def converged(
         converged  bool
             If the exploration is converged.
         """
-        return self.accurate_ratio() >= self.conv_accuracy
+        accurate_ratio = self.accurate_ratio()
+        assert isinstance(accurate_ratio, float)
+        return accurate_ratio >= self.conv_accuracy
 
     def get_candidate_ids(
         self,
         max_nframes: Optional[int] = None,
+        clear: bool = True,
     ) -> List[List[int]]:
         ntraj = len(self.traj_nframes)
         id_cand = self._get_candidates(max_nframes)
         id_cand_list = [[] for ii in range(ntraj)]
         for ii in id_cand:
             id_cand_list[ii[0]].append(ii[1])
+        # free the memory, this method should only be called once
+        if clear:
+            self.clear()
         return id_cand_list
 
     def _get_candidates(

dpgen2/exploration/report/report_trust_levels_random.py

@@ -41,17 +41,23 @@ def converged(
         converged  bool
             If the exploration is converged.
         """
-        return self.accurate_ratio() >= self.conv_accuracy
+        accurate_ratio = self.accurate_ratio()
+        assert isinstance(accurate_ratio, float)
+        return accurate_ratio >= self.conv_accuracy
 
     def get_candidate_ids(
         self,
         max_nframes: Optional[int] = None,
+        clear: bool = True,
     ) -> List[List[int]]:
         ntraj = len(self.traj_nframes)
         id_cand = self._get_candidates(max_nframes)
         id_cand_list = [[] for ii in range(ntraj)]
         for ii in id_cand:
             id_cand_list[ii[0]].append(ii[1])
+        # free the memory, this method should only be called once
+        if clear:
+            self.clear()
         return id_cand_list
 
     def _get_candidates(

tests/exploration/test_report_adaptive_lower.py

@@ -88,7 +88,7 @@ class MockedReport:
         self.assertFalse(ter.converged([mr, mr1, mr]))
         self.assertTrue(ter.converged([mr1, mr, mr]))
 
-        picked = ter.get_candidate_ids(2)
+        picked = ter.get_candidate_ids(2, clear=False)
         npicked = 0
         self.assertEqual(len(picked), 2)
         for ii in range(2):
@@ -218,12 +218,12 @@ def faked_choices(
             return ret
 
         ter.record(model_devi)
-        with mock.patch("random.choices", faked_choices):
-            picked = ter.get_candidate_ids(11)
-        self.assertFalse(ter.converged([]))
         self.assertEqual(ter.candi, expected_cand)
         self.assertEqual(ter.accur, expected_accu)
         self.assertEqual(set(ter.failed), expected_fail)
+        with mock.patch("random.choices", faked_choices):
+            picked = ter.get_candidate_ids(11)
+        self.assertFalse(ter.converged([]))
         self.assertEqual(len(picked), 2)
         self.assertEqual(sorted(picked[0]), [1, 3])
         self.assertEqual(sorted(picked[1]), [1, 5, 7])