Reduce unecessary work (faster!)

Author: devongovett

README.md

@@ -68,8 +68,8 @@ cssnano: 542.956ms
 esbuild: 17.411ms
 160332 bytes
 
-parcel-css: 4.961ms
-143662 bytes
+parcel-css: 4.74ms
+143985 bytes
 
 
 $ node bench.js animate.css
@@ -79,8 +79,8 @@ cssnano: 283.105ms
 esbuild: 11.858ms
 72183 bytes
 
-parcel-css: 2.039ms
-23707 bytes
+parcel-css: 1.989ms
+23666 bytes
 
 
 $ node bench.js tailwind.css 
@@ -90,6 +90,6 @@ cssnano: 2.198s
 esbuild: 107.668ms
 1961642 bytes
 
-parcel-css: 42.568ms
-1905068 bytes
+parcel-css: 45.701ms
+1799209 bytes
 ```

src/macros.rs

@@ -177,18 +177,23 @@ macro_rules! shorthand_handler {
       $(
         pub $key: Option<$type>,
       )*
+      has_any: bool
     }
 
     impl PropertyHandler for $name {
       fn handle_property(&mut self, property: &Property, dest: &mut DeclarationList) -> bool {
         match property {
           $(
-            Property::$prop(val) => self.$key = Some(val.clone()),
+            Property::$prop(val) => {
+              self.$key = Some(val.clone());
+              self.has_any = true;
+            },
           )+
           Property::$shorthand(val) => {
             $(
               self.$key = Some(val.$key.clone());
             )+
+            self.has_any = true;
           }
           Property::Unparsed(val) if matches!(val.property_id, $( PropertyId::$prop | )+ PropertyId::$shorthand) => {
             self.finalize(dest);
@@ -201,6 +206,12 @@ macro_rules! shorthand_handler {
       }
 
       fn finalize(&mut self, dest: &mut DeclarationList) {
+        if !self.has_any {
+          return
+        }
+
+        self.has_any = false;
+
         $(
           let $key = std::mem::take(&mut self.$key);
         )+

src/properties/align.rs

@@ -730,7 +730,8 @@ pub(crate) struct AlignHandler {
   flex_align: Option<(FlexAlign, VendorPrefix)>,
   justify_items: Option<JustifyItems>,
   row_gap: Option<GapValue>,
-  column_gap: Option<GapValue>
+  column_gap: Option<GapValue>,
+  has_any: bool
 }
 
 impl AlignHandler {
@@ -761,7 +762,8 @@ impl PropertyHandler for AlignHandler {
           *val = $val.clone();
           *prefixes |= *$vp;
         } else {
-          self.$prop = Some(($val.clone(), *$vp))
+          self.$prop = Some(($val.clone(), *$vp));
+          self.has_any = true;
         }
       }};
     }
@@ -791,7 +793,10 @@ impl PropertyHandler for AlignHandler {
         property!(align_self, val, vp);
       },
       FlexItemAlign(val, vp) => property!(flex_item_align, val, vp),
-      JustifySelf(val) => self.justify_self = Some(val.clone()),
+      JustifySelf(val) => {
+        self.justify_self = Some(val.clone());
+        self.has_any = true;
+      },
       PlaceSelf(val) => {
         self.flex_item_align = None;
         property!(align_self, &val.align, &VendorPrefix::None);
@@ -804,18 +809,28 @@ impl PropertyHandler for AlignHandler {
       },
       BoxAlign(val, vp) => property!(box_align, val, vp),
       FlexAlign(val, vp) => property!(flex_align, val, vp),
-      JustifyItems(val) => self.justify_items = Some(val.clone()),
+      JustifyItems(val) => {
+        self.justify_items = Some(val.clone());
+        self.has_any = true;
+      },
       PlaceItems(val) => {
         self.box_align = None;
         self.flex_align = None;
         property!(align_items, &val.align, &VendorPrefix::None);
         self.justify_items = Some(val.justify.clone());
       }
-      RowGap(val) => self.row_gap = Some(val.clone()),
-      ColumnGap(val) => self.column_gap = Some(val.clone()),
+      RowGap(val) => {
+        self.row_gap = Some(val.clone());
+        self.has_any = true;
+      },
+      ColumnGap(val) => {
+        self.column_gap = Some(val.clone());
+        self.has_any = true;
+      },
       Gap(val) => {
         self.row_gap = Some(val.row.clone());
         self.column_gap = Some(val.column.clone());
+        self.has_any = true;
       }
       Unparsed(val) if is_align_property(&val.property_id) => {
         self.flush(dest);
@@ -834,6 +849,12 @@ impl PropertyHandler for AlignHandler {
 
 impl AlignHandler {
   fn flush(&mut self, dest: &mut DeclarationList) {
+    if !self.has_any {
+      return
+    }
+
+    self.has_any = false;
+
     let mut align_content = std::mem::take(&mut self.align_content);
     let mut justify_content = std::mem::take(&mut self.justify_content);
     let mut align_self = std::mem::take(&mut self.align_self);

src/properties/animation.rs

@@ -208,7 +208,8 @@ pub(crate) struct AnimationHandler {
   directions: Option<(SmallVec<[AnimationDirection; 1]>, VendorPrefix)>,
   play_states: Option<(SmallVec<[AnimationPlayState; 1]>, VendorPrefix)>,
   delays: Option<(SmallVec<[Time; 1]>, VendorPrefix)>,
-  fill_modes: Option<(SmallVec<[AnimationFillMode; 1]>, VendorPrefix)>
+  fill_modes: Option<(SmallVec<[AnimationFillMode; 1]>, VendorPrefix)>,
+  has_any: bool
 }
 
 impl AnimationHandler {
@@ -245,7 +246,8 @@ impl PropertyHandler for AnimationHandler {
           *val = $val.clone();
           *prefixes |= *$vp;
         } else {
-          self.$prop = Some(($val.clone(), *$vp))
+          self.$prop = Some(($val.clone(), *$vp));
+          self.has_any = true;
         }
       }};
     }
@@ -310,6 +312,12 @@ impl PropertyHandler for AnimationHandler {
 
 impl AnimationHandler {
   fn flush(&mut self, dest: &mut DeclarationList) {
+    if !self.has_any {
+      return
+    }
+
+    self.has_any = false;
+
     let mut names = std::mem::take(&mut self.names);
     let mut durations = std::mem::take(&mut self.durations);
     let mut timing_functions = std::mem::take(&mut self.timing_functions);

src/properties/background.rs

@@ -374,7 +374,8 @@ pub(crate) struct BackgroundHandler {
   attachments: Option<SmallVec<[BackgroundAttachment; 1]>>,
   origins: Option<SmallVec<[BackgroundBox; 1]>>,
   clips: Option<SmallVec<[BackgroundClip; 1]>>,
-  decls: Vec<Property>
+  decls: Vec<Property>,
+  has_any: bool
 }
 
 impl BackgroundHandler {
@@ -445,6 +446,7 @@ impl PropertyHandler for BackgroundHandler {
       _ => return false
     }
 
+    self.has_any = true;
     true
   }
 
@@ -462,6 +464,12 @@ impl PropertyHandler for BackgroundHandler {
 
 impl BackgroundHandler {
   fn flush(&mut self, dest: &mut DeclarationList) {    
+    if !self.has_any {
+      return
+    }
+
+    self.has_any = false;
+
     let color = std::mem::take(&mut self.color);
     let mut images = std::mem::take(&mut self.images);
     let mut x_positions = std::mem::take(&mut self.x_positions);

src/properties/border.rs

@@ -220,7 +220,8 @@ pub(crate) struct BorderHandler {
   border_inline_end: BorderShorthand,
   category: BorderCategory,
   border_image_handler: BorderImageHandler,
-  border_radius_handler: BorderRadiusHandler
+  border_radius_handler: BorderRadiusHandler,
+  has_any: bool
 }
 
 impl BorderHandler {
@@ -245,6 +246,7 @@ impl PropertyHandler for BorderHandler {
         }
         self.$key.$prop = Some($val.clone());
         self.category = $category;
+        self.has_any = true;
       }};
     }
 
@@ -255,6 +257,7 @@ impl PropertyHandler for BorderHandler {
         }
         self.$key.set_border($val);
         self.category = $category;
+        self.has_any = true;
       }};
     }
 
@@ -332,6 +335,7 @@ impl PropertyHandler for BorderHandler {
         self.border_block_end.width = None;
         self.border_inline_start.width = None;
         self.border_inline_end.width = None;
+        self.has_any = true;
       }
       BorderStyle(val) => {
         self.border_top.style = Some(val.0.clone());
@@ -342,6 +346,7 @@ impl PropertyHandler for BorderHandler {
         self.border_block_end.style = None;
         self.border_inline_start.style = None;
         self.border_inline_end.style = None;
+        self.has_any = true;
       }
       BorderColor(val) => {
         self.border_top.color = Some(val.0.clone());
@@ -352,6 +357,7 @@ impl PropertyHandler for BorderHandler {
         self.border_block_end.color = None;
         self.border_inline_start.color = None;
         self.border_inline_end.color = None;
+        self.has_any = true;
       }
       Border(val) => {
         // dest.clear();
@@ -366,6 +372,7 @@ impl PropertyHandler for BorderHandler {
 
         // Setting the `border` property resets `border-image`.
         self.border_image_handler.reset();
+        self.has_any = true;
       }
       Unparsed(val) if is_border_property(&val.property_id) => {
         self.flush(dest);
@@ -388,6 +395,12 @@ impl PropertyHandler for BorderHandler {
 
 impl BorderHandler {
   fn flush(&mut self, dest: &mut DeclarationList) {
+    if !self.has_any {
+      return
+    }
+
+    self.has_any = false;
+
     use Property::*;
 
     macro_rules! flush_category {

src/properties/border_image.rs

@@ -249,7 +249,8 @@ pub(crate) struct BorderImageHandler {
   width: Option<Rect<BorderImageSideWidth>>,
   outset: Option<Rect<LengthOrNumber>>,
   repeat: Option<BorderImageRepeat>,
-  vendor_prefix: VendorPrefix
+  vendor_prefix: VendorPrefix,
+  has_any: bool
 }
 
 impl BorderImageHandler {
@@ -272,6 +273,7 @@ impl PropertyHandler for BorderImageHandler {
         }
         self.vendor_prefix = VendorPrefix::None;
         self.$name = Some($val.clone());
+        self.has_any = true;
       }};
     }
 
@@ -284,6 +286,7 @@ impl PropertyHandler for BorderImageHandler {
       BorderImage(val, vp) => {
         self.set_border_image(val);
         self.vendor_prefix |= *vp;
+        self.has_any = true;
       },
       Unparsed(val) if is_border_image_property(&val.property_id) => {
         self.flush(dest);
@@ -327,6 +330,12 @@ impl BorderImageHandler {
   }
 
   fn flush(&mut self, dest: &mut DeclarationList) {
+    if !self.has_any {
+      return
+    }
+
+    self.has_any = false;
+
     let source = std::mem::take(&mut self.source);
     let slice = std::mem::take(&mut self.slice);
     let width = std::mem::take(&mut self.width);

src/properties/border_radius.rs

@@ -57,7 +57,8 @@ pub(crate) struct BorderRadiusHandler {
   top_right: Option<(Size2D<LengthPercentage>, VendorPrefix)>,
   bottom_left: Option<(Size2D<LengthPercentage>, VendorPrefix)>,
   bottom_right: Option<(Size2D<LengthPercentage>, VendorPrefix)>,
-  logical: Vec<Property>
+  logical: Vec<Property>,
+  has_any: bool
 }
 
 impl BorderRadiusHandler {
@@ -88,7 +89,8 @@ impl PropertyHandler for BorderRadiusHandler {
           *val = $val.clone();
           *prefixes |= *$vp;
         } else {
-          self.$prop = Some(($val.clone(), *$vp))
+          self.$prop = Some(($val.clone(), *$vp));
+          self.has_any = true;
         }
       }};
     }
@@ -101,6 +103,7 @@ impl PropertyHandler for BorderRadiusHandler {
       BorderStartStartRadius(_) | BorderStartEndRadius(_) | BorderEndStartRadius(_) | BorderEndEndRadius(_) => {
         self.flush(dest);
         self.logical.push(property.clone());
+        self.has_any = true;
       }
       BorderRadius(val, vp) => {
         self.logical.clear();
@@ -135,6 +138,12 @@ impl PropertyHandler for BorderRadiusHandler {
 
 impl BorderRadiusHandler {
   fn flush(&mut self, dest: &mut DeclarationList) {
+    if !self.has_any {
+      return
+    }
+
+    self.has_any = true;
+
     let mut top_left = std::mem::take(&mut self.top_left);
     let mut top_right = std::mem::take(&mut self.top_right);
     let mut bottom_left = std::mem::take(&mut self.bottom_left);

src/properties/display.rs

@@ -339,6 +339,10 @@ impl PropertyHandler for DisplayHandler {
   }
 
   fn finalize(&mut self, dest: &mut DeclarationList) {
+    if self.display.is_none() {
+      return
+    }
+    
     dest.extend(&mut self.decls);
 
     if let Some(display) = std::mem::take(&mut self.display) {