Refactoring the master_preferences functions....

chrome/installer/util/master_preferences.cc

Index: chrome/installer/util/master_preferences.cc
===================================================================
--- chrome/installer/util/master_preferences.cc	(revision 64604)
+++ chrome/installer/util/master_preferences.cc	(working copy)
@@ -9,6 +9,7 @@
 #include "base/path_service.h"
 #include "base/string_util.h"
 #include "chrome/common/json_value_serializer.h"
+#include "chrome/installer/util/master_preferences_constants.h"
 #include "chrome/installer/util/util_constants.h"
 #include "googleurl/src/gurl.h"
 
@@ -16,6 +17,7 @@
 namespace {
 
 const char kDistroDict[] = "distribution";
+const char kFirstRunTabs[] = "first_run_tabs";
 
 bool GetGURLFromValue(const Value* in_value, GURL* out_value) {
   if (!in_value || !out_value)
@@ -47,130 +49,11 @@
   return list;
 }
 
-}  // namespace
-
-namespace installer_util {
-
-bool GetDistroBooleanPreference(const DictionaryValue* prefs,
-                                const std::string& name,
-                                bool* value) {
-  if (!prefs || !value)
-    return false;
-
-  DictionaryValue* distro = NULL;
-  if (!prefs->GetDictionary(kDistroDict, &distro) || !distro)
-    return false;
-
-  if (!distro->GetBoolean(name, value))
-    return false;
-
-  return true;
-}
-
-bool GetDistroStringPreference(const DictionaryValue* prefs,
-                               const std::string& name,
-                               std::string* value) {
-  if (!prefs || !value)
-    return false;
-
-  DictionaryValue* distro = NULL;
-  if (!prefs->GetDictionary(kDistroDict, &distro) || !distro)
-    return false;
-
-  std::string str_value;
-  if (!distro->GetString(name, &str_value))
-    return false;
-
-  if (str_value.empty())
-    return false;
-
-  *value = str_value;
-  return true;
-}
-
-bool GetDistroIntegerPreference(const DictionaryValue* prefs,
-                                const std::string& name,
-                                int* value) {
-  if (!prefs || !value)
-    return false;
-
-  DictionaryValue* distro = NULL;
-  if (!prefs->GetDictionary(kDistroDict, &distro) || !distro)
-    return false;
-
-  if (!distro->GetInteger(name, value))
-    return false;
-
-  return true;
-}
-
-DictionaryValue* GetInstallPreferences(const CommandLine& cmd_line) {
-  DictionaryValue* prefs = NULL;
-#if defined(OS_WIN)
-  if (cmd_line.HasSwitch(installer_util::switches::kInstallerData)) {
-    FilePath prefs_path = cmd_line.GetSwitchValuePath(
-        installer_util::switches::kInstallerData);
-    prefs = installer_util::ParseDistributionPreferences(prefs_path);
-  }
-
-  if (!prefs)
-    prefs = new DictionaryValue();
-
-  if (cmd_line.HasSwitch(installer_util::switches::kChromeFrame))
-    installer_util::SetDistroBooleanPreference(
-        prefs, installer_util::master_preferences::kChromeFrame, true);
-
-  if (cmd_line.HasSwitch(installer_util::switches::kCreateAllShortcuts))
-    installer_util::SetDistroBooleanPreference(
-        prefs, installer_util::master_preferences::kCreateAllShortcuts, true);
-
-  if (cmd_line.HasSwitch(installer_util::switches::kDoNotCreateShortcuts))
-    installer_util::SetDistroBooleanPreference(
-        prefs, installer_util::master_preferences::kDoNotCreateShortcuts, true);
-
-  if (cmd_line.HasSwitch(installer_util::switches::kMsi))
-    installer_util::SetDistroBooleanPreference(
-        prefs, installer_util::master_preferences::kMsi, true);
-
-  if (cmd_line.HasSwitch(
-        installer_util::switches::kDoNotRegisterForUpdateLaunch))
-    installer_util::SetDistroBooleanPreference(
-        prefs,
-        installer_util::master_preferences::kDoNotRegisterForUpdateLaunch,
-        true);
-
-  if (cmd_line.HasSwitch(installer_util::switches::kDoNotLaunchChrome))
-    installer_util::SetDistroBooleanPreference(
-        prefs, installer_util::master_preferences::kDoNotLaunchChrome, true);
-
-  if (cmd_line.HasSwitch(installer_util::switches::kMakeChromeDefault))
-    installer_util::SetDistroBooleanPreference(
-        prefs, installer_util::master_preferences::kMakeChromeDefault, true);
-
-  if (cmd_line.HasSwitch(installer_util::switches::kSystemLevel))
-    installer_util::SetDistroBooleanPreference(
-        prefs, installer_util::master_preferences::kSystemLevel, true);
-
-  if (cmd_line.HasSwitch(installer_util::switches::kVerboseLogging))
-    installer_util::SetDistroBooleanPreference(
-        prefs, installer_util::master_preferences::kVerboseLogging, true);
-
-  if (cmd_line.HasSwitch(installer_util::switches::kAltDesktopShortcut))
-    installer_util::SetDistroBooleanPreference(
-        prefs, installer_util::master_preferences::kAltShortcutText, true);
-#endif
-
-  return prefs;
-}
-
 DictionaryValue* ParseDistributionPreferences(
     const FilePath& master_prefs_path) {
-  if (!file_util::PathExists(master_prefs_path))
-    return NULL;
-
   std::string json_data;
   if (!file_util::ReadFileToString(master_prefs_path, &json_data)) {
-    LOG(WARNING) << "Failed to read master prefs file.";
+    LOG(WARNING) << "Failed to read master prefs file. ";
     return NULL;
   }
   JSONStringValueSerializer json(json_data);
@@ -188,23 +71,112 @@
   return static_cast<DictionaryValue*>(root.release());
 }
 
-std::vector<GURL> GetFirstRunTabs(const DictionaryValue* prefs) {
-  return GetNamedList("first_run_tabs", prefs);
+}  // namespace
+
+namespace installer_util {
+
+MasterPreferences::MasterPreferences(const CommandLine& cmd_line)
+    : distribution_(NULL), preferences_read_from_file_(false) {
+#if defined(OS_WIN)
+  if (cmd_line.HasSwitch(installer_util::switches::kInstallerData)) {
+    FilePath prefs_path(cmd_line.GetSwitchValuePath(
+        installer_util::switches::kInstallerData));
+    this->MasterPreferences::MasterPreferences(prefs_path);
+  } else {
+    master_dictionary_.reset(new DictionaryValue());
+  }
+
+  DCHECK(master_dictionary_.get());
+
+  // A simple map from command line switches to equivalent switches in the
+  // distribution dictionary.  Currently all switches added will be set to
+  // 'true'.
+  static const struct CmdLineSwitchToDistributionSwitch {
+    const wchar_t* cmd_line_switch;
+    const char* distribution_switch;
+  } translate_switches[] = {
+    { installer_util::switches::kChromeFrame,
+      installer_util::master_preferences::kChromeFrame },
+    { installer_util::switches::kCreateAllShortcuts,
+      installer_util::master_preferences::kCreateAllShortcuts },
+    { installer_util::switches::kDoNotCreateShortcuts,
+      installer_util::master_preferences::kDoNotCreateShortcuts },
+    { installer_util::switches::kMsi,
+      installer_util::master_preferences::kMsi },
+    { installer_util::switches::kDoNotRegisterForUpdateLaunch,
+      installer_util::master_preferences::kDoNotRegisterForUpdateLaunch },
+    { installer_util::switches::kDoNotLaunchChrome,
+      installer_util::master_preferences::kDoNotLaunchChrome },
+    { installer_util::switches::kMakeChromeDefault,
+      installer_util::master_preferences::kMakeChromeDefault },
+    { installer_util::switches::kSystemLevel,
+      installer_util::master_preferences::kSystemLevel },
+    { installer_util::switches::kVerboseLogging,
+      installer_util::master_preferences::kVerboseLogging },
+    { installer_util::switches::kAltDesktopShortcut,
+      installer_util::master_preferences::kAltShortcutText },
+  };
+
+  std::string name(kDistroDict);
+  for (int i = 0; i < arraysize(translate_switches); ++i) {
+    if (cmd_line.HasSwitch(translate_switches[i].cmd_line_switch)) {
+      name.resize(arraysize(kDistroDict) - 1);
+      name.append(".").append(translate_switches[i].distribution_switch);
+      master_dictionary_->SetBoolean(name, true);
+    }
+  }
+
+  // Cache a pointer to the distribution dictionary. Ignore errors if any.
+  master_dictionary_->GetDictionary(kDistroDict, &distribution_);
+#endif
 }
 
-bool SetDistroBooleanPreference(DictionaryValue* prefs,
-                                const std::string& name,
-                                bool value) {
-  if (!prefs || name.empty())
-    return false;
-  prefs->SetBoolean(std::string(kDistroDict) + "." + name, value);
-  return true;
+MasterPreferences::MasterPreferences(const FilePath& prefs_path)
+    : distribution_(NULL), preferences_read_from_file_(false) {
+  master_dictionary_.reset(ParseDistributionPreferences(prefs_path));
+  LOG_IF(ERROR, !master_dictionary_.get()) << "Failed to parse "
+      << prefs_path.value();
+  if (!master_dictionary_.get()) {
+    master_dictionary_.reset(new DictionaryValue());
+  } else {
+    preferences_read_from_file_ = true;
+    // Cache a pointer to the distribution dictionary.
+    master_dictionary_->GetDictionary(kDistroDict, &distribution_);
+  }
 }
 
-bool HasExtensionsBlock(const DictionaryValue* prefs,
-                        DictionaryValue** extensions) {
-  return (prefs->GetDictionary(master_preferences::kExtensionsBlock,
-                               extensions));
+MasterPreferences::~MasterPreferences() {
 }
 
+bool MasterPreferences::GetBool(const std::string& name, bool* value) const {
+  bool ret = false;
+  if (distribution_)
+    ret = distribution_->GetBoolean(name, value);
+  return ret;
+}
+
+bool MasterPreferences::GetInt(const std::string& name, int* value) const {
+  bool ret = false;
+  if (distribution_)
+    ret = distribution_->GetInteger(name, value);
+  return ret;
+}
+
+bool MasterPreferences::GetString(const std::string& name,
+                                  std::string* value) const {
+  bool ret = false;
+  if (distribution_)
+    ret = (distribution_->GetString(name, value) && !value->empty());
+  return ret;
+}
+
+std::vector<GURL> MasterPreferences::GetFirstRunTabs() const {
+  return GetNamedList(kFirstRunTabs, master_dictionary_.get());
+}
+
+bool MasterPreferences::GetExtensionsBlock(DictionaryValue** extensions) const {
+  return master_dictionary_->GetDictionary(
+      master_preferences::kExtensionsBlock, extensions);
+}
+
 }  // installer_util