From 485d278b8c7968f3b37181f8040370c2084f068d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ivan=20Sto=C5=A1i=C4=87?= <ivan100sic@gmail.com>
Date: Tue, 5 Jan 2021 14:00:39 +0100
Subject: [PATCH] [FancyZones] Refactor/improve saving JSON files (#8947)

* Divide SaveFancyZonesData into two functions

* Removed unused function, continued refactoring

* Use SaveAppZoneHistory in some places

* Revert "Use SaveAppZoneHistory in some places"

This reverts commit 74a4a1e467dc78f17b142d3667529db98365e8b3.

* Only save files if the contents are about to be changed

* Restore FileWatcher
---
 src/modules/fancyzones/lib/FancyZones.cpp     |  4 +---
 src/modules/fancyzones/lib/FancyZonesData.cpp | 19 +++++++++++----
 src/modules/fancyzones/lib/FancyZonesData.h   |  2 ++
 src/modules/fancyzones/lib/JsonHelpers.cpp    | 24 +++++++++++--------
 src/modules/fancyzones/lib/JsonHelpers.h      |  8 +++----
 5 files changed, 34 insertions(+), 23 deletions(-)

diff --git a/src/modules/fancyzones/lib/FancyZones.cpp b/src/modules/fancyzones/lib/FancyZones.cpp
index dc18dd6419..86d0d643ec 100644
--- a/src/modules/fancyzones/lib/FancyZones.cpp
+++ b/src/modules/fancyzones/lib/FancyZones.cpp
@@ -53,9 +53,7 @@ public:
             PostMessageW(m_window, WM_PRIV_LOCATIONCHANGE, NULL, NULL);
         }),
         m_fileWatcher(FancyZonesDataInstance().GetZonesSettingsFileName(), [this]() {
-            // This is commented out until we figure out why calling UpdateZoneSets() in response to this message
-            // causes Win+Arrow to break.
-            //PostMessageW(m_window, WM_PRIV_FILE_UPDATE, NULL, NULL);
+            PostMessageW(m_window, WM_PRIV_FILE_UPDATE, NULL, NULL);
         })
     {
         m_settings->SetCallback(this);
diff --git a/src/modules/fancyzones/lib/FancyZonesData.cpp b/src/modules/fancyzones/lib/FancyZonesData.cpp
index 7880714642..a1b79b06ca 100644
--- a/src/modules/fancyzones/lib/FancyZonesData.cpp
+++ b/src/modules/fancyzones/lib/FancyZonesData.cpp
@@ -553,11 +553,20 @@ void FancyZonesData::LoadFancyZonesData()
 void FancyZonesData::SaveFancyZonesData() const
 {
     std::scoped_lock lock{ dataLock };
-    JSONHelpers::SaveFancyZonesData(zonesSettingsFileName,
-                                    appZoneHistoryFileName,
-                                    deviceInfoMap,
-                                    customZoneSetsMap,
-                                    appZoneHistoryMap);
+    JSONHelpers::SaveZoneSettings(zonesSettingsFileName, deviceInfoMap, customZoneSetsMap);
+    JSONHelpers::SaveAppZoneHistory(appZoneHistoryFileName, appZoneHistoryMap);
+}
+
+void FancyZonesData::SaveZoneSettings() const
+{
+    std::scoped_lock lock{ dataLock };
+    JSONHelpers::SaveZoneSettings(zonesSettingsFileName, deviceInfoMap, customZoneSetsMap);
+}
+
+void FancyZonesData::SaveAppZoneHistory() const
+{
+    std::scoped_lock lock{ dataLock };
+    JSONHelpers::SaveAppZoneHistory(appZoneHistoryFileName, appZoneHistoryMap);
 }
 
 void FancyZonesData::RemoveDesktopAppZoneHistory(const std::wstring& desktopId)
diff --git a/src/modules/fancyzones/lib/FancyZonesData.h b/src/modules/fancyzones/lib/FancyZonesData.h
index 62360c5b04..e88573bca7 100644
--- a/src/modules/fancyzones/lib/FancyZonesData.h
+++ b/src/modules/fancyzones/lib/FancyZonesData.h
@@ -85,6 +85,8 @@ public:
 
     void LoadFancyZonesData();
     void SaveFancyZonesData() const;
+    void SaveZoneSettings() const;
+    void SaveAppZoneHistory() const;
 
 private:
 #if defined(UNIT_TESTS)
diff --git a/src/modules/fancyzones/lib/JsonHelpers.cpp b/src/modules/fancyzones/lib/JsonHelpers.cpp
index 503914ccaf..192c667949 100644
--- a/src/modules/fancyzones/lib/JsonHelpers.cpp
+++ b/src/modules/fancyzones/lib/JsonHelpers.cpp
@@ -532,17 +532,10 @@ namespace JSONHelpers
         }
     }
 
-    void SaveFancyZonesData(const std::wstring& zonesSettingsFileName,
-                            const std::wstring& appZoneHistoryFileName,
-                            const TDeviceInfoMap& deviceInfoMap,
-                            const TCustomZoneSetsMap& customZoneSetsMap,
-                            const TAppZoneHistoryMap& appZoneHistoryMap)
-
+    void SaveZoneSettings(const std::wstring& zonesSettingsFileName, const TDeviceInfoMap& deviceInfoMap, const TCustomZoneSetsMap& customZoneSetsMap)
     {
         json::JsonObject root{};
-        json::JsonObject appZoneHistoryRoot{};
 
-        appZoneHistoryRoot.SetNamedValue(NonLocalizable::AppZoneHistoryStr, JSONHelpers::SerializeAppZoneHistory(appZoneHistoryMap));
         root.SetNamedValue(NonLocalizable::DevicesStr, JSONHelpers::SerializeDeviceInfos(deviceInfoMap));
         root.SetNamedValue(NonLocalizable::CustomZoneSetsStr, JSONHelpers::SerializeCustomZoneSets(customZoneSetsMap));
 
@@ -550,10 +543,21 @@ namespace JSONHelpers
         if (!before.has_value() || before.value().Stringify() != root.Stringify())
         {
             Trace::FancyZones::DataChanged();
+            json::to_file(zonesSettingsFileName, root);
         }
+    }
 
-        json::to_file(zonesSettingsFileName, root);
-        json::to_file(appZoneHistoryFileName, appZoneHistoryRoot);
+    void SaveAppZoneHistory(const std::wstring& appZoneHistoryFileName, const TAppZoneHistoryMap& appZoneHistoryMap)
+    {
+        json::JsonObject root{};
+
+        root.SetNamedValue(NonLocalizable::AppZoneHistoryStr, JSONHelpers::SerializeAppZoneHistory(appZoneHistoryMap));
+
+        auto before = json::from_file(appZoneHistoryFileName);
+        if (!before.has_value() || before.value().Stringify() != root.Stringify())
+        {
+            json::to_file(appZoneHistoryFileName, root);
+        }
     }
 
     TAppZoneHistoryMap ParseAppZoneHistory(const json::JsonObject& fancyZonesDataJSON)
diff --git a/src/modules/fancyzones/lib/JsonHelpers.h b/src/modules/fancyzones/lib/JsonHelpers.h
index 81f5911391..1a838a46e6 100644
--- a/src/modules/fancyzones/lib/JsonHelpers.h
+++ b/src/modules/fancyzones/lib/JsonHelpers.h
@@ -67,11 +67,9 @@ namespace JSONHelpers
     };
 
     json::JsonObject GetPersistFancyZonesJSON(const std::wstring& zonesSettingsFileName, const std::wstring& appZoneHistoryFileName);
-    void SaveFancyZonesData(const std::wstring& zonesSettingsFileName,
-                            const std::wstring& appZoneHistoryFileName,
-                            const TDeviceInfoMap& deviceInfoMap,
-                            const TCustomZoneSetsMap& customZoneSetsMap,
-                            const TAppZoneHistoryMap& appZoneHistoryMap);
+
+    void SaveZoneSettings(const std::wstring& zonesSettingsFileName, const TDeviceInfoMap& deviceInfoMap, const TCustomZoneSetsMap& customZoneSetsMap);
+    void SaveAppZoneHistory(const std::wstring& appZoneHistoryFileName, const TAppZoneHistoryMap& appZoneHistoryMap);
 
     TAppZoneHistoryMap ParseAppZoneHistory(const json::JsonObject& fancyZonesDataJSON);
     json::JsonArray SerializeAppZoneHistory(const TAppZoneHistoryMap& appZoneHistoryMap);