From d30c7d54c8a28a36e8b7b121f9719978087e888f Mon Sep 17 00:00:00 2001
From: pedrocarlo <pedro.muniz.carlo@gmail.com>
Date: Mon, 28 Jul 2025 13:29:42 -0300
Subject: [PATCH] change all Arc<Completion> to Completion

---
 bindings/javascript/src/lib.rs |  6 +++---
 bindings/wasm/lib.rs           | 20 ++++++++------------
 core/io/generic.rs             | 15 ++++++---------
 core/io/io_uring.rs            | 23 ++++++++++++-----------
 core/io/memory.rs              | 10 +++++-----
 core/io/mod.rs                 | 14 +++++---------
 core/io/unix.rs                | 14 +++++++-------
 core/io/vfs.rs                 | 10 +++++-----
 core/io/windows.rs             | 10 +++++-----
 core/storage/database.rs       | 18 +++++++++---------
 core/storage/pager.rs          |  2 +-
 core/storage/sqlite3_ondisk.rs |  8 ++++----
 core/storage/wal.rs            |  8 ++++----
 core/vdbe/sorter.rs            |  4 ++--
 simulator/runner/file.rs       | 16 ++++++----------
 simulator/runner/io.rs         |  2 +-
 16 files changed, 83 insertions(+), 97 deletions(-)

diff --git a/bindings/javascript/src/lib.rs b/bindings/javascript/src/lib.rs
index 7abdfd521..ecb5d84ff 100644
--- a/bindings/javascript/src/lib.rs
+++ b/bindings/javascript/src/lib.rs
@@ -694,7 +694,7 @@ impl turso_core::DatabaseStorage for DatabaseFile {
         &self,
         page_idx: usize,
         c: turso_core::Completion,
-    ) -> turso_core::Result<Arc<turso_core::Completion>> {
+    ) -> turso_core::Result<turso_core::Completion> {
         let r = c.as_read();
         let size = r.buf().len();
         assert!(page_idx > 0);
@@ -710,13 +710,13 @@ impl turso_core::DatabaseStorage for DatabaseFile {
         page_idx: usize,
         buffer: Arc<std::cell::RefCell<turso_core::Buffer>>,
         c: turso_core::Completion,
-    ) -> turso_core::Result<Arc<turso_core::Completion>> {
+    ) -> turso_core::Result<turso_core::Completion> {
         let size = buffer.borrow().len();
         let pos = (page_idx - 1) * size;
         self.file.pwrite(pos, buffer, c.into())
     }
 
-    fn sync(&self, c: turso_core::Completion) -> turso_core::Result<Arc<turso_core::Completion>> {
+    fn sync(&self, c: turso_core::Completion) -> turso_core::Result<turso_core::Completion> {
         self.file.sync(c.into())
     }
 
diff --git a/bindings/wasm/lib.rs b/bindings/wasm/lib.rs
index e9b435a57..e244f0c6b 100644
--- a/bindings/wasm/lib.rs
+++ b/bindings/wasm/lib.rs
@@ -213,11 +213,7 @@ impl turso_core::File for File {
         Ok(())
     }
 
-    fn pread(
-        &self,
-        pos: usize,
-        c: Arc<turso_core::Completion>,
-    ) -> Result<Arc<turso_core::Completion>> {
+    fn pread(&self, pos: usize, c: turso_core::Completion) -> Result<turso_core::Completion> {
         let r = c.as_read();
         let nr = {
             let mut buf = r.buf_mut();
@@ -233,8 +229,8 @@ impl turso_core::File for File {
         &self,
         pos: usize,
         buffer: Arc<std::cell::RefCell<turso_core::Buffer>>,
-        c: Arc<turso_core::Completion>,
-    ) -> Result<Arc<turso_core::Completion>> {
+        c: turso_core::Completion,
+    ) -> Result<turso_core::Completion> {
         let w = c.as_write();
         let buf = buffer.borrow();
         let buf: &[u8] = buf.as_slice();
@@ -244,7 +240,7 @@ impl turso_core::File for File {
         Ok(c)
     }
 
-    fn sync(&self, c: Arc<turso_core::Completion>) -> Result<Arc<turso_core::Completion>> {
+    fn sync(&self, c: turso_core::Completion) -> Result<turso_core::Completion> {
         self.vfs.sync(self.fd);
         c.complete(0);
         #[allow(clippy::arc_with_non_send_sync)]
@@ -288,7 +284,7 @@ impl turso_core::IO for PlatformIO {
         }))
     }
 
-    fn wait_for_completion(&self, c: Arc<turso_core::Completion>) -> Result<()> {
+    fn wait_for_completion(&self, c: turso_core::Completion) -> Result<()> {
         while !c.is_completed() {
             self.run_once()?;
         }
@@ -342,7 +338,7 @@ impl turso_core::DatabaseStorage for DatabaseFile {
         &self,
         page_idx: usize,
         c: turso_core::Completion,
-    ) -> Result<Arc<turso_core::Completion>> {
+    ) -> Result<turso_core::Completion> {
         let r = c.as_read();
         let size = r.buf().len();
         assert!(page_idx > 0);
@@ -358,13 +354,13 @@ impl turso_core::DatabaseStorage for DatabaseFile {
         page_idx: usize,
         buffer: Arc<std::cell::RefCell<turso_core::Buffer>>,
         c: turso_core::Completion,
-    ) -> Result<Arc<turso_core::Completion>> {
+    ) -> Result<turso_core::Completion> {
         let size = buffer.borrow().len();
         let pos = (page_idx - 1) * size;
         self.file.pwrite(pos, buffer, c.into())
     }
 
-    fn sync(&self, c: turso_core::Completion) -> Result<Arc<turso_core::Completion>> {
+    fn sync(&self, c: turso_core::Completion) -> Result<turso_core::Completion> {
         self.file.sync(c.into())
     }
 
diff --git a/core/io/generic.rs b/core/io/generic.rs
index ebbd67d17..15ce52564 100644
--- a/core/io/generic.rs
+++ b/core/io/generic.rs
@@ -35,7 +35,7 @@ impl IO for GenericIO {
         }))
     }
 
-    fn wait_for_completion(&self, c: Arc<Completion>) -> Result<()> {
+    fn wait_for_completion(&self, c: Completion) -> Result<()> {
         while !c.is_completed() {
             self.run_once()?;
         }
@@ -86,14 +86,11 @@ impl File for GenericFile {
         Ok(())
     }
 
-    fn pread(&self, pos: usize, c: Arc<Completion>) -> Result<Arc<Completion>> {
+    fn pread(&self, pos: usize, c: Completion) -> Result<Completion> {
         let mut file = self.file.borrow_mut();
         file.seek(std::io::SeekFrom::Start(pos as u64))?;
         {
-            let r = match c.completion_type {
-                CompletionType::Read(ref r) => r,
-                _ => unreachable!(),
-            };
+            let r = c.as_read();
             let mut buf = r.buf_mut();
             let buf = buf.as_mut_slice();
             file.read_exact(buf)?;
@@ -106,8 +103,8 @@ impl File for GenericFile {
         &self,
         pos: usize,
         buffer: Arc<RefCell<crate::Buffer>>,
-        c: Arc<Completion>,
-    ) -> Result<Arc<Completion>> {
+        c: Completion,
+    ) -> Result<Completion> {
         let mut file = self.file.borrow_mut();
         file.seek(std::io::SeekFrom::Start(pos as u64))?;
         let buf = buffer.borrow();
@@ -117,7 +114,7 @@ impl File for GenericFile {
         Ok(c)
     }
 
-    fn sync(&self, c: Arc<Completion>) -> Result<Arc<Completion>> {
+    fn sync(&self, c: Completion) -> Result<Completion> {
         let mut file = self.file.borrow_mut();
         file.sync_all().map_err(|err| LimboError::IOError(err))?;
         c.complete(0);
diff --git a/core/io/io_uring.rs b/core/io/io_uring.rs
index aa0f21f3c..2ccb3e30a 100644
--- a/core/io/io_uring.rs
+++ b/core/io/io_uring.rs
@@ -1,6 +1,6 @@
 #![allow(clippy::arc_with_non_send_sync)]
 
-use super::{common, Completion, File, OpenFlags, IO};
+use super::{common, Completion, CompletionInner, File, OpenFlags, IO};
 use crate::io::clock::{Clock, Instant};
 use crate::{turso_assert, LimboError, MemoryIO, Result};
 use rustix::fs::{self, FlockOperation, OFlags};
@@ -168,7 +168,7 @@ impl IO for UringIO {
         Ok(uring_file)
     }
 
-    fn wait_for_completion(&self, c: Arc<Completion>) -> Result<()> {
+    fn wait_for_completion(&self, c: Completion) -> Result<()> {
         while !c.is_completed() {
             self.run_once()?;
         }
@@ -225,14 +225,15 @@ impl Clock for UringIO {
 #[inline(always)]
 /// use the callback pointer as the user_data for the operation as is
 /// common practice for io_uring to prevent more indirection
-fn get_key(c: Arc<Completion>) -> u64 {
-    Arc::into_raw(c) as u64
+fn get_key(c: Completion) -> u64 {
+    Arc::into_raw(c.inner) as u64
 }
 
 #[inline(always)]
-/// convert the user_data back to an Arc<Completion> pointer
-fn completion_from_key(key: u64) -> Arc<Completion> {
-    unsafe { Arc::from_raw(key as *const Completion) }
+/// convert the user_data back to an Completion pointer
+fn completion_from_key(key: u64) -> Completion {
+    let c_inner = unsafe { Arc::from_raw(key as *const CompletionInner) };
+    Completion { inner: c_inner }
 }
 
 pub struct UringFile {
@@ -297,7 +298,7 @@ impl File for UringFile {
         Ok(())
     }
 
-    fn pread(&self, pos: usize, c: Arc<Completion>) -> Result<Arc<Completion>> {
+    fn pread(&self, pos: usize, c: Completion) -> Result<Completion> {
         let r = c.as_read();
         trace!("pread(pos = {}, length = {})", pos, r.buf().len());
         let mut io = self.io.borrow_mut();
@@ -320,8 +321,8 @@ impl File for UringFile {
         &self,
         pos: usize,
         buffer: Arc<RefCell<crate::Buffer>>,
-        c: Arc<Completion>,
-    ) -> Result<Arc<Completion>> {
+        c: Completion,
+    ) -> Result<Completion> {
         let mut io = self.io.borrow_mut();
         let write = {
             let buf = buffer.borrow();
@@ -337,7 +338,7 @@ impl File for UringFile {
         Ok(c)
     }
 
-    fn sync(&self, c: Arc<Completion>) -> Result<Arc<Completion>> {
+    fn sync(&self, c: Completion) -> Result<Completion> {
         let mut io = self.io.borrow_mut();
         trace!("sync()");
         let sync = with_fd!(self, |fd| {
diff --git a/core/io/memory.rs b/core/io/memory.rs
index 597696605..ac81b39bc 100644
--- a/core/io/memory.rs
+++ b/core/io/memory.rs
@@ -53,7 +53,7 @@ impl IO for MemoryIO {
         Ok(())
     }
 
-    fn wait_for_completion(&self, _c: Arc<Completion>) -> Result<()> {
+    fn wait_for_completion(&self, _c: Completion) -> Result<()> {
         todo!();
     }
 
@@ -83,7 +83,7 @@ impl File for MemoryFile {
         Ok(())
     }
 
-    fn pread(&self, pos: usize, c: Arc<Completion>) -> Result<Arc<Completion>> {
+    fn pread(&self, pos: usize, c: Completion) -> Result<Completion> {
         let r = c.as_read();
         let buf_len = r.buf().len();
         if buf_len == 0 {
@@ -128,8 +128,8 @@ impl File for MemoryFile {
         &self,
         pos: usize,
         buffer: Arc<RefCell<Buffer>>,
-        c: Arc<Completion>,
-    ) -> Result<Arc<Completion>> {
+        c: Completion,
+    ) -> Result<Completion> {
         let buf = buffer.borrow();
         let buf_len = buf.len();
         if buf_len == 0 {
@@ -165,7 +165,7 @@ impl File for MemoryFile {
         Ok(c)
     }
 
-    fn sync(&self, c: Arc<Completion>) -> Result<Arc<Completion>> {
+    fn sync(&self, c: Completion) -> Result<Completion> {
         // no-op
         c.complete(0);
         Ok(c)
diff --git a/core/io/mod.rs b/core/io/mod.rs
index a2717db0b..b58c17ab6 100644
--- a/core/io/mod.rs
+++ b/core/io/mod.rs
@@ -14,14 +14,10 @@ use std::{
 pub trait File: Send + Sync {
     fn lock_file(&self, exclusive: bool) -> Result<()>;
     fn unlock_file(&self) -> Result<()>;
-    fn pread(&self, pos: usize, c: Arc<Completion>) -> Result<Arc<Completion>>;
-    fn pwrite(
-        &self,
-        pos: usize,
-        buffer: Arc<RefCell<Buffer>>,
-        c: Arc<Completion>,
-    ) -> Result<Arc<Completion>>;
-    fn sync(&self, c: Arc<Completion>) -> Result<Arc<Completion>>;
+    fn pread(&self, pos: usize, c: Completion) -> Result<Completion>;
+    fn pwrite(&self, pos: usize, buffer: Arc<RefCell<Buffer>>, c: Completion)
+        -> Result<Completion>;
+    fn sync(&self, c: Completion) -> Result<Completion>;
     fn size(&self) -> Result<u64>;
 }
 
@@ -47,7 +43,7 @@ pub trait IO: Clock + Send + Sync {
 
     fn run_once(&self) -> Result<()>;
 
-    fn wait_for_completion(&self, c: Arc<Completion>) -> Result<()>;
+    fn wait_for_completion(&self, c: Completion) -> Result<()>;
 
     fn generate_random_number(&self) -> i64;
 
diff --git a/core/io/unix.rs b/core/io/unix.rs
index 1526e13e4..cfe6d37fe 100644
--- a/core/io/unix.rs
+++ b/core/io/unix.rs
@@ -286,7 +286,7 @@ impl IO for UnixIO {
         Ok(())
     }
 
-    fn wait_for_completion(&self, c: Arc<Completion>) -> Result<()> {
+    fn wait_for_completion(&self, c: Completion) -> Result<()> {
         while !c.is_completed() {
             self.run_once()?;
         }
@@ -305,10 +305,10 @@ impl IO for UnixIO {
 }
 
 enum CompletionCallback {
-    Read(Arc<Mutex<std::fs::File>>, Arc<Completion>, usize),
+    Read(Arc<Mutex<std::fs::File>>, Completion, usize),
     Write(
         Arc<Mutex<std::fs::File>>,
-        Arc<Completion>,
+        Completion,
         Arc<RefCell<crate::Buffer>>,
         usize,
     ),
@@ -364,7 +364,7 @@ impl File for UnixFile<'_> {
     }
 
     #[instrument(err, skip_all, level = Level::TRACE)]
-    fn pread(&self, pos: usize, c: Arc<Completion>) -> Result<Arc<Completion>> {
+    fn pread(&self, pos: usize, c: Completion) -> Result<Completion> {
         let file = self.file.lock().unwrap();
         let result = {
             let r = c.as_read();
@@ -401,8 +401,8 @@ impl File for UnixFile<'_> {
         &self,
         pos: usize,
         buffer: Arc<RefCell<crate::Buffer>>,
-        c: Arc<Completion>,
-    ) -> Result<Arc<Completion>> {
+        c: Completion,
+    ) -> Result<Completion> {
         let file = self.file.lock().unwrap();
         let result = {
             let buf = buffer.borrow();
@@ -432,7 +432,7 @@ impl File for UnixFile<'_> {
     }
 
     #[instrument(err, skip_all, level = Level::TRACE)]
-    fn sync(&self, c: Arc<Completion>) -> Result<Arc<Completion>> {
+    fn sync(&self, c: Completion) -> Result<Completion> {
         let file = self.file.lock().unwrap();
         let result = fs::fsync(file.as_fd());
         match result {
diff --git a/core/io/vfs.rs b/core/io/vfs.rs
index bad8a5940..545ce61a1 100644
--- a/core/io/vfs.rs
+++ b/core/io/vfs.rs
@@ -43,7 +43,7 @@ impl IO for VfsMod {
         Ok(())
     }
 
-    fn wait_for_completion(&self, _c: Arc<Completion>) -> Result<()> {
+    fn wait_for_completion(&self, _c: Completion) -> Result<()> {
         todo!();
     }
 
@@ -97,7 +97,7 @@ impl File for VfsFileImpl {
         Ok(())
     }
 
-    fn pread(&self, pos: usize, c: Arc<Completion>) -> Result<Arc<Completion>> {
+    fn pread(&self, pos: usize, c: Completion) -> Result<Completion> {
         let r = c.as_read();
         let result = {
             let mut buf = r.buf_mut();
@@ -117,8 +117,8 @@ impl File for VfsFileImpl {
         &self,
         pos: usize,
         buffer: Arc<RefCell<Buffer>>,
-        c: Arc<Completion>,
-    ) -> Result<Arc<Completion>> {
+        c: Completion,
+    ) -> Result<Completion> {
         let buf = buffer.borrow();
         let count = buf.as_slice().len();
         if self.vfs.is_null() {
@@ -142,7 +142,7 @@ impl File for VfsFileImpl {
         }
     }
 
-    fn sync(&self, c: Arc<Completion>) -> Result<Arc<Completion>> {
+    fn sync(&self, c: Completion) -> Result<Completion> {
         let vfs = unsafe { &*self.vfs };
         let result = unsafe { (vfs.sync)(self.file) };
         if result < 0 {
diff --git a/core/io/windows.rs b/core/io/windows.rs
index 6ffdc005b..701e61269 100644
--- a/core/io/windows.rs
+++ b/core/io/windows.rs
@@ -33,7 +33,7 @@ impl IO for WindowsIO {
     }
 
     #[instrument(err, skip_all, level = Level::TRACE)]
-    fn wait_for_completion(&self, c: Arc<Completion>) -> Result<()> {
+    fn wait_for_completion(&self, c: Completion) -> Result<()> {
         while !c.is_completed() {
             self.run_once()?;
         }
@@ -84,7 +84,7 @@ impl File for WindowsFile {
     }
 
     #[instrument(skip(self, c), level = Level::TRACE)]
-    fn pread(&self, pos: usize, c: Arc<Completion>) -> Result<Arc<Completion>> {
+    fn pread(&self, pos: usize, c: Completion) -> Result<Completion> {
         let mut file = self.file.write();
         file.seek(std::io::SeekFrom::Start(pos as u64))?;
         let nr = {
@@ -103,8 +103,8 @@ impl File for WindowsFile {
         &self,
         pos: usize,
         buffer: Arc<RefCell<crate::Buffer>>,
-        c: Arc<Completion>,
-    ) -> Result<Arc<Completion>> {
+        c: Completion,
+    ) -> Result<Completion> {
         let mut file = self.file.write();
         file.seek(std::io::SeekFrom::Start(pos as u64))?;
         let buf = buffer.borrow();
@@ -115,7 +115,7 @@ impl File for WindowsFile {
     }
 
     #[instrument(err, skip_all, level = Level::TRACE)]
-    fn sync(&self, c: Arc<Completion>) -> Result<Arc<Completion>> {
+    fn sync(&self, c: Completion) -> Result<Completion> {
         let file = self.file.write();
         file.sync_all().map_err(LimboError::IOError)?;
         c.complete(0);
diff --git a/core/storage/database.rs b/core/storage/database.rs
index 5d00a09a6..75278dbdb 100644
--- a/core/storage/database.rs
+++ b/core/storage/database.rs
@@ -9,14 +9,14 @@ use tracing::{instrument, Level};
 /// the storage medium. A database can either be a file on disk, like in SQLite,
 /// or something like a remote page server service.
 pub trait DatabaseStorage: Send + Sync {
-    fn read_page(&self, page_idx: usize, c: Completion) -> Result<Arc<Completion>>;
+    fn read_page(&self, page_idx: usize, c: Completion) -> Result<Completion>;
     fn write_page(
         &self,
         page_idx: usize,
         buffer: Arc<RefCell<Buffer>>,
         c: Completion,
-    ) -> Result<Arc<Completion>>;
-    fn sync(&self, c: Completion) -> Result<Arc<Completion>>;
+    ) -> Result<Completion>;
+    fn sync(&self, c: Completion) -> Result<Completion>;
     fn size(&self) -> Result<u64>;
 }
 
@@ -33,7 +33,7 @@ unsafe impl Sync for DatabaseFile {}
 #[cfg(feature = "fs")]
 impl DatabaseStorage for DatabaseFile {
     #[instrument(skip_all, level = Level::DEBUG)]
-    fn read_page(&self, page_idx: usize, c: Completion) -> Result<Arc<Completion>> {
+    fn read_page(&self, page_idx: usize, c: Completion) -> Result<Completion> {
         let r = c.as_read();
         let size = r.buf().len();
         assert!(page_idx > 0);
@@ -50,7 +50,7 @@ impl DatabaseStorage for DatabaseFile {
         page_idx: usize,
         buffer: Arc<RefCell<Buffer>>,
         c: Completion,
-    ) -> Result<Arc<Completion>> {
+    ) -> Result<Completion> {
         let buffer_size = buffer.borrow().len();
         assert!(page_idx > 0);
         assert!(buffer_size >= 512);
@@ -61,7 +61,7 @@ impl DatabaseStorage for DatabaseFile {
     }
 
     #[instrument(skip_all, level = Level::DEBUG)]
-    fn sync(&self, c: Completion) -> Result<Arc<Completion>> {
+    fn sync(&self, c: Completion) -> Result<Completion> {
         self.file.sync(c.into())
     }
 
@@ -87,7 +87,7 @@ unsafe impl Sync for FileMemoryStorage {}
 
 impl DatabaseStorage for FileMemoryStorage {
     #[instrument(skip_all, level = Level::DEBUG)]
-    fn read_page(&self, page_idx: usize, c: Completion) -> Result<Arc<Completion>> {
+    fn read_page(&self, page_idx: usize, c: Completion) -> Result<Completion> {
         let r = c.as_read();
         let size = r.buf().len();
         assert!(page_idx > 0);
@@ -104,7 +104,7 @@ impl DatabaseStorage for FileMemoryStorage {
         page_idx: usize,
         buffer: Arc<RefCell<Buffer>>,
         c: Completion,
-    ) -> Result<Arc<Completion>> {
+    ) -> Result<Completion> {
         let buffer_size = buffer.borrow().len();
         assert!(buffer_size >= 512);
         assert!(buffer_size <= 65536);
@@ -114,7 +114,7 @@ impl DatabaseStorage for FileMemoryStorage {
     }
 
     #[instrument(skip_all, level = Level::DEBUG)]
-    fn sync(&self, c: Completion) -> Result<Arc<Completion>> {
+    fn sync(&self, c: Completion) -> Result<Completion> {
         self.file.sync(c.into())
     }
 
diff --git a/core/storage/pager.rs b/core/storage/pager.rs
index b531f86ef..426b305d0 100644
--- a/core/storage/pager.rs
+++ b/core/storage/pager.rs
@@ -1167,7 +1167,7 @@ impl Pager {
     }
 
     #[instrument(skip_all, level = Level::DEBUG)]
-    pub fn wal_get_frame(&self, frame_no: u32, frame: &mut [u8]) -> Result<Arc<Completion>> {
+    pub fn wal_get_frame(&self, frame_no: u32, frame: &mut [u8]) -> Result<Completion> {
         let wal = self.wal.borrow();
         wal.read_frame_raw(frame_no.into(), frame)
     }
diff --git a/core/storage/sqlite3_ondisk.rs b/core/storage/sqlite3_ondisk.rs
index 4ec89d300..5a1ab7305 100644
--- a/core/storage/sqlite3_ondisk.rs
+++ b/core/storage/sqlite3_ondisk.rs
@@ -762,7 +762,7 @@ pub fn begin_read_page(
     buffer_pool: Arc<BufferPool>,
     page: PageRef,
     page_idx: usize,
-) -> Result<Arc<Completion>> {
+) -> Result<Completion> {
     tracing::trace!("begin_read_btree_page(page_idx = {})", page_idx);
     let buf = buffer_pool.get();
     let drop_fn = Rc::new(move |buf| {
@@ -813,7 +813,7 @@ pub fn begin_write_btree_page(
     pager: &Pager,
     page: &PageRef,
     write_counter: Rc<RefCell<usize>>,
-) -> Result<Arc<Completion>> {
+) -> Result<Completion> {
     tracing::trace!("begin_write_btree_page(page={})", page.get().id);
     let page_source = &pager.db_file;
     let page_finish = page.clone();
@@ -1575,7 +1575,7 @@ pub fn begin_read_wal_frame_raw(
     offset: usize,
     page_size: u32,
     complete: Box<dyn Fn(Arc<RefCell<Buffer>>, i32)>,
-) -> Result<Arc<Completion>> {
+) -> Result<Completion> {
     tracing::trace!("begin_read_wal_frame_raw(offset={})", offset);
     let drop_fn = Rc::new(|_buf| {});
     let buf = Arc::new(RefCell::new(Buffer::allocate(
@@ -1593,7 +1593,7 @@ pub fn begin_read_wal_frame(
     offset: usize,
     buffer_pool: Arc<BufferPool>,
     complete: Box<dyn Fn(Arc<RefCell<Buffer>>, i32)>,
-) -> Result<Arc<Completion>> {
+) -> Result<Completion> {
     tracing::trace!("begin_read_wal_frame(offset={})", offset);
     let buf = buffer_pool.get();
     let drop_fn = Rc::new(move |buf| {
diff --git a/core/storage/wal.rs b/core/storage/wal.rs
index 747bd631c..705484e6d 100644
--- a/core/storage/wal.rs
+++ b/core/storage/wal.rs
@@ -209,7 +209,7 @@ pub trait Wal {
     fn read_frame(&self, frame_id: u64, page: PageRef, buffer_pool: Arc<BufferPool>) -> Result<()>;
 
     /// Read a raw frame (header included) from the WAL.
-    fn read_frame_raw(&self, frame_id: u64, frame: &mut [u8]) -> Result<Arc<Completion>>;
+    fn read_frame_raw(&self, frame_id: u64, frame: &mut [u8]) -> Result<Completion>;
 
     /// Write a raw frame (header included) from the WAL.
     /// Note, that turso-db will use page_no and size_after fields from the header, but will overwrite checksum with proper value
@@ -284,7 +284,7 @@ impl Wal for DummyWAL {
         Ok(())
     }
 
-    fn read_frame_raw(&self, _frame_id: u64, _frame: &mut [u8]) -> Result<Arc<Completion>> {
+    fn read_frame_raw(&self, _frame_id: u64, _frame: &mut [u8]) -> Result<Completion> {
         todo!();
     }
 
@@ -636,7 +636,7 @@ impl Wal for WalFile {
     }
 
     #[instrument(skip_all, level = Level::DEBUG)]
-    fn read_frame_raw(&self, frame_id: u64, frame: &mut [u8]) -> Result<Arc<Completion>> {
+    fn read_frame_raw(&self, frame_id: u64, frame: &mut [u8]) -> Result<Completion> {
         tracing::debug!("read_frame({})", frame_id);
         let offset = self.frame_offset(frame_id);
         let (frame_ptr, frame_len) = (frame.as_mut_ptr(), frame.len());
@@ -731,7 +731,7 @@ impl Wal for WalFile {
             db_size as u32,
             page,
         );
-        let c = Arc::new(Completion::new_write(|_| {}));
+        let c = Completion::new_write(|_| {});
         let c = shared.file.pwrite(offset, frame_bytes, c)?;
         self.io.wait_for_completion(c)?;
         self.complete_append_frame(page_id, frame_id, checksums);
diff --git a/core/vdbe/sorter.rs b/core/vdbe/sorter.rs
index 021256d2a..dd84fa195 100644
--- a/core/vdbe/sorter.rs
+++ b/core/vdbe/sorter.rs
@@ -402,7 +402,7 @@ impl SortedChunk {
             read_buffer_ref,
             read_complete,
         )));
-        self.file.pread(self.total_bytes_read.get(), Arc::new(c))?;
+        self.file.pread(self.total_bytes_read.get(), c)?;
         Ok(())
     }
 
@@ -448,7 +448,7 @@ impl SortedChunk {
         });
 
         let c = Completion::new(CompletionType::Write(WriteCompletion::new(write_complete)));
-        self.file.pwrite(0, buffer_ref, Arc::new(c))?;
+        self.file.pwrite(0, buffer_ref, c)?;
         Ok(())
     }
 }
diff --git a/simulator/runner/file.rs b/simulator/runner/file.rs
index d1682c353..3905a3ce7 100644
--- a/simulator/runner/file.rs
+++ b/simulator/runner/file.rs
@@ -38,12 +38,12 @@ pub(crate) struct SimulatorFile {
 
     pub latency_probability: usize,
 
-    pub sync_completion: RefCell<Option<Arc<turso_core::Completion>>>,
+    pub sync_completion: RefCell<Option<turso_core::Completion>>,
     pub queued_io: RefCell<Vec<DelayedIo>>,
     pub clock: Arc<SimulatorClock>,
 }
 
-type IoOperation = Box<dyn FnOnce(&SimulatorFile) -> Result<Arc<turso_core::Completion>>>;
+type IoOperation = Box<dyn FnOnce(&SimulatorFile) -> Result<turso_core::Completion>>;
 
 pub struct DelayedIo {
     pub time: turso_core::Instant,
@@ -149,11 +149,7 @@ impl File for SimulatorFile {
         self.inner.unlock_file()
     }
 
-    fn pread(
-        &self,
-        pos: usize,
-        c: Arc<turso_core::Completion>,
-    ) -> Result<Arc<turso_core::Completion>> {
+    fn pread(&self, pos: usize, c: turso_core::Completion) -> Result<turso_core::Completion> {
         self.nr_pread_calls.set(self.nr_pread_calls.get() + 1);
         if self.fault.get() {
             tracing::debug!("pread fault");
@@ -178,8 +174,8 @@ impl File for SimulatorFile {
         &self,
         pos: usize,
         buffer: Arc<RefCell<turso_core::Buffer>>,
-        c: Arc<turso_core::Completion>,
-    ) -> Result<Arc<turso_core::Completion>> {
+        c: turso_core::Completion,
+    ) -> Result<turso_core::Completion> {
         self.nr_pwrite_calls.set(self.nr_pwrite_calls.get() + 1);
         if self.fault.get() {
             tracing::debug!("pwrite fault");
@@ -200,7 +196,7 @@ impl File for SimulatorFile {
         }
     }
 
-    fn sync(&self, c: Arc<turso_core::Completion>) -> Result<Arc<turso_core::Completion>> {
+    fn sync(&self, c: turso_core::Completion) -> Result<turso_core::Completion> {
         self.nr_sync_calls.set(self.nr_sync_calls.get() + 1);
         if self.fault.get() {
             // TODO: Enable this when https://github.com/tursodatabase/turso/issues/2091 is fixed.
diff --git a/simulator/runner/io.rs b/simulator/runner/io.rs
index 7c888cc7f..29973f889 100644
--- a/simulator/runner/io.rs
+++ b/simulator/runner/io.rs
@@ -104,7 +104,7 @@ impl IO for SimulatorIO {
         Ok(file)
     }
 
-    fn wait_for_completion(&self, c: Arc<turso_core::Completion>) -> Result<()> {
+    fn wait_for_completion(&self, c: turso_core::Completion) -> Result<()> {
         while !c.is_completed() {
             self.run_once()?;
         }