Large/small file I/O test passed.

easy-fs/src/bin/main.rs

@@ -9,6 +9,7 @@ use std::fs::{File, OpenOptions};
 use std::io::{Read, Write, Seek, SeekFrom};
 use std::sync::Mutex;
 use alloc::sync::Arc;
+use rand;
 
 const BLOCK_SZ: usize = 512;
 
@@ -37,6 +38,11 @@ fn main() {
 }
 
 fn easy_fs_pack() -> std::io::Result<()> {
+    Ok(())
+}
+
+#[test]
+fn efs_test() -> std::io::Result<()> {
     let block_file = Arc::new(BlockFile(Mutex::new(
         OpenOptions::new()
             .read(true)
@@ -55,16 +61,49 @@ fn easy_fs_pack() -> std::io::Result<()> {
     for name in root_inode.ls() {
         println!("{}", name);
     }
-    {
-        let filea = root_inode.find("filea").unwrap();
-        println!("writing filea!");
-        filea.write_at(0, "Hello, world!".as_bytes());
-    }
-    {
-        let filea = root_inode.find("filea").unwrap();
-        let mut buffer = [0u8; 512];
-        let len = filea.read_at(0, &mut buffer);
-        println!("{}", core::str::from_utf8(&buffer[..len]).unwrap());
-    }
+    let filea = root_inode.find("filea").unwrap();
+    let greet_str = "Hello, world!";
+    filea.write_at(0, greet_str.as_bytes());
+    let mut buffer = [0u8; 512];
+    let len = filea.read_at(0, &mut buffer);
+    assert_eq!(
+        greet_str,
+        core::str::from_utf8(&buffer[..len]).unwrap(),
+    );
+
+    let mut random_str_test = |len: usize| {
+        filea.clear();
+        assert_eq!(
+            filea.read_at(0, &mut buffer),
+            0,
+        );
+        let mut str = String::new();
+        // random digit
+        for _ in 0..len {
+            str.push(char::from('0' as u8 + rand::random::<u8>() % 10));
+        }
+        filea.write_at(0, str.as_bytes());
+        let mut read_buffer = [0u8; 127];
+        let mut offset = 0usize;
+        let mut read_str = String::new();
+        loop {
+            let len = filea.read_at(offset, &mut read_buffer);
+            if len == 0 {
+                break;
+            }
+            offset += len;
+            read_str.push_str(
+                core::str::from_utf8(&read_buffer[..len]).unwrap()
+            );
+        }
+        assert_eq!(str, read_str);
+    };
+
+    random_str_test(4 * BLOCK_SZ);
+    random_str_test(8 * BLOCK_SZ + BLOCK_SZ / 2);
+    random_str_test(100 * BLOCK_SZ);
+    random_str_test(70 * BLOCK_SZ + BLOCK_SZ / 7);
+    random_str_test((12 + 128) * BLOCK_SZ);
+
     Ok(())
 }