refactor(ext/fs): abstract FS via FileSystem trait (#18599)

This commit abstracts out the specifics of the underlying system calls
FS operations behind a new `FileSystem` and `File` trait in the
`ext/fs` extension.

This allows other embedders to re-use ext/fs, but substituting in a
different FS backend.

This is likely not the final form of these traits. Eventually they will
be entirely `deno_core::Resource` agnostic, and will live in a seperate
crate.

---------

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

1 files changed, 57 insertions, 24 deletions

diff --git a/ext/io/lib.rs b/ext/io/lib.rs
index 69f8c9da5..c85b4baf6 100644
--- a/ext/io/lib.rs
+++ b/ext/io/lib.rs
@@ -20,6 +20,7 @@ use once_cell::sync::Lazy;
 use std::borrow::Cow;
 use std::cell::RefCell;
 use std::fs::File as StdFile;
+use std::io;
 use std::io::ErrorKind;
 use std::io::Read;
 use std::io::Write;
@@ -452,21 +453,21 @@ impl StdFileResource {
     }
   }
 
-  fn with_inner_and_metadata<TResult>(
+  fn with_inner_and_metadata<TResult, E>(
     &self,
     action: impl FnOnce(
       &mut StdFileResourceInner,
       &Arc<Mutex<FileMetadata>>,
-    ) -> Result<TResult, AnyError>,
-  ) -> Result<TResult, AnyError> {
+    ) -> Result<TResult, E>,
+  ) -> Option<Result<TResult, E>> {
     match self.cell.try_borrow_mut() {
       Ok(mut cell) => {
         let mut file = cell.take().unwrap();
         let result = action(&mut file.inner, &file.meta_data);
         cell.replace(file);
-        result
+        Some(result)
       }
-      Err(_) => Err(resource_unavailable()),
+      Err(_) => None,
     }
   }
 
@@ -537,11 +538,16 @@ impl StdFileResource {
   }
 
   fn read_byob_sync(&self, buf: &mut [u8]) -> Result<usize, AnyError> {
-    self.with_inner_and_metadata(|inner, _| inner.read(buf).map_err(Into::into))
+    self
+      .with_inner_and_metadata(|inner, _| inner.read(buf))
+      .ok_or_else(resource_unavailable)?
+      .map_err(Into::into)
   }
 
   fn write_sync(&self, data: &[u8]) -> Result<usize, AnyError> {
-    self.with_inner_and_metadata(|inner, _| inner.write_and_maybe_flush(data))
+    self
+      .with_inner_and_metadata(|inner, _| inner.write_and_maybe_flush(data))
+      .ok_or_else(resource_unavailable)?
   }
 
   fn with_resource<F, R>(
@@ -565,10 +571,19 @@ impl StdFileResource {
     F: FnOnce(&mut StdFile) -> Result<R, AnyError>,
   {
     Self::with_resource(state, rid, move |resource| {
-      resource.with_inner_and_metadata(move |inner, _| inner.with_file(f))
+      resource
+        .with_inner_and_metadata(move |inner, _| inner.with_file(f))
+        .ok_or_else(resource_unavailable)?
     })
   }
 
+  pub fn with_file2<F, R>(self: Rc<Self>, f: F) -> Option<Result<R, io::Error>>
+  where
+    F: FnOnce(&mut StdFile) -> Result<R, io::Error>,
+  {
+    self.with_inner_and_metadata(move |inner, _| inner.with_file(f))
+  }
+
   pub fn with_file_and_metadata<F, R>(
     state: &mut OpState,
     rid: ResourceId,
@@ -578,9 +593,11 @@ impl StdFileResource {
     F: FnOnce(&mut StdFile, &Arc<Mutex<FileMetadata>>) -> Result<R, AnyError>,
   {
     Self::with_resource(state, rid, move |resource| {
-      resource.with_inner_and_metadata(move |inner, metadata| {
-        inner.with_file(move |file| f(file, metadata))
-      })
+      resource
+        .with_inner_and_metadata(move |inner, metadata| {
+          inner.with_file(move |file| f(file, metadata))
+        })
+        .ok_or_else(resource_unavailable)?
     })
   }
 
@@ -602,6 +619,18 @@ impl StdFileResource {
       .await
   }
 
+  pub async fn with_file_blocking_task2<F, R: Send + 'static>(
+    self: Rc<Self>,
+    f: F,
+  ) -> Result<R, io::Error>
+  where
+    F: (FnOnce(&mut StdFile) -> Result<R, io::Error>) + Send + 'static,
+  {
+    self
+      .with_inner_blocking_task(move |inner| inner.with_file(f))
+      .await
+  }
+
   pub fn clone_file(
     state: &mut OpState,
     rid: ResourceId,
@@ -616,13 +645,15 @@ impl StdFileResource {
     rid: u32,
   ) -> Result<std::process::Stdio, AnyError> {
     Self::with_resource(state, rid, |resource| {
-      resource.with_inner_and_metadata(|inner, _| match inner.kind {
-        StdFileResourceKind::File => {
-          let file = inner.file.try_clone()?;
-          Ok(file.into())
-        }
-        _ => Ok(std::process::Stdio::inherit()),
-      })
+      resource
+        .with_inner_and_metadata(|inner, _| match inner.kind {
+          StdFileResourceKind::File => {
+            let file = inner.file.try_clone()?;
+            Ok(file.into())
+          }
+          _ => Ok(std::process::Stdio::inherit()),
+        })
+        .ok_or_else(resource_unavailable)?
     })
   }
 }
@@ -679,8 +710,8 @@ impl Resource for StdFileResource {
     use std::os::unix::io::AsRawFd;
     self
       .with_inner_and_metadata(move |std_file, _| {
-        Ok(std_file.with_file(|f| f.as_raw_fd()))
-      })
+        Ok::<_, ()>(std_file.with_file(|f| f.as_raw_fd()))
+      })?
       .ok()
   }
 }
@@ -694,9 +725,11 @@ pub fn op_print(
 ) -> Result<(), AnyError> {
   let rid = if is_err { 2 } else { 1 };
   StdFileResource::with_resource(state, rid, move |resource| {
-    resource.with_inner_and_metadata(|inner, _| {
-      inner.write_all_and_maybe_flush(msg.as_bytes())?;
-      Ok(())
-    })
+    resource
+      .with_inner_and_metadata(|inner, _| {
+        inner.write_all_and_maybe_flush(msg.as_bytes())?;
+        Ok(())
+      })
+      .ok_or_else(resource_unavailable)?
   })
 }