[leveldb] Searching db on both key and value? (bi-directional approach)

[Harit Himanshu]

Hello there


I am new to LevelDB, and exploring it since the project I started to work
on is using it.
We have started hitting situations where we store too much data and I
started looking into what we do at our application level.

String key = // generated from somewhere
String hashedKey = // encrypt key and save

mapDb.put(key, hashedKey)
decryptMapDb(hashKey, key)


Our *key* and *hashedKey* both are unique

The reason we put it there is application specific but we need to keep both
*key* and *hashedKey* searchable. As we could see that we store same data
twice to make sure we could search both ways.
I was looking for a way to reduce this storage if leveldb has a
bi-directional search.

I started looking but the one I found was BidiMap
<http://commons.apache.org/proper/commons-collections/apidocs/org/apache/commons/collections4/BidiMap.html>
in Google Collections Library

Questions

1. Is there a BiDirectionalMap so that I save my data just once?
2. What are other alternatives/recommendations?


Thank you in advance
+ Harit Himanshu