3 unstable releases
0.2.1 | Mar 11, 2020 |
---|---|
0.2.0 | Feb 25, 2020 |
0.1.0 | Feb 11, 2020 |
#2417 in Database interfaces
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24KB
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CQL TinyText
This crate implements various CqlType derivatives for storing String values of up to (and including) 255 chars in a CQL database.
Will allocate 1020 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
, but please be aware that they will allocate ~102MB of disk space. The read_to_stream benchmarks also differ slightly from
other CqlType derivatives as they stream into a Vector, not an Array.
Operation | Database dimensions | Mean time (ns) |
---|---|---|
Single point read | 1 | 3 060 (+/- 200) |
Single point read | 4 | 15 800 (+/- 1 100) |
Single point write | 1 | 2 800 (+/- 300) |
Single point write | 4 | 15 400 (+/- 1 000) |
Stream read 1 point | 1 | 3 500 (+/- 300) |
Stream read 1 point | 4 | 15 500 (+/- 1 100) |
Stream read 50 000 points | 1 | 56 700 000 (+/- 800 000) |
Stream read 50 000 points | 4 | 56 400 000 (+/- 150 000) |
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_tiny_text = "^0.2"
Then need to create a folder where you want the database to live, and then try out the below:
use std::convert::TryFrom;
use std::io::{ Cursor, SeekFrom, Seek };
use std::error::Error;
use cql_tiny_text::{ TinyText, unpack_stream };
const DATABASE_LOCATION: &str = "PATH_TO_YOUR_DATABASE_DIRECTORY";
pub fn example_cql() -> Result<(), Box<dyn Error>> {
let value1 = "item one";
let value3 = "شماره ۳";
cql_db::create_db::<TinyText>(
DATABASE_LOCATION,
&[3]
)?;
cql_db::write_value::<TinyText>(
DATABASE_LOCATION,
&[1],
TinyText::try_from(value1)?
)?;
cql_db::write_value::<TinyText>(
DATABASE_LOCATION,
&[3],
TinyText::try_from(value3)?
)?;
let mut result = Vec::with_capacity(3);
let mut stream = Cursor::new(Vec::new());
cql_db::read_to_stream::<TinyText>(
DATABASE_LOCATION,
&mut stream,
&[1],
3
)?;
stream.seek(SeekFrom::Start(0));
unpack_stream(&mut stream, 3, |_, value| {
result.push(value)
})?;
assert_eq!(result[0], TinyText::try_from(value1)?);
assert_eq!(result[1], TinyText::new());
assert_eq!(result[2], TinyText::try_from(value3)?);
Ok(())
}
More info
For further information and more examples, please see the rustdocs. Additional storage types are documented in the cql_db crate.
Dependencies
~120KB