PPAPI: Reduce string copying in SerializedVar.

ppapi/shared_impl/var.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ppapi/shared_impl/var.h"
 
 #include <limits>
 
 #include "base/logging.h"
 #include "base/string_number_conversions.h"
@@ skipping 106 matching lines @@
     : value_(str) {
 }
 
 StringVar::StringVar(const char* str, uint32 len)
     : value_(str, len) {
 }
 
 StringVar::~StringVar() {
 }
 
+StringVar::StringVar(scoped_ptr<std::string> str) {
+  // Swap the given string's contents in to value to avoid copying.
+  str->swap(value_);
+}
+
 StringVar* StringVar::AsStringVar() {
   return this;
 }
 
 PP_VarType StringVar::GetType() const {
   return PP_VARTYPE_STRING;
 }
 
 // static
 PP_Var StringVar::StringToPPVar(const std::string& var) {
   return StringToPPVar(var.c_str(), var.size());
 }
 
 // static
 PP_Var StringVar::StringToPPVar(const char* data, uint32 len) {
   scoped_refptr<StringVar> str(new StringVar(data, len));
   if (!str || !IsStringUTF8(str->value()))
     return PP_MakeNull();
   return str->GetPPVar();
 }
 
 // static
+PP_Var StringVar::StringToPPVar(scoped_ptr<std::string> str) {
+  DCHECK(str.get());
+  if (!str.get())
+    return PP_MakeNull();
+  scoped_refptr<StringVar> str_var(new StringVar(str.Pass()));
+  if (!str_var || !IsStringUTF8(str_var->value()))
+    return PP_MakeNull();
+  return str_var->GetPPVar();
+}
+
+// static
 StringVar* StringVar::FromPPVar(PP_Var var) {
   if (var.type != PP_VARTYPE_STRING)
     return NULL;
   scoped_refptr<Var> var_object(
       PpapiGlobals::Get()->GetVarTracker()->GetVar(var));
   if (!var_object)
     return NULL;
   return var_object->AsStringVar();
 }
 
@@ skipping 19 matching lines @@
     return NULL;
   scoped_refptr<Var> var_object(
       PpapiGlobals::Get()->GetVarTracker()->GetVar(var));
   if (!var_object)
     return NULL;
   return var_object->AsArrayBufferVar();
 }
 
 }  // namespace ppapi