OffHeap Data Container

We want to be able to allocate data off-heap.
Requirements / ideas:

• data should be stored in Direct ByteBuffers, or easily accessible as such so that integration with other types of I/O (clustering, persistence, server) can be done efficiently
• consider both raw byte[] storage (such as that performed by servers) and store as binary
• allocator should be pluggable
• out-of-the-box implementation should use Netty Buffers
• type of allocation (heap or off-heap) should be per-cache
• off-heap allocation configuration should be global (per-container) or possibly shared among multiple containers
• optional off-heap allocation for keys
• ability to monitor both global and per-cache memory usage