Open-source alternatives to Freecache

go-cache is a thread-safe, in-memory cache library for Go that stores arbitrary objects with per-item expiration timestamps. It provides a concurrent key-value store where multiple goroutines can safely read and write shared cached data without external synchronization, using a mutex-guarded map for access control. The library distinguishes itself through its expiration management and optional disk persistence. Each cached item carries its own time-to-live, and a background goroutine periodically purges expired entries. The cache can serialize its entire contents to disk using Go's gob encodi

Memcached is a high-performance, distributed, in-memory key-value storage and request routing engine. It functions as a volatile data store designed to accelerate dynamic applications by caching objects in RAM, thereby reducing backend database load and providing sub-millisecond response times. The system utilizes a specialized architecture that organizes memory into fixed-size slabs to minimize fragmentation and maximize throughput for high-concurrency workloads. The project distinguishes itself through a multi-threaded, lock-friendly design that scales across CPU cores and supports complex

Redis is a high-performance in-memory key-value store that functions as a distributed cache, message broker, and NoSQL database. It provides sub-millisecond read and write access to data stored in RAM and can operate as a vector database for indexing high-dimensional embeddings. The system supports a wide range of data storage and synchronization primitives, including the management of strings, hashes, lists, sets, and JSON documents. It enables real-time data operations through atomic transactions, hybrid persistence using snapshots and append-only logs, and high-availability configurations

Bigcache is a thread-safe, in-memory key-value store for Go designed to minimize garbage collection pauses. It functions as a memory-optimized cache capable of storing gigabytes of data while maintaining low latency during high-volume operations. The system avoids garbage collection overhead by managing memory through large byte arrays and manual allocation. It utilizes a circular-buffer layout to reuse space and lock-striped sharding to reduce contention during concurrent read and write access. The project provides capabilities for high-volume in-memory caching and low-latency data retrieva

Hazelcast is a distributed data platform that combines an in-memory data grid with a stream processing engine to support real-time analytics and event-driven applications. It functions as a partitioned, distributed key-value store that replicates data across cluster nodes to provide low-latency access and high availability. The platform also serves as a distributed SQL query engine, allowing users to execute standard SQL statements against both in-memory datasets and external data sources. What distinguishes Hazelcast is its use of a distributed consensus subsystem to maintain strongly consis

Olric is a distributed data grid and in-memory key-value store that partitions and replicates data across a cluster of servers. It serves as a shared memory system for managing distributed maps, performing atomic operations, and acting as an in-memory data cache. The system provides a distributed locking mechanism for concurrency control and a pub-sub messaging system that broadcasts and routes messages over named channels across the cluster. The platform covers wide-ranging capabilities including cluster management and orchestration, data replication with configurable quorums, and automated

go-cache is a thread-safe, in-memory key-value store for single-machine applications. It provides a local caching mechanism that stores objects in RAM to reduce redundant data retrieval and avoid the overhead of network protocols or serialization. The system features a persistent cache store that saves the in-memory state to a local file, allowing data recovery across application restarts. The project manages concurrent data access across multiple routines and implements time-to-live expiration for cached entries. A background process periodically scans the store to delete expired items and

This project is a disk-backed key-value store and persistent data structure library for Python. It provides a mechanism for persisting mappings, sets, and queues to the local filesystem to bypass memory limitations and cache expensive function results across threads and processes. The system serves as a cross-process synchronization tool, offering distributed locks, semaphores, and barriers to coordinate shared resource access. It implements advanced caching strategies such as probabilistic stampede prevention, sharded data partitioning to increase throughput, and least-recently-used eviction

LMCache is a distributed key-value cache manager and tiering system designed to accelerate large language model inference. It functions as a tiered storage layer that offloads tensors from GPU memory to CPU RAM, local disks, or remote object stores, enabling the reuse of cached prefixes across different inference sessions and serving engines. The system differentiates itself through a disaggregated prefill-decode model, which separates prompt processing from token generation by transferring caches between distributed compute nodes. It utilizes peer-to-peer orchestration to share and retrieve

NutsDB is an ACID-compliant, embedded transactional storage engine that functions as both a disk-backed key-value store and an in-memory data structure store. It provides atomic and serializable transactions with commit and rollback capabilities to ensure strict data consistency for applications requiring a lightweight persistence layer. The engine distinguishes itself by supporting a variety of complex data types, including lists, sets, and sorted sets, alongside standard byte-slice storage. It implements a transactional storage model featuring hot backups and a compaction algorithm to maint

Caffeine is a high-performance caching library for the Java virtual machine designed to manage object lifecycles within the application heap. It functions as a thread-safe, memory-resident data store that reduces latency by keeping frequently accessed objects available for immediate retrieval. The library distinguishes itself through a sophisticated eviction strategy that balances recency and frequency to determine which entries to retain. It utilizes a frequency-based admission policy to evaluate the historical access patterns of new data, ensuring that the cache remains populated with the m

This project is a collection of educational resources and technical guides focused on Go performance optimization. It provides instruction on improving execution speed and reducing memory usage through code and architectural refinements. The guides cover advanced strategies for low-level programming, including the use of assembly for SIMD instructions and unsafe pointers for direct memory manipulation. It also details concurrency optimization techniques such as lock sharding and cache-line padding to reduce contention and improve hardware utilization. The material encompasses broad capabilit

Lancet is a comprehensive extension of the Go standard library, providing a collection of reusable functions and data structures designed to reduce boilerplate code in applications. It serves as a general-purpose toolkit across multiple domains, including concurrency, security, networking, and functional logic. The project distinguishes itself through specialized toolkits for Go concurrency, such as keyed locking and channel-based stream processing, and a dedicated functional programming kit that supports currying and function composition. It also includes a dedicated cryptography library imp

This project is an educational resource and technical manual for Apache Spark, focused on the architecture and practical application of large-scale data processing. It serves as a guide for big data engineering and distributed computing, covering the principles of parallel processing and fault-tolerant data distribution. The material provides instructional content on designing distributed ETL pipelines and implementing data analysis workflows. It includes tutorials for polyglot data processing, offering patterns and examples for using Python, Scala, and Java within a unified environment. The

MapDB is an embedded database engine and disk-backed collection library that stores Java collections on disk or off-heap. It functions as a local data processing engine designed to handle datasets that exceed available physical RAM. The project utilizes off-heap data storage to eliminate garbage collection overhead and employs disk overflow caching to balance memory and disk usage. It provides specialized utilities for filtering and analyzing large volumes of local data on a single machine. The system ensures data integrity through ACID-compliant transactions and multi-version concurrency co

This project is a detailed analysis and study of the Nginx source code, focusing on high-performance server architecture and function call flows. It serves as a technical examination of the internal C implementation used to build high-concurrency networking systems. The project deconstructs the internal mechanisms of the web server, including the multi-process master-worker model, event-driven asynchronous I/O, and non-blocking socket communication. It analyzes the phase-based request processing lifecycle, from URI matching and header parsing to final content generation. The study covers a b

Guava is a Java standard library extension and utility toolkit that provides optimized data structures, concurrency tools, and core extensions. It serves as a comprehensive set of helpers for Java development, focusing on reducing repetitive boilerplate logic. The project is distinguished by its specialized implementations of immutable collections, which ensure thread safety and data consistency by preventing accidental modification. It also includes a dedicated graph data structure library for modeling and traversing networks of interconnected nodes and edges, alongside advanced collection t

Collections is a JavaScript data structure library that provides unified interfaces for sets, maps, ordered sequences, and key-value storage. It includes capacity-bounded eviction mechanisms, categorical grouping, and set membership collections designed to organize and manage complex datasets through consistent traversal methods. The library offers advanced primitives such as circular ring buffers that automatically discard old entries upon reaching capacity limits, and comparator-driven sorted sequences maintained through binary search positioning. It supports persistent state snapshotting v

Chronicle Queue is a high-performance data handling system featuring off-heap message queues, memory-mapped file stores, and replicated message stores. It provides a binary compatible memory layout that enables different programming languages to share data without serialization overhead. The system utilizes a replicated message store to synchronize data across multiple nodes, ensuring high availability and instant failover. Its memory-mapped architecture supports deterministic replay from disk and low-latency data recording. The project implements off-heap memory management and zero-allocati

Mooncake is a disaggregated large language model serving platform and distributed key-value store designed for high-performance inference infrastructure. It functions as a GPU memory orchestrator and KV cache management system that pools and transfers key-value caches across clusters to accelerate inference. The system distinguishes itself by separating the prefill and decode phases of inference into distinct hardware clusters to optimize resource utilization. It utilizes a high-performance RDMA distributed cache with zero-copy transfers to move data between compute nodes, bypassing the CPU t

This project is a single-producer single-consumer concurrent queue for C++ designed for lock-free data exchange between threads. It provides a thread-safe mechanism to transfer data without the use of mutexes or locks. The queue is implemented as a contiguous circular buffer that supports dynamic capacity growth to prevent data loss when the queue reaches its limit. It utilizes atomic synchronization and wait-free index management to coordinate data access between the writing and reading threads. The library covers inter-thread communication and buffer management, offering both blocking and

mQuickjs is a compact JavaScript engine designed for memory-constrained devices, such as microcontrollers, requiring as little as 10 KB of RAM and 100 KB of ROM. It achieves this through a fixed-buffer memory allocation scheme that avoids system heap usage, a compacting tracing garbage collector that eliminates fragmentation, and a ROM-embedded standard library that reduces both memory footprint and startup time. The engine compiles JavaScript source into portable bytecode that can be stored in persistent memory and executed without reparsing, and it emulates IEEE 754 floating-point arithmetic

This library is an Arduino-compatible client for the messaging protocol designed for resource-constrained embedded systems. It provides a messaging interface that enables microcontrollers to establish persistent connections with brokers to exchange data and control signals. The library distinguishes itself through a focus on predictable resource usage, utilizing manual memory buffer management and a state-machine approach to handle connection persistence and automatic reconnections. It operates on a stream-oriented network abstraction, allowing it to interface with various hardware transport

jemalloc is a general purpose C memory allocator designed as a replacement for the standard library malloc and free functions. It is a multi-threaded allocation library that emphasizes fragmentation avoidance and scalable concurrency for high-performance applications. The project reduces lock contention by using multiple independent memory arenas and thread-local cache layers. It minimizes latency by offloading the reclamation of unused memory pages to asynchronous background threads and utilizes huge page metadata storage to reduce translation lookaside buffer misses. The system includes a

Concurrent-map is a lock-striped hash map and sharded concurrent cache for Go, designed as a high-performance key-value store that enables thread-safe parallel reads and writes with minimal blocking. It replaces a single global mutex with per-shard locking, using hash-based key distribution to assign entries to independent segments, allowing multiple goroutines to operate simultaneously without race conditions. The library achieves its performance through fine-grained locking and a lock-free read path, where each shard operates independently with its own lock, enabling parallel reads and writ

LogicStack-LeetCode is a curated repository of solved algorithm problems and data structure implementations, primarily drawn from the LeetCode platform. Its core identity is a structured collection of solutions designed to support technical interview preparation and competitive programming practice, with each solution accompanied by complexity analyses to help engineers understand performance trade-offs. The repository distinguishes itself through its breadth of coverage across fundamental algorithmic patterns and data structures. It includes implementations for array manipulation, string pro

ioredis is a performance-focused Redis client for Node.js applications. It provides a comprehensive interface for interacting with Redis servers, including specialized clients for sharded clusters and Sentinel-based high availability environments. The project distinguishes itself through advanced networking and execution capabilities, such as automatic event-loop pipelining to reduce overhead and a system for routing read-write traffic between primary and replica nodes. It also features a dedicated Lua scripting interface that allows server-side scripts to be registered as custom client comma