optuna-dashboard/optuna_dashboard/serializer.py

from typing import Any, Dict, List, Tuple

from optuna.distributions import BaseDistribution
from optuna.study import StudySummary
from optuna.trial import FrozenTrial

try:
    from typing import TypedDict
except ImportError:
    from typing_extensions import TypedDict


MAX_ATTR_LENGTH = 128
Attribute = TypedDict(
    "Attribute",
    {
        "key": str,
        "value": str,
    },
)
IntermediateValue = TypedDict(
    "IntermediateValue",
    {
        "step": int,
        "value": float,
    },
)
TrialParam = TypedDict(
    "TrialParam",
    {
        "name": str,
        "value": str,
    },
)


def serialize_attrs(attrs: Dict[str, Any]) -> List[Attribute]:
    serialized: List[Attribute] = []
    for k, v in attrs.items():
        value: str
        if isinstance(v, str):
            value = v[:MAX_ATTR_LENGTH] if len(v) > MAX_ATTR_LENGTH else v
        elif isinstance(v, (bool, float, int)):
            value = str(v)
        elif isinstance(v, bytes):
            value = "<binary object>"
        elif v is None:
            value = "None"
        else:  # unsupported type
            continue
        serialized.append({"key": k, "value": value})
    return serialized


def serialize_intermediate_values(values: Dict[int, float]) -> List[IntermediateValue]:
    return [{"step": step, "value": value} for step, value in values.items()]


def serialize_trial_params(params: Dict[str, Any]) -> List[TrialParam]:
    return [{"name": name, "value": str(value)} for name, value in params.items()]


def serialize_study_summary(summary: StudySummary) -> Dict[str, Any]:
    serialized = {
        "study_id": summary._study_id,
        "study_name": summary.study_name,
        "directions": [d.name.lower() for d in summary.directions],
        "user_attrs": serialize_attrs(summary.user_attrs),
        "system_attrs": serialize_attrs(summary.system_attrs),
    }

    if summary.datetime_start is not None:
        serialized["datetime_start"] = (summary.datetime_start.isoformat(),)

    if summary.best_trial:
        serialized["best_trial"] = serialize_frozen_trial(
            summary._study_id, summary.best_trial
        )

    return serialized


def serialize_study_detail(
    summary: StudySummary,
    trials: List[FrozenTrial],
    intersection: List[Tuple[str, BaseDistribution]],
    union: List[Tuple[str, BaseDistribution]],
) -> Dict[str, Any]:
    serialized: Dict[str, Any] = {
        "name": summary.study_name,
        "directions": [d.name.lower() for d in summary.directions],
    }
    if summary.datetime_start is not None:
        serialized["datetime_start"] = summary.datetime_start.isoformat()

    if summary.best_trial is not None:
        serialized["best_trial"] = serialize_frozen_trial(
            summary._study_id, summary.best_trial
        )

    serialized["trials"] = [
        serialize_frozen_trial(summary._study_id, trial) for trial in trials
    ]

    serialized["intersection_search_space"] = serialize_search_space(intersection)
    serialized["union_search_space"] = serialize_search_space(union)
    return serialized


def serialize_frozen_trial(study_id: int, trial: FrozenTrial) -> Dict[str, Any]:
    serialized = {
        "trial_id": trial._trial_id,
        "study_id": study_id,
        "number": trial.number,
        "state": trial.state.name.capitalize(),
        "intermediate_values": serialize_intermediate_values(trial.intermediate_values),
        "params": serialize_trial_params(trial.params),
        "user_attrs": serialize_attrs(trial.user_attrs),
        "system_attrs": serialize_attrs(trial.system_attrs),
    }

    if trial.values is not None:
        serialized["values"] = trial.values

    if trial.datetime_start is not None:
        serialized["datetime_start"] = trial.datetime_start.isoformat()

    if trial.datetime_complete is not None:
        serialized["datetime_complete"] = trial.datetime_complete.isoformat()

    return serialized


def serialize_search_space(
    search_space: List[Tuple[str, BaseDistribution]]
) -> List[Dict[str, Any]]:
    serialized = []
    for param_name, distribution in search_space:
        serialized.append(
            {
                "name": param_name,
                "type": distribution.__class__.__name__,
                "attributes": distribution._asdict(),
            }
        )
    return serialized