Move util::vec::ForgetfulSink to style::sink and simplify it

14 files changed, 58 insertions, 89 deletions

diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index 479a73dee86..d9535663d46 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -75,7 +75,6 @@ use selectors::matching::{DeclarationBlock, ElementFlags, matches};
 use selectors::matching::{HAS_SLOW_SELECTOR, HAS_EDGE_CHILD_SELECTOR, HAS_SLOW_SELECTOR_LATER_SIBLINGS};
 use selectors::matching::{common_style_affecting_attributes, rare_style_affecting_attributes};
 use selectors::parser::{AttrSelector, NamespaceConstraint, parse_author_origin_selector_list_from_str};
-use smallvec::VecLike;
 use std::ascii::AsciiExt;
 use std::borrow::Cow;
 use std::cell::{Cell, Ref};
@@ -91,6 +90,7 @@ use style::properties::DeclaredValue;
 use style::properties::longhands::{self, background_image, border_spacing, font_family, overflow_x, font_size};
 use style::properties::{PropertyDeclaration, PropertyDeclarationBlock, parse_style_attribute};
 use style::selector_impl::{NonTSPseudoClass, ServoSelectorImpl};
+use style::sink::Push;
 use style::values::CSSFloat;
 use style::values::specified::{self, CSSColor, CSSRGBA, LengthOrPercentage};
 
@@ -275,7 +275,7 @@ pub trait LayoutElementHelpers {
 
     #[allow(unsafe_code)]
     unsafe fn synthesize_presentational_hints_for_legacy_attributes<V>(&self, &mut V)
-        where V: VecLike<DeclarationBlock<Vec<PropertyDeclaration>>>;
+        where V: Push<DeclarationBlock<Vec<PropertyDeclaration>>>;
     #[allow(unsafe_code)]
     unsafe fn get_colspan(self) -> u32;
     #[allow(unsafe_code)]
@@ -308,7 +308,7 @@ impl LayoutElementHelpers for LayoutJS<Element> {
 
     #[allow(unsafe_code)]
     unsafe fn synthesize_presentational_hints_for_legacy_attributes<V>(&self, hints: &mut V)
-        where V: VecLike<DeclarationBlock<Vec<PropertyDeclaration>>>
+        where V: Push<DeclarationBlock<Vec<PropertyDeclaration>>>
     {
         #[inline]
         fn from_declaration(rule: PropertyDeclaration) -> DeclarationBlock<Vec<PropertyDeclaration>> {
diff --git a/components/script/layout_wrapper.rs b/components/script/layout_wrapper.rs
index 681fdab9c46..779c37a5d52 100644
--- a/components/script/layout_wrapper.rs
+++ b/components/script/layout_wrapper.rs
@@ -49,7 +49,6 @@ use script_layout_interface::{HTMLCanvasData, LayoutNodeType, TrustedNodeAddress
 use script_layout_interface::{OpaqueStyleAndLayoutData, PartialStyleAndLayoutData};
 use selectors::matching::{DeclarationBlock, ElementFlags};
 use selectors::parser::{AttrSelector, NamespaceConstraint};
-use smallvec::VecLike;
 use std::marker::PhantomData;
 use std::mem::{transmute, transmute_copy};
 use string_cache::{Atom, BorrowedAtom, BorrowedNamespace, Namespace};
@@ -63,6 +62,7 @@ use style::refcell::{Ref, RefCell, RefMut};
 use style::restyle_hints::ElementSnapshot;
 use style::selector_impl::{NonTSPseudoClass, ServoSelectorImpl};
 use style::servo::{PrivateStyleData, SharedStyleContext};
+use style::sink::Push;
 use url::Url;
 use util::str::is_whitespace;
 
@@ -360,7 +360,7 @@ pub struct ServoLayoutElement<'le> {
 
 impl<'le> PresentationalHintsSynthetizer for ServoLayoutElement<'le> {
     fn synthesize_presentational_hints_for_legacy_attributes<V>(&self, hints: &mut V)
-        where V: VecLike<DeclarationBlock<Vec<PropertyDeclaration>>>
+        where V: Push<DeclarationBlock<Vec<PropertyDeclaration>>>
     {
         unsafe {
             self.element.synthesize_presentational_hints_for_legacy_attributes(hints);
@@ -995,5 +995,5 @@ impl <'le> ::selectors::Element for ServoThreadSafeLayoutElement<'le> {
 
 impl<'le> PresentationalHintsSynthetizer for ServoThreadSafeLayoutElement<'le> {
     fn synthesize_presentational_hints_for_legacy_attributes<V>(&self, _hints: &mut V)
-        where V: VecLike<DeclarationBlock<Vec<PropertyDeclaration>>> {}
+        where V: Push<DeclarationBlock<Vec<PropertyDeclaration>>> {}
 }
diff --git a/components/servo/Cargo.lock b/components/servo/Cargo.lock
index b886ef4296f..4c68a576fe3 100644
--- a/components/servo/Cargo.lock
+++ b/components/servo/Cargo.lock
@@ -2471,7 +2471,6 @@ dependencies = [
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.7.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_macros 0.7.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "smallvec 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "xdg 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
diff --git a/components/style/dom.rs b/components/style/dom.rs
index 4f7eeaff169..11cc5f93a0e 100644
--- a/components/style/dom.rs
+++ b/components/style/dom.rs
@@ -15,7 +15,7 @@ use restyle_hints::{ElementSnapshot, RESTYLE_DESCENDANTS, RESTYLE_LATER_SIBLINGS
 use selector_impl::{ElementExt, SelectorImplExt};
 use selectors::Element;
 use selectors::matching::DeclarationBlock;
-use smallvec::VecLike;
+use sink::Push;
 use std::ops::BitOr;
 use std::sync::Arc;
 use string_cache::{Atom, Namespace};
@@ -194,7 +194,7 @@ pub trait TDocument : Sized + Copy + Clone {
 
 pub trait PresentationalHintsSynthetizer {
     fn synthesize_presentational_hints_for_legacy_attributes<V>(&self, hints: &mut V)
-        where V: VecLike<DeclarationBlock<Vec<PropertyDeclaration>>>;
+        where V: Push<DeclarationBlock<Vec<PropertyDeclaration>>>;
 }
 
 pub trait TElement : Sized + Copy + Clone + ElementExt + PresentationalHintsSynthetizer {
diff --git a/components/style/lib.rs b/components/style/lib.rs
index ae1e8c84d7c..54510250eda 100644
--- a/components/style/lib.rs
+++ b/components/style/lib.rs
@@ -88,6 +88,7 @@ pub mod selector_impl;
 pub mod selector_matching;
 pub mod sequential;
 pub mod servo;
+pub mod sink;
 pub mod stylesheets;
 pub mod traversal;
 #[macro_use]
diff --git a/components/style/matching.rs b/components/style/matching.rs
index 7f865cf9a72..d3dd3742d3d 100644
--- a/components/style/matching.rs
+++ b/components/style/matching.rs
@@ -17,6 +17,7 @@ use selectors::Element;
 use selectors::bloom::BloomFilter;
 use selectors::matching::{CommonStyleAffectingAttributeMode, CommonStyleAffectingAttributes};
 use selectors::matching::{common_style_affecting_attributes, rare_style_affecting_attributes};
+use sink::ForgetfulSink;
 use smallvec::SmallVec;
 use std::collections::HashMap;
 use std::hash::{BuildHasherDefault, Hash, Hasher};
@@ -26,7 +27,6 @@ use string_cache::{Atom, Namespace};
 use util::arc_ptr_eq;
 use util::cache::{LRUCache, SimpleHashCache};
 use util::opts;
-use util::vec::ForgetfulSink;
 
 fn create_common_style_affecting_attributes_from_element<E: TElement>(element: &E)
                                                          -> CommonStyleAffectingAttributes {
diff --git a/components/style/selector_matching.rs b/components/style/selector_matching.rs
index 35a38d5ed14..74718d4b69b 100644
--- a/components/style/selector_matching.rs
+++ b/components/style/selector_matching.rs
@@ -18,6 +18,7 @@ use selectors::bloom::BloomFilter;
 use selectors::matching::DeclarationBlock as GenericDeclarationBlock;
 use selectors::matching::{Rule, SelectorMap};
 use selectors::parser::SelectorImpl;
+use sink::Push;
 use smallvec::VecLike;
 use std::collections::HashMap;
 use std::hash::BuildHasherDefault;
@@ -389,7 +390,7 @@ impl<Impl: SelectorImplExt> Stylist<Impl> {
                                         applicable_declarations: &mut V)
                                         -> bool
                                         where E: Element<Impl=Impl> + PresentationalHintsSynthetizer,
-                                              V: VecLike<DeclarationBlock> {
+                                              V: Push<DeclarationBlock> + VecLike<DeclarationBlock> {
         assert!(!self.is_device_dirty);
         assert!(style_attribute.is_none() || pseudo_element.is_none(),
                 "Style attributes do not apply to pseudo-elements");
@@ -430,7 +431,8 @@ impl<Impl: SelectorImplExt> Stylist<Impl> {
         // Step 4: Normal style attributes.
         style_attribute.map(|sa| {
             shareable = false;
-            applicable_declarations.push(
+            Push::push(
+                applicable_declarations,
                 GenericDeclarationBlock::from_declarations(sa.normal.clone()))
         });
 
@@ -443,7 +445,8 @@ impl<Impl: SelectorImplExt> Stylist<Impl> {
         // Step 6: `!important` style attributes.
         style_attribute.map(|sa| {
             shareable = false;
-            applicable_declarations.push(
+            Push::push(
+                applicable_declarations,
                 GenericDeclarationBlock::from_declarations(sa.important.clone()))
         });
 
diff --git a/components/style/sink.rs b/components/style/sink.rs
new file mode 100644
index 00000000000..33aa26ac1af
--- /dev/null
+++ b/components/style/sink.rs
@@ -0,0 +1,40 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use smallvec::{Array, SmallVec};
+use std::marker::PhantomData;
+
+pub trait Push<T> {
+    fn push(&mut self, value: T);
+}
+
+impl<T> Push<T> for Vec<T> {
+    fn push(&mut self, value: T) {
+        Vec::push(self, value);
+    }
+}
+
+impl<A: Array> Push<A::Item> for SmallVec<A> {
+    fn push(&mut self, value: A::Item) {
+        SmallVec::push(self, value);
+    }
+}
+
+pub struct ForgetfulSink<T>(bool, PhantomData<T>);
+
+impl<T> ForgetfulSink<T> {
+    pub fn new() -> Self {
+        ForgetfulSink(true, PhantomData)
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.0
+    }
+}
+
+impl<T> Push<T> for ForgetfulSink<T> {
+    fn push(&mut self, _value: T) {
+        self.0 = false;
+    }
+}
diff --git a/components/util/Cargo.toml b/components/util/Cargo.toml
index 83b23c78c87..b693a0f8c5b 100644
--- a/components/util/Cargo.toml
+++ b/components/util/Cargo.toml
@@ -31,7 +31,6 @@ rand = "0.3"
 rustc-serialize = "0.3"
 serde = {version = "0.7.11", optional = true}
 serde_macros = {version = "0.7.11", optional = true}
-smallvec = "0.1"
 url = "1.0.0"
 
 [target.'cfg(all(unix, not(target_os = "macos"), not(target_os = "ios"), not(target_os = "android")))'.dependencies]
diff --git a/components/util/lib.rs b/components/util/lib.rs
index 46c194ca91a..3a5c362f443 100644
--- a/components/util/lib.rs
+++ b/components/util/lib.rs
@@ -27,7 +27,6 @@ extern crate num_traits;
 extern crate rand;
 extern crate rustc_serialize;
 #[cfg(feature = "servo")] extern crate serde;
-extern crate smallvec;
 extern crate url;
 #[cfg(all(unix, not(target_os = "macos"), not(target_os = "ios"), not(target_os = "android")))]
 extern crate xdg;
diff --git a/components/util/vec.rs b/components/util/vec.rs
index 639e1c260da..2aa6b7d4a41 100644
--- a/components/util/vec.rs
+++ b/components/util/vec.rs
@@ -2,10 +2,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use std::marker::PhantomData;
-use std::ops;
-use super::smallvec::VecLike;
-
 // TODO(pcwalton): Speed up with SIMD, or better yet, find some way to not do this.
 pub fn byte_swap(data: &mut [u8]) {
     let length = data.len();
@@ -18,70 +14,3 @@ pub fn byte_swap(data: &mut [u8]) {
         i += 4;
     }
 }
-
-/// A `VecLike` that only tracks whether or not something was ever pushed to it.
-pub struct ForgetfulSink<T> {
-    empty: bool,
-    _data: PhantomData<T>,
-}
-
-impl<T> ForgetfulSink<T> {
-    pub fn new() -> ForgetfulSink<T> {
-        ForgetfulSink {
-            empty: true,
-            _data: PhantomData,
-        }
-    }
-
-    pub fn is_empty(&self) -> bool {
-        self.empty
-    }
-}
-
-impl<T> ops::Deref for ForgetfulSink<T> {
-    type Target = [T];
-    fn deref(&self) -> &[T] {
-        unreachable!()
-    }
-}
-
-impl<T> ops::DerefMut for ForgetfulSink<T> {
-    fn deref_mut(&mut self) -> &mut [T] {
-        unreachable!()
-    }
-}
-
-macro_rules! impl_index {
-    ($index_type: ty, $output_type: ty) => {
-        impl<T> ops::Index<$index_type> for ForgetfulSink<T> {
-            type Output = $output_type;
-            fn index(&self, _index: $index_type) -> &$output_type {
-                unreachable!()
-            }
-        }
-
-        impl<T> ops::IndexMut<$index_type> for ForgetfulSink<T> {
-            fn index_mut(&mut self, _index: $index_type) -> &mut $output_type {
-                unreachable!()
-            }
-        }
-    }
-}
-
-impl_index!(usize, T);
-impl_index!(ops::Range<usize>, [T]);
-impl_index!(ops::RangeFrom<usize>, [T]);
-impl_index!(ops::RangeTo<usize>, [T]);
-impl_index!(ops::RangeFull, [T]);
-
-impl<T> VecLike<T> for ForgetfulSink<T> {
-    #[inline]
-    fn len(&self) -> usize {
-        unreachable!()
-    }
-
-    #[inline]
-    fn push(&mut self, _value: T) {
-        self.empty = false;
-    }
-}
diff --git a/ports/cef/Cargo.lock b/ports/cef/Cargo.lock
index 7150e137bd1..dc0b6af49f6 100644
--- a/ports/cef/Cargo.lock
+++ b/ports/cef/Cargo.lock
@@ -2340,7 +2340,6 @@ dependencies = [
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.7.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_macros 0.7.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "smallvec 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "xdg 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
diff --git a/ports/geckolib/Cargo.lock b/ports/geckolib/Cargo.lock
index 7b94768e030..ddd1c911aab 100644
--- a/ports/geckolib/Cargo.lock
+++ b/ports/geckolib/Cargo.lock
@@ -577,7 +577,6 @@ dependencies = [
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.7.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_macros 0.7.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "smallvec 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "xdg 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
diff --git a/ports/geckolib/wrapper.rs b/ports/geckolib/wrapper.rs
index 83dbac01064..2c32643c008 100644
--- a/ports/geckolib/wrapper.rs
+++ b/ports/geckolib/wrapper.rs
@@ -50,6 +50,7 @@ use style::properties::{PropertyDeclaration, PropertyDeclarationBlock};
 use style::refcell::{Ref, RefCell, RefMut};
 use style::restyle_hints::ElementSnapshot;
 use style::selector_impl::ElementExt;
+use style::sink::Push;
 #[allow(unused_imports)] // Used in commented-out code.
 use url::Url;
 
@@ -377,7 +378,7 @@ impl<'le> TElement for GeckoElement<'le> {
 
 impl<'le> PresentationalHintsSynthetizer for GeckoElement<'le> {
     fn synthesize_presentational_hints_for_legacy_attributes<V>(&self, _hints: &mut V)
-        where V: VecLike<DeclarationBlock<Vec<PropertyDeclaration>>>
+        where V: Push<DeclarationBlock<Vec<PropertyDeclaration>>>
     {
         // FIXME(bholley) - Need to implement this.
     }