Changeset 241938 in webkit for trunk/Source/JavaScriptCore/parser/VariableEnvironment.h

Timestamp:

Feb 22, 2019, 1:08:35 AM (6 years ago)

Author:

Tadeu Zagallo

Message:

Cache CompactVariableMap::Handle instead of VariableEnvironment for UnlinkedFunctionExecutable
​https://bugs.webkit.org/show_bug.cgi?id=194706

Reviewed by Saam Barati.

In ​https://bugs.webkit.org/show_bug.cgi?id=194583 we started using a
CompactVariableMap::Handle instead of VariableEnvironment for
UnlinkedFunctionExecutables, but we were creating the full environment
to encode the executable in the bytecode cache. This patch changes it so
that we cache the handle instead of the environment. This avoids duplicating
the VariableEnvironment whenever we have to cache two handles that point
to the environment.

• bytecode/UnlinkedFunctionExecutable.h:
• parser/VariableEnvironment.cpp:

(JSC::CompactVariableMap::get):

• parser/VariableEnvironment.h:
• runtime/CachedTypes.cpp:

(JSC::CachedCompactVariableEnvironment::encode):
(JSC::CachedCompactVariableEnvironment::decode const):
(JSC::CachedCompactVariableMapHandle::encode):
(JSC::CachedCompactVariableMapHandle::decode const):
(JSC::CachedFunctionExecutable::encode):
(JSC::CachedFunctionExecutable::decode const):
(JSC::UnlinkedFunctionExecutable::UnlinkedFunctionExecutable):

File:

• trunk/Source/JavaScriptCore/parser/VariableEnvironment.h (modified) (4 diffs)

trunk/Source/JavaScriptCore/parser/VariableEnvironment.h

@@ -126 +126 @@
     WTF_MAKE_FAST_ALLOCATED;
     WTF_MAKE_NONCOPYABLE(CompactVariableEnvironment);
+
+    friend class CachedCompactVariableEnvironment;
+
 public:
     CompactVariableEnvironment(const VariableEnvironment&);
@@ -134 +137 @@
 
 private:
+    CompactVariableEnvironment() = default;
+
     Vector<RefPtr<UniquedStringImpl>> m_variables;
     Vector<VariableEnvironmentEntry> m_variableMetadata;
@@ -205 +210 @@
 public:
     class Handle {
+        friend class CachedCompactVariableMapHandle;
+
     public:
         Handle() = default;
@@ -242 +249 @@
 private:
     friend class Handle;
+    friend class CachedCompactVariableMapHandle;
+
+    Handle get(CompactVariableEnvironment*, bool& isNewEntry);
+
     HashMap<CompactVariableMapKey, unsigned> m_map;
 };