feat: Attempt to improve performance for async

.envrc

@@ -0,0 +1 @@
+use_nix

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "tmp-postgrust"
-version = "0.9.0"
+version = "0.10.0"
 authors = ["John Children <[email protected]>"]
 license = "MIT"
 edition = "2018"

shell.nix

@@ -0,0 +1,18 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+pkgs.mkShell {
+  name = "diesel-tracing-dev-env";
+  buildInputs = with pkgs; [
+    cargo
+    rustc
+    rustfmt
+    clippy
+
+    pkg-config
+    postgresql
+    libmysqlclient
+    sqlite
+  ];
+
+  LD_LIBRARY_PATH = "${pkgs.postgresql.lib}/lib";
+}

src/asynchronous.rs

@@ -9,7 +9,6 @@ use tempfile::TempDir;
 use tokio::fs::create_dir_all;
 use tokio::io::Lines;
 use tokio::process::{ChildStderr, ChildStdout};
-use tokio::sync::{Semaphore, SemaphorePermit};
 use tokio::{
     io::BufReader,
     process::{Child, Command},
@@ -20,9 +19,6 @@ use crate::errors::{ProcessCapture, TmpPostgrustError, TmpPostgrustResult};
 use crate::search::{all_dir_entries, build_copy_dst_path, find_postgresql_command};
 use crate::POSTGRES_UID_GID;
 
-/// Limit the total processes that can be running at any one time.
-pub(crate) static MAX_CONCURRENT_PROCESSES: Semaphore = Semaphore::const_new(8);
-
 #[instrument(skip(command, fail))]
 async fn exec_process(
     command: &mut Command,
@@ -94,12 +90,18 @@ pub(crate) async fn exec_copy_dir(src_dir: &Path, dst_dir: &Path) -> TmpPostgrus
             .await
             .map_err(TmpPostgrustError::CopyCachedInitDBFailedFileNotFound)?;
     }
+    let src_dir = src_dir.to_owned();
+    let dst_dir = dst_dir.to_owned();
 
-    for entry in others {
-        reflink_copy::reflink_or_copy(&entry, build_copy_dst_path(&entry, src_dir, dst_dir)?)
-            .map_err(TmpPostgrustError::CopyCachedInitDBFailedFileNotFound)?;
-    }
-
+    tokio::task::spawn_blocking(move || {
+        for entry in others {
+            reflink_copy::reflink_or_copy(&entry, build_copy_dst_path(&entry, &src_dir, &dst_dir)?)
+                .map_err(TmpPostgrustError::CopyCachedInitDBFailedFileNotFound)?;
+        }
+        Ok(())
+    })
+    .await
+    .unwrap()?;
     Ok(())
 }
 
@@ -193,8 +195,6 @@ pub struct ProcessGuard {
     /// Socket directory for connection to the running process.
     pub(crate) socket_dir: Arc<TempDir>,
     pub(crate) postgres_process: Child,
-    // Limit the total concurrent processes.
-    pub(crate) _process_permit: SemaphorePermit<'static>,
 }
 
 impl Drop for ProcessGuard {