High-performance external sorter that can spill data to disk when memory is exhausted. It uses off-heap memory (via `sun.misc.Unsafe`) and a `BytesToBytesMap` for in-memory sorting, merging multiple sorted runs from disk. This component is adapted from Apache Spark's Tungsten sort and can be extracted for any project needing large-scale, memory-efficient sorting of key-value records.

Lock-free multi-producer sequencer implementing a ring buffer pattern similar to LMAX Disruptor. It supports multiple producers claiming slots simultaneously using atomic operations and a configurable wait strategy. The class is well-encapsulated and can be reused for high-throughput event processing, message queuing, or any scenario requiring low-latency inter-thread communication.

A partition algorithm that uses hash modulus to distribute rows across shards. Implements the `AbstractPartitionAlgorithm` interface with a simple `calculate` method that computes a hash of the partition key and maps it to a data node. The component is self-contained, configurable via XML, and can be reused in any system requiring deterministic sharding logic.

Abstract memory allocator with on-heap and off-heap implementations. Provides `allocate(long size)` and `free(Object memory)` methods. The off-heap allocator uses `sun.misc.Unsafe` for direct memory operations. This component is the foundation for Mycat's memory pool and can be extracted for any low-level memory management task where performance and control over allocation are critical.

A highly optimized `Set` implementation for storing a small number of elements (typically <= 2). Internally, it uses a single array and linear search without hashing overhead. The component is a clean, reusable drop-in replacement for `HashSet` in performance-sensitive code paths where the set size is known to be small.