breve 0.1.0

In-memory cache implementation with Uno as the admission policy and S3-FIFO as the eviction policy
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43

# Breve

Breve is a cache implementation that combines lightweight machine learning with efficient eviction strategies. It uses Uno as the admission policy and [S3-FIFO](https://s3fifo.com/) as the eviction policy. This project is inspired by [TinyUFO](https://github.com/cloudflare/pingora/tree/main/tinyufo) (Cloudflare) and builds upon its foundation with significant improvements.

## Key Features

- **Lightweight Machine Learning**: Utilizes the Uno algorithm for cache admission decisions, employing a simple linear regression model to predict item access value
- **Efficient Eviction Strategy**: Based on an improved version of S3-FIFO, optimizing cache hit rates through separated queues and access counting
- **Concurrency Safety**: Thread-safe implementation using atomic operations and lock-free data structures
- **Memory Efficiency**: Offers both compact and fast storage backends to suit different needs

## Core Components

### Uno Admission Policy (by [PsiACE](https://github.com/PsiACE))

Uno is a lightweight machine learning algorithm designed to predict the access value of cache items. It consists of two main components:

- **UnoSketch**: A Count-Min Sketch based implementation for estimating item access frequency and reuse distance
- **UnoLearner**: A simple linear regression model that optimizes prediction accuracy through online learning

### S3-FIFO Eviction Policy

S3-FIFO is an efficient cache eviction algorithm, which Breve enhances with the following improvements:

- Separates cache into small and large queues for better handling of different access patterns
- Uses access counting to optimize eviction decisions
- Supports weight-aware cache management


## Why "Breve"?

> There are a lot of really good caching libraries named in relation to coffee, so I chose to use Breve. 
> Although I have been having two cappuccinos a day for the last few days.

Breve is particularly well-suited for:

- High-concurrency cache systems
- Applications with strict memory efficiency requirements
- Scenarios requiring adaptive cache strategies

## License

Breve is licensed under the [Apache 2.0](./LICENSE) License. Same as TinyUFO.