Revert "Diagnostic map semantics."

This reverts commit f5c5be0.

components/hashglobe/src/fake.rs

@@ -76,24 +76,10 @@ impl<K, V, S> HashMap<K, V, S>
         Ok(self.entry(key))
     }
 
-    #[inline(always)]
-    pub fn try_get_or_insert_with<F: FnOnce() -> V>(
-        &mut self,
-        key: K,
-        default: F
-    ) -> Result<&mut V, FailedAllocationError> {
-        Ok(self.entry(key).or_insert_with(default))
-    }
-
     #[inline]
     pub fn try_insert(&mut self, k: K, v: V) -> Result<Option<V>, FailedAllocationError> {
         Ok(self.insert(k, v))
     }
-
-    #[inline(always)]
-    pub fn begin_mutation(&mut self) {}
-    #[inline(always)]
-    pub fn end_mutation(&mut self) {}
 }
 
 #[derive(Clone)]

components/hashglobe/src/lib.rs

@@ -9,7 +9,6 @@
 // except according to those terms.
 
 pub mod alloc;
-pub mod diagnostic;
 pub mod hash_map;
 pub mod hash_set;
 mod shim;

components/malloc_size_of/lib.rs

@@ -499,25 +499,6 @@ impl<K, V, S> MallocSizeOf for hashglobe::hash_map::HashMap<K, V, S>
     }
 }
 
-impl<K, V, S> MallocShallowSizeOf for hashglobe::diagnostic::DiagnosticHashMap<K, V, S>
-    where K: Eq + Hash,
-          S: BuildHasher
-{
-    fn shallow_size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
-        self.inner().shallow_size_of(ops)
-    }
-}
-
-impl<K, V, S> MallocSizeOf for hashglobe::diagnostic::DiagnosticHashMap<K, V, S>
-    where K: Eq + Hash + MallocSizeOf,
-          V: MallocSizeOf,
-          S: BuildHasher,
-{
-    fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
-        self.inner().size_of(ops)
-    }
-}
-
 impl<K, V, S> MallocShallowSizeOf for hashglobe::fake::HashMap<K, V, S>
     where K: Eq + Hash,
           S: BuildHasher,

components/style/context.rs

@@ -322,6 +322,8 @@ pub struct TraversalStatistics {
     pub selectors: u32,
     /// The number of revalidation selectors.
     pub revalidation_selectors: u32,
+    /// The number of state/attr dependencies in the dependency set.
+    pub dependency_selectors: u32,
     /// The number of declarations in the stylist.
     pub declarations: u32,
     /// The number of times the stylist was rebuilt.
@@ -342,6 +344,7 @@ impl<'a> ops::Add for &'a TraversalStatistics {
                       "traversal_time_ms should be set at the end by the caller");
         debug_assert!(self.selectors == 0, "set at the end");
         debug_assert!(self.revalidation_selectors == 0, "set at the end");
+        debug_assert!(self.dependency_selectors == 0, "set at the end");
         debug_assert!(self.declarations == 0, "set at the end");
         debug_assert!(self.stylist_rebuilds == 0, "set at the end");
         TraversalStatistics {
@@ -352,6 +355,7 @@ impl<'a> ops::Add for &'a TraversalStatistics {
             styles_reused: self.styles_reused + other.styles_reused,
             selectors: 0,
             revalidation_selectors: 0,
+            dependency_selectors: 0,
             declarations: 0,
             stylist_rebuilds: 0,
             traversal_time_ms: 0.0,
@@ -379,6 +383,7 @@ impl fmt::Display for TraversalStatistics {
         writeln!(f, "[PERF],styles_reused,{}", self.styles_reused)?;
         writeln!(f, "[PERF],selectors,{}", self.selectors)?;
         writeln!(f, "[PERF],revalidation_selectors,{}", self.revalidation_selectors)?;
+        writeln!(f, "[PERF],dependency_selectors,{}", self.dependency_selectors)?;
         writeln!(f, "[PERF],declarations,{}", self.declarations)?;
         writeln!(f, "[PERF],stylist_rebuilds,{}", self.stylist_rebuilds)?;
         writeln!(f, "[PERF],traversal_time_ms,{}", self.traversal_time_ms)?;
@@ -400,6 +405,7 @@ impl TraversalStatistics {
         self.traversal_time_ms = (time::precise_time_s() - start) * 1000.0;
         self.selectors = stylist.num_selectors() as u32;
         self.revalidation_selectors = stylist.num_revalidation_selectors() as u32;
+        self.dependency_selectors = stylist.num_invalidations() as u32;
         self.declarations = stylist.num_declarations() as u32;
         self.stylist_rebuilds = stylist.num_rebuilds() as u32;
     }

components/style/custom_properties.rs

@@ -10,7 +10,7 @@ use Atom;
 use cssparser::{Delimiter, Parser, ParserInput, SourcePosition, Token, TokenSerializationType};
 use precomputed_hash::PrecomputedHash;
 use properties::{CSSWideKeyword, DeclaredValue};
-use selector_map::{PrecomputedHashSet, PrecomputedHashMap, PrecomputedDiagnosticHashMap};
+use selector_map::{PrecomputedHashSet, PrecomputedHashMap};
 use selectors::parser::SelectorParseErrorKind;
 use servo_arc::Arc;
 use smallvec::SmallVec;
@@ -88,7 +88,7 @@ where
     /// Key index.
     index: Vec<K>,
     /// Key-value map.
-    values: PrecomputedDiagnosticHashMap<K, V>,
+    values: PrecomputedHashMap<K, V>,
 }
 
 impl<K, V> OrderedMap<K, V>
@@ -99,7 +99,7 @@ where
     pub fn new() -> Self {
         OrderedMap {
             index: Vec::new(),
-            values: PrecomputedDiagnosticHashMap::default(),
+            values: PrecomputedHashMap::default(),
         }
     }
 
@@ -108,9 +108,7 @@ where
         if !self.values.contains_key(&key) {
             self.index.push(key.clone());
         }
-        self.values.begin_mutation();
-        self.values.try_insert(key, value).unwrap();
-        self.values.end_mutation();
+        self.values.insert(key, value);
     }
 
     /// Get a value given its key.
@@ -160,10 +158,7 @@ where
             None => return None,
         };
         self.index.remove(index);
-        self.values.begin_mutation();
-        let result = self.values.remove(key);
-        self.values.end_mutation();
-        result
+        self.values.remove(key)
     }
 
     fn remove_set<S>(&mut self, set: &::hash::HashSet<K, S>)
@@ -211,7 +206,7 @@ where
         };
 
         self.pos += 1;
-        let value = &self.inner.values.get(key).unwrap();
+        let value = &self.inner.values[key];
 
         Some((key, value))
     }

components/style/hash.rs

@@ -13,15 +13,10 @@ use fnv;
 pub use hashglobe::hash_map::HashMap;
 #[cfg(feature = "gecko")]
 pub use hashglobe::hash_set::HashSet;
-#[cfg(feature = "gecko")]
-pub use hashglobe::diagnostic::DiagnosticHashMap;
 
-#[cfg(feature = "servo")]
-pub use hashglobe::fake::{HashMap, HashSet};
 
-/// Alias to use regular HashMaps everywhere in Servo.
 #[cfg(feature = "servo")]
-pub type DiagnosticHashMap<K, V, S> = HashMap<K, V, S>;
+pub use hashglobe::fake::{HashMap, HashSet};
 
 /// Appropriate reexports of hash_map types
 pub mod map {

components/style/invalidation/element/invalidation_map.rs

@@ -172,6 +172,18 @@ impl InvalidationMap {
         }
     }
 
+    /// Returns the number of dependencies stored in the invalidation map.
+    pub fn len(&self) -> usize {
+        self.state_affecting_selectors.len() +
+        self.other_attribute_affecting_selectors.len() +
+        self.id_to_selector.iter().fold(0, |accum, (_, ref v)| {
+            accum + v.len()
+        }) +
+        self.class_to_selector.iter().fold(0, |accum, (_, ref v)| {
+            accum + v.len()
+        })
+    }
+
     /// Adds a selector to this `InvalidationMap`.  Returns Err(..) to
     /// signify OOM.
     pub fn note_selector(
@@ -234,7 +246,8 @@ impl InvalidationMap {
 
             for class in compound_visitor.classes {
                 self.class_to_selector
-                    .try_get_or_insert_with(class, quirks_mode, SmallVec::new)?
+                    .entry(class, quirks_mode)
+                    .or_insert_with(SmallVec::new)
                     .try_push(Dependency {
                         selector: selector.clone(),
                         selector_offset: sequence_start,
@@ -243,7 +256,8 @@ impl InvalidationMap {
 
             for id in compound_visitor.ids {
                 self.id_to_selector
-                    .try_get_or_insert_with(id, quirks_mode, SmallVec::new)?
+                    .entry(id, quirks_mode)
+                    .or_insert_with(SmallVec::new)
                     .try_push(Dependency {
                         selector: selector.clone(),
                         selector_offset: sequence_start,
@@ -279,22 +293,6 @@ impl InvalidationMap {
 
         Ok(())
     }
-
-    /// Allows mutation of this InvalidationMap.
-    pub fn begin_mutation(&mut self) {
-        self.class_to_selector.begin_mutation();
-        self.id_to_selector.begin_mutation();
-        self.state_affecting_selectors.begin_mutation();
-        self.other_attribute_affecting_selectors.begin_mutation();
-    }
-
-    /// Disallows mutation of this InvalidationMap.
-    pub fn end_mutation(&mut self) {
-        self.class_to_selector.end_mutation();
-        self.id_to_selector.end_mutation();
-        self.state_affecting_selectors.end_mutation();
-        self.other_attribute_affecting_selectors.end_mutation();
-    }
 }
 
 /// A struct that collects invalidations for a given compound selector.