|
| 1 | +import os |
| 2 | +import pickle |
| 3 | +import threading |
| 4 | +from collections import OrderedDict |
| 5 | +from collections.abc import Iterable |
| 6 | +from functools import wraps |
| 7 | +from typing import Any, Callable |
| 8 | + |
| 9 | + |
| 10 | +class PerSmilesPerModelLRUCache: |
| 11 | + """ |
| 12 | + A thread-safe, optionally persistent LRU cache for storing |
| 13 | + (SMILES, model_name) → result mappings. |
| 14 | + """ |
| 15 | + |
| 16 | + def __init__(self, max_size: int = 100, persist_path: str | None = None): |
| 17 | + """ |
| 18 | + Initialize the cache. |
| 19 | +
|
| 20 | + Args: |
| 21 | + max_size (int): Maximum number of items to keep in the cache. |
| 22 | + persist_path (str | None): Optional path to persist cache using pickle. |
| 23 | + """ |
| 24 | + self._cache: OrderedDict[tuple[str, str], Any] = OrderedDict() |
| 25 | + self._max_size = max_size |
| 26 | + self._lock = threading.Lock() |
| 27 | + self._persist_path = persist_path |
| 28 | + |
| 29 | + self.hits = 0 |
| 30 | + self.misses = 0 |
| 31 | + |
| 32 | + if self._persist_path: |
| 33 | + self._load_cache() |
| 34 | + |
| 35 | + def get(self, smiles: str, model_name: str) -> Any | None: |
| 36 | + """ |
| 37 | + Retrieve value from cache if present, otherwise return None. |
| 38 | +
|
| 39 | + Args: |
| 40 | + smiles (str): SMILES string key. |
| 41 | + model_name (str): Model identifier. |
| 42 | +
|
| 43 | + Returns: |
| 44 | + Any | None: Cached value or None. |
| 45 | + """ |
| 46 | + key = (smiles, model_name) |
| 47 | + with self._lock: |
| 48 | + if key in self._cache: |
| 49 | + self._cache.move_to_end(key) |
| 50 | + self.hits += 1 |
| 51 | + return self._cache[key] |
| 52 | + else: |
| 53 | + self.misses += 1 |
| 54 | + return None |
| 55 | + |
| 56 | + def set(self, smiles: str, model_name: str, value: Any) -> None: |
| 57 | + """ |
| 58 | + Store value in cache under (smiles, model_name) key. |
| 59 | +
|
| 60 | + Args: |
| 61 | + smiles (str): SMILES string key. |
| 62 | + model_name (str): Model identifier. |
| 63 | + value (Any): Value to cache. |
| 64 | + """ |
| 65 | + assert value is not None, "Value must not be None" |
| 66 | + key = (smiles, model_name) |
| 67 | + with self._lock: |
| 68 | + if key in self._cache: |
| 69 | + self._cache.move_to_end(key) |
| 70 | + self._cache[key] = value |
| 71 | + if len(self._cache) > self._max_size: |
| 72 | + self._cache.popitem(last=False) |
| 73 | + |
| 74 | + def clear(self) -> None: |
| 75 | + """ |
| 76 | + Clear the cache and remove the persistence file if present. |
| 77 | + """ |
| 78 | + self._save_cache() |
| 79 | + with self._lock: |
| 80 | + self._cache.clear() |
| 81 | + self.hits = 0 |
| 82 | + self.misses = 0 |
| 83 | + if self._persist_path and os.path.exists(self._persist_path): |
| 84 | + os.remove(self._persist_path) |
| 85 | + |
| 86 | + def stats(self) -> dict[str, int]: |
| 87 | + """ |
| 88 | + Return cache hit/miss statistics. |
| 89 | +
|
| 90 | + Returns: |
| 91 | + dict[str, int]: Dictionary with 'hits' and 'misses' keys. |
| 92 | + """ |
| 93 | + return {"hits": self.hits, "misses": self.misses} |
| 94 | + |
| 95 | + def batch_decorator(self, func: Callable) -> Callable: |
| 96 | + """ |
| 97 | + Decorator for class methods that accept a batch of SMILES as a list, |
| 98 | + and cache predictions per (smiles, model_name) key. |
| 99 | +
|
| 100 | + The instance is expected to have a `model_name` attribute. |
| 101 | +
|
| 102 | + Args: |
| 103 | + func (Callable): The method to decorate. |
| 104 | +
|
| 105 | + Returns: |
| 106 | + Callable: The wrapped method. |
| 107 | + """ |
| 108 | + |
| 109 | + @wraps(func) |
| 110 | + def wrapper(instance, smiles_list: list[str]) -> list[Any]: |
| 111 | + assert isinstance(smiles_list, list), "smiles_list must be a list." |
| 112 | + model_name = getattr(instance, "model_name", None) |
| 113 | + assert model_name is not None, "Instance must have a model_name attribute." |
| 114 | + |
| 115 | + missing_smiles: list[str] = [] |
| 116 | + missing_indices: list[int] = [] |
| 117 | + ordered_results: list[Any] = [None] * len(smiles_list) |
| 118 | + |
| 119 | + # First: try to fetch all from cache |
| 120 | + for idx, smiles in enumerate(smiles_list): |
| 121 | + prediction = self.get(smiles=smiles, model_name=model_name) |
| 122 | + if prediction is not None: |
| 123 | + # For debugging purposes, you can uncomment the print statement below |
| 124 | + # print( |
| 125 | + # f"[Cache Hit] Prediction for smiles: {smiles} and model: {model_name} are retrieved from cache." |
| 126 | + # ) |
| 127 | + ordered_results[idx] = prediction |
| 128 | + else: |
| 129 | + missing_smiles.append(smiles) |
| 130 | + missing_indices.append(idx) |
| 131 | + |
| 132 | + # If some are missing, call original function |
| 133 | + if missing_smiles: |
| 134 | + new_results = func(instance, tuple(missing_smiles)) |
| 135 | + assert isinstance( |
| 136 | + new_results, Iterable |
| 137 | + ), "Function must return an Iterable." |
| 138 | + |
| 139 | + # Save to cache and append |
| 140 | + for smiles, prediction, missing_idx in zip( |
| 141 | + missing_smiles, new_results, missing_indices |
| 142 | + ): |
| 143 | + if prediction is not None: |
| 144 | + self.set(smiles, model_name, prediction) |
| 145 | + ordered_results[missing_idx] = prediction |
| 146 | + |
| 147 | + return ordered_results |
| 148 | + |
| 149 | + return wrapper |
| 150 | + |
| 151 | + def __len__(self) -> int: |
| 152 | + """ |
| 153 | + Return number of items in the cache. |
| 154 | +
|
| 155 | + Returns: |
| 156 | + int: Number of entries in the cache. |
| 157 | + """ |
| 158 | + with self._lock: |
| 159 | + return len(self._cache) |
| 160 | + |
| 161 | + def __repr__(self) -> str: |
| 162 | + """ |
| 163 | + String representation of the underlying cache. |
| 164 | +
|
| 165 | + Returns: |
| 166 | + str: String version of the OrderedDict. |
| 167 | + """ |
| 168 | + return self._cache.__repr__() |
| 169 | + |
| 170 | + def save(self) -> None: |
| 171 | + """ |
| 172 | + Save the cache to disk, if persistence is enabled. |
| 173 | + """ |
| 174 | + self._save_cache() |
| 175 | + |
| 176 | + def load(self) -> None: |
| 177 | + """ |
| 178 | + Load the cache from disk, if persistence is enabled. |
| 179 | + """ |
| 180 | + self._load_cache() |
| 181 | + |
| 182 | + def _save_cache(self) -> None: |
| 183 | + """ |
| 184 | + Serialize the cache to disk using pickle. |
| 185 | + """ |
| 186 | + if self._persist_path: |
| 187 | + try: |
| 188 | + with open(self._persist_path, "wb") as f: |
| 189 | + pickle.dump(self._cache, f) |
| 190 | + except Exception as e: |
| 191 | + print(f"[Cache Save Error] {e}") |
| 192 | + |
| 193 | + def _load_cache(self) -> None: |
| 194 | + """ |
| 195 | + Load the cache from disk, if the file exists and is non-empty. |
| 196 | + """ |
| 197 | + if ( |
| 198 | + self._persist_path |
| 199 | + and os.path.exists(self._persist_path) |
| 200 | + and os.path.getsize(self._persist_path) > 0 |
| 201 | + ): |
| 202 | + try: |
| 203 | + with open(self._persist_path, "rb") as f: |
| 204 | + loaded = pickle.load(f) |
| 205 | + if isinstance(loaded, OrderedDict): |
| 206 | + self._cache = loaded |
| 207 | + except Exception as e: |
| 208 | + print(f"[Cache Load Error] {e}") |
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