5 releases
0.2.3 | Mar 11, 2020 |
---|---|
0.2.2 | Feb 25, 2020 |
0.2.1 | Feb 25, 2020 |
0.2.0 | Feb 25, 2020 |
0.1.0 | Feb 10, 2020 |
#2901 in Database interfaces
25 downloads per month
Used in 7 crates
(via cql_db)
18KB
80 lines
CQL U64
This crate implements various CqlType derivatives for storing u64
values in a CQL database.
Will allocate 8 bytes per value linked.
Benchmarks
Benchmarks supplied below are fairly rudimentary (and rounded) and are there to give a rough idea of relative costs.
Full benchmark code can be found in github and can be run with
rustup run nightly cargo bench
.
Operation | Database dimensions | Mean time _unchecked (ns) | Mean time (ns) |
---|---|---|---|
Single point read | 1 | 2 450 (+/- 300) | 7 500 (+/- 600) |
Single point read | 4 | 14 850 (+/- 1 000) | 37 550 (+/- 2 300) |
Single point write | 1 | 2 800 (+/- 400) | 7 700 (+/- 400) |
Single point write | 4 | 15 400 (+/- 2 500) | 37 700 (+/- 3 000) |
Stream read 1 point | 1 | 2 500 (+/- 300) | 10 000 (+/- 850) |
Stream read 1 point | 4 | 14 900 (+/- 600) | 42 500 (+/- 6 500) |
Stream read 50 000 points | 1 | 27 650 000 (+/- 31 000) | 27 630 000 (+/- 180 000) |
Stream read 50 000 points | 4 | 27 660 000 (+/- 1 200 000) | 27 620 000 (+/- 480 000) |
Getting started
To get started, add the below dependencies to your Cargo.toml:
[dependencies]
//... (any existing dependencies you may have)
cql_db = "^0.2.4"
cql_u64 = "^0.2"
Then need to create a folder where you want the database to live, and then try out the below:
use std::io::{ Cursor, SeekFrom, Seek };
use cql_db::error::Error;
use cql_u64::{ U64, unpack_stream };
const DATABASE_LOCATION: &str = "PATH_TO_YOUR_DATABASE_DIRECTORY";
pub fn example_cql() -> Result<(), Error> {
// create a one dimensional database to hold 3 points
cql_db::create_db::<U64>(
DATABASE_LOCATION,
&[3]
)?;
// write '1', to [1]
cql_db::write_value::<U64>(
DATABASE_LOCATION,
&[1],
1
)?;
let mut result = [0; 2];
let mut stream = Cursor::new(Vec::new());
// read 2 values from [1] to 'stream'
cql_db::read_to_stream::<U64>(
DATABASE_LOCATION,
&mut stream,
&[1],
2
)?;
stream.seek(SeekFrom::Start(0)).unwrap();
unpack_stream(&mut stream, 2, |idx, value| {
result[idx] = value
})?;
assert_eq!(result[0], 1);
assert_eq!(result[1], 0);
Ok(())
}
More info
For further information and more examples, please see the rustdocs. Additional storage types are documented in the cql_db crate.
Dependencies
~115KB