Rewrite Stdin/Stdout

os/src/mm/page_table.rs

@@ -138,9 +138,7 @@ impl PageTable {
     pub fn translate_va(&self, va: VirtAddr) -> Option<PhysAddr> {
         self.find_pte(va.clone().floor())
             .map(|pte| {
-                //println!("translate_va:va = {:?}", va);
                 let aligned_pa: PhysAddr = pte.ppn().into();
-                //println!("translate_va:pa_align = {:?}", aligned_pa);
                 let offset = va.page_offset();
                 let aligned_pa_usize: usize = aligned_pa.into();
                 (aligned_pa_usize + offset).into()
@@ -189,9 +187,60 @@ pub fn translated_str(token: usize, ptr: *const u8) -> String {
 }
 
 pub fn translated_refmut<T>(token: usize, ptr: *mut T) -> &'static mut T {
-    //println!("into translated_refmut!");
     let page_table = PageTable::from_token(token);
     let va = ptr as usize;
-    //println!("translated_refmut: before translate_va");
     page_table.translate_va(VirtAddr::from(va)).unwrap().get_mut()
+}
+
+pub struct UserBuffer {
+    pub buffers: Vec<&'static mut [u8]>,
+}
+
+impl UserBuffer {
+    pub fn new(buffers: Vec<&'static mut [u8]>) -> Self {
+        Self { buffers }
+    }
+    pub fn len(&self) -> usize {
+        let mut total: usize = 0;
+        for b in self.buffers.iter() {
+            total += b.len();
+        }
+        total
+    }
+}
+
+impl IntoIterator for UserBuffer {
+    type Item = *mut u8;
+    type IntoIter = UserBufferIterator;
+    fn into_iter(self) -> Self::IntoIter {
+        UserBufferIterator {
+            buffers: self.buffers,
+            current_buffer: 0,
+            current_idx: 0,
+        }
+    }
+}
+
+pub struct UserBufferIterator {
+    buffers: Vec<&'static mut [u8]>,
+    current_buffer: usize,
+    current_idx: usize,
+}
+
+impl Iterator for UserBufferIterator {
+    type Item = *mut u8;
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.current_buffer >= self.buffers.len() {
+            None
+        } else {
+            let r = &mut self.buffers[self.current_buffer][self.current_idx] as *mut _;
+            if self.current_idx + 1 == self.buffers[self.current_buffer].len() {
+                self.current_idx = 0;
+                self.current_buffer += 1;
+            } else {
+                self.current_idx += 1;
+            }
+            Some(r)
+        }
+    }
 }