Add Buffer::render_internal method to speedup reserve method

sailfish/src/runtime/buffer.rs

@@ -84,14 +84,10 @@ impl Buffer {
         self.len == 0
     }
 
-    #[inline(never)]
+    #[inline]
     pub fn reserve(&mut self, size: usize) {
         if size > self.capacity - self.len {
-            unsafe {
-                let new_capacity = std::cmp::max(self.capacity * 2, self.len + size);
-                self.realloc(new_capacity);
-                self.capacity = new_capacity;
-            }
+            self.reserve_internal(size);
         }
     }
 
@@ -110,7 +106,7 @@ impl Buffer {
     pub fn push_str(&mut self, data: &str) {
         let size = data.len();
         if size > self.capacity - self.len {
-            self.reserve(size);
+            self.reserve_internal(size);
         }
         unsafe {
             let p = self.data.add(self.len);
@@ -125,6 +121,15 @@ impl Buffer {
         self.push_str(data.encode_utf8(&mut buf));
     }
 
+    #[inline(never)]
+    fn reserve_internal(&mut self, size: usize) {
+        unsafe {
+            let new_capacity = std::cmp::max(self.capacity * 2, self.len + size);
+            self.realloc(new_capacity);
+            self.capacity = new_capacity;
+        }
+    }
+
     unsafe fn realloc(&mut self, cap: usize) {
         if self.capacity == 0 {
             let new_layout = Layout::from_size_align_unchecked(cap, 1);

sailfish/src/runtime/render.rs

@@ -134,9 +134,7 @@ macro_rules! render_int {
                 fn render(&self, b: &mut Buffer) -> Result<(), RenderError> {
                     use super::integer::Integer;
 
-                    if Self::MAX_LEN > b.capacity() - b.len() {
-                        b.reserve(Self::MAX_LEN);
-                    }
+                    b.reserve(Self::MAX_LEN);
 
                     unsafe {
                         let ptr = b.as_mut_ptr().add(b.len());