[settings] add versioning support

13 files changed, 72 insertions, 10 deletions

diff --git a/system/settings/android.xml b/system/settings/android.xml
index dab3be1c0a..53d2c10650 100644
--- a/system/settings/android.xml
+++ b/system/settings/android.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<settings>
+<settings version="1">
   <section id="system">
     <category id="display">
       <group id="1">
diff --git a/system/settings/darwin.xml b/system/settings/darwin.xml
index b948ed843d..e18be78430 100644
--- a/system/settings/darwin.xml
+++ b/system/settings/darwin.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<settings>
+<settings version="1">
   <section id="system">
     <category id="display">
       <group id="1">
diff --git a/system/settings/darwin_ios.xml b/system/settings/darwin_ios.xml
index e7c41543ce..329a9c9a5f 100644
--- a/system/settings/darwin_ios.xml
+++ b/system/settings/darwin_ios.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<settings>
+<settings version="1">
   <section id="player" label="14200" help="">
     <category id="videoplayer">
       <group id="2">
diff --git a/system/settings/darwin_osx.xml b/system/settings/darwin_osx.xml
index a81fe9a80a..852f524618 100644
--- a/system/settings/darwin_osx.xml
+++ b/system/settings/darwin_osx.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<settings>
+<settings version="1">
   <section id="system">
     <category id="display">
       <group id="1">
diff --git a/system/settings/imx6.xml b/system/settings/imx6.xml
index 3af9b3f9d2..a1cac3abaa 100644
--- a/system/settings/imx6.xml
+++ b/system/settings/imx6.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<settings>
+<settings version="1">
   <section id="player">
     <category id="videoplayer">
       <group id="3">
diff --git a/system/settings/linux.xml b/system/settings/linux.xml
index dee93a61d8..7456a57982 100644
--- a/system/settings/linux.xml
+++ b/system/settings/linux.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<settings>
+<settings version="1">
   <section id="system">
     <category id="display">
       <group id="1">
diff --git a/system/settings/rbp.xml b/system/settings/rbp.xml
index 62e9c8ed21..7337d13f4c 100644
--- a/system/settings/rbp.xml
+++ b/system/settings/rbp.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<settings>
+<settings version="1">
   <section id="player">
     <category id="videoplayer">
       <group id="3">
diff --git a/system/settings/rbp2.xml b/system/settings/rbp2.xml
index 50bd55e9c9..15b98bd07c 100644
--- a/system/settings/rbp2.xml
+++ b/system/settings/rbp2.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<settings>
+<settings version="1">
   <section id="player">
     <category id="videoplayer">
       <group id="3">
diff --git a/system/settings/settings.xml b/system/settings/settings.xml
index f0b3e25bfb..c036bc0807 100755
--- a/system/settings/settings.xml
+++ b/system/settings/settings.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<settings>
+<settings version="1">
   <section id="player" label="14200" help="38100">
     <category id="videoplayer" label="14215" help="38103">
       <group id="1" label="14230">
diff --git a/system/settings/win32.xml b/system/settings/win32.xml
index a017d30c24..da1e9a0f25 100644
--- a/system/settings/win32.xml
+++ b/system/settings/win32.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<settings>
+<settings version="1">
   <section id="services">
     <category id="general">
       <group id="2">
diff --git a/xbmc/settings/lib/SettingDefinitions.h b/xbmc/settings/lib/SettingDefinitions.h
index 2b35def865..51a337b9d9 100644
--- a/xbmc/settings/lib/SettingDefinitions.h
+++ b/xbmc/settings/lib/SettingDefinitions.h
@@ -24,6 +24,7 @@
 #include <vector>
 
 #define SETTING_XML_ROOT              "settings"
+#define SETTING_XML_ROOT_VERSION      "version"
 
 #define SETTING_XML_ELM_SECTION       "section"
 #define SETTING_XML_ELM_CATEGORY      "category"
diff --git a/xbmc/settings/lib/SettingsManager.cpp b/xbmc/settings/lib/SettingsManager.cpp
index 9b8d5f1aed..f7dbbd0070 100644
--- a/xbmc/settings/lib/SettingsManager.cpp
+++ b/xbmc/settings/lib/SettingsManager.cpp
@@ -73,6 +73,15 @@ CSettingsManager::~CSettingsManager()
   Clear();
 }
 
+uint32_t CSettingsManager::ParseVersion(const TiXmlElement* root) const
+{
+  // try to get and check the version
+  uint32_t version = 0;
+  root->QueryUnsignedAttribute(SETTING_XML_ROOT_VERSION, &version);
+
+  return version;
+}
+
 bool CSettingsManager::Initialize(const TiXmlElement *root)
 {
   CExclusiveLock lock(m_critical);
@@ -86,6 +95,22 @@ bool CSettingsManager::Initialize(const TiXmlElement *root)
     return false;
   }
 
+  // try to get and check the version
+  uint32_t version = ParseVersion(root);
+  if (version == 0)
+    CLog::Log(LOGWARNING, "CSettingsManager: missing " SETTING_XML_ROOT_VERSION " attribute");
+
+  if (version < MinimumSupportedVersion)
+  {
+    CLog::Log(LOGERROR, "CSettingsManager: unable to read setting definitions from version %u (minimum version: %u)", version, MinimumSupportedVersion);
+    return false;
+  }
+  if (version > Version)
+  {
+    CLog::Log(LOGERROR, "CSettingsManager: unable to read setting definitions from version %u (current version: %u)", version, Version);
+    return false;
+  }
+
   const TiXmlNode *sectionNode = root->FirstChild(SETTING_XML_ELM_SECTION);
   while (sectionNode != NULL)
   {
@@ -126,6 +151,22 @@ bool CSettingsManager::Load(const TiXmlElement *root, bool &updated, bool trigge
   if (triggerEvents && !OnSettingsLoading())
     return false;
 
+  // try to get and check the version
+  uint32_t version = ParseVersion(root);
+  if (version == 0)
+    CLog::Log(LOGWARNING, "CSettingsManager: missing " SETTING_XML_ROOT_VERSION " attribute");
+
+  if (version < MinimumSupportedVersion)
+  {
+    CLog::Log(LOGERROR, "CSettingsManager: unable to read setting values from version %u (minimum version: %u)", version, MinimumSupportedVersion);
+    return false;
+  }
+  if (version > Version)
+  {
+    CLog::Log(LOGERROR, "CSettingsManager: unable to read setting values from version %u (current version: %u)", version, Version);
+    return false;
+  }
+
   if (!Deserialize(root, updated, loadedSettings))
     return false;
 
@@ -150,6 +191,15 @@ bool CSettingsManager::Save(TiXmlNode *root) const
   if (!OnSettingsSaving())
     return false;
 
+  // save the current version
+  TiXmlElement* rootElement = root->ToElement();
+  if (rootElement == nullptr)
+  {
+    CLog::Log(LOGERROR, "CSettingsManager: failed to save settings");
+    return false;
+  }
+  rootElement->SetAttribute(SETTING_XML_ROOT_VERSION, Version);
+
   if (!Serialize(root))
   {
     CLog::Log(LOGERROR, "CSettingsManager: failed to save settings");
diff --git a/xbmc/settings/lib/SettingsManager.h b/xbmc/settings/lib/SettingsManager.h
index f9faba21e6..2e644be13f 100644
--- a/xbmc/settings/lib/SettingsManager.h
+++ b/xbmc/settings/lib/SettingsManager.h
@@ -56,6 +56,9 @@ public:
   CSettingsManager();
   virtual ~CSettingsManager();
 
+  static const uint32_t Version = 1;
+  static const uint32_t MinimumSupportedVersion = 0;
+
   // implementation of ISettingCreator
   virtual CSetting* CreateSetting(const std::string &settingType, const std::string &settingId, CSettingsManager *settingsManager = NULL) const override;
 
@@ -63,6 +66,14 @@ public:
   virtual ISettingControl* CreateControl(const std::string &controlType) const override;
 
   /*!
+   \brief Try to get the version of the setting definitions/values represented by the given XML element.
+
+   \param root XML element representing setting definitions/values
+   \return Version of the setting definitions/values or 0 if no version has been specified
+   */
+  uint32_t ParseVersion(const TiXmlElement* root) const;
+
+  /*!
    \brief Initializes the settings manager using the setting definitions
    represented by the given XML element.