Random nano optimizations (#6801)

* Don't call Screen:afterPaint if nothing was actually painted

* Stupid micro-optimization (os.)time! (pun intended :D)

frontend/apps/reader/modules/readerview.lua

@@ -927,11 +927,11 @@ function ReaderView:checkAutoSaveSettings()
     if not interval then -- no auto save
         return
     end
-    if os.time() - self.settings_last_save_ts >= interval*60 then
-        self.settings_last_save_ts = os.time()
+    local now_ts = os.time()
+    if now_ts - self.settings_last_save_ts >= interval*60 then
+        self.settings_last_save_ts = now_ts
         UIManager:nextTick(function()
             self.ui:saveSettings()
-            self.settings_last_save_ts = os.time() -- re-set when saving done
         end)
     end
 end

frontend/device/generic/powerd.lua

@@ -133,9 +133,10 @@ function BasePowerD:setIntensity(intensity)
 end
 
 function BasePowerD:getCapacity()
-    if os.time() - self.last_capacity_pull_time >= 60 then
+    local now_ts = os.time()
+    if now_ts - self.last_capacity_pull_time >= 60 then
         self.battCapacity = self:getCapacityHW()
-        self.last_capacity_pull_time = os.time()
+        self.last_capacity_pull_time = now_ts
     end
     return self.battCapacity
 end

frontend/ui/uimanager.lua

@@ -1132,7 +1132,12 @@ function UIManager:_repaint()
             refresh.region.w, refresh.region.h,
             refresh.dither)
     end
-    Screen:afterPaint()
+
+    -- Don't trigger afterPaint if we did not, in fact, paint anything
+    if dirty then
+        Screen:afterPaint()
+    end
+
     self._refresh_stack = {}
     self.refresh_counted = false
 end

plugins/autosuspend.koplugin/main.lua

@@ -70,8 +70,9 @@ function AutoSuspend:_schedule()
         delay_suspend = self.auto_suspend_sec
         delay_shutdown = self.autoshutdown_timeout_seconds
     else
-        delay_suspend = self.last_action_sec + self.auto_suspend_sec - os.time()
-        delay_shutdown = self.last_action_sec + self.autoshutdown_timeout_seconds - os.time()
+        local now_ts = os.time()
+        delay_suspend = self.last_action_sec + self.auto_suspend_sec - now_ts
+        delay_shutdown = self.last_action_sec + self.autoshutdown_timeout_seconds - now_ts
     end
 
     -- Try to shutdown first, as we may have been woken up from suspend just for the sole purpose of doing that.
@@ -83,11 +84,11 @@ function AutoSuspend:_schedule()
         UIManager:suspend()
     else
         if self:_enabled() then
-            logger.dbg("AutoSuspend: schedule suspend at ", os.time() + delay_suspend)
+            logger.dbg("AutoSuspend: schedule suspend in", delay_suspend)
             UIManager:scheduleIn(delay_suspend, self._schedule, self)
         end
         if self:_enabledShutdown() then
-            logger.dbg("AutoSuspend: schedule shutdown at ", os.time() + delay_shutdown)
+            logger.dbg("AutoSuspend: schedule shutdown in", delay_shutdown)
             UIManager:scheduleIn(delay_shutdown, self._schedule, self)
         end
     end
@@ -100,8 +101,9 @@ end
 
 function AutoSuspend:_start()
     if self:_enabled() or self:_enabledShutdown() then
-        logger.dbg("AutoSuspend: start at ", os.time())
-        self.last_action_sec = os.time()
+        local now_ts = os.time()
+        logger.dbg("AutoSuspend: start at", now_ts)
+        self.last_action_sec = now_ts
         self:_schedule()
     end
 end

plugins/autoturn.koplugin/main.lua

@@ -27,9 +27,9 @@ function AutoTurn:_schedule(settings_id)
         return
     end
     if self.settings_id ~= settings_id then
-        logger.dbg("AutoTurn:_schedule registered settings_id ",
+        logger.dbg("AutoTurn:_schedule registered settings_id",
                    settings_id,
-                   " does not equal to current one ",
+                   "does not equal to current one",
                    self.settings_id)
         return
     end
@@ -41,10 +41,10 @@ function AutoTurn:_schedule(settings_id)
             logger.dbg("AutoTurn: go to next page")
             self.ui:handleEvent(Event:new("GotoViewRel", self.autoturn_distance))
         end
-        logger.dbg("AutoTurn: schedule at ", os.time() + self.autoturn_sec)
+        logger.dbg("AutoTurn: schedule in", self.autoturn_sec)
         UIManager:scheduleIn(self.autoturn_sec, function() self:_schedule(settings_id) end)
     else
-        logger.dbg("AutoTurn: schedule at ", os.time() + delay)
+        logger.dbg("AutoTurn: schedule in", delay)
         UIManager:scheduleIn(delay, function() self:_schedule(settings_id) end)
     end
 end
@@ -52,14 +52,15 @@ end
 function AutoTurn:_deprecateLastTask()
     PluginShare.pause_auto_suspend = false
     self.settings_id = self.settings_id + 1
-    logger.dbg("AutoTurn: deprecateLastTask ", self.settings_id)
+    logger.dbg("AutoTurn: deprecateLastTask", self.settings_id)
 end
 
 function AutoTurn:_start()
     if self:_enabled() then
-        logger.dbg("AutoTurn: start at ", os.time())
+        local now_ts = os.time()
+        logger.dbg("AutoTurn: start at", now_ts)
         PluginShare.pause_auto_suspend = true
-        self.last_action_sec = os.time()
+        self.last_action_sec = now_ts
         self:_schedule(self.settings_id)
 
         local text

plugins/statistics.koplugin/calendarview.lua

@@ -449,13 +449,14 @@ function CalendarView:init()
     outer_padding = math.floor((self.dimen.w - 7*self.day_width - 6*self.inner_padding) / 2)
     self.content_width = self.dimen.w - 2*outer_padding
 
+    local now_ts = os.time()
     if not MIN_MONTH then
         local min_ts = self.reader_statistics:getFirstTimestamp()
-        if not min_ts then min_ts = os.time() end
+        if not min_ts then min_ts = now_ts end
         MIN_MONTH = os.date("%Y-%m", min_ts)
     end
     self.min_month = MIN_MONTH
-    self.max_month = os.date("%Y-%m", os.time())
+    self.max_month = os.date("%Y-%m", now_ts)
     if not self.cur_month then
         self.cur_month = self.max_month
     end

plugins/statistics.koplugin/main.lua

@@ -1241,6 +1241,7 @@ function ReaderStatistics:getCurrentStat(id_book)
     --       which is computed slightly differently (c.f., insertDB), we'll be using this tweaked book read time
     --       to compute the other time-based statistics...
     local __, book_read_time = self:getPageTimeTotalStats(id_book)
+    local now_ts = os.time()
 
     if total_time_book == nil then
         total_time_book = 0
@@ -1249,14 +1250,14 @@ function ReaderStatistics:getCurrentStat(id_book)
         total_read_pages = 0
     end
     if first_open == nil then
-        first_open = os.time()
+        first_open = now_ts
     end
     self.data.pages = self.view.document:getPageCount()
     total_time_book = tonumber(total_time_book)
     total_read_pages = tonumber(total_read_pages)
     local time_to_read = (self.data.pages - self.view.state.page) * self.avg_time
     local estimate_days_to_read = math.ceil(time_to_read/(book_read_time/tonumber(total_days)))
-    local estimate_end_of_read_date = os.date("%Y-%m-%d", tonumber(os.time() + estimate_days_to_read * 86400))
+    local estimate_end_of_read_date = os.date("%Y-%m-%d", tonumber(now_ts + estimate_days_to_read * 86400))
     local formatstr = "%.0f%%"
     return {
         -- Global statistics (may consider other books than current book)