Macro define_schema

macro_rules! define_schema {
    ($schema_type:ident, $key_type:ty, $value_type:ty, $cf_name:expr) => { ... };
}

A utility macro to define Schema implementors. You must specify the Schema implementor’s name, the key type, the value type, and the column family name.

Example

use anyhow::Context;

use sov_schema_db::define_schema;
use sov_schema_db::schema::{
    Schema, KeyEncoder, KeyDecoder, ValueCodec, Result,
};

define_schema!(PersonAgeByName, String, u32, "person_age_by_name");

impl KeyEncoder<PersonAgeByName> for String {
    fn encode_key(&self) -> Result<Vec<u8>> {
        Ok(self.as_bytes().to_vec())
    }
}

impl KeyDecoder<PersonAgeByName> for String {
    fn decode_key(data: &[u8]) -> Result<Self> {
        Ok(String::from_utf8(data.to_vec()).context("Can't read key")?)
    }
}

impl ValueCodec<PersonAgeByName> for u32 {
    fn encode_value(&self) -> Result<Vec<u8>> {
        Ok(self.to_le_bytes().to_vec())
    }

    fn decode_value(data: &[u8]) -> Result<Self> {
        let mut buf = [0u8; 4];
        buf.copy_from_slice(data);
        Ok(u32::from_le_bytes(buf))
    }
}