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Fetchable

fetch_file

Trait Fetchable 

Source 
pub trait Fetchable {
    // Required methods
    fn deserialize_l<T: DeserializeOwned + Default + Fetchable>(
        f_path: &PathBuf,
    ) -> Result<T, Box<dyn Error>>;
    fn serialize_l(&self) -> Result<Vec<u8>, Box<dyn Error>>
       where Self: Serialize + Fetchable;

    // Provided methods
    fn deserialize_bin<T>(f_path: &PathBuf) -> Result<T, Box<dyn Error>>
       where T: DeserializeOwned + Default { ... }
    fn deserialize_json<T>(f_path: &PathBuf) -> Result<T, Box<dyn Error>>
       where T: DeserializeOwned + Default { ... }
    fn deserialize_ron<T>(f_path: &PathBuf) -> Result<T, Box<dyn Error>>
       where T: DeserializeOwned + Default { ... }
    fn serialize_bin(&self) -> Result<Vec<u8>, Box<dyn Error>>
       where Self: Serialize { ... }
    fn serialize_ron(&self) -> Result<Vec<u8>, Box<dyn Error>>
       where Self: Serialize { ... }
    fn serialize_json(&self) -> Result<Vec<u8>, Box<dyn Error>>
       where Self: Serialize { ... }
    fn save(&self, path: &PathBuf) -> Result<(), Box<dyn Error>>
       where Self: Serialize + Fetchable { ... }
    fn fetch_or_default<T>(
        file_path: &PathBuf,
    ) -> Result<(T, bool), Box<dyn Error>>
       where T: Default + DeserializeOwned + Fetchable { ... }
}
Expand description

§

§Fetch

Simple trait that can be implemented on structs/enums for serialisation to and from disk.

  • deserialize_l: impl to pick specific

  • serialize_l: ..

use std::env;
use std::error::Error;
use std::path::PathBuf;
use serde::*;
use serde::de::DeserializeOwned;
use fetch_file::Fetchable;

#[derive(Deserialize, Serialize)]
pub struct Config {
    setting1: usize,
    setting2: usize
}

impl Default for Config {
    fn default() -> Self {
        Config {
            setting1: 0,
            setting2: 5,
        }
    }
}

impl Fetchable for Config {
    fn deserialize_l<T>(f_path: &PathBuf) -> Result<T, Box<dyn Error>>
        where T: DeserializeOwned + Default + Fetchable {
        //Config::deserialize_ron(f_path)
        //Config::deserialize_json(f_path)
        Config::deserialize_bin(f_path)
     }

    fn serialize_l(&self) -> Result<Vec<u8>, Box<dyn Error>>
        where Self: serde::Serialize + Fetchable {
        //self.serialize_ron()
        //self.serialize_json()
        self.serialize_bin()
    }
}

fn main() -> std::result::Result<(),  Box<dyn Error>> {
    // Example directory
    let mut path = env::current_dir()?;
    // adding file name
    path.push("config.bin");
    // fetch or default will either open file from disk and deserialize
    // or return the default for Config and a boolean indicating the
    // config is default.
    let config: (Config, bool) = Config::fetch_or_default(&path)?;
    if config.1 {
        //config.0.save(&path);
    }
    let config = config.0;
    println!("Config: {}, {}", config.setting1, config.setting2);
    Ok(())
}

Required Methods§

Source

fn deserialize_l<T: DeserializeOwned + Default + Fetchable>( f_path: &PathBuf, ) -> Result<T, Box<dyn Error>>

§
§Parameters

f_path: Path to file to open /path/to/your/file.txt

Impl this method to define behavior.

T::deserialize_json

Source

fn serialize_l(&self) -> Result<Vec<u8>, Box<dyn Error>>
where Self: Serialize + Fetchable,

§
§Impl method

Impl this method to define behavior.

Provided Methods§

Source

fn deserialize_bin<T>(f_path: &PathBuf) -> Result<T, Box<dyn Error>>
where T: DeserializeOwned + Default,

§

Deserialize from bincode format.

§Parameters

f_path: Path to file to open /path/to/your/file.txt

§Panics

If File::open fails

Source

fn deserialize_json<T>(f_path: &PathBuf) -> Result<T, Box<dyn Error>>
where T: DeserializeOwned + Default,

§

Deserialize from Json format.

§Parameters

f_path: Path to file to open /path/to/your/file.txt

§Panics

Panics if File::open fails

Source

fn deserialize_ron<T>(f_path: &PathBuf) -> Result<T, Box<dyn Error>>
where T: DeserializeOwned + Default,

§

Deserialize from ron format.

§Parameters

f_path: Path to file to open /home/$USER/folder/file.txt

§Panics

Panics if File::open fails

Source

fn serialize_bin(&self) -> Result<Vec<u8>, Box<dyn Error>>
where Self: Serialize,

§
§Bin
Source

fn serialize_ron(&self) -> Result<Vec<u8>, Box<dyn Error>>
where Self: Serialize,

§
§RON
Source

fn serialize_json(&self) -> Result<Vec<u8>, Box<dyn Error>>
where Self: Serialize,

§
§Json
Source

fn save(&self, path: &PathBuf) -> Result<(), Box<dyn Error>>
where Self: Serialize + Fetchable,

§
§Save

Use this version of save when container cannot be implemented.

Source

fn fetch_or_default<T>(file_path: &PathBuf) -> Result<(T, bool), Box<dyn Error>>
where T: Default + DeserializeOwned + Fetchable,

§

Fetch an item serialized to file

§Parameters
  • file_path - Reference to path buffer of file of type T
§Returns
  • Result<(T, bool)> - Returns tuple containing T and a bool value indicating if a config was retrieved or default. True for default config use.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§