switch to zstd for asset archive

Cargo.toml

@@ -45,20 +45,20 @@ tokio = { version = "1", features = ["rt", "macros", "sync", "time", "signal", "
 url = "2"
 serde_repr = "0.1"
 webpki-roots = "0.26"
-xz2 = { version = "0.1", features = ["static"] }
 ar = "0.9"
 quick-xml = { version = "0.31", features = ["serialize"] }
 semver = "1"
 futures-util = "0.3"
 self-replace = "1"
+zstd = { version = "0.13", default-features = false }
 
 [target.'cfg(target_arch = "x86_64")'.dependencies]
 raw-cpuid = "11"
 
 [build-dependencies]
 glob = "0.3"
-xz2 = "0.1"
 ar = "0.9"
+zstd = { version = "0.13", default-features = false }
 
 [target.'cfg(windows)'.build-dependencies]
 winres = "0.1"

build.rs

@@ -3,7 +3,7 @@
 use std::{env, fs, fs::File, io::Write, path::Path, process::Command};
 
 use glob::glob;
-use xz2::write::XzEncoder;
+use zstd::stream::write::Encoder as ZstdEncoder;
 
 const EVAL_FILE: &str = "nn-b1a57edbea57.nnue";
 const EVAL_FILE_SMALL: &str = "nn-baff1ede1f90.nnue";
@@ -16,10 +16,13 @@ fn main() {
 
     hooks();
 
-    let mut archive = ar::Builder::new(XzEncoder::new(
-        File::create(Path::new(&env::var("OUT_DIR").unwrap()).join("assets.ar.xz")).unwrap(),
-        6,
-    ));
+    let mut archive = ar::Builder::new(
+        ZstdEncoder::new(
+            File::create(Path::new(&env::var("OUT_DIR").unwrap()).join("assets.ar.xz")).unwrap(),
+            6,
+        )
+        .unwrap(),
+    );
     stockfish_build(&mut archive);
     stockfish_eval_file(EVAL_FILE, &mut archive);
     stockfish_eval_file(EVAL_FILE_SMALL, &mut archive);

src/assets.rs

@@ -10,7 +10,7 @@ use ar::Archive;
 use bitflags::bitflags;
 use serde::Serialize;
 use tempfile::TempDir;
-use xz2::read::XzDecoder;
+use zstd::stream::read::Decoder as ZstdDecoder;
 
 static ASSETS_AR_XZ: &[u8] = include_bytes!(concat!(env!("OUT_DIR"), "/assets.ar.xz"));
 
@@ -189,7 +189,7 @@ impl Assets {
         let mut stockfish = ByEngineFlavor::<Option<PathBuf>>::default();
         let dir = tempfile::Builder::new().prefix("fishnet-").tempdir()?;
 
-        let mut archive = Archive::new(XzDecoder::new(ASSETS_AR_XZ));
+        let mut archive = Archive::new(ZstdDecoder::new(ASSETS_AR_XZ)?);
         while let Some(entry) = archive.next_entry() {
             let mut entry = entry?;
             let filename = str::from_utf8(entry.header().identifier()).expect("utf-8 filename");