exp: Generate a human-readable name beforehand.

- Add `get_random_exp_name` to utils.
Generates a name (`f"{adjective}-{noun}"`) by randomly chosing pairs of adjetive, noun.
Recieves `scm` and `baseline_rev` and retries the random choice until a non-existing ref is found.

Closes https://github.com/iterative/dvc/issues/8650

dvc/repo/experiments/__init__.py

@@ -32,7 +32,7 @@ from .refs import (
     ExpRefInfo,
 )
 from .stash import ExpStashEntry
-from .utils import exp_refs_by_rev, unlocked_repo
+from .utils import check_ref_format, exp_refs_by_rev, unlocked_repo
 
 logger = logging.getLogger(__name__)
 
@@ -236,17 +236,6 @@ class Experiments:
             "\tdvc exp branch <exp> <branch>\n"
         )
 
-    def _validate_new_ref(self, exp_ref: ExpRefInfo):
-        from .utils import check_ref_format
-
-        if not exp_ref.name:
-            return
-
-        check_ref_format(self.scm, exp_ref)
-
-        if self.scm.get_ref(str(exp_ref)):
-            raise ExperimentExistsError(exp_ref.name)
-
     def new(
         self,
         queue: BaseStashQueue,
@@ -265,13 +254,15 @@ class Experiments:
 
         name = kwargs.get("name", None)
         baseline_sha = kwargs.get("baseline_rev") or self.repo.scm.get_rev()
-        exp_ref = ExpRefInfo(baseline_sha=baseline_sha, name=name)
 
-        try:
-            self._validate_new_ref(exp_ref)
-        except ExperimentExistsError as err:
-            if not (kwargs.get("force", False) or kwargs.get("reset", False)):
-                raise err
+        if name:
+            exp_ref = ExpRefInfo(baseline_sha=baseline_sha, name=name)
+            check_ref_format(self.scm, exp_ref)
+            force = kwargs.get("force", False)
+            reset = kwargs.get("reset", False)
+            if self.scm.get_ref(str(exp_ref)) and not (force or reset):
+                raise ExperimentExistsError(exp_ref.name)
+
         return queue.put(*args, **kwargs)
 
     def _resume_checkpoint(

dvc/repo/experiments/queue/base.py

@@ -30,7 +30,13 @@ from ..executor.base import BaseExecutor, ExecutorResult
 from ..executor.local import WorkspaceExecutor
 from ..refs import ExpRefInfo
 from ..stash import ExpStash, ExpStashEntry
-from ..utils import EXEC_PID_DIR, EXEC_TMP_DIR, exp_refs_by_rev, get_exp_rwlock
+from ..utils import (
+    EXEC_PID_DIR,
+    EXEC_TMP_DIR,
+    exp_refs_by_rev,
+    get_exp_rwlock,
+    get_random_exp_name,
+)
 from .utils import get_remote_executor_refs
 
 if TYPE_CHECKING:
@@ -281,7 +287,7 @@ class BaseStashQueue(ABC):
                 output.
         """
 
-    def _stash_exp(
+    def _stash_exp(  # noqa: C901
         self,
         *args,
         params: Optional[Dict[str, List[str]]] = None,
@@ -399,8 +405,9 @@ class BaseStashQueue(ABC):
                     run_env = {
                         DVC_EXP_BASELINE_REV: baseline_rev,
                     }
-                    if name:
-                        run_env[DVC_EXP_NAME] = name
+                    if not name:
+                        name = get_random_exp_name(self.scm, baseline_rev)
+                    run_env[DVC_EXP_NAME] = name
                     if resume_rev:
                         run_env[DVCLIVE_RESUME] = "1"
                     self._pack_args(*args, run_env=run_env, **kwargs)

tests/func/experiments/test_experiments.py

@@ -684,7 +684,7 @@ def test_experiments_workspace_not_log_exception(caplog, dvc, scm):
     assert not caplog.text
 
 
-def test_run_env(tmp_dir, dvc, scm):
+def test_run_env(tmp_dir, dvc, scm, mocker):
     dump_run_env = dedent(
         """\
         import os
@@ -703,7 +703,7 @@ def test_run_env(tmp_dir, dvc, scm):
     )
     dvc.experiments.run()
     assert (tmp_dir / "DVC_EXP_BASELINE_REV").read_text().strip() == baseline
-    assert (tmp_dir / "DVC_EXP_NAME").read_text().strip() == ""
+    assert (tmp_dir / "DVC_EXP_NAME").read_text().strip() != ""
 
     dvc.experiments.run(name="foo")
     assert (tmp_dir / "DVC_EXP_BASELINE_REV").read_text().strip() == baseline

tests/func/experiments/test_show.py

@@ -220,6 +220,7 @@ def test_show_failed_experiment(tmp_dir, scm, dvc, failed_exp_stage):
                 "msg": "Experiment run failed.",
                 "type": "",
             },
+            "name": ANY,
         }
     }
 

tests/func/experiments/test_utils.py

@@ -0,0 +1,29 @@
+from funcy import first
+
+
+def test_generate_random_exp_name(tmp_dir, dvc, scm, exp_stage, mocker):
+    mocker.patch(
+        "dvc.repo.experiments.utils.random.choice",
+        side_effect=[
+            0,
+            0,
+            0,
+            0,
+            1,
+            1,
+            0,
+            0,
+        ],
+    )
+
+    ref = first(dvc.experiments.run(exp_stage.addressing, params=["foo=1"]))
+    assert dvc.experiments.get_exact_name([ref])[ref] == "0-0"
+
+    # Causes 1 retry
+    ref = first(dvc.experiments.run(exp_stage.addressing, params=["foo=2"]))
+    assert dvc.experiments.get_exact_name([ref])[ref] == "1-1"
+
+    tmp_dir.scm_gen({"foo": "bar"}, commit="foo")
+    # Can use same name because of different baseline_rev
+    ref = first(dvc.experiments.run(exp_stage.addressing, params=["foo=1"]))
+    assert dvc.experiments.get_exact_name([ref])[ref] == "0-0"