Cypher Lite / GQLite

CI

An embedded graph database implemented in Rust. This is currently a pre-release. It has not been extensively tested with 'real-world work-loads', and the file-format and API are not yet stabilized.

The longer term goal is to create an in-process graph database with a stable on-disk format and support for a wide range of programming languages.

```rust use gqlite::Graph;

let graph = Graph::open_anon()?;

let mut txn = graph.muttxn()?; let edge: u64 = graph.prepare( " CREATE (a:PERSON { name: 'Peter Parker' }) CREATE (b:PERSON { name: 'Clark Kent' }) CREATE (a) -[e:KNOWS]-> (b) RETURN ID(e) " )? .querymap(&mut txn, (), |m| m.get(0))? .next() .unwrap()?; txn.commit()?;

let name: String = graph.prepare( " MATCH (p:PERSON) <-[e:KNOWS]- (:PERSON) WHERE ID(e) = $edge RETURN p.name " )? .querymap(&mut graph.txn()?, ("edge", edge), |m| m.get(0))? .next() .unwrap()?; asserteq!("Clark Kent", name); ```

Architecture Overview

Parser :: src/parser

PEG grammar and parser for a subset of the CYPHER graph query language

Query Planner :: src/planner

Transforms a parsed query ast into a logical query plan. Performs some optimizations on the query plan.

Byte-Code Interpreter :: src/runtime

Defines a simple 'byte' code (Instructions) and can execute those against a given database, as well as generate instructions for a given query plan.

Storage Backend :: src/store

Uses a disc-backed btree to provide basic storage, iteration and lockup for nodes and edges.