Keep natives source code in external strings instead of putting...

src/bootstrapper.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 18 matching lines @@
 
 #include "accessors.h"
 #include "api.h"
 #include "bootstrapper.h"
 #include "compiler.h"
 #include "debug.h"
 #include "execution.h"
 #include "global-handles.h"
 #include "macro-assembler.h"
 #include "natives.h"
+#include "snapshot.h"
 
 namespace v8 {
 namespace internal {
 
 // A SourceCodeCache uses a FixedArray to store pairs of
 // (AsciiString*, JSFunction*), mapping names of native code files
 // (runtime.js, etc.) to precompiled functions. Instead of mapping
 // names to functions it might make sense to let the JS2C tool
 // generate an index for each native JS file.
 class SourceCodeCache BASE_EMBEDDED {
@@ skipping 36 matching lines @@
   }
 
  private:
   Script::Type type_;
   FixedArray* cache_;
   DISALLOW_COPY_AND_ASSIGN(SourceCodeCache);
 };
 
 static SourceCodeCache natives_cache(Script::TYPE_NATIVE);
 static SourceCodeCache extensions_cache(Script::TYPE_EXTENSION);
+// This is for delete, not delete[].
+static List<char*>* delete_these_non_arrays_on_tear_down = NULL;
 
 
 Handle<String> Bootstrapper::NativesSourceLookup(int index) {
   ASSERT(0 <= index && index < Natives::GetBuiltinsCount());
   if (Heap::natives_source_cache()->get(index)->IsUndefined()) {
-    Handle<String> source_code =
-      Factory::NewStringFromAscii(Natives::GetScriptSource(index));
-    Heap::natives_source_cache()->set(index, *source_code);
+    if (!Snapshot::IsEnabled || FLAG_new_snapshot) {
+      if (delete_these_non_arrays_on_tear_down == NULL) {
+        delete_these_non_arrays_on_tear_down = new List<char*>(2);
+      }
+      // We can use external strings for the natives.
+      NativesExternalStringResource* resource =
+          new NativesExternalStringResource(
+              Natives::GetScriptSource(index).start());
+      // The resources are small objects and we only make a fixed number of
+      // them, but lets clean them up on exit for neatness.
+      delete_these_non_arrays_on_tear_down->
+          Add(reinterpret_cast<char*>(resource));
+      Handle<String> source_code =
+          Factory::NewExternalStringFromAscii(resource);
+      Heap::natives_source_cache()->set(index, *source_code);
+    } else {
+      // Old snapshot code can't cope with external strings at all.
+      Handle<String> source_code =
+        Factory::NewStringFromAscii(Natives::GetScriptSource(index));
+      Heap::natives_source_cache()->set(index, *source_code);
+    }
   }
   Handle<Object> cached_source(Heap::natives_source_cache()->get(index));
   return Handle<String>::cast(cached_source);
 }
 
 
 bool Bootstrapper::NativesCacheLookup(Vector<const char> name,
                                       Handle<JSFunction>* handle) {
   return natives_cache.Lookup(name, handle);
 }
 
 
 void Bootstrapper::NativesCacheAdd(Vector<const char> name,
                                    Handle<JSFunction> fun) {
   natives_cache.Add(name, fun);
 }
 
 
 void Bootstrapper::Initialize(bool create_heap_objects) {
   natives_cache.Initialize(create_heap_objects);
   extensions_cache.Initialize(create_heap_objects);
 }
 
 
 void Bootstrapper::TearDown() {
+  if (delete_these_non_arrays_on_tear_down != NULL) {
+    int len = delete_these_non_arrays_on_tear_down->length();
+    ASSERT(len < 20);  // Don't use this mechanism for unbounded allocations.
+    for (int i = 0; i < len; i++) {
+      delete delete_these_non_arrays_on_tear_down->at(i);
+    }
+    delete delete_these_non_arrays_on_tear_down;
+    delete_these_non_arrays_on_tear_down = NULL;
+  }
+
   natives_cache.Initialize(false);  // Yes, symmetrical
   extensions_cache.Initialize(false);
 }
 
 
 // Pending fixups are code positions that refer to builtin code
 // objects that were not available at the time the code was generated.
 // The pending list is processed whenever an environment has been
 // created.
 class PendingFixups : public AllStatic {
@@ skipping 1464 matching lines @@
 }
 
 
 // Restore statics that are thread local.
 char* Genesis::RestoreState(char* from) {
   current_ = *reinterpret_cast<Genesis**>(from);
   return from + sizeof(current_);
 }
 
 } }  // namespace v8::internal