Add Cache to avoid frequently loading cache

qlib/__init__.py

@@ -15,6 +15,16 @@
 
 # init qlib
 def init(default_conf="client", **kwargs):
+    """
+
+    Parameters
+    ----------
+    **kwargs :
+        clear_mem_cache: str
+            the default value is True;
+            Will the memory cache be clear.
+            It is often used to improve performance when init will be called for multiple times
+    """
     from .config import C
     from .data.cache import H
 
@@ -28,7 +38,9 @@ def init(default_conf="client", **kwargs):
         logger.warning("Skip initialization because `skip_if_reg is True`")
         return
 
-    H.clear()
+    clear_mem_cache = kwargs.pop("clear_mem_cache", True)
+    if clear_mem_cache:
+        H.clear()
     C.set(default_conf, **kwargs)
 
     # mount nfs

qlib/config.py

@@ -10,6 +10,7 @@
 - server
 
 """
+from __future__ import annotations
 
 import os
 import re
@@ -18,7 +19,11 @@
 import platform
 import multiprocessing
 from pathlib import Path
-from typing import Union
+from typing import Optional, Union
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from qlib.utils.time import Freq
 
 
 class Config:
@@ -296,7 +301,9 @@ def get_uri_type(uri: Union[str, Path]):
             else:
                 return QlibConfig.LOCAL_URI
 
-        def get_data_uri(self, freq: str = None) -> Path:
+        def get_data_uri(self, freq: Optional[Union[str, Freq]] = None) -> Path:
+            if freq is not None:
+                freq = str(freq)  # converting Freq to string
             if freq is None or freq not in self.provider_uri:
                 freq = QlibConfig.DEFAULT_FREQ
             _provider_uri = self.provider_uri[freq]

qlib/data/data.py

@@ -27,7 +27,6 @@
 
 from ..log import get_module_logger
 from ..utils.time import Freq
-from ..utils.resam import resam_calendar
 from .cache import DiskDatasetCache, DiskExpressionCache
 from ..utils import (
     Wrapper,

qlib/data/storage/file_storage.py

@@ -11,6 +11,7 @@
 from qlib.utils.time import Freq
 from qlib.utils.resam import resam_calendar
 from qlib.config import C
+from qlib.data.cache import H
 from qlib.log import get_module_logger
 from qlib.data.storage import CalendarStorage, InstrumentStorage, FeatureStorage, CalVT, InstKT, InstVT
 
@@ -33,15 +34,15 @@ def support_freq(self) -> List[str]:
         if hasattr(self, _v):
             return getattr(self, _v)
         if len(self.provider_uri) == 1 and C.DEFAULT_FREQ in self.provider_uri:
-            freq = filter(
+            freq_l = filter(
                 lambda _freq: not _freq.endswith("_future"),
                 map(lambda x: x.stem, self.dpm.get_data_uri(C.DEFAULT_FREQ).joinpath("calendars").glob("*.txt")),
             )
         else:
-            freq = self.provider_uri.keys()
-        freq = list(freq)
-        setattr(self, _v, freq)
-        return freq
+            freq_l = self.provider_uri.keys()
+        freq_l = [Freq(freq) for freq in freq_l]
+        setattr(self, _v, freq_l)
+        return freq_l
 
     @property
     def uri(self) -> Path:
@@ -65,15 +66,28 @@ def __init__(self, freq: str, future: bool, provider_uri: dict, **kwargs):
         super(FileCalendarStorage, self).__init__(freq, future, **kwargs)
         self.future = future
         self.provider_uri = C.DataPathManager.format_provider_uri(provider_uri)
-        self.resample_freq = None
+        self.enable_read_cache = True  # TODO: make it configurable
 
     @property
     def file_name(self) -> str:
-        return f"{self.use_freq}_future.txt" if self.future else f"{self.use_freq}.txt".lower()
+        return f"{self._freq_file}_future.txt" if self.future else f"{self._freq_file}.txt".lower()
 
     @property
-    def use_freq(self) -> str:
-        return self.freq if self.resample_freq is None else self.resample_freq
+    def _freq_file(self) -> str:
+        """the freq to read from file"""
+        if not hasattr(self, "_freq_file_cache"):
+            freq = Freq(self.freq)
+            if freq not in self.support_freq:
+                # NOTE: uri
+                #   1. If `uri` does not exist
+                #       - Get the `min_uri` of the closest `freq` under the same "directory" as the `uri`
+                #       - Read data from `min_uri` and resample to `freq`
+
+                freq = Freq.get_recent_freq(freq, self.support_freq)
+                if freq is None:
+                    raise ValueError(f"can't find a freq from {self.support_freq} that can resample to {self.freq}!")
+            self._freq_file_cache = freq
+        return self._freq_file_cache
 
     def _read_calendar(self, skip_rows: int = 0, n_rows: int = None) -> List[CalVT]:
         if not self.uri.exists():
@@ -90,25 +104,21 @@ def _write_calendar(self, values: Iterable[CalVT], mode: str = "wb"):
 
     @property
     def uri(self) -> Path:
-        freq = self.freq
-        if freq not in self.support_freq:
-            # NOTE: uri
-            #   1. If `uri` does not exist
-            #       - Get the `min_uri` of the closest `freq` under the same "directory" as the `uri`
-            #       - Read data from `min_uri` and resample to `freq`
-
-            freq = Freq.get_recent_freq(freq, self.support_freq)
-            if freq is None:
-                raise ValueError(f"can't find a freq from {self.support_freq} that can resample to {self.freq}!")
-            self.resample_freq = freq
-        return self.dpm.get_data_uri(self.use_freq).joinpath(f"{self.storage_name}s", self.file_name)
+        return self.dpm.get_data_uri(self._freq_file).joinpath(f"{self.storage_name}s", self.file_name)
 
     @property
     def data(self) -> List[CalVT]:
         self.check()
-        _calendar = self._read_calendar()
-        if self.resample_freq is not None:
-            _calendar = resam_calendar(np.array(list(map(pd.Timestamp, _calendar))), self.resample_freq, self.freq)
+        # If cache is enabled, then return cache directly
+        if self.enable_read_cache:
+            key = "orig_file" + str(self.uri)
+            if not key in H["c"]:
+                H["c"][key] = self._read_calendar()
+            _calendar = H["c"][key]
+        else:
+            _calendar = self._read_calendar()
+        if Freq(self._freq_file) != Freq(self.freq):
+            _calendar = resam_calendar(np.array(list(map(pd.Timestamp, _calendar))), self._freq_file, self.freq)
         return _calendar
 
     def _get_storage_freq(self) -> List[str]:

qlib/utils/resam.py

@@ -8,7 +8,7 @@
 from .time import Freq, cal_sam_minute
 
 
-def resam_calendar(calendar_raw: np.ndarray, freq_raw: str, freq_sam: str) -> np.ndarray:
+def resam_calendar(calendar_raw: np.ndarray, freq_raw: Union[str, Freq], freq_sam: Union[str, Freq]) -> np.ndarray:
     """
     Resample the calendar with frequency freq_raw into the calendar with frequency freq_sam
     Assumption:
@@ -28,36 +28,36 @@ def resam_calendar(calendar_raw: np.ndarray, freq_raw: str, freq_sam: str) -> np
     np.ndarray
         The calendar with frequency freq_sam
     """
-    raw_count, freq_raw = Freq.parse(freq_raw)
-    sam_count, freq_sam = Freq.parse(freq_sam)
+    freq_raw = Freq(freq_raw)
+    freq_sam = Freq(freq_sam)
     if not len(calendar_raw):
         return calendar_raw
 
     # if freq_sam is xminute, divide each trading day into several bars evenly
-    if freq_sam == Freq.NORM_FREQ_MINUTE:
-        if freq_raw != Freq.NORM_FREQ_MINUTE:
+    if freq_sam.base == Freq.NORM_FREQ_MINUTE:
+        if freq_raw.base != Freq.NORM_FREQ_MINUTE:
             raise ValueError("when sampling minute calendar, freq of raw calendar must be minute or min")
         else:
-            if raw_count > sam_count:
+            if freq_raw.count > freq_sam.count:
                 raise ValueError("raw freq must be higher than sampling freq")
-        _calendar_minute = np.unique(list(map(lambda x: cal_sam_minute(x, sam_count), calendar_raw)))
+        _calendar_minute = np.unique(list(map(lambda x: cal_sam_minute(x, freq_sam.count), calendar_raw)))
         return _calendar_minute
 
     # else, convert the raw calendar into day calendar, and divide the whole calendar into several bars evenly
     else:
         _calendar_day = np.unique(list(map(lambda x: pd.Timestamp(x.year, x.month, x.day, 0, 0, 0), calendar_raw)))
-        if freq_sam == Freq.NORM_FREQ_DAY:
-            return _calendar_day[::sam_count]
+        if freq_sam.base == Freq.NORM_FREQ_DAY:
+            return _calendar_day[:: freq_sam.count]
 
-        elif freq_sam == Freq.NORM_FREQ_WEEK:
+        elif freq_sam.base == Freq.NORM_FREQ_WEEK:
             _day_in_week = np.array(list(map(lambda x: x.dayofweek, _calendar_day)))
             _calendar_week = _calendar_day[np.ediff1d(_day_in_week, to_begin=-1) < 0]
-            return _calendar_week[::sam_count]
+            return _calendar_week[:: freq_sam.count]
 
-        elif freq_sam == Freq.NORM_FREQ_MONTH:
+        elif freq_sam.base == Freq.NORM_FREQ_MONTH:
             _day_in_month = np.array(list(map(lambda x: x.day, _calendar_day)))
             _calendar_month = _calendar_day[np.ediff1d(_day_in_month, to_begin=-1) < 0]
-            return _calendar_month[::sam_count]
+            return _calendar_month[:: freq_sam.count]
         else:
             raise ValueError("sampling freq must be xmin, xd, xw, xm")
 

qlib/utils/time.py

@@ -5,7 +5,7 @@
 """
 import bisect
 from datetime import datetime, time, date
-from typing import List, Tuple, Union
+from typing import List, Optional, Tuple, Union
 import functools
 import re
 
@@ -69,13 +69,29 @@ class Freq:
     NORM_FREQ_MONTH = "month"
     NORM_FREQ_WEEK = "week"
     NORM_FREQ_DAY = "day"
-    NORM_FREQ_MINUTE = "minute"
+    NORM_FREQ_MINUTE = "min"  # using min instead of minute for align with Qlib's data filename
     SUPPORT_CAL_LIST = [NORM_FREQ_MINUTE, NORM_FREQ_DAY]  # FIXME: this list should from data
 
     MIN_CAL = get_min_cal()
 
-    def __init__(self, freq: str) -> None:
-        self.count, self.base = self.parse(freq)
+    def __init__(self, freq: Union[str, "Freq"]) -> None:
+        if isinstance(freq, str):
+            self.count, self.base = self.parse(freq)
+        elif isinstance(freq, Freq):
+            self.count, self.base = freq.count, freq.base
+        else:
+            raise NotImplementedError(f"This type of input is not supported")
+
+    def __eq__(self, freq):
+        freq = Freq(freq)
+        return freq.count == self.count and freq.base == self.base
+
+    def __str__(self):
+        # trying to align to the filename of Qlib: day, 30min, 5min, 1min...
+        return f"{self.count if self.count != 1 or self.base != 'day' else ''}{self.base}"
+
+    def __repr__(self) -> str:
+        return f"{self.__class__.__name__}({str(self)})"
 
     @staticmethod
     def parse(freq: str) -> Tuple[int, str]:
@@ -159,14 +175,14 @@ def get_min_delta(left_frq: str, right_freq: str):
             Freq.NORM_FREQ_WEEK: 7 * 60 * 24,
             Freq.NORM_FREQ_MONTH: 30 * 7 * 60 * 24,
         }
-        left_freq = Freq.parse(left_frq)
-        left_minutes = left_freq[0] * minutes_map[left_freq[1]]
-        right_freq = Freq.parse(right_freq)
-        right_minutes = right_freq[0] * minutes_map[right_freq[1]]
+        left_freq = Freq(left_frq)
+        left_minutes = left_freq.count * minutes_map[left_freq.base]
+        right_freq = Freq(right_freq)
+        right_minutes = right_freq.count * minutes_map[right_freq.base]
         return left_minutes - right_minutes
 
     @staticmethod
-    def get_recent_freq(base_freq: str, freq_list: List[str]) -> str:
+    def get_recent_freq(base_freq: Union[str, "Freq"], freq_list: List[Union[str, "Freq"]]) -> Optional["Freq"]:
         """Get the closest freq to base_freq from freq_list
 
         Parameters
@@ -176,17 +192,22 @@ def get_recent_freq(base_freq: str, freq_list: List[str]) -> str:
 
         Returns
         -------
-
+        if the recent frequency is found
+            Freq
+        else:
+            None
         """
+        base_freq = Freq(base_freq)
         # use the nearest freq greater than 0
         _freq_minutes = []
         min_freq = None
         for _freq in freq_list:
+            freq = Freq(_freq)
             _min_delta = Freq.get_min_delta(base_freq, _freq)
             if _min_delta < 0:
                 continue
             if min_freq is None:
-                min_freq = (_min_delta, _freq)
+                min_freq = (_min_delta, str(_freq))
                 continue
             min_freq = min_freq if min_freq[0] <= _min_delta else (_min_delta, _freq)
         return min_freq[1] if min_freq else None