https://github.com/bustle/nemesis-db
An Open Source Port of the Gradius API Storage Engine
https://github.com/bustle/nemesis-db
Last synced: over 1 year ago
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An Open Source Port of the Gradius API Storage Engine
- Host: GitHub
- URL: https://github.com/bustle/nemesis-db
- Owner: bustle
- License: other
- Created: 2018-07-29T03:16:59.000Z (almost 8 years ago)
- Default Branch: master
- Last Pushed: 2022-12-07T21:55:19.000Z (over 3 years ago)
- Last Synced: 2025-04-19T05:24:49.537Z (over 1 year ago)
- Language: TypeScript
- Homepage:
- Size: 347 KB
- Stars: 22
- Watchers: 2
- Forks: 1
- Open Issues: 10
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Nemesis DB
[](https://travis-ci.org/reconbot/nemesis-db)
[](https://codecov.io/gh/reconbot/nemesis-db)
[Nemesis DB](https://www.arcade-museum.com/game_detail.php?game_id=8842) is an open source port of Bustle's Gradius graph database.
## Intro
This is a simple adjacency graph database with only a few features. It has been designed for very fast reads. While it handles writes with ease whenever a tradeoff favors reads, that tradeoff will be taken.
## Features
- [x] 32 bit GUID
- [x] Schemaless Nodes
- [x] Weighted Edges
- [x] Compression
## Future Features
- Node Schemas, types and Interfaces
- filtering edges based upon weight
- Deleting
- Edge Schemas
- Field Validations
- Edge Validations
- Edge scanning
- Node scanning
- Named Edges
- Field Indexing
- Binary packing
## Examples
```js
import { Graph } from 'nememis-db'
const graph = new Graph('redis://localhost/1')
const book = await graph.createNode({ title: 'foo', pages: 24 })
assert.deepEqual(book, { id: 1, title: 'foo', pages: 24 })
// update the data of an existing node
const updatedBook = await graph.updateNode({ id: book.id, title: 'bar' })
assert.deepEqual(updatedBook, { id: 1, title: 'bar', pages: 24 })
// replace the data of an existing node
const replacedBook = await graph.putNode({ id: book.id, title: 'foo' })
assert.deepEqual(replacedBook, { id: 1, title: 'foo' })
const author = await graph.createNode({ name: 'james' })
assert.deepEqual(author, { id: 2, name: 'james' })
// connect the book and it's author
const edge = await graph.createEdge({ subject: book.id, predicate: 'BookHasAuthor', object: author.id })
assert.deepEqual(edge, { subject: 1, predicate: 'BookHasAuthor', object: 2, weight: 0 })
const authors = await graph.findEdges({ subject: book.id, predicate: 'BookHasAuthor' })
assert.deepEqual(authors, [{ subject: 1, predicate: 'BookHasAuthor', object: 2, weight: 0 }])
const object = await graph.findNode(authors[0].object)
assert.deepEqual(object, { id: 2, name: 'james' })
// Get an async iterator of all the nodes
for await (node of graph.allNodes()) {
console.log(node)
}
// { id: 1, title: 'foo' }
// { id: 2, name: 'james' }
// use streaming-iterables to make an array of the async iterator
const allNodes = await collect(graph.allNodes())
assert.deepEqual(allNodes, [{ id: 1, title: 'foo' }, { id: 2, name: 'james' }])
```
## API Type Defs
```ts
export declare class Graph {
readonly config: GraphConfig;
readonly messagePack: messagePack.MessagePack;
readonly redis: Redis.Redis;
constructor(redisUrl: string, config?: GraphConfigInput);
allNodes({ batchSize }?: NodeScanOptions): AsyncIterableIterator;
createEdge({ subject, predicate, object, weight }: EdgeInput): Promise;
createNode(attributes: any): Promise;
disconnect(): void;
findEdges(edge: SubjectEdgeSearch | ObjectEdgeSearch): Promise>;
findNode(id: number): Promise;
nodeExists(id: number): Promise;
putNode(node: Node): Promise;
updateNode(node: Node): Promise;
private evalCommands;
private evalCreateEdge;
private getNextId;
private nodeKey;
}
export interface Node {
readonly id: number;
readonly [key: string]: any;
}
export interface GraphConfigInput {
readonly compressors?: ReadonlyArray
readonly edgePrefix?: string;
readonly guidKey?: string;
readonly nodeIndexKey?: string;
readonly nodeKeyPrefix?: string;
}
export interface GraphConfig {
readonly edgePrefix: string;
readonly guidKey: string;
readonly nodeIndexKey: string;
readonly nodeKeyPrefix: string;
}
export interface EdgeInput {
readonly object: number;
readonly predicate: string;
readonly subject: number;
readonly weight?: number;
}
export interface Edge {
readonly object: number;
readonly predicate: string;
readonly subject: number;
readonly weight: number;
}
export interface SubjectEdgeSearch {
readonly limit?: number;
readonly offset?: number;
readonly predicate: string;
readonly subject: number;
}
export interface ObjectEdgeSearch {
readonly limit?: number;
readonly object: number;
readonly offset?: number;
readonly predicate: string;
}
export interface NodeScanOptions {
readonly batchSize?: number;
}
export interface Compressor {
readonly compress: (Buffer: any) => Buffer | Promise;
readonly decompress: (Buffer: any) => Buffer | Promise;
readonly name: string;
}
```
## Developing
Tests use your local redis db 2 by default and are destructive. To use another DB submit a patch to make this configurable.