add readable and writable futures to WasiFile trait

crates/wasi-common/cap-std-sync/src/file.rs

@@ -119,6 +119,12 @@ impl WasiFile for File {
     async fn num_ready_bytes(&self) -> Result<u64, Error> {
         Ok(self.0.num_ready_bytes()?)
     }
+    async fn readable(&mut self) -> Result<(), Error> {
+        Err(Error::badf())
+    }
+    async fn writable(&mut self) -> Result<(), Error> {
+        Err(Error::badf())
+    }
 }
 
 pub fn filetype_from(ft: &cap_std::fs::FileType) -> FileType {

crates/wasi-common/cap-std-sync/src/stdio.rs

@@ -103,6 +103,12 @@ impl WasiFile for Stdin {
     async fn num_ready_bytes(&self) -> Result<u64, Error> {
         Ok(self.0.num_ready_bytes()?)
     }
+    async fn readable(&mut self) -> Result<(), Error> {
+        Err(Error::badf())
+    }
+    async fn writable(&mut self) -> Result<(), Error> {
+        Err(Error::badf())
+    }
 }
 #[cfg(windows)]
 impl AsRawHandle for Stdin {
@@ -203,6 +209,12 @@ macro_rules! wasi_file_write_impl {
             async fn num_ready_bytes(&self) -> Result<u64, Error> {
                 Ok(0)
             }
+            async fn readable(&mut self) -> Result<(), Error> {
+                Err(Error::badf())
+            }
+            async fn writable(&mut self) -> Result<(), Error> {
+                Err(Error::badf())
+            }
         }
         #[cfg(windows)]
         impl AsRawHandle for $ty {

crates/wasi-common/src/file.rs

@@ -36,6 +36,9 @@ pub trait WasiFile {
     async fn seek(&self, pos: std::io::SeekFrom) -> Result<u64, Error>; // file op that generates a new stream from a file will supercede this
     async fn peek(&self, buf: &mut [u8]) -> Result<u64, Error>; // read op
     async fn num_ready_bytes(&self) -> Result<u64, Error>; // read op
+
+    async fn readable(&mut self) -> Result<(), Error>;
+    async fn writable(&mut self) -> Result<(), Error>;
 }
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]

crates/wasi-common/src/pipe.rs

@@ -183,6 +183,12 @@ impl<R: Read + Any> WasiFile for ReadPipe<R> {
     async fn num_ready_bytes(&self) -> Result<u64, Error> {
         Ok(0)
     }
+    async fn readable(&mut self) -> Result<(), Error> {
+        Err(Error::badf())
+    }
+    async fn writable(&mut self) -> Result<(), Error> {
+        Err(Error::badf())
+    }
 }
 
 /// A virtual pipe write end.
@@ -336,4 +342,10 @@ impl<W: Write + Any> WasiFile for WritePipe<W> {
     async fn num_ready_bytes(&self) -> Result<u64, Error> {
         Ok(0)
     }
+    async fn readable(&mut self) -> Result<(), Error> {
+        Err(Error::badf())
+    }
+    async fn writable(&mut self) -> Result<(), Error> {
+        Err(Error::badf())
+    }
 }

crates/wasi-common/tokio/src/file.rs

@@ -184,6 +184,12 @@ impl WasiFile for File {
         use unsafe_io::AsUnsafeFile;
         asyncify(|| self.0.as_file_view().num_ready_bytes()).await
     }
+    async fn readable(&mut self) -> Result<(), Error> {
+        todo!("implement this in terms of tokio::io::AsyncFd")
+    }
+    async fn writable(&mut self) -> Result<(), Error> {
+        todo!("implement this in terms of tokio::io::AsyncFd")
+    }
 }
 pub fn filetype_from(ft: &cap_std::fs::FileType) -> FileType {
     use cap_fs_ext::FileTypeExt;