CODEWITHSUNDEEP
javacollectionsconcurrencyguava
Andy
Andy

Reputation: 1484

Concurrent blocking map with entries eviction

What I need is a fairly complex data structure with the following requirements:

  1. It should support concurrent reads/writes without any excessive locking (like java.util.concurrent.ConcurrentHashMap)

  2. It should have capacity limit and block once the limit is reached (just like BlockingQueue implementations)

  3. It should have efficient search mechanism, like Map/HashSet do: given an ID of an object, I need to be able to find it without sequential scan.

  4. It should be possible to evict elements on timeout, for instance: if an entry is put in this structure more than X minutes ago, it should be automatically removed.

Of course, there's always a chance to implement it on my own, but I'd prefer to find something existing, optimized and well-tested.

The only thing that's near is Guava's cache, but it seems to be missing #2. Any ideas on known implementations of this?

Upvotes: 0

Views: 837

Answers (1)

MikeFHay
MikeFHay

Reputation: 9023

You could write a simple BlockingCache, which wraps an existing Guava Cache and checks capacity on put operations, so the put would look something like this:

public V put(K key, V value)
{
    while (size() >= capacity) Thread.sleep(100);
    return innerCache.put(key, value);
}

Upvotes: 1

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