Keep initial values in a lazy static instead of passing a parameter around.

Thanks to @Kimundi for https://gist.github.com/Kimundi/8782487

Makefile.in

@@ -261,7 +261,7 @@ DONE_script = $(B)src/components/script/libscript.dummy
 
 DEPS_script = $(CRATE_script) $(SRC_script) $(DONE_SUBMODULES) $(DONE_util) $(DONE_style) $(DONE_net) $(DONE_msg) $(DONE_macros)
 
-RFLAGS_style = $(strip $(CFG_RUSTC_FLAGS)) $(addprefix -L $(B)src/,$(DEPS_SUBMODULES)) -L $(B)src/components/util
+RFLAGS_style = $(strip $(CFG_RUSTC_FLAGS)) $(addprefix -L $(B)src/,$(DEPS_SUBMODULES)) -L $(B)src/components/util -L$(B)src/components/macros
 MAKO_ZIP = $(S)src/components/style/Mako-0.9.1.zip
 MAKO_style = $(S)src/components/style/properties.rs
 MAKO_SRC_style = $(MAKO_style).mako
@@ -269,7 +269,7 @@ SRC_style = $(call rwildcard,$(S)src/components/style/,*.rs) $(MAKO_style)
 CRATE_style = $(S)src/components/style/style.rs
 DONE_style = $(B)src/components/style/libstyle.dummy
 
-DEPS_style = $(CRATE_style) $(SRC_style) $(DONE_SUBMODULES) $(DONE_util)
+DEPS_style = $(CRATE_style) $(SRC_style) $(DONE_SUBMODULES) $(DONE_util) $(DONE_macros)
 
 RFLAGS_servo = $(strip $(CFG_RUSTC_FLAGS)) $(addprefix -L $(B)src/,$(DEPS_SUBMODULES)) -L $(B)src/components/gfx -L $(B)src/components/util -L $(B)src/components/net -L $(B)src/components/script -L $(B)src/components/style -L $(B)src/components/msg -L$(B)src/components/macros
 

src/components/macros/macros.rs

@@ -9,6 +9,11 @@
 
 #![feature(macro_rules)]
 
+
+#[cfg(test)]
+extern crate sync;
+
+
 #[macro_export]
 macro_rules! bitfield(
     ($bitfieldname:ident, $getter:ident, $setter:ident, $value:expr) => (
@@ -28,3 +33,66 @@ macro_rules! bitfield(
     )
 )
 
+
+#[macro_export]
+macro_rules! lazy_init(
+    ($(static ref $N:ident : $T:ty = $e:expr;)*) => (
+        $(
+            #[allow(non_camel_case_types)]
+            struct $N {__unit__: ()}
+            static $N: $N = $N {__unit__: ()};
+            impl Deref<$T> for $N {
+                fn deref<'a>(&'a self) -> &'a $T {
+                    unsafe {
+                        static mut s: *$T = 0 as *$T;
+                        static mut ONCE: ::sync::one::Once = ::sync::one::ONCE_INIT;
+                        ONCE.doit(|| {
+                            s = ::std::cast::transmute::<~$T, *$T>(~($e));
+                        });
+                        &*s
+                    }
+                }
+            }
+
+        )*
+    )
+)
+
+
+#[cfg(test)]
+mod tests {
+    extern crate collections;
+
+    lazy_init! {
+        static ref NUMBER: uint = times_two(3);
+        static ref VEC: [~uint, ..3] = [~1, ~2, ~3];
+        static ref OWNED_STRING: ~str = ~"hello";
+        static ref HASHMAP: collections::HashMap<uint, &'static str> = {
+            let mut m = collections::HashMap::new();
+            m.insert(0u, "abc");
+            m.insert(1, "def");
+            m.insert(2, "ghi");
+            m
+        };
+    }
+
+    fn times_two(n: uint) -> uint {
+        n * 2
+    }
+
+    #[test]
+    fn test_basic() {
+        assert_eq!(*OWNED_STRING, ~"hello");
+        assert_eq!(*NUMBER, 6);
+        assert!(HASHMAP.find(&1).is_some());
+        assert!(HASHMAP.find(&3).is_none());
+        assert_eq!(VEC.as_slice(), &[~1, ~2, ~3]);
+    }
+
+    #[test]
+    fn test_repeat() {
+        assert_eq!(*NUMBER, 6);
+        assert_eq!(*NUMBER, 6);
+        assert_eq!(*NUMBER, 6);
+    }
+}

src/components/main/css/matching.rs

@@ -309,7 +309,6 @@ pub trait MatchMethods {
 
     unsafe fn cascade_node(&self,
                            parent: Option<LayoutNode>,
-                           initial_values: &ComputedValues,
                            applicable_declarations: &ApplicableDeclarations,
                            applicable_declarations_cache: &mut ApplicableDeclarationsCache);
 }
@@ -319,7 +318,6 @@ trait PrivateMatchMethods {
                                    parent_style: Option<&Arc<ComputedValues>>,
                                    applicable_declarations: &[MatchedProperty],
                                    style: &mut Option<Arc<ComputedValues>>,
-                                   initial_values: &ComputedValues,
                                    applicable_declarations_cache: &mut
                                    ApplicableDeclarationsCache,
                                    shareable: bool);
@@ -335,7 +333,6 @@ impl<'ln> PrivateMatchMethods for LayoutNode<'ln> {
                                    parent_style: Option<&Arc<ComputedValues>>,
                                    applicable_declarations: &[MatchedProperty],
                                    style: &mut Option<Arc<ComputedValues>>,
-                                   initial_values: &ComputedValues,
                                    applicable_declarations_cache: &mut
                                    ApplicableDeclarationsCache,
                                    shareable: bool) {
@@ -352,7 +349,6 @@ impl<'ln> PrivateMatchMethods for LayoutNode<'ln> {
                 let (the_style, is_cacheable) = cascade(applicable_declarations,
                                                         shareable,
                                                         Some(&***parent_style),
-                                                        initial_values,
                                                         cached_computed_values);
                 cacheable = is_cacheable;
                 this_style = Arc::new(the_style);
@@ -361,7 +357,6 @@ impl<'ln> PrivateMatchMethods for LayoutNode<'ln> {
                 let (the_style, is_cacheable) = cascade(applicable_declarations,
                                                         shareable,
                                                         None,
-                                                        initial_values,
                                                         None);
                 cacheable = is_cacheable;
                 this_style = Arc::new(the_style);
@@ -492,9 +487,7 @@ impl<'ln> MatchMethods for LayoutNode<'ln> {
                 }
 
                 unsafe {
-                    let initial_values = &*layout_context.initial_css_values;
                     self.cascade_node(parent,
-                                      initial_values,
                                       applicable_declarations,
                                       applicable_declarations_cache)
                 }
@@ -528,7 +521,6 @@ impl<'ln> MatchMethods for LayoutNode<'ln> {
 
     unsafe fn cascade_node(&self,
                            parent: Option<LayoutNode>,
-                           initial_values: &ComputedValues,
                            applicable_declarations: &ApplicableDeclarations,
                            applicable_declarations_cache: &mut ApplicableDeclarationsCache) {
         // Get our parent's style. This must be unsafe so that we don't touch the parent's
@@ -559,14 +551,12 @@ impl<'ln> MatchMethods for LayoutNode<'ln> {
                 self.cascade_node_pseudo_element(parent_style,
                                                  applicable_declarations.normal.as_slice(),
                                                  &mut layout_data.shared_data.style,
-                                                 initial_values,
                                                  applicable_declarations_cache,
                                                  applicable_declarations.normal_shareable);
                 if applicable_declarations.before.len() > 0 {
                     self.cascade_node_pseudo_element(parent_style,
                                                      applicable_declarations.before.as_slice(),
                                                      &mut layout_data.data.before_style,
-                                                     initial_values,
                                                      applicable_declarations_cache,
                                                      false);
                 }
@@ -574,7 +564,6 @@ impl<'ln> MatchMethods for LayoutNode<'ln> {
                     self.cascade_node_pseudo_element(parent_style,
                                                      applicable_declarations.after.as_slice(),
                                                      &mut layout_data.data.after_style,
-                                                     initial_values,
                                                      applicable_declarations_cache,
                                                      false);
                 }

src/components/main/layout/box_.rs

@@ -44,7 +44,7 @@ use std::from_str::FromStr;
 use std::iter::AdditiveIterator;
 use std::mem;
 use std::num::Zero;
-use style::{ComputedValues, TElement, TNode, cascade, initial_values};
+use style::{ComputedValues, TElement, TNode, cascade};
 use style::computed_values::{LengthOrPercentageOrAuto, overflow, LPA_Auto, background_attachment};
 use style::computed_values::{background_repeat, border_style, clear, position, text_align};
 use style::computed_values::{text_decoration, vertical_align, visibility, white_space};
@@ -343,8 +343,7 @@ impl Box {
         //
         // Anonymous table boxes, TableRowBox and TableCellBox, are generated around `Foo`, but it shouldn't inherit the border.
 
-        let (node_style, _) = cascade(&[], false, Some(&**node.style()),
+        let (node_style, _) = cascade(&[], false, Some(&**node.style()), None);
-                                      &initial_values(), None);
         Box {
             node: OpaqueNodeMethods::from_thread_safe_layout_node(node),
             style: Arc::new(node_style),

src/components/main/layout/context.rs

@@ -24,8 +24,7 @@ use std::ptr;
 use std::rt::local::Local;
 #[cfg(not(target_os="android"))]
 use std::rt::task::Task;
-use style::{ComputedValues, Stylist};
+use style::Stylist;
-use sync::Arc;
 use url::Url;
 
 #[cfg(target_os="android")]
@@ -77,9 +76,6 @@ pub struct LayoutContext {
     /// FIXME(pcwalton): Make this no longer an unsafe pointer once we have fast `RWArc`s.
     pub stylist: *Stylist,
 
-    /// The initial set of CSS properties.
-    pub initial_css_values: Arc<ComputedValues>,
-
     /// The root node at which we're starting the layout.
     pub reflow_root: OpaqueNode,
 

src/components/main/layout/layout_task.rs

@@ -59,8 +59,7 @@ use std::comm::{channel, Sender, Receiver};
 use std::mem;
 use std::ptr;
 use std::task;
-use style::{AuthorOrigin, ComputedValues, Stylesheet, Stylist};
+use style::{AuthorOrigin, Stylesheet, Stylist};
-use style;
 use sync::{Arc, Mutex};
 use url::Url;
 
@@ -98,9 +97,6 @@ pub struct LayoutTask {
 
     pub stylist: ~Stylist,
 
-    /// The initial set of CSS values.
-    pub initial_css_values: Arc<ComputedValues>,
-
     /// The workers that we use for parallel operation.
     pub parallel_traversal: Option<WorkQueue<*mut LayoutContext,PaddedUnsafeFlow>>,
 
@@ -344,7 +340,6 @@ impl LayoutTask {
 
             display_list: None,
             stylist: ~new_stylist(),
-            initial_css_values: Arc::new(style::initial_values()),
             parallel_traversal: parallel_traversal,
             profiler_chan: profiler_chan,
             opts: opts.clone(),
@@ -374,7 +369,6 @@ impl LayoutTask {
             layout_chan: self.chan.clone(),
             font_context_info: font_context_info,
             stylist: &*self.stylist,
-            initial_css_values: self.initial_css_values.clone(),
             url: (*url).clone(),
             reflow_root: OpaqueNodeMethods::from_layout_node(reflow_root),
             opts: self.opts.clone(),

src/components/main/layout/parallel.rs

@@ -274,7 +274,6 @@ fn recalc_style_for_node(unsafe_layout_node: UnsafeLayoutNode,
 
                 // Perform the CSS cascade.
                 node.cascade_node(parent_opt,
-                                  &*layout_context.initial_css_values,
                                   &applicable_declarations,
                                   layout_context.applicable_declarations_cache());
 

src/components/style/properties.rs.mako

@@ -1593,9 +1593,9 @@ impl ComputedValues {
     }
 }
 
-/// Returns the initial values for all style structs as defined by the specification.
+/// The initial values for all style structs as defined by the specification.
-pub fn initial_values() -> ComputedValues {
+lazy_init! {
-    ComputedValues {
+    static ref INITIAL_VALUES: ComputedValues = ComputedValues {
         % for style_struct in STYLE_STRUCTS:
             ${style_struct.name}: CowArc::new(style_structs::${style_struct.name} {
                 % for longhand in style_struct.longhands:
@@ -1604,7 +1604,7 @@ pub fn initial_values() -> ComputedValues {
             }),
         % endfor
         shareable: true,
-    }
+    };
 }
 
 /// Fast path for the function below. Only computes new inherited styles.
@@ -1702,8 +1702,6 @@ fn cascade_with_cached_declarations(applicable_declarations: &[MatchedProperty],
 ///
 ///   * `parent_style`: The parent style, if applicable; if `None`, this is the root node.
 ///
-///   * `initial_values`: The initial set of CSS values as defined by the specification.
-///
 ///   * `cached_style`: If present, cascading is short-circuited for everything but inherited
 ///     values and these values are used instead. Obviously, you must be careful when supplying
 ///     this that it is safe to only provide inherited declarations. If `parent_style` is `None`,
@@ -1713,9 +1711,9 @@ fn cascade_with_cached_declarations(applicable_declarations: &[MatchedProperty],
 pub fn cascade(applicable_declarations: &[MatchedProperty],
                shareable: bool,
                parent_style: Option< &ComputedValues >,
-               initial_values: &ComputedValues,
                cached_style: Option< &ComputedValues >)
                -> (ComputedValues, bool) {
+    let initial_values = &*INITIAL_VALUES;
     let (is_root_element, inherited_style) = match parent_style {
         Some(parent_style) => (false, parent_style),
         None => (true, initial_values),

src/components/style/style.rs

@@ -15,15 +15,19 @@
 #![feature(phase)]
 #[phase(syntax, link)] extern crate log;
 
-extern crate cssparser;
 extern crate collections;
-extern crate encoding;
 extern crate num;
 extern crate serialize;
-extern crate servo_util = "util";
 extern crate sync;
 extern crate url;
 
+extern crate cssparser;
+extern crate encoding;
+
+#[phase(syntax)]
+extern crate servo_macros = "macros";
+extern crate servo_util = "util";
+
 
 // Public API
 pub use stylesheets::{Stylesheet, CSSRule, StyleRule};
@@ -31,7 +35,7 @@ pub use selector_matching::{Stylist, StylesheetOrigin, UserAgentOrigin, AuthorOr
 pub use selector_matching::{MatchedProperty};
 pub use properties::{cascade, PropertyDeclaration, ComputedValues, computed_values, style_structs};
 pub use properties::{PropertyDeclarationBlock, parse_style_attribute};  // Style attributes
-pub use properties::{initial_values, CSSFloat, DeclaredValue, PropertyDeclarationParseResult};
+pub use properties::{CSSFloat, DeclaredValue, PropertyDeclarationParseResult};
 pub use properties::longhands;
 pub use errors::with_errors_silenced;
 pub use node::{TElement, TNode};