eyros

eyros (εύρος) is a multi-dimensional interval database.

The database is based on bkd and interval trees.

• high batch-write performance
• designed for peer-to-peer distribution and query-driven sparse replication
• compiles to web assembly for use in the browser
• good for geospatial and time-series data

eyros operates on scalar (x) or interval (min,max) coordinates for each dimension. There are 2 operations: batched write (for inserting and deleting) and query by bounding box. All features that intersect the bounding box are returned in the query results.

example

This example inserts 5000 records, writes the data to disk, then queries and prints records inside the bounding box ((-120.0,20.0,10_000),(-100.0,35.0,20_000)).

The bounding box is of the form ((min_x,min_y,min_z),(max_x,max_y,max_z)).

use eyros::{Row,Coord};
use rand::random;
use async_std::prelude::*;

type P = (Coord<f32>,Coord<f32>,Coord<u16>);
type V = u64;
type E = Box<dyn std::error::Error+Sync+Send>;

#[async_std::main]
async fn main() -> Result<(),E> {
  let mut db = eyros::open_from_path3(
    &std::path::PathBuf::from("/tmp/eyros.db")
  ).await?;
  let batch: Vec<Row<P,V>> = (0..5_000).map(|i| {
    let xmin = (random::<f32>()*2.0-1.0)*180.0;
    let xmax = xmin + random::<f32>().powf(16.0)*(180.0-xmin);
    let ymin = (random::<f32>()*2.0-1.0)*90.0;
    let ymax = ymin + random::<f32>().powf(16.0)*(90.0-ymin);
    let z = random::<u16>();
    let point = (
      Coord::Interval(xmin,xmax),
      Coord::Interval(ymin,ymax),
      Coord::Scalar(z)
    );
    Row::Insert(point, i)
  }).collect();
  db.batch(&batch).await?;
  db.sync().await?;

  let bbox = ((-120.0,20.0,10_000),(-100.0,35.0,20_000));
  let mut stream = db.query(&bbox).await?;
  while let Some(result) = stream.next().await {
    println!("{:?}", result?);
  }
  Ok(())
}

The output from this program is of the form (coords, value):

$ cargo run --example polygons -q
((Interval(-100.94689, -100.94689), Interval(20.108843, 20.109331), Scalar(16522)), 4580)
((Interval(-111.62768, -110.40406), Interval(-7.519809, 86.154755), Scalar(12384)), 2603)
((Interval(-114.46505, -31.340988), Interval(-57.901405, 20.235504), Scalar(11360)), 1245)
((Interval(-159.97859, 121.304184), Interval(32.35743, 32.35743), Scalar(10164)), 3294)
((Interval(-150.29192, -35.475517), Interval(-39.97779, 29.163605), Scalar(15333)), 2336)
((Interval(-162.45879, -92.46166), Interval(31.187943, 31.187975), Scalar(12221)), 2826)
((Interval(-160.53441, -88.66396), Interval(10.031784, 21.852394), Scalar(11711)), 2366)
((Interval(-132.39021, -98.14838), Interval(-0.06010294, 53.88453), Scalar(10685)), 3441)

license

bsd