Impl truncate for the remainder of IO modules

core/io/memory.rs

@@ -174,6 +174,20 @@ impl File for MemoryFile {
         Ok(c)
     }
 
+    fn truncate(&self, len: u64, c: Completion) -> Result<Arc<Completion>> {
+        let new_size = len as usize;
+        if new_size < self.size.get() {
+            // Truncate pages
+            unsafe {
+                let pages = &mut *self.pages.get();
+                pages.retain(|&k, _| k * PAGE_SIZE < new_size);
+            }
+        }
+        self.size.set(new_size);
+        c.complete(0);
+        Ok(Arc::new(c))
+    }
+
     fn size(&self) -> Result<u64> {
         Ok(self.size.get() as u64)
     }

core/io/unix.rs

@@ -450,6 +450,21 @@ impl File for UnixFile<'_> {
         let file = self.file.lock().unwrap();
         Ok(file.metadata()?.len())
     }
+
+    #[instrument(err, skip_all, level = Level::INFO)]
+    fn truncate(&self, len: u64, c: Completion) -> Result<Arc<Completion>> {
+        let file = self.file.borrow();
+        let result = file.set_len(len);
+        let c = Arc::new(c);
+        match result {
+            Ok(()) => {
+                trace!("file truncated to len=({})", len);
+                c.complete(0);
+                Ok(c)
+            }
+            Err(e) => Err(e.into()),
+        }
+    }
 }
 
 impl Drop for UnixFile<'_> {

core/io/windows.rs

@@ -123,6 +123,13 @@ impl File for WindowsFile {
     }
 
     #[instrument(err, skip_all, level = Level::TRACE)]
+    fn truncate(&self, len: u64, c: Completion) -> Result<()> {
+        let mut file = self.file.borrow_mut();
+        file.set_len(len).map_err(LimboError::IOError)?;
+        c.complete(0);
+        Ok(())
+    }
+
     fn size(&self) -> Result<u64> {
         let file = self.file.read();
         Ok(file.metadata().unwrap().len())