Array based LRU Cache Implementation in Go

A Least Recently Used (LRU) cache implementation with both CLI and TCP server interfaces.

Usage

go run main.go

TCP Server Example

Start the server:

go run main.go -only tcp -port 7333 -buffer 256

Connect using netcat or telnet:

nc localhost 7333

Command Line Arguments

• -port: TCP server port (default: "7333", range: 1024-65535)
• -buffer: TCP buffer size in bytes (default: 256, range: 16-1024)
• -only: Run specific interface ("tcp" or "cli")

Available Commands

Cache Management:

• CREATE <cache_name> <capacity>: Create a new cache with specified capacity
• DESTROY <cache_name>: Remove a cache instance
• LIST: Show all available caches

Cache Operations:

• SET <cache_name> <key> <value>: Add or update a key-value pair in specified cache
• GET <cache_name> <key>: Retrieve a value by key from specified cache
• DEL <cache_name> <key>: Remove a key-value pair from specified cache
• PRINT <cache_name>: Display specified cache contents
• CLEAR <cache_name>: Remove all entries from specified cache
• CLEAR_ALL: Clear all caches
• HELP: Show available commands

Implementation Details

• Uses an array-based storage with index recycling
• Implements a free list for efficient memory management
• When cache is full:
  • Evicts least recently used item
  • Directly reuses the freed slot for new entries
  • No additional memory allocation during eviction
• Double-linked list for O(1) LRU operations
• Thread-safe with minimal lock contention using sync.RWMutex

Performance Considerations

• Optimized eviction process with direct slot reuse
• No memory allocation during eviction cycles
• Efficient index management using free list
• Minimal pointer chasing with array-based storage

License

This project is licensed under the GNU Affero General Public License v3.0 - see the LICENSE file for details.