Expand description
Loaders for definitions.
Custom loaders
If you need a certain loader and this crate doesn’t provide it you can use the below example to help you make your own loader if you desperately need it.
use std::{collections::HashMap, io::{ self, BufReader, }};
use rscache::{
Cache, extension::ReadExt,
definition::osrs::{ Definition, FetchDefinition },
};
fn main() -> Result<(), rscache::Error> {
let cache = Cache::new("./data/osrs_cache")?;
let custom_loader = CustomLoader::new(&cache)?;
let definition = custom_loader.load(1042);
if let Some(def) = definition {
println!("id: {}, name: {}", def.id, def.name);
}
Ok(())
}
// Newtype defining the loader.
struct CustomLoader(HashMap<u16, CustomDefinition>);
impl CustomLoader {
fn new(cache: &Cache) -> Result<Self, rscache::Error> {
// Some definitions are all contained within one archive.
// Other times one archive only contains one definition, but in most cases
// for OSRS they are stored as multiple definitions per archive.
let index_id = 2; // Config index.
let archive_id = 10; // Contains all ItemDefinitions.
let map = CustomDefinition::fetch_from_archive(cache, index_id, archive_id)?;
Ok(Self(map))
}
// Simple HashMap lookup.
fn load(&self, id: u16) -> Option<&CustomDefinition> {
self.0.get(&id)
}
}
// Your definition with all the required fields. (in this example it's just a ItemDefinition)
#[derive(Default)]
struct CustomDefinition {
pub id: u16,
pub name: String,
}
impl Definition for CustomDefinition {
fn new(id: u16, buffer: &[u8]) -> Result<Self, rscache::Error> {
let mut reader = BufReader::new(buffer);
let def = decode_buffer(id, &mut reader)?;
Ok(def)
}
}
fn decode_buffer(id: u16, reader: &mut BufReader<&[u8]>) -> io::Result<CustomDefinition> {
// Parse the buffer into a definition.
let mut def = CustomDefinition {
id,
.. CustomDefinition::default()
};
loop {
let opcode = reader.read_u8()?;
match opcode {
// 0 indicates to stop parsing. Skipping for now because we are
// only interested in the name.
// 0 => break,
2 => { def.name = reader.read_string()?; break; },
// Skipping the rest of the buffer for the sake of the example,
// every opcode should be parsed into values of the definition.
_ => { if reader.buffer().len() == 0 { break; } }
// Should normally be:
// _ => unreachable!()
}
}
Ok(def)
}