lru

Android LruCache (Android 3.1) thread safety

由 感情迁移 提交于 2019-12-10 01:34:54
问题 Is the new Android class LruCache thread safe? The java doc says: This class is thread-safe. Perform multiple cache operations atomically by synchronizing on the cache: synchronized (cache) { if (cache.get(key) == null) { cache.put(key, value); }} Did they mean to say NOT thread-safe? Why would one have to synchronize if the class is thread safe? Thanks! 回答1: Doesn't matter whether the class is thread-safe or not. If you use multiple operations you may still need to synchronize. Depends on

Redis Vs. Memcached

由 ℡╲_俬逩灬. 提交于 2019-12-10 00:18:20
问题 I am using memcached right now as a LRU cache to cache big data. I've set the max object size to 128 MB (I know this is inefficient and not recommended) and total memcached to 1 GB. But 128 MB is not enough for my purposes so I am planning to move to Redis. A couple questions: memcached is extremely slow - My current memcached setup is taking 3-4 seconds to return just one request. This is extremely slow. I sometimes need to make up to 30 memcached requests to serve one user request. And just

Memory-Leaks Image-Gallery Android - How can other applications handle it?

由 江枫思渺然 提交于 2019-12-08 18:21:22
i'm trying to implement a image gallery, which should show ~ 5-15 smaller images and one "current selected" bigger image. It looks like: http://www.mobisoftinfotech.com/blog/wp-content/uploads/2012/06/galleryDemo.png I've looked up many sources and now decided to use a bitmap-cache (lru-cache) (thanks to a person from this forum!). I don't get memory-leaks at the moment, but i'm not happy with this solution because everytime i scroll, some images are removed from the cache and i've to reload them... so the user has to wait for reloading images... It's really annoying to wait 0.5 - 1 second

LRU cache with Doubly Linked List from scratch - moveToHead (Java)

由 ≯℡__Kan透↙ 提交于 2019-12-08 11:29:44
问题 I have implemented a simple LRU cache as a doubly linked list written manually from scratch. The cache is filled with objects Request distinguished by their numeric (integer) ID. These Request objects are generated as a stream of L random independent and identically distributed requests for a set of N < L predefined Request objects and arrive to the cache one by one (i.e. in a serial fashion). Then I check for cache hit or miss and if the current cache size has reached the maximum cache size

Memory-Leaks Image-Gallery Android - How can other applications handle it?

由 允我心安 提交于 2019-12-08 07:12:21
问题 i'm trying to implement a image gallery, which should show ~ 5-15 smaller images and one "current selected" bigger image. It looks like: http://www.mobisoftinfotech.com/blog/wp-content/uploads/2012/06/galleryDemo.png I've looked up many sources and now decided to use a bitmap-cache (lru-cache) (thanks to a person from this forum!). I don't get memory-leaks at the moment, but i'm not happy with this solution because everytime i scroll, some images are removed from the cache and i've to reload

LRU Page Replacement algorithm C#

由 余生长醉 提交于 2019-12-08 05:48:03
问题 I am trying to write a function which simulates LRU page replacement. I understand LRU pretty well but am having problems coding it. The following things are being passed into the LRU function. The user specifies the 20 character reference string of #'s 1-9 which is stored in an array called refString of size 20. The number of frames the user enters (1-7) is stored in a variable numFrames. Finally, an array of size 7 called frame is passed in. Here is the code I have, and I am getting a close

Memoize a function so that it isn't reset when I rerun the file in Python

由 泄露秘密 提交于 2019-12-07 22:42:49
问题 I often do interactive work in Python that involves some expensive operations that I don't want to repeat often. I'm generally running whatever Python file I'm working on frequently. If I write: import functools32 @functools32.lru_cache() def square(x): print "Squaring", x return x*x I get this behavior: >>> square(10) Squaring 10 100 >>> square(10) 100 >>> runfile(...) >>> square(10) Squaring 10 100 That is, rerunning the file clears the cache. This works: try: safe_square except NameError:

Java LinkedHashMap with removeEldestEntry causes java.lang.NullPointerException

由 不问归期 提交于 2019-12-07 19:30:23
问题 The error looks like this Exception in thread "Thread-1" java.lang.NullPointerException at java.util.LinkedHashMap$Entry.remove(LinkedHashMap.java:332) at java.util.LinkedHashMap$Entry.recordAccess(LinkedHashMap.java:356) at java.util.LinkedHashMap.get(LinkedHashMap.java:304) at Server.getLastFinishedCommands(Server.java:9086) at Server.processPacket(Server.java:484) at PacketWorker.run(PacketWorker.java:34) at java.lang.Thread.run(Thread.java:744) Inside getLastFinishedCommands I use public

Better understanding the LRU algorithm

由 点点圈 提交于 2019-12-07 18:48:17
问题 I need to implement a LRU algorithm in a 3D renderer for texture caching. I write the code in C++ on Linux. In my case I will use texture caching to store "tiles" of image data (16x16 pixels block). Now imagine that I do a lookup in the cache, get a hit (tile is in the cache). How do I return the content of the "cache" for that entry to the function caller? I explain. I imagine that when I load a tile in the cache memory, I allocate the memory to store 16x16 pixels for example, then load the

LRU Cache Implementation in Java

由 大城市里の小女人 提交于 2019-12-07 02:48:27
问题 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 removing elements till it gets this condition true while(concurrentLinkedQueue.size() >=maxSize) Any pointers around this would be great. Here is the Implementation: public class LRUCache<K,V> { private ConcurrentLinkedQueue<K>
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