Transparent chunk transformation (compression) of index directory [LUCENE-2583]

In some cases user is willing to sacrifice speed for space efficiency or better data security. I've developed driver for Directory that enables transparent compression (any transformation) of directory files, by using decorator pattern. With current experience, compression ratios are between 1:5 to 1:10, which depends on type of data stored in index.

Directory files are sliced into fixed chunks, each chunk separately transformed (eg. compressed, encrypted, ...) and written to supporting (nested) directory for storage.

I've create project page at and am also prepared to join contrib/store.

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Migrated from [LUCENE-2583](https://issues.apache.org/jira/browse/LUCENE-2583) by Mitja Lenič, updated Nov 30 2013

Start by reviewing the existing Directory implementations and the contrib/store area mentioned in the issue, then compare them with the external lucenetransform project page. Done would mean a supported Directory decorator that chunks and transforms index files transparently while preserving the stated storage behavior.

Written by the indexing model from the issue text.