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Questions tagged [lru]

LRU is a family of caching algorithms, where LRU stands for least recently used.

LRU is a family of caching algorithms, where LRU stands for least recently used. As the name implies, a cache discards the least recently used items from the cache, when the contents exceed a certain threshold. In this algorithm, writes are quite expensive, as you always need to write the change the usage information when you use an item.

More information at Wikipedia.

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Python LRU cache's global and per instance behavioral differences

I'm going through the implementation details of Python's LRU cache decorator. To understand the behavior of the lru_cache decorator in different scenarios properly, I've also gone through the following SO answers: Python LRU Cache Decorator Per…
Redowan Delowar
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How to lru_cache a function when arguments are object instances and the cache needs to look into instance attributes?

I am trying to implement the lru_cache on a function that takes in a python object as an argument. The function should return a cached value only if it's argument's attributes have not changed. However, it looks like the lru_cache only does a…
Anubhav
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limit the size of a std::set

I have a short question about the std::set container. Right now I am feeding my set using the pushback function. Of corse the set becomes larger and larger for every push_back. I am only intrested in the latest 30 elements or so... The older…
Lumpi
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LRU Cache Implementation in Java

I have seen the following code, and I think that there is a useless while loop in the implementation of addElement method. It should never happen to have more elements than size+1 since there is already a write lock. So why is the addElement method…
Sandeep Kaul
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Implementing LRU with timestamp: How expensive is memory store and load?

I'm talking about LRU memory page replacement algorithm implement in C, NOT in Java or C++. According to the OS course notes: OK, so how do we actually implement a LRU? Idea 1): mark everything we touch with a timestamp. Whenever we need to…
Junji Zhi
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Android LRUCache Retrieval

I have implemented a standard LRUCache in Android that stores Objects. Each key is a unique ObjectId associated with the Object stored. My problem is that the only way to retrieve an Object from cache is by the ObjectId (no iterator). What would be…
Nelson.b.austin
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Redis Internals - LRU Implementation For Sampling

Does someone know about the internals of Redis LRU based eviction / deletion. How does Redis ensure that the older (lesser used) keys are deleted first (in case we do not have volatile keys and we are not setting TTL expiration)? I know for sure…
Gur Kamal Singh Badal
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Python lru_cache: how can currsize < misses < maxsize?

I have a class with a method that is annotated with the lru_cache annotation: CACHE_SIZE=16384 class MyClass: [...] @lru_cache(maxsize=CACHE_SIZE) def _my_method(self, texts: Tuple[str]): def…
Carsten
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How to combine dataclass, property, and lru_cache

I'm trying to combine dataclasses, properties and lru_caches for some computational science code: from dataclasses import dataclass from typing import Any from functools import lru_cache @dataclass class F: a: Any = 1 b: Any = 2 c: Any =…
Bananach
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pickling lru_cached function on object

As part of parallellizing some existing code (with multiprocessing), I run into the situation that something similar to the class below needs to be pickled. Starting from: import pickle from functools import lru_cache class Test: def…
Bram
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LRU Cache in Node js

I need to implement caching for my project(for my organisation), we are planing to have a in-memory LRU caching, I have got some packages but I am not sure about the licensing term, the best I found was…
user3649361
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LRU cache on top of shared preferences

I would like to create an LRU cache that is backed by the shared preferences. Basically I would like to store a specific number of strings (around 20) and have an LRU behavior. I know that LinkedHashMap is an LRU in java but is there a way to…
Jim
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In which case LFU is better than LRU?

I have been trying to find a good case in which LFU is better than LRU but I am not sure for that. What I have managed to do (but not sure if it is a good example) is the case when you have a cache with capacity 3 and the cache requests are 4 (like…
Argiris
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Erlang LRU Cache

How to implement a LRU Cache with Erlang? LRU Cache Wiki Top starred Github project was fogfish/cache, but Segmented table was not quite fit for my data. barrel-db/erlang-lru was using a List. after testing, it would be slow if there were too much…
user3644708
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LinkedHashMap LRU Cache - Determine what values are removed?

Background Information You can make a LRU cache with a LinkedHashMap as shown at this link. Basically, you just: Extend linked hash map. Provide a capacity parameter. Initialize the super class (LinkedHashMap) with parameters to tell it its…
John Humphreys
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