Big Queue - A big, fast and persistent queue based on memory mapped file.

A big, fast and persistent queue based on memory mapped file.

Features include:

1. Fast: close to the speed of direct memory access, both enqueue and dequeue are close to O(1) memory access.
2. Big: the total size of the queue is only limited by the available disk space.
3. Persistent: all data in the queue is persisted on disk, and is crash resistant.
4. Reliable: OS will be responsible to presist the produced messages even your process crashes.
5. Realtime: messages produced by producer threads will be immediately visible to consumer threads.
6. Memory-efficient: automatic paging & swapping algorithm, only most-recently accessed data is kept in memory.
7. Thread-safe: multiple threads can concurrently enqueue and dequeue without data corruption.
8. Simple&Light-weight: current number of source files is 12 and the library jar is less than 30K.