From 6d05a6ec2093e7eeb15b7eefecb0c402814649a2 Mon Sep 17 00:00:00 2001
From: DYefremov <dmitry.v.yefremov@gmail.com>
Date: Fri, 17 Jun 2022 17:53:39 +0300
Subject: [PATCH] lazy xmltv loading

---
 app/tools/epg.py  | 14 +++++++-------
 app/ui/epg/epg.py | 10 +++++++---
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/app/tools/epg.py b/app/tools/epg.py
index 5e043a15..193c35df 100644
--- a/app/tools/epg.py
+++ b/app/tools/epg.py
@@ -237,7 +237,7 @@ class XmlTvReader(Reader):
 
     @run_task
     def download(self, clb=None):
-        """ Downloads and processes an XMLTV file. """
+        """ Downloads an XMLTV file. """
         res = urlparse(self._url)
         if not all((res.scheme, res.netloc)):
             log(f"{self.__class__.__name__} [download] error: Invalid URL {self._url}")
@@ -310,15 +310,13 @@ class XmlTvReader(Reader):
             import gzip
 
             with gzip.open(self._path, "rb") as gzf:
-                self.process_data(gzf)
+                log("Processing XMLTV data...")
+                for n in ET.iterparse(gzf):
+                    yield from self.process_node(n)
+                log("XMLTV data parsing is complete.")
         except OSError as e:
             log(f"{self.__class__.__name__} [parse] error: {e}")
 
-    def process_data(self, data):
-        log("Processing XMLTV data...")
-        list(map(self.process_node, ET.iterparse(data)))
-        log("XMLTV data parsing is complete.")
-
     def process_node(self, node):
         event, element = node
         if element.tag == self.CH_TAG:
@@ -352,6 +350,8 @@ class XmlTvReader(Reader):
                 if all((start, stop, title)):
                     events.append(self.Event(start, stop, title, desc))
 
+        yield node
+
     def to_epg_dat(self):
         """ Converts and saves imported data to 'epg.dat' file. """
         raise ValueError("Not implemented yet!")
diff --git a/app/ui/epg/epg.py b/app/ui/epg/epg.py
index b0358923..04530bc8 100644
--- a/app/ui/epg/epg.py
+++ b/app/ui/epg/epg.py
@@ -69,20 +69,24 @@ class EpgCache(dict):
 
         self.init()
 
-    @run_task
+    @run_idle
     def init(self):
         if self._src is EpgSource.XML:
             url = self._settings.epg_xml_source
             gz_file = f"{self._settings.profile_data_path}epg{os.sep}epg.gz"
             self._reader = XmlTvReader(gz_file, url)
 
+            def process_data():
+                gen = self._reader.parse()
+                GLib.idle_add(lambda: next(gen, False), priority=GLib.PRIORITY_LOW)
+
             if os.path.isfile(gz_file):
                 # Difference calculation between the current time and file modification.
                 dif = datetime.now() - datetime.fromtimestamp(os.path.getmtime(gz_file))
                 # We will update daily. -> Temporarily!!!
-                self._reader.download(self._reader.parse) if dif.days > 0 else self._reader.parse()
+                self._reader.download(process_data) if dif.days > 0 else process_data()
             else:
-                self._reader.download(self._reader.parse)
+                self._reader.download(process_data)
         elif self._src is EpgSource.DAT:
             self._reader = EPG.DatReader(f"{self._settings.profile_data_path}epg{os.sep}epg.dat")
             self._reader.download()