revert DateServiceInner changes

actix-http/src/config.rs

@@ -1,4 +1,4 @@
-use std::cell::Cell;
+use std::cell::UnsafeCell;
 use std::fmt;
 use std::fmt::Write;
 use std::rc::Rc;
@@ -162,13 +162,17 @@ impl ServiceConfig {
     pub fn set_date(&self, dst: &mut BytesMut) {
         let mut buf: [u8; 39] = [0; 39];
         buf[..6].copy_from_slice(b"date: ");
-        buf[6..35].copy_from_slice(&self.0.timer.date().bytes);
+        self.0
+            .timer
+            .set_date(|date| buf[6..35].copy_from_slice(&date.bytes));
         buf[35..].copy_from_slice(b"\r\n\r\n");
         dst.extend_from_slice(&buf);
     }
 
     pub(crate) fn set_date_header(&self, dst: &mut BytesMut) {
-        dst.extend_from_slice(&self.0.timer.date().bytes);
+        self.0
+            .timer
+            .set_date(|date| dst.extend_from_slice(&date.bytes));
     }
 }
 
@@ -206,28 +210,24 @@ impl fmt::Write for Date {
 struct DateService(Rc<DateServiceInner>);
 
 struct DateServiceInner {
-    current: Cell<Option<(Date, Instant)>>,
+    current: UnsafeCell<Option<(Date, Instant)>>,
 }
 
 impl DateServiceInner {
     fn new() -> Self {
         DateServiceInner {
-            current: Cell::new(None),
+            current: UnsafeCell::new(None),
         }
     }
 
-    fn get(&self) -> Option<(Date, Instant)> {
-        self.current.get()
-    }
-
     fn reset(&self) {
-        self.current.set(None);
+        unsafe { (&mut *self.current.get()).take() };
     }
 
     fn update(&self) {
         let now = Instant::now();
         let date = Date::new();
-        self.current.set(Some((date, now)));
+        *(unsafe { &mut *self.current.get() }) = Some((date, now));
     }
 }
 
@@ -237,7 +237,7 @@ impl DateService {
     }
 
     fn check_date(&self) {
-        if self.0.get().is_none() {
+        if unsafe { (&*self.0.current.get()).is_none() } {
             self.0.update();
 
             // periodic date update
@@ -253,13 +253,12 @@ impl DateService {
 
     fn now(&self) -> Instant {
         self.check_date();
-        self.0.get().unwrap().1
+        unsafe { (&*self.0.current.get()).as_ref().unwrap().1 }
     }
 
-    fn date(&self) -> Date {
+    fn set_date<F: FnMut(&Date)>(&self, mut f: F) {
         self.check_date();
-
-        self.0.get().unwrap().0
+        f(&unsafe { (&*self.0.current.get()).as_ref().unwrap().0 })
     }
 }