首发于Enaium的个人博客
首先我们需要添加几个依赖。
model = { path = "../model" }
parse = { path = "../parse" }
reqwest = { version = "0.12", features = ["blocking", "json"] }
file-hashing = { version = "0.1" }
sha1 = { version = "0.10" }
reqwest用于发送请求，file-hashing用于计算文件的hash，sha1用于计算sha1。
之后我们需要添加下载的trait。
pub trait Download {fn download(&self, game_dir: &Path) -> Result<(), Box<dyn std::error::Error>>;
}
接着我们需要使用Client::builder()来创建一个Client，因为默认的get方法会用有个超时时间，而我们需要设置超时时间为无限。
pub fn get<T: reqwest::IntoUrl>(url: T) -> reqwest::Result<reqwest::blocking::Response> {reqwest::blocking::Client::builder().timeout(None).build()?.get(url).send()
}
最后我们需要创建一个计算文件hash的函数。
pub fn sha1<P: AsRef<Path>>(path: P) -> Result<String, std::io::Error> {let mut hasher = Sha1::new();file_hashing::get_hash_file(path, &mut hasher)
}
之后需要出创建asset.rs、library.rs、version.rs文件，分别对应下载资源、下载库、下载游戏版本。
asset.rs
use std::{fs, path::Path};use model::asset::*;
use parse::Parse;use crate::{get, Download};impl Download for AssetIndex {fn download(&self, game_dir: &Path) -> Result<(), Box<dyn std::error::Error>> {println!("Downloading asset index:{}", self.id);let indexes_dir = &game_dir.join("assets").join("indexes");if !indexes_dir.exists() {std::fs::create_dir_all(indexes_dir)?;}let path = &indexes_dir.join(&format!("{}.json", self.id));std::fs::File::create(path)?;let url = &self.url;let text = &get(url)?.text()?;std::fs::write(path, text)?;let index = Index::parse(text)?;let objects_dir = &game_dir.join("assets").join("objects");if !objects_dir.exists() {std::fs::create_dir_all(objects_dir)?;}for (_, value) in index.objects {let hash = &value.hash;let hash_first_two = &hash.chars().take(2).collect::<String>();let first_two_dir = &objects_dir.join(hash_first_two);if !first_two_dir.exists() {std::fs::create_dir_all(first_two_dir)?;}let path = &first_two_dir.join(hash);if path.exists() {if crate::sha1(path)?.eq(hash) {continue;} else {std::fs::remove_file(path)?;}}std::fs::File::create(path)?;let url = format!("https://resources.download.minecraft.net/{}/{}",hash_first_two, hash);println!("Downloading:{}", url);let bytes = get(&url)?.bytes()?;fs::write(path, bytes)?;}Ok(())}
}#[cfg(test)]
mod tests {use super::*;#[test]fn test_asset_index() {let asset_index = model::asset::AssetIndex {id: "17".to_string(),sha1: "fab15439bdef669e389e25e815eee8f1b2aa915e".to_string(),size: 447033,total_size: 799252591,url: "https://piston-meta.mojang.com/v1/packages/fab15439bdef669e389e25e815eee8f1b2aa915e/17.json".to_string(),};let download_path = &std::env::temp_dir().join("rust-minecraft-client-launch");std::fs::create_dir_all(download_path).unwrap_or_else(|err| panic!("{:?}", err));if let Err(err) = asset_index.download(download_path) {panic!("{:?}", err);}}
}
library.rs
use std::path::Path;use model::{library, version::Libraries};use crate::{Download, LibraryAllowed};impl LibraryAllowed for library::Library {fn allowed(&self) -> bool {let mut allowed = true;if self.rules.is_some() {for rule in self.rules.as_ref().unwrap() {if rule.os.name == "osx" && !cfg!(target_os = "macos") {allowed = false;break;} else if rule.os.name == "linux" && !cfg!(target_os = "linux") {allowed = false;break;} else if rule.os.name == "windows" && !cfg!(target_os = "windows") {allowed = false;break;}}}if self.name.contains("natives") {if self.name.contains("x86") && !cfg!(target_arch = "x86") {allowed = false;} else if self.name.contains("arm64") && !cfg!(target_arch = "aarch64") {allowed = false;} else if !cfg!(target_arch = "x86_64") {allowed = false;}}allowed}
}impl Download for Libraries {fn download(&self, game_dir: &Path) -> Result<(), Box<dyn std::error::Error>> {println!("Downloading libraries");let libraries_dir = &game_dir.join("libraries");if !libraries_dir.exists() {std::fs::create_dir_all(libraries_dir)?;}for library in self {if !library.allowed() {continue;}let library_file = &library.downloads.artifact.path;let library_path = &libraries_dir.join(library_file);if !library_path.parent().unwrap().exists() {std::fs::create_dir_all(library_path.parent().unwrap())?;}if library_path.exists() {if crate::sha1(library_path)? == library.downloads.artifact.sha1 {continue;} else {std::fs::remove_file(library_path)?;}}std::fs::File::create(&library_path)?;let url = &library.downloads.artifact.url;println!("Downloading: {}", url);let bytes = crate::get(url)?.bytes()?;std::fs::write(library_path, bytes)?;}Ok(())}
}#[cfg(test)]
mod tests {use super::*;use model::version::Version;#[test]fn test_download() {let game = reqwest::blocking::get("https://piston-meta.mojang.com/v1/packages/177e49d3233cb6eac42f0495c0a48e719870c2ae/1.21.json").unwrap().json::<Version>().unwrap();let download_path = &std::env::temp_dir().join("rust-minecraft-client-launch");std::fs::create_dir_all(download_path).unwrap_or_else(|err| panic!("{:?}", err));if let Err(err) = game.libraries.download(download_path) {panic!("{:?}", err);}}
}
这里我们需要添加一个trait，用于判断库是否允许下载。
pub trait LibraryAllowed {fn allowed(&self) -> bool;
}
version.rs
use std::path::Path;use model::version_manifest::Version;use crate::{get, sha1, Download};impl Download for Version {fn download(&self, game_dir: &Path) -> Result<(), Box<dyn std::error::Error>> {let game = get(&self.url)?.json::<model::version::Version>()?;let versions_dir = &game_dir.join(game_dir).join("versions").join(&self.id);if !versions_dir.exists() {std::fs::create_dir_all(versions_dir)?;}game.libraries.download(game_dir)?;game.asset_index.download(game_dir)?;let version_config = &game_dir.join("versions").join(&self.id).join(&format!("{}.json", &self.id));if version_config.exists() {std::fs::remove_file(version_config).unwrap();}std::fs::File::create(version_config).unwrap();std::fs::write(version_config, get(&self.url).unwrap().bytes().unwrap()).unwrap();let path = &versions_dir.join(versions_dir).join(&format!("{}.jar", &self.id));if path.exists() {if sha1(path)? == game.downloads.client.sha1 {return Ok(());} else {std::fs::remove_file(path)?;}}std::fs::File::create(path)?;let bytes = crate::get(&game.downloads.client.url)?.bytes()?;std::fs::write(path, bytes)?;Ok(())}
}#[cfg(test)]
mod tests {use super::*;#[test]fn test_download() {let version = Version {id: "1.21".to_string(),type_: "release".to_string(),url: "https://piston-meta.mojang.com/v1/packages/177e49d3233cb6eac42f0495c0a48e719870c2ae/1.21.json".to_string(),time : "2024-06-13T08:32:38+00:00".to_string(),release_time : "2024-06-13T08:24:03+00:00".to_string(),};let download_path = &std::env::temp_dir().join("rust-minecraft-client-launch");std::fs::create_dir_all(download_path).unwrap_or_else(|err| panic!("{:?}", err));if let Err(err) = version.download(download_path) {panic!("{:?}", err);}}
}
好了，现在我们可以测试下载资源了。
项目地址