Added wasm32 part for vfs file access

lib/vfs/src/host_fs.rs

@@ -9,6 +9,8 @@ use std::fs;
 use std::io::{self, Read, Seek, Write};
 #[cfg(unix)]
 use std::os::unix::io::{AsRawFd, RawFd};
+#[cfg(target_arch = "wasm32")]
+use std::os::wasi::io::{AsRawFd, RawFd};
 #[cfg(windows)]
 use std::os::windows::io::{AsRawHandle, RawHandle};
 use std::path::{Path, PathBuf};
@@ -67,6 +69,31 @@ impl TryInto<RawHandle> for FileDescriptor {
     }
 }
 
+#[cfg(target_arch = "wasm32")]
+impl<T> TryIntoFileDescriptor for T
+where
+    T: AsRawFd,
+{
+    type Error = FsError;
+
+    fn try_into_filedescriptor(&self) -> std::result::Result<FileDescriptor, Self::Error> {
+        Ok(FileDescriptor(
+            self.as_raw_fd()
+                .try_into()
+                .map_err(|_| FsError::InvalidFd)?,
+        ))
+    }
+}
+
+#[cfg(target_arch = "wasm32")]
+impl TryInto<RawFd> for FileDescriptor {
+    type Error = FsError;
+
+    fn try_into(self) -> std::result::Result<RawFd, Self::Error> {
+        self.0.try_into().map_err(|_| FsError::InvalidFd)
+    }
+}
+
 #[derive(Debug, Default, Clone)]
 #[cfg_attr(feature = "enable-serde", derive(Serialize, Deserialize))]
 pub struct FileSystem;