Introduce --storage-class to support journal storages

optuna_dashboard/_app.py

@@ -37,6 +37,7 @@
 from ._pareto_front import get_pareto_front_trials
 from ._serializer import serialize_study_detail
 from ._serializer import serialize_study_summary
+from ._storage_url import get_storage
 from .artifact._backend import delete_all_artifacts
 from .artifact._backend import register_artifact_route
 
@@ -503,19 +504,6 @@ def _frozen_study_to_study_summary(frozen_study: "FrozenStudy") -> StudySummary:
     )
 
 
-def get_storage(storage: Union[str, BaseStorage]) -> BaseStorage:
-    if isinstance(storage, str):
-        if storage.startswith("redis"):
-            raise ValueError(
-                "RedisStorage is unsupported from Optuna v3.1 or Optuna Dashboard v0.8.0"
-            )
-        elif version.parse(optuna_ver) >= version.Version("v3.0.0"):
-            return RDBStorage(storage, skip_compatibility_check=True, skip_table_creation=True)
-        else:
-            return RDBStorage(storage, skip_compatibility_check=True)
-    return storage
-
-
 def run_server(
     storage: Union[str, BaseStorage],
     host: str = "localhost",

optuna_dashboard/_cli.py

@@ -15,8 +15,8 @@
 
 from . import __version__
 from ._app import create_app
-from ._app import get_storage
 from ._sql_profiler import register_profiler_view
+from ._storage_url import get_storage
 from .artifact.file_system import FileSystemBackend
 
 
@@ -84,7 +84,13 @@ def auto_select_server(
 
 def main() -> None:
     parser = argparse.ArgumentParser(description="Real-time dashboard for Optuna.")
-    parser.add_argument("storage", help="DB URL (e.g. sqlite:///example.db)", type=str)
+    parser.add_argument("storage", help="Storage URL (e.g. sqlite:///example.db)", type=str)
+    parser.add_argument(
+        "--storage-class",
+        help="Storage class hint (e.g. JournalFileStorage)",
+        type=str,
+        default=None,
+    )
     parser.add_argument(
         "--port", help="port number (default: %(default)s)", type=int, default=8080
     )
@@ -105,7 +111,7 @@ def main() -> None:
     args = parser.parse_args()
 
     storage: BaseStorage
-    storage = get_storage(args.storage)
+    storage = get_storage(args.storage, storage_class=args.storage_class)
 
     artifact_backend = None
     if args.artifact_dir is not None:

optuna_dashboard/_storage_url.py

@@ -0,0 +1,96 @@
+from __future__ import annotations
+
+import os.path
+import re
+from typing import TYPE_CHECKING
+
+from optuna.storages import BaseStorage
+from optuna.storages import RDBStorage
+from optuna.version import __version__ as optuna_ver
+from packaging import version
+
+
+if TYPE_CHECKING:
+    from typing import Optional
+    from typing import Union
+
+    from optuna.storages import JournalStorage
+
+
+# https://github.com/zzzeek/sqlalchemy/blob/c6554ac52/lib/sqlalchemy/engine/url.py#L234-L292
+rfc1738_pattern = re.compile(
+    r"""
+        (?P<name>[\w\+]+)://
+        (?:
+            (?P<username>[^:/]*)
+            (?::(?P<password>.*))?
+        @)?
+        (?:
+            (?:
+                \[(?P<ipv6host>[^/]+)\] |
+                (?P<ipv4host>[^/:]+)
+            )?
+            (?::(?P<port>[^/]*))?
+        )?
+        (?:/(?P<database>.*))?
+        """,
+    re.X,
+)
+
+
+def get_storage(
+    storage: Union[str, BaseStorage], storage_class: Optional[str] = None
+) -> BaseStorage:
+    if isinstance(storage, BaseStorage):
+        return storage
+
+    if storage_class:
+        if storage_class == "RDBStorage":
+            return get_rdb_storage(storage)
+        if storage_class == "JournalRedisStorage":
+            return get_journal_redis_storage(storage)
+        if storage_class == "JournalFileStorage":
+            return get_journal_file_storage(storage)
+        raise ValueError("Unexpected storage_class")
+
+    return guess_storage_from_url(storage)
+
+
+def guess_storage_from_url(storage_url: str) -> BaseStorage:
+    if storage_url.startswith("redis"):
+        return get_journal_redis_storage(storage_url)
+
+    if os.path.isfile(storage_url):
+        return get_journal_file_storage(storage_url)
+
+    if rfc1738_pattern.match(storage_url) is not None:
+        return get_rdb_storage(storage_url)
+
+    raise ValueError("Failed to guess storage class from storage_url")
+
+
+def get_rdb_storage(storage_url: str) -> RDBStorage:
+    if version.parse(optuna_ver) >= version.Version("v3.0.0"):
+        return RDBStorage(storage_url, skip_compatibility_check=True, skip_table_creation=True)
+    else:
+        return RDBStorage(storage_url, skip_compatibility_check=True)
+
+
+def get_journal_file_storage(file_path: str) -> JournalStorage:
+    if version.parse(optuna_ver) < version.Version("v3.1.0"):
+        raise ValueError("JournalRedisStorage is available from Optuna v3.1.0")
+
+    from optuna.storages import JournalFileStorage
+    from optuna.storages import JournalStorage
+
+    return JournalStorage(JournalFileStorage(file_path=file_path))
+
+
+def get_journal_redis_storage(redis_url: str) -> JournalStorage:
+    if version.parse(optuna_ver) < version.Version("v3.1.0"):
+        raise ValueError("JournalRedisStorage is available from Optuna v3.1.0")
+
+    from optuna.storages import JournalRedisStorage
+    from optuna.storages import JournalStorage
+
+    return JournalStorage(JournalRedisStorage(redis_url))