From c134f7587088989bde999cf5d6ae78796b33f342 Mon Sep 17 00:00:00 2001
From: Sebastian Ullrich <sebasti@nullri.ch>
Date: Sun, 19 Oct 2025 13:18:58 +0200
Subject: [PATCH] perf: try dropping written files async

---
 Cargo.lock                             | 26 +++++++++++++++++++
 src/elan-dist/Cargo.toml               |  1 +
 src/elan-dist/src/component/package.rs | 36 +++++++++++++++++++++++++-
 3 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/Cargo.lock b/Cargo.lock
index 0ed0148..c54e0ff 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -511,6 +511,7 @@ dependencies = [
  "serde_derive",
  "sha2",
  "tar",
+ "threadpool",
  "time",
  "toml",
  "url",
@@ -847,6 +848,12 @@ version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d231dfb89cfffdbc30e7fc41579ed6066ad03abda9e567ccafae602b97ec5024"
 
+[[package]]
+name = "hermit-abi"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc0fef456e4baa96da950455cd02c081ca953b141298e41db3fc7e36b1da849c"
+
 [[package]]
 name = "hmac"
 version = "0.12.1"
@@ -1299,6 +1306,16 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "51d515d32fb182ee37cda2ccdcb92950d6a3c2893aa280e540671c2cd0f3b1d9"
 
+[[package]]
+name = "num_cpus"
+version = "1.17.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "91df4bbde75afed763b708b7eee1e8e7651e02d97f6d5dd763e89367e957b23b"
+dependencies = [
+ "hermit-abi 0.5.2",
+ "libc",
+]
+
 [[package]]
 name = "object"
 version = "0.36.5"
@@ -1954,6 +1971,15 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "threadpool"
+version = "1.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d050e60b33d41c19108b32cea32164033a9013fe3b46cbd4457559bfbf77afaa"
+dependencies = [
+ "num_cpus",
+]
+
 [[package]]
 name = "time"
 version = "0.3.41"
diff --git a/src/elan-dist/Cargo.toml b/src/elan-dist/Cargo.toml
index 7d07413..1d48275 100644
--- a/src/elan-dist/Cargo.toml
+++ b/src/elan-dist/Cargo.toml
@@ -30,6 +30,7 @@ time = "0.3"
 serde = "1.0.119"
 serde_derive = "1.0.119"
 fslock = "0.2.1"
+threadpool = "1.8.1"
 
 [target."cfg(windows)".dependencies]
 winapi = { version = "0.3.9", features = ["handleapi", "sysinfoapi", "tlhelp32", "winnt"] }
diff --git a/src/elan-dist/src/component/package.rs b/src/elan-dist/src/component/package.rs
index 89ff5ce..6a1aba0 100644
--- a/src/elan-dist/src/component/package.rs
+++ b/src/elan-dist/src/component/package.rs
@@ -7,10 +7,27 @@ use crate::errors::*;
 use std::fs::{self, File};
 use std::io::{self, Read, Seek};
 use std::path::{Path, PathBuf};
+#[cfg(windows)]
+use std::sync::OnceLock;
 
 use time::OffsetDateTime;
 use zip::ZipArchive;
 
+// Thread pool for handling expensive file handle drops on Windows
+#[cfg(windows)]
+static DROP_POOL: OnceLock<threadpool::ThreadPool> = OnceLock::new();
+
+#[cfg(windows)]
+fn get_drop_pool() -> &'static threadpool::ThreadPool {
+    DROP_POOL.get_or_init(|| {
+        threadpool::Builder::new()
+            .thread_name("FileDrop".into())
+            .num_threads(8)
+            .thread_stack_size(1_048_576)
+            .build()
+    })
+}
+
 #[derive(Debug)]
 pub struct TarPackage();
 
@@ -48,9 +65,26 @@ fn unpack_without_first_dir<R: Read>(archive: &mut tar::Archive<R>, path: &Path)
             _ => (),
         };
 
-        entry
+        let unpacked = entry
             .unpack(&full_path)
             .chain_err(|| ErrorKind::ExtractingPackage)?;
+
+        #[cfg(windows)]
+        {
+            let pool = get_drop_pool();
+            pool.execute(move || {
+                drop(unpacked);
+            });
+        }
+        #[cfg(not(windows))]
+        {
+            drop(unpacked);
+        }
+    }
+
+    #[cfg(windows)]
+    {
+        get_drop_pool().join();
     }
 
     Ok(())