Port unitframe and actionbar performance fixes from Duciel/pfUI@45f8ca6

Unitframes: only set the unit attribute when it changes, poll group frame indicators every 3s since events already cover them, and limit full refreshes on eventless frames to unit changes or once a second.

Actionbar: handle UNIT_INVENTORY_CHANGED with a light count/cooldown/usable pass instead of a full update of every button, and skip hidden buttons in the cached passes, catching them up once they become visible.

api/unitframes.lua

@@ -318,10 +318,16 @@ function pfUI.uf:UpdateVisibility()
     self._label, self._id = nil, nil
   end
 
-  local unitstr = ("%s%s"):format(self.label or "", self.id or "")
-  self.unitstr = unitstr ~= "" and unitstr or nil
-  self:SetAttribute("unit", self.unitstr)
-  local visibility = ("[target=%s,exists] show; hide"):format(unitstr)
+  -- this runs for every frame five times a second, so only touch the
+  -- attribute when the unit actually changed
+  local unitstr = (self.label or "") .. (self.id or "")
+  local unit = unitstr ~= "" and unitstr or nil
+  if unit ~= self.unitstr then
+    self.unitstr = unit
+    self:SetAttribute("unit", unit)
+  end
+  -- anything but "show"/"hide" means "show if the unit exists"
+  local visibility = "exists"
 
   -- Group frames are redundant when the group is already shown as a raid grid:
   -- either an actual raid, or a party promoted to the raid grid via
@@ -1088,7 +1094,18 @@ function pfUI.uf.OnUpdate()
         end
       else
         pfUI.uf:RefreshUnitState(this)
-        pfUI.uf:RefreshIndicators(this)
+        -- group frames get their leader/loot/raid mark icons refreshed by
+        -- events through update_indicators, so polling them is only a safety
+        -- net; frames whose unit changes without events keep polling per tick
+        local label = this.label
+        if label == "raid" or label == "party" or label == "raidpet" or label == "partypet" then
+          if (this.lastIndicatorPoll or 0) < now then
+            this.lastIndicatorPoll = now + 3
+            pfUI.uf:RefreshIndicators(this)
+          end
+        else
+          pfUI.uf:RefreshIndicators(this)
+        end
       end
 
       if this.config and this.config.glowaggro == "1" and pfUI.api.UnitHasAggro(unitstr) > 0 then
@@ -1101,9 +1118,18 @@ function pfUI.uf.OnUpdate()
         this.glow:Hide()
       end
 
-      -- update everything on eventless frames (targettarget, etc)
+      -- update eventless frames (targettarget, etc). A full refresh rescans
+      -- every aura and the portrait, so only do it when the unit behind the
+      -- frame changes or once a second; other ticks refresh the bars only.
       if this.tick then
-        pfUI.uf:RefreshUnit(this, "all")
+        local guid = UnitGUID(unitstr)
+        if guid ~= this.tickGuid or (this.tickFull or 0) < now then
+          this.tickGuid = guid
+          this.tickFull = now + 1
+          pfUI.uf:RefreshUnit(this, "all")
+        else
+          pfUI.uf:RefreshUnit(this, "base")
+        end
       end
     end