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138 lines
4.5 KiB
138 lines
4.5 KiB
# MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization
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# Copyright (C) 2020-2021, UChicago Argonne, LLC. All rights reserved.
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# Released under the modified BSD license. See COPYING.md for more details.
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import gc
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import gzip
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import os
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import pickle
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from typing import Optional, Any, List, Hashable, cast, IO
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from overrides import overrides
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from miplearn.instance.base import logger, Instance
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from miplearn.types import VariableName, Category
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class PickleGzInstance(Instance):
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"""
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An instance backed by a gzipped pickle file.
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The instance is only loaded to memory after an operation is called (for example,
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`to_model`).
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Parameters
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----------
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filename: str
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Path of the gzipped pickle file that should be loaded.
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"""
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# noinspection PyMissingConstructor
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def __init__(self, filename: str) -> None:
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assert os.path.exists(filename), f"File not found: {filename}"
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self.instance: Optional[Instance] = None
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self.filename: str = filename
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@overrides
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def to_model(self) -> Any:
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assert self.instance is not None
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return self.instance.to_model()
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@overrides
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def get_instance_features(self) -> List[float]:
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assert self.instance is not None
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return self.instance.get_instance_features()
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@overrides
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def get_variable_features(self, var_name: VariableName) -> List[float]:
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assert self.instance is not None
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return self.instance.get_variable_features(var_name)
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@overrides
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def get_variable_category(self, var_name: VariableName) -> Optional[Category]:
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assert self.instance is not None
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return self.instance.get_variable_category(var_name)
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@overrides
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def get_constraint_features(self, cid: str) -> Optional[List[float]]:
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assert self.instance is not None
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return self.instance.get_constraint_features(cid)
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@overrides
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def get_constraint_category(self, cid: str) -> Optional[Hashable]:
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assert self.instance is not None
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return self.instance.get_constraint_category(cid)
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@overrides
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def has_static_lazy_constraints(self) -> bool:
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assert self.instance is not None
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return self.instance.has_static_lazy_constraints()
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@overrides
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def has_dynamic_lazy_constraints(self) -> bool:
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assert self.instance is not None
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return self.instance.has_dynamic_lazy_constraints()
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@overrides
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def is_constraint_lazy(self, cid: str) -> bool:
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assert self.instance is not None
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return self.instance.is_constraint_lazy(cid)
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@overrides
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def find_violated_lazy_constraints(self, model: Any) -> List[Hashable]:
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assert self.instance is not None
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return self.instance.find_violated_lazy_constraints(model)
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@overrides
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def build_lazy_constraint(self, model: Any, violation: Hashable) -> Any:
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assert self.instance is not None
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return self.instance.build_lazy_constraint(model, violation)
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@overrides
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def find_violated_user_cuts(self, model: Any) -> List[Hashable]:
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assert self.instance is not None
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return self.instance.find_violated_user_cuts(model)
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@overrides
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def build_user_cut(self, model: Any, violation: Hashable) -> Any:
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assert self.instance is not None
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return self.instance.build_user_cut(model, violation)
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@overrides
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def load(self) -> None:
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if self.instance is None:
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obj = read_pickle_gz(self.filename)
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assert isinstance(obj, Instance)
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self.instance = obj
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self.features = self.instance.features
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self.training_data = self.instance.training_data
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@overrides
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def free(self) -> None:
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self.instance = None # type: ignore
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self.features = None # type: ignore
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self.training_data = None # type: ignore
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gc.collect()
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@overrides
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def flush(self) -> None:
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write_pickle_gz(self.instance, self.filename)
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def write_pickle_gz(obj: Any, filename: str) -> None:
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logger.info(f"Writing: {filename}")
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os.makedirs(os.path.dirname(filename), exist_ok=True)
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with gzip.GzipFile(filename, "wb") as file:
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pickle.dump(obj, cast(IO[bytes], file))
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def read_pickle_gz(filename: str) -> Any:
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logger.info(f"Reading: {filename}")
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with gzip.GzipFile(filename, "rb") as file:
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return pickle.load(cast(IO[bytes], file))
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def write_pickle_gz_multiple(objs: List[Any], dirname: str) -> None:
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for (i, obj) in enumerate(objs):
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write_pickle_gz(obj, f"{dirname}/{i:05d}.pkl.gz")
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