refactor everything

lib/runtime-abi/src/vfs/device_file.rs

@@ -1,25 +1,60 @@
 use crate::vfs::file_like::{FileLike, Metadata};
 use failure::Error;
+use std::io;
+use std::io::{Read, Write};
 
 pub struct Stdin;
 pub struct Stdout;
 pub struct Stderr;
 
 impl FileLike for Stdin {
-    fn write(&mut self, _buf: &[u8], count: usize, _offset: usize) -> Result<usize, Error> {
-        println!("writing to {} byte to dev stream...", count);
-        Ok(count)
-    }
-
-    fn read(&mut self, _buf: &mut [u8]) -> Result<usize, Error> {
-        unimplemented!()
-    }
-
-    fn close(&self) -> Result<(), Error> {
-        Ok(())
-    }
-
     fn metadata(&self) -> Result<Metadata, Error> {
         unimplemented!()
     }
+
+    fn write_file(&mut self, _buf: &[u8], _offset: usize) -> Result<usize, io::Error> {
+        unimplemented!()
+    }
+}
+
+impl Read for Stdin {
+    fn read(&mut self, _buf: &mut [u8]) -> Result<usize, io::Error> {
+        unimplemented!()
+    }
+}
+
+impl FileLike for Stdout {
+    fn metadata(&self) -> Result<Metadata, failure::Error> {
+        unimplemented!()
+    }
+
+    fn write_file(&mut self, buf: &[u8], _offset: usize) -> Result<usize, io::Error> {
+        let stdout = io::stdout();
+        let mut handle = stdout.lock();
+        handle.write(buf)
+    }
+}
+
+impl Read for Stdout {
+    fn read(&mut self, _buf: &mut [u8]) -> Result<usize, io::Error> {
+        unimplemented!()
+    }
+}
+
+impl FileLike for Stderr {
+    fn metadata(&self) -> Result<Metadata, failure::Error> {
+        unimplemented!()
+    }
+
+    fn write_file(&mut self, buf: &[u8], _offset: usize) -> Result<usize, io::Error> {
+        let stderr = io::stderr();
+        let mut handle = stderr.lock();
+        handle.write(buf)
+    }
+}
+
+impl Read for Stderr {
+    fn read(&mut self, _buf: &mut [u8]) -> Result<usize, io::Error> {
+        unimplemented!()
+    }
 }