From c92d94af4d4a2e85b7d7a64c9d1b3e192185930a Mon Sep 17 00:00:00 2001
From: hius07 <62179190+hius07@users.noreply.github.com>
Date: Tue, 17 Oct 2023 07:42:07 +0300
Subject: [PATCH] writeToFile: centralize (#11012)

---
 frontend/docsettings.lua | 36 +++---------------------------------
 frontend/luadefaults.lua | 27 ++-------------------------
 frontend/luasettings.lua | 39 +++++++++++++++++----------------------
 frontend/readhistory.lua |  7 +------
 frontend/util.lua        | 20 ++++++++++++++++++++
 5 files changed, 43 insertions(+), 86 deletions(-)

diff --git a/frontend/docsettings.lua b/frontend/docsettings.lua
index 52ab683e5..c10360513 100644
--- a/frontend/docsettings.lua
+++ b/frontend/docsettings.lua
@@ -290,14 +290,6 @@ function DocSettings:open(doc_path)
     return new
 end
 
-local function writeToFile(data, file)
-    file:write("-- we can read Lua syntax here!\nreturn ")
-    file:write(data)
-    file:write("\n")
-    ffiutil.fsyncOpenedFile(file) -- force flush to the storage device
-    file:close()
-end
-
 --- Serializes settings and writes them to `metadata.lua`.
 function DocSettings:flush(data, no_custom_metadata)
     -- Depending on the settings, doc_settings are saved to the book folder or
@@ -321,29 +313,9 @@ function DocSettings:flush(data, no_custom_metadata)
     for _, s in ipairs(serials) do
         local sidecar_dir, sidecar_file = unpack(s)
         util.makePath(sidecar_dir)
-        local directory_updated = false
-        if lfs.attributes(sidecar_file, "mode") == "file" then
-            -- As an additional safety measure (to the ffiutil.fsync* calls used below),
-            -- we only backup the file to .old when it has not been modified in the last 60 seconds.
-            -- This should ensure in the case the fsync calls are not supported
-            -- that the OS may have itself sync'ed that file content in the meantime.
-            local mtime = lfs.attributes(sidecar_file, "modification")
-            if mtime < os.time() - 60 then
-                logger.dbg("DocSettings: Renamed", sidecar_file, "to", sidecar_file .. ".old")
-                os.rename(sidecar_file, sidecar_file .. ".old")
-                directory_updated = true -- fsync directory content too below
-            end
-        end
         logger.dbg("DocSettings: Writing to", sidecar_file)
-        local f_out = io.open(sidecar_file, "w")
-        if f_out ~= nil then
-            writeToFile(s_out, f_out)
-
-            if directory_updated then
-                -- Ensure the file renaming is flushed to storage device
-                ffiutil.fsyncDirectory(sidecar_file)
-            end
-
+        local directory_updated = LuaSettings:backup(sidecar_file)
+        if util.writeToFile(s_out, sidecar_file, true, true, directory_updated) then
             -- move custom cover file and custom metadata file to the metadata file location
             if not no_custom_metadata then
                 local metadata_file, filepath, filename
@@ -614,9 +586,7 @@ function DocSettings:flushCustomMetadata(doc_path)
     local s_out = dump(self.data, nil, true)
     for _, sidecar_dir in ipairs(sidecar_dirs) do
         util.makePath(sidecar_dir)
-        local f_out = io.open(sidecar_dir .. "/" .. custom_metadata_filename, "w")
-        if f_out ~= nil then
-            writeToFile(s_out, f_out)
+        if util.writeToFile(s_out, sidecar_dir .. "/" .. custom_metadata_filename, true, true) then
             new_sidecar_dir = sidecar_dir .. "/"
             break
         end
diff --git a/frontend/luadefaults.lua b/frontend/luadefaults.lua
index e2fc4d820..aca6e525d 100644
--- a/frontend/luadefaults.lua
+++ b/frontend/luadefaults.lua
@@ -5,7 +5,6 @@ Subclass of LuaSettings dedicated to handling the legacy global constants.
 local DataStorage = require("datastorage")
 local LuaSettings = require("luasettings")
 local dump = require("dump")
-local ffiutil = require("ffi/util")
 local util = require("util")
 local lfs = require("libs/libkoreader-lfs")
 local logger = require("logger")
@@ -153,30 +152,8 @@ function LuaDefaults:reset() end
 --- Writes settings to disk.
 function LuaDefaults:flush()
     if not self.file then return end
-    local directory_updated = false
-    if lfs.attributes(self.file, "mode") == "file" then
-        -- As an additional safety measure (to the ffiutil.fsync* calls used below),
-        -- we only backup the file to .old when it has not been modified in the last 60 seconds.
-        -- This should ensure in the case the fsync calls are not supported
-        -- that the OS may have itself sync'ed that file content in the meantime.
-        local mtime = lfs.attributes(self.file, "modification")
-        if mtime < os.time() - 60 then
-            os.rename(self.file, self.file .. ".old")
-            directory_updated = true -- fsync directory content too below
-        end
-    end
-    local f_out = io.open(self.file, "w")
-    if f_out ~= nil then
-        f_out:write("-- we can read Lua syntax here!\nreturn ")
-        f_out:write(dump(self.rw, nil, true))
-        f_out:write("\n")
-        ffiutil.fsyncOpenedFile(f_out) -- force flush to the storage device
-        f_out:close()
-    end
-    if directory_updated then
-        -- Ensure the file renaming is flushed to storage device
-        ffiutil.fsyncDirectory(self.file)
-    end
+    local directory_updated = self:backup() -- LuaSettings
+    util.writeToFile(dump(self.rw, nil, true), self.file, true, true, directory_updated)
     return self
 end
 
diff --git a/frontend/luasettings.lua b/frontend/luasettings.lua
index bc3c06173..6b7796f3d 100644
--- a/frontend/luasettings.lua
+++ b/frontend/luasettings.lua
@@ -3,9 +3,9 @@ This module handles generic settings as well as KOReader's global settings syste
 ]]
 
 local dump = require("dump")
-local ffiutil = require("ffi/util")
 local lfs = require("libs/libkoreader-lfs")
 local logger = require("logger")
+local util = require("util")
 
 local LuaSettings = {}
 
@@ -249,33 +249,28 @@ function LuaSettings:reset(table)
     return self
 end
 
---- Writes settings to disk.
-function LuaSettings:flush()
-    if not self.file then return end
-    local directory_updated = false
-    if lfs.attributes(self.file, "mode") == "file" then
-        -- As an additional safety measure (to the ffiutil.fsync* calls used below),
+function LuaSettings:backup(file)
+    file = file or self.file
+    local directory_updated
+    if lfs.attributes(file, "mode") == "file" then
+        -- As an additional safety measure (to the ffiutil.fsync* calls used in util.writeToFile),
         -- we only backup the file to .old when it has not been modified in the last 60 seconds.
         -- This should ensure in the case the fsync calls are not supported
         -- that the OS may have itself sync'ed that file content in the meantime.
-        local mtime = lfs.attributes(self.file, "modification")
+        local mtime = lfs.attributes(file, "modification")
         if mtime < os.time() - 60 then
-            os.rename(self.file, self.file .. ".old")
-            directory_updated = true -- fsync directory content too below
+            os.rename(file, file .. ".old")
+            directory_updated = true -- fsync directory content
         end
     end
-    local f_out = io.open(self.file, "w")
-    if f_out ~= nil then
-        f_out:write("-- we can read Lua syntax here!\nreturn ")
-        f_out:write(dump(self.data, nil, true))
-        f_out:write("\n")
-        ffiutil.fsyncOpenedFile(f_out) -- force flush to the storage device
-        f_out:close()
-    end
-    if directory_updated then
-        -- Ensure the file renaming is flushed to storage device
-        ffiutil.fsyncDirectory(self.file)
-    end
+    return directory_updated
+end
+
+--- Writes settings to disk.
+function LuaSettings:flush()
+    if not self.file then return end
+    local directory_updated = self:backup()
+    util.writeToFile(dump(self.data, nil, true), self.file, true, true, directory_updated)
     return self
 end
 
diff --git a/frontend/readhistory.lua b/frontend/readhistory.lua
index 3a6dec044..9d582e869 100644
--- a/frontend/readhistory.lua
+++ b/frontend/readhistory.lua
@@ -94,12 +94,7 @@ function ReadHistory:_flush()
             file = v.file
         })
     end
-    local f = io.open(history_file, "w")
-    if f then
-        f:write("return " .. dump(content) .. "\n")
-        ffiutil.fsyncOpenedFile(f) -- force flush to the storage device
-        f:close()
-    end
+    util.writeToFile(dump(content), history_file, true, true)
     self:ensureLastFile()
 end
 
diff --git a/frontend/util.lua b/frontend/util.lua
index cab70d9f1..fe003dbaf 100644
--- a/frontend/util.lua
+++ b/frontend/util.lua
@@ -1034,6 +1034,26 @@ function util.partialMD5(filepath)
     return update()
 end
 
+function util.writeToFile(data, filepath, force_flush, lua_dofile_ready, directory_updated)
+    if not filepath then return end
+    if lua_dofile_ready then
+        local t = { "-- ", filepath, "\nreturn ", data, "\n" }
+        data = table.concat(t)
+    end
+    local file, err = io.open(filepath, "wb")
+    if not file then
+        return nil, err
+    end
+    file:write(data)
+    if force_flush then
+        BaseUtil.fsyncOpenedFile(file)
+    end
+    file:close()
+    if directory_updated then
+        BaseUtil.fsyncDirectory(filepath)
+    end
+    return true
+end
 
 --[[--
 Replaces invalid UTF-8 characters with a replacement string.