A generic, concurrency-safe LRU cache with configurable capacity, size tracking via a Size() method, and optional eviction callbacks. It is self-contained and can be extracted as a standalone library for caching any type of items with memory-aware eviction.

A typed concurrent FIFO queue with a bounded channel and an overflow list for burst handling. It provides non-blocking push and pop operations with context support, and is safe for use across multiple goroutines. This is a clean, reusable implementation of a classic producer-consumer pattern.

A batch writer that accumulates items until a configurable threshold (number of items or time interval) is reached, then flushes them as a batch to a write function. It is designed to batch database writes for efficiency, with graceful shutdown and error handling. The pattern is generic and applicable to any sink that benefits from batching.

A bounded, in-memory chain of headers with O(log n) ancestor lookup via skip pointers. It maintains a fixed-size window of headers and provides efficient ancestry queries for reorg handling. The skip-list implementation is non-obvious and demonstrates advanced data structure design, and the component is self-contained enough to be reused in any blockchain-related project.

A heap-based priority queue for scheduling work items with configurable ordering, used by the query work manager. It supports push, pop, and removal of items, and is designed to be goroutine-safe. The pattern is a clean separation of scheduling logic and can be extracted for any task queue requiring priority-based execution.

A persistent ban store that records banned IP networks with reasons and expiration times. It serializes bans to a simple file format and provides methods to add, remove, check, and expire bans. The implementation is self-contained and demonstrates a robust pattern for managing peer bans in a P2P network, suitable for extraction into other networking projects.