valkey: use VecDeque for the command queues; LinearFifo rejects droppable items

src/collections/linear_fifo.rs

@@ -161,6 +161,12 @@ pub struct LinearFifo<T, B: LinearFifoBuffer<T>> {
 impl<T, const N: usize> LinearFifo<T, StaticBuffer<T, N>> {
     /// `init` for `.Static`.
     pub fn init() -> Self {
+        const {
+            assert!(
+                !mem::needs_drop::<T>(),
+                "LinearFifo does not drop its items; use VecDeque for types with drop glue"
+            )
+        };
         Self {
             buf: StaticBuffer([const { MaybeUninit::uninit() }; N]),
             head: 0,
@@ -173,6 +179,12 @@ impl<T, const N: usize> LinearFifo<T, StaticBuffer<T, N>> {
 impl<T> LinearFifo<T, DynamicBuffer<T>> {
     /// `init` for `.Dynamic`.
     pub fn init() -> Self {
+        const {
+            assert!(
+                !mem::needs_drop::<T>(),
+                "LinearFifo does not drop its items; use VecDeque for types with drop glue"
+            )
+        };
         Self {
             buf: DynamicBuffer(Box::new([])),
             head: 0,
@@ -182,8 +194,11 @@ impl<T> LinearFifo<T, DynamicBuffer<T>> {
     }
 }
 
-// `pub fn deinit` → Drop. Dynamic frees `buf` via `Box` drop; Static/Slice are
-// no-ops. Field drop glue covers it; no explicit impl needed.
+// `pub fn deinit` → Drop. Dynamic frees `buf` via `Box` drop; Static is a
+// no-op. Items are never dropped: the ring is for POD/pointer payloads only,
+// and the `!needs_drop::<T>()` const assert in each `init` enforces it, so
+// e.g. `LinearFifo::<Box<u8>, DynamicBuffer<_>>::init()` fails to compile at
+// monomorphization.
 
 impl<T, B: LinearFifoBuffer<T>> LinearFifo<T, B> {
     #[inline]

src/runtime/valkey_jsc/ValkeyCommand.rs

@@ -1,4 +1,3 @@
-use bun_collections::linear_fifo::{DynamicBuffer, LinearFifo};
 use bun_jsc::{self as jsc, JSGlobalObject, JSValue, JsResult};
 use bun_valkey::valkey_protocol as protocol;
 
@@ -114,7 +113,7 @@ pub struct Entry {
 // Inherent associated
 // types are unstable on stable Rust, so expose as a sibling module alias instead.
 pub mod entry {
-    pub(crate) type Queue = super::LinearFifo<super::Entry, super::DynamicBuffer<super::Entry>>;
+    pub(crate) type Queue = std::collections::VecDeque<super::Entry>;
 }
 
 impl Entry {
@@ -248,8 +247,7 @@ pub struct PromisePair {
 
 // See `entry` note above.
 pub mod promise_pair {
-    pub(crate) type Queue =
-        super::LinearFifo<super::PromisePair, super::DynamicBuffer<super::PromisePair>>;
+    pub(crate) type Queue = std::collections::VecDeque<super::PromisePair>;
 }
 
 impl PromisePair {

src/runtime/valkey_jsc/js_valkey.rs

@@ -758,8 +758,8 @@ impl JSValkeyClient {
                 protocol: uri,
                 username,
                 password,
-                in_flight: command::promise_pair::Queue::init(),
-                queue: command::entry::Queue::init(),
+                in_flight: command::promise_pair::Queue::new(),
+                queue: command::entry::Queue::new(),
                 status: valkey::Status::NeverConnected,
                 connection_strings,
                 socket: Socket::SocketTcp(uws::SocketTCP {
@@ -867,8 +867,8 @@ impl JSValkeyClient {
                 protocol: client.protocol,
                 username,
                 password,
-                in_flight: command::promise_pair::Queue::init(),
-                queue: command::entry::Queue::init(),
+                in_flight: command::promise_pair::Queue::new(),
+                queue: command::entry::Queue::new(),
                 status: valkey::Status::NeverConnected,
                 connection_strings: connection_strings_copy,
                 socket: Socket::SocketTcp(uws::SocketTCP {
@@ -1610,13 +1610,12 @@ impl JSValkeyClient {
         memory_cost += client.read_buffer.byte_list.capacity() as usize;
 
         // Add queue sizes
-        memory_cost += client.in_flight.readable_length()
-            * core::mem::size_of::<super::valkey_command::PromisePair>();
-        for command in client.queue.readable_slice(0) {
+        memory_cost +=
+            client.in_flight.len() * core::mem::size_of::<super::valkey_command::PromisePair>();
+        for command in client.queue.iter() {
             memory_cost += command.serialized_data.len();
         }
-        memory_cost +=
-            client.queue.readable_length() * core::mem::size_of::<super::valkey_command::Entry>();
+        memory_cost += client.queue.len() * core::mem::size_of::<super::valkey_command::Entry>();
         memory_cost
     }