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。
