Rewrite DefaultPrefStore for performance

base/prefs/default_pref_store.cc

 // Copyright (c) 2012 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 "base/prefs/default_pref_store.h"
 
 using base::Value;
 
 DefaultPrefStore::DefaultPrefStore() {}
 
+PrefStore::ReadResult DefaultPrefStore::GetValue(
+    const std::string& key,
+    const base::Value** result) const {
+  const const_iterator entry = prefs_.find(key);

[Bernhard Bauer, 2012/11/06 18:25:02]

Nit: I think a const const_iterator is overkill ;-)

[Mattias Nissler (ping if slow), 2012/11/07 08:24:02]

It's correct w.r.t. the style guide though.

[Anthony Berent, 2012/11/07 11:22:54]

This code actually goes away as a result of Mattlas's other comment.

+  if (entry != prefs_.end()) {
+    if (result)
+      *result = entry->second;
+    return READ_OK;
+  }
+  return READ_NO_VALUE;
+}
+
 void DefaultPrefStore::SetDefaultValue(const std::string& key, Value* value) {
   CHECK(GetValue(key, NULL) == READ_NO_VALUE);
-  SetValue(key, value);
+  prefs_.insert(std::make_pair(key, value));
 }
 
 void DefaultPrefStore::RemoveDefaultValue(const std::string& key) {
   CHECK(GetValue(key, NULL) == READ_OK);
-  RemoveValue(key);
+  prefs_.erase(key);
 }
 
 base::Value::Type DefaultPrefStore::GetType(const std::string& key) const {
   const Value* value;
   return GetValue(key, &value) == READ_OK ? value->GetType() : Value::TYPE_NULL;
 }
 
+DefaultPrefStore::const_iterator DefaultPrefStore::begin() const {
+  return prefs_.begin();
+}
+
+DefaultPrefStore::const_iterator DefaultPrefStore::end() const {
+  return prefs_.end();
+}
+
 DefaultPrefStore::~DefaultPrefStore() {}