Replace lazy_static & once_cell with std::sync::OnceLock

Cargo.toml

@@ -20,11 +20,9 @@ futures-core = "0.3"
 futures-util = "0.3"
 futures-sink = "0.3"
 keyed_priority_queue = "0.4"
-lazy_static = "1"
 lru = "0.12.0"
 mio = { version = "0.8.0", features = ["os-poll", "net"] }
 mysql_common = { version = "0.32", default-features = false }
-once_cell = "1.7.2"
 pem = "3.0"
 percent-encoding = "2.1.0"
 pin-project = "1.0.2"

src/conn/mod.rs

@@ -581,7 +581,7 @@ impl Conn {
         );
 
         // Serialize here to satisfy borrow checker.
-        let mut buf = crate::BUFFER_POOL.get();
+        let mut buf = crate::buffer_pool().get();
         handshake_response.serialize(buf.as_mut());
 
         self.write_packet(buf).await?;
@@ -633,7 +633,7 @@ impl Conn {
             if let Some(plugin_data) = plugin_data {
                 self.write_struct(&plugin_data.into_owned()).await?;
             } else {
-                self.write_packet(crate::BUFFER_POOL.get()).await?;
+                self.write_packet(crate::buffer_pool().get()).await?;
             }
 
             self.continue_auth().await?;
@@ -701,7 +701,7 @@ impl Conn {
                 }
                 Some(0x04) => {
                     let pass = self.inner.opts.pass().unwrap_or_default();
-                    let mut pass = crate::BUFFER_POOL.get_with(pass.as_bytes());
+                    let mut pass = crate::buffer_pool().get_with(pass.as_bytes());
                     pass.as_mut().push(0);
 
                     if self.is_secure() || self.is_socket() {
@@ -838,13 +838,13 @@ impl Conn {
 
     /// Writes bytes to a server.
     pub(crate) async fn write_bytes(&mut self, bytes: &[u8]) -> Result<()> {
-        let buf = crate::BUFFER_POOL.get_with(bytes);
+        let buf = crate::buffer_pool().get_with(bytes);
         self.write_packet(buf).await
     }
 
     /// Sends a serializable structure to a server.
     pub(crate) async fn write_struct<T: MySerialize>(&mut self, x: &T) -> Result<()> {
-        let mut buf = crate::BUFFER_POOL.get();
+        let mut buf = crate::buffer_pool().get();
         x.serialize(buf.as_mut());
         self.write_packet(buf).await
     }
@@ -870,7 +870,7 @@ impl Conn {
         T: AsRef<[u8]>,
     {
         let cmd_data = cmd_data.as_ref();
-        let mut buf = crate::BUFFER_POOL.get();
+        let mut buf = crate::buffer_pool().get();
         let body = buf.as_mut();
         body.push(cmd as u8);
         body.extend_from_slice(cmd_data);

src/io/mod.rs

@@ -75,7 +75,7 @@ impl Default for PacketCodec {
     fn default() -> Self {
         Self {
             inner: Default::default(),
-            decode_buf: crate::BUFFER_POOL.get(),
+            decode_buf: crate::buffer_pool().get(),
         }
     }
 }
@@ -100,7 +100,7 @@ impl Decoder for PacketCodec {
 
     fn decode(&mut self, src: &mut BytesMut) -> std::result::Result<Option<Self::Item>, IoError> {
         if self.inner.decode(src, self.decode_buf.as_mut())? {
-            let new_buf = crate::BUFFER_POOL.get();
+            let new_buf = crate::buffer_pool().get();
             Ok(Some(replace(&mut self.decode_buf, new_buf)))
         } else {
             Ok(None)

src/lib.rs

@@ -453,8 +453,11 @@ mod queryable;
 
 type BoxFuture<'a, T> = futures_core::future::BoxFuture<'a, Result<T>>;
 
-static BUFFER_POOL: once_cell::sync::Lazy<Arc<crate::buffer_pool::BufferPool>> =
-    once_cell::sync::Lazy::new(Default::default);
+fn buffer_pool() -> &'static Arc<crate::buffer_pool::BufferPool> {
+    static BUFFER_POOL: std::sync::OnceLock<Arc<crate::buffer_pool::BufferPool>> =
+        std::sync::OnceLock::new();
+    BUFFER_POOL.get_or_init(Default::default)
+}
 
 #[cfg(feature = "binlog")]
 #[doc(inline)]
@@ -608,9 +611,8 @@ pub mod prelude {
 
 #[doc(hidden)]
 pub mod test_misc {
-    use lazy_static::lazy_static;
-
     use std::env;
+    use std::sync::OnceLock;
 
     use crate::opts::{Opts, OptsBuilder, SslOpts};
 
@@ -621,26 +623,17 @@ pub mod test_misc {
         _dummy(err);
     }
 
-    lazy_static! {
-        pub static ref DATABASE_URL: String = {
+    pub fn get_opts() -> OptsBuilder {
+        static DATABASE_OPTS: OnceLock<Opts> = OnceLock::new();
+        let database_opts = DATABASE_OPTS.get_or_init(|| {
             if let Ok(url) = env::var("DATABASE_URL") {
-                let opts = Opts::from_url(&url).expect("DATABASE_URL invalid");
-                if opts
-                    .db_name()
-                    .expect("a database name is required")
-                    .is_empty()
-                {
-                    panic!("database name is empty");
-                }
-                url
+                Opts::from_url(&url).expect("DATABASE_URL invalid")
             } else {
-                "mysql://root:password@localhost:3307/mysql".into()
+                Opts::from_url("mysql://root:password@localhost:3307/mysql").unwrap()
             }
-        };
-    }
+        });
 
-    pub fn get_opts() -> OptsBuilder {
-        let mut builder = OptsBuilder::from_opts(Opts::from_url(&DATABASE_URL).unwrap());
+        let mut builder = OptsBuilder::from_opts(database_opts.clone());
         if test_ssl() {
             let ssl_opts = SslOpts::default()
                 .with_danger_skip_domain_validation(true)