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Will the LRU delete entries that have not been used for some amount of time?

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问题 When in memcache the available memory is full, memcache uses the LRU (last recently used) algorithm to free memory. My question is will the LRU Algorithm rather delete entries that have not been used for some amount of time (last recently used) than expired items? Entries that are expiring are not deleted on that exact moment but when the next time someone tries to access it (AFAIR). So will the LRU Algorithm (also) account for the expiry of keys? 回答1: To understand how memcached does LRU you

LRU implementation in production code

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I have some C++ code where I need to implement cache replacement using LRU technique. So far I know two methods to implement LRU cache replacement: Using timeStamp for each time the cached data is accessed and finally comparing the timeStamps at time of replacement. Using a stack of cached items and moving them to the top if they are accessed recently, so finally the bottom will contain the LRU Candidate. So, which of these is better to be used in production code? Are their any other better methods? Recently I implemented a LRU cache using a linked list spread over a hash map. /// Typedef for

Make @lru_cache ignore some of the function arguments

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问题 How can I make @functools.lru_cache decorator ignore some of the function arguments with regard to caching key? For example, I have a function that looks like this: def find_object(db_handle, query): # (omitted code) return result If I apply lru_cache decorator just like that, db_handle will be included in the cache key. As a result, if I try to call the function with the same query , but different db_handle , it will be executed again, which I'd like to avoid. I want lru_cache to consider

What is the difference between LRU and LFU

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问题 What is the difference between LRU and LFU cache implementations? I know that LRU can be implemented using LinkedHashMap . But how to implement LFU cache? 回答1: Let's consider a constant stream of cache requests with a cache capacity of 3, see below: A, B, C, A, A, A, A, A, A, A, A, A, A, A, B, C, D If we just consider a Least Recently Used (LRU) cache with a HashMap + doubly linked list implementation with O(1) eviction time and O(1) load time, we would have the following elements cached

LRU cache design

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Least Recently Used (LRU) Cache is to discard the least recently used items first How do you design and implement such a cache class? The design requirements are as follows: 1) find the item as fast as we can 2) Once a cache misses and a cache is full, we need to replace the least recently used item as fast as possible. How to analyze and implement this question in terms of design pattern and algorithm design? A linked list + hashtable of pointers to the linked list nodes is the usual way to implement LRU caches. This gives O(1) operations (assuming a decent hash). Advantage of this (being O(1

Easy, simple to use LRU cache in java

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I know it's simple to implement, but I want to reuse something that already exist. Problem I want to solve is that I load configuration (from XML so I want to cache them) for different pages, roles, ... so the combination of inputs can grow quite much (but in 99% will not). To handle this 1%, I want to have some max number of items in cache... Till know I have found org.apache.commons.collections.map.LRUMap in apache commons and it looks fine but want to check also something else. Any recommendations? You can use a LinkedHashMap (Java 1.4+) : // Create cache final int MAX_ENTRIES = 100; Map

LRU cache design

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问题 Least Recently Used (LRU) Cache is to discard the least recently used items first How do you design and implement such a cache class? The design requirements are as follows: 1) find the item as fast as we can 2) Once a cache misses and a cache is full, we need to replace the least recently used item as fast as possible. How to analyze and implement this question in terms of design pattern and algorithm design? 回答1: A linked list + hashtable of pointers to the linked list nodes is the usual

Easy, simple to use LRU cache in java

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问题 I know it\'s simple to implement, but I want to reuse something that already exist. Problem I want to solve is that I load configuration (from XML so I want to cache them) for different pages, roles, ... so the combination of inputs can grow quite much (but in 99% will not). To handle this 1%, I want to have some max number of items in cache... Till know I have found org.apache.commons.collections.map.LRUMap in apache commons and it looks fine but want to check also something else. Any