Merge pull request #25 from Databean/arc_raf

Implement `ReadAt` and `Size` for `Arc<RandomAccessFile>`

Author: vasi

Diff for: src/raf.rs

@@ -4,7 +4,7 @@ use std::io::{Seek, SeekFrom};
 use std::os::unix::fs::FileExt;
 #[cfg(windows)]
 use std::os::windows::fs::FileExt;
-use std::{fs::File, io, io::Write, path::Path};
+use std::{fs::File, io, io::Write, path::Path, sync::Arc};
 
 use super::{ReadAt, Size, WriteAt};
 
@@ -151,3 +151,17 @@ impl Size for RandomAccessFile {
         self.file.size()
     }
 }
+
+impl ReadAt for Arc<RandomAccessFile> {
+    #[inline]
+    fn read_at(&self, pos: u64, buf: &mut [u8]) -> io::Result<usize> {
+        (**self).read_at(pos, buf)
+    }
+}
+
+impl Size for Arc<RandomAccessFile> {
+    #[inline]
+    fn size(&self) -> io::Result<Option<u64>> {
+        (**self).size()
+    }
+}

Diff for: tests/test.rs

@@ -3,6 +3,7 @@ use std::{
     fs::File,
     io::{Error, ErrorKind, Read, Result, Seek, SeekFrom},
     str,
+    sync::Arc,
 };
 
 #[cfg(feature = "byteorder")]
@@ -118,6 +119,22 @@ fn test_size_cursor() {
     assert!(s.contains("\n"));
 }
 
+#[test]
+fn test_clone_size_cursor() {
+    let file = Arc::new(RandomAccessFile::open("tests/pi.txt").unwrap());
+    let mut curs = SizeCursor::new(file);
+    let mut curs_copy = curs.clone();
+
+    let mut buf = [0; 4];
+    assert_eq!(4, curs.read(&mut buf).unwrap());
+    let s = str::from_utf8(buf.as_ref()).unwrap();
+    assert_eq!(s, "3.14");
+
+    assert_eq!(4, curs_copy.read(&mut buf).unwrap());
+    let s = str::from_utf8(buf.as_ref()).unwrap();
+    assert_eq!(s, "3.14");
+}
+
 #[test]
 #[cfg(feature = "byteorder")]
 fn test_byteio() {