make file like implement the std::io traits instead and wrap zbox file

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

@@ -1,7 +1,6 @@
 use crate::vfs::file_like::{FileLike, Metadata};
 use failure::Error;
 use std::io;
-use std::io::{Seek, Write};
 
 pub struct Stdin;
 pub struct Stdout;
@@ -12,19 +11,27 @@ impl FileLike for Stdin {
         unimplemented!()
     }
 
-    fn write_file(&mut self, _buf: &[u8], _offset: usize) -> Result<usize, io::Error> {
-        unimplemented!()
-    }
-
-    fn read_file(&mut self, _buf: &mut [u8], _offset: usize) -> Result<usize, io::Error> {
-        unimplemented!()
-    }
-
     fn set_file_len(&mut self, _len: usize) -> Result<(), failure::Error> {
         panic!("Cannot set length of stdin");
     }
 }
 
+impl io::Read for Stdin {
+    fn read(&mut self, _buf: &mut [u8]) -> Result<usize, io::Error> {
+        unimplemented!()
+    }
+}
+
+impl io::Write for Stdin {
+    fn write(&mut self, _buf: &[u8]) -> Result<usize, io::Error> {
+        unimplemented!()
+    }
+
+    fn flush(&mut self) -> Result<(), io::Error> {
+        unimplemented!()
+    }
+}
+
 impl io::Seek for Stdin {
     fn seek(&mut self, _pos: io::SeekFrom) -> Result<u64, io::Error> {
         unimplemented!()
@@ -36,18 +43,28 @@ impl FileLike for Stdout {
         unimplemented!()
     }
 
-    fn write_file(&mut self, buf: &[u8], _offset: usize) -> Result<usize, io::Error> {
+    fn set_file_len(&mut self, _len: usize) -> Result<(), failure::Error> {
+        panic!("Cannot set length of stdout");
+    }
+}
+
+impl io::Read for Stdout {
+    fn read(&mut self, _buf: &mut [u8]) -> Result<usize, io::Error> {
+        unimplemented!()
+    }
+}
+
+impl io::Write for Stdout {
+    fn write(&mut self, buf: &[u8]) -> Result<usize, io::Error> {
         let stdout = io::stdout();
         let mut handle = stdout.lock();
         handle.write(buf)
     }
 
-    fn read_file(&mut self, _buf: &mut [u8], _offset: usize) -> Result<usize, io::Error> {
-        unimplemented!()
-    }
-
-    fn set_file_len(&mut self, _len: usize) -> Result<(), failure::Error> {
-        panic!("Cannot set length of stdout");
+    fn flush(&mut self) -> Result<(), io::Error> {
+        let stdout = io::stdout();
+        let mut handle = stdout.lock();
+        handle.flush()
     }
 }
 
@@ -62,18 +79,28 @@ impl FileLike for Stderr {
         unimplemented!()
     }
 
-    fn write_file(&mut self, buf: &[u8], _offset: usize) -> Result<usize, io::Error> {
+    fn set_file_len(&mut self, _len: usize) -> Result<(), failure::Error> {
+        panic!("Cannot set length of stderr");
+    }
+}
+
+impl io::Read for Stderr {
+    fn read(&mut self, _buf: &mut [u8]) -> Result<usize, io::Error> {
+        unimplemented!()
+    }
+}
+
+impl io::Write for Stderr {
+    fn write(&mut self, buf: &[u8]) -> Result<usize, io::Error> {
         let stderr = io::stderr();
         let mut handle = stderr.lock();
         handle.write(buf)
     }
 
-    fn read_file(&mut self, _buf: &mut [u8], _offset: usize) -> Result<usize, io::Error> {
-        unimplemented!()
-    }
-
-    fn set_file_len(&mut self, _len: usize) -> Result<(), failure::Error> {
-        panic!("Cannot set length of stderr");
+    fn flush(&mut self) -> Result<(), io::Error> {
+        let stderr = io::stderr();
+        let mut handle = stderr.lock();
+        handle.flush()
     }
 }
 

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

@@ -1,5 +1,3 @@
-use std::io;
-
 pub type Fd = isize;
 
 #[derive(Debug)]
@@ -8,16 +6,17 @@ pub struct Metadata {
     pub is_file: bool,
 }
 
-pub trait FileLike: std::io::Seek {
+pub trait FileLike: std::io::Write + std::io::Read + std::io::Seek {
     // get metadata
     fn metadata(&self) -> Result<Metadata, failure::Error>;
 
     // write
-    fn write_file(&mut self, buf: &[u8], offset: usize) -> Result<usize, io::Error>;
+//    fn write_file(&mut self, buf: &[u8]) -> Result<usize, io::Error>;
 
     // read
-    fn read_file(&mut self, buf: &mut [u8], offset: usize) -> Result<usize, io::Error>;
+//    fn read_file(&mut self, buf: &mut [u8]) -> Result<usize, io::Error>;
 
     // set_file_len
     fn set_file_len(&mut self, len: usize) -> Result<(), failure::Error>;
 }
+

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

@@ -8,6 +8,7 @@ use std::path::{Path, PathBuf};
 use std::rc::Rc;
 use tar::EntryType;
 use zbox::{init_env, OpenOptions, Repo, RepoOpener};
+use crate::vfs::virtual_file::VirtualFile;
 
 pub struct Vfs {
     repo: Repo,
@@ -103,7 +104,7 @@ impl Vfs {
         init_env();
         let path = convert_to_absolute_path(path);
         if let Ok(file) = OpenOptions::new().write(true).open(&mut self.repo, &path) {
-            Some(Rc::new(RefCell::new(file)))
+            Some(Rc::new(RefCell::new(VirtualFile::new(file))))
         } else if let Some(dev_file) = self.device_files.get(&path) {
             Some(dev_file.clone())
         } else {

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

@@ -1,12 +1,16 @@
 use failure::Error;
-
 use crate::vfs::file_like::{FileLike, Metadata};
 use std::io;
-use std::io::{Read, Seek, SeekFrom, Write};
 
-impl FileLike for zbox::File {
+pub struct VirtualFile(zbox::File);
+
+impl VirtualFile {
+    pub fn new(file: zbox::File) -> Self { VirtualFile(file) }
+}
+
+impl FileLike for VirtualFile {
     fn metadata(&self) -> Result<Metadata, Error> {
-        self.metadata()
+        self.0.metadata()
             .map(|m| Metadata {
                 len: m.content_len(),
                 is_file: m.is_file(),
@@ -14,19 +18,31 @@ impl FileLike for zbox::File {
             .map_err(|e: zbox::Error| e.into())
     }
 
-    fn write_file(&mut self, buf: &[u8], offset: usize) -> Result<usize, io::Error> {
-        self.seek(SeekFrom::Start(offset as _))?;
-        let result = self.write(buf);
-        self.finish().unwrap();
-        result
-    }
-
-    fn read_file(&mut self, buf: &mut [u8], offset: usize) -> Result<usize, io::Error> {
-        self.seek(io::SeekFrom::Start(offset as u64))?;
-        self.read(buf)
-    }
-
     fn set_file_len(&mut self, len: usize) -> Result<(), failure::Error> {
-        self.set_len(len).map_err(|e| e.into())
+        self.0.set_len(len).map_err(|e| e.into())
+    }
+}
+
+impl io::Write for VirtualFile {
+    fn write(&mut self, buf: &[u8]) -> Result<usize, io::Error> {
+        let result = self.0.write(buf)?;
+        self.0.finish().unwrap();
+        Ok(result)
+    }
+
+    fn flush(&mut self) -> Result<(), io::Error> {
+        self.0.flush()
+    }
+}
+
+impl io::Read for VirtualFile {
+    fn read(&mut self, buf: &mut [u8]) -> Result<usize, io::Error> {
+        self.0.read(buf)
+    }
+}
+
+impl io::Seek for VirtualFile {
+    fn seek(&mut self, pos: io::SeekFrom) -> Result<u64, io::Error> {
+        self.0.seek(pos)
     }
 }