From 75dbc31e2b807249fd59dac98e99dde57c82b071 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sun, 28 Jan 2018 09:06:19 +0530
Subject: [PATCH] E-book viewer: Use a temp dir in the cache

Try to combat the recent epidemic of bug reports caused by temp file
cleaners on windows. Hopefully by moving the temp files used by the
ebook iterator into the cache dir, we prevent the temp file cleaners
from deleting them.
---
 src/calibre/ebooks/oeb/iterator/book.py | 15 ++++++++++-----
 src/calibre/gui2/viewer/main.py         |  2 +-
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/calibre/ebooks/oeb/iterator/book.py b/src/calibre/ebooks/oeb/iterator/book.py
index 08208c9150..19de65b6f4 100644
--- a/src/calibre/ebooks/oeb/iterator/book.py
+++ b/src/calibre/ebooks/oeb/iterator/book.py
@@ -16,9 +16,10 @@ import re, os, math
 from functools import partial
 
 from calibre.ebooks.metadata.opf2 import OPF
-from calibre.ptempfile import TemporaryDirectory
+from calibre.ptempfile import PersistentTemporaryDirectory, remove_dir
 from calibre.utils.config import DynamicConfig
 from calibre.utils.logging import default_log
+from calibre.utils.tdir_in_cache import tdir_in_cache
 from calibre import guess_type, prepare_string_for_xml
 from calibre.ebooks.oeb.transforms.cover import CoverManager
 from calibre.ebooks.oeb.iterator.spine import (SpineItem, create_indexing_data)
@@ -92,8 +93,9 @@ class EbookIterator(BookmarksMixin):
 
     CHARACTERS_PER_PAGE = 1000
 
-    def __init__(self, pathtoebook, log=None, copy_bookmarks_to_file=True):
+    def __init__(self, pathtoebook, log=None, copy_bookmarks_to_file=True, use_tdir_in_cache=False):
         BookmarksMixin.__init__(self, copy_bookmarks_to_file=copy_bookmarks_to_file)
+        self.use_tdir_in_cache = use_tdir_in_cache
         self.log = log or default_log
         pathtoebook = pathtoebook.strip()
         self.pathtoebook = os.path.abspath(pathtoebook)
@@ -138,8 +140,11 @@ class EbookIterator(BookmarksMixin):
         display in viewers/preprocessing etc. '''
 
         self.delete_on_exit = []
-        self._tdir = TemporaryDirectory('_ebook_iter')
-        self.base  = os.path.realpath(self._tdir.__enter__())
+        if self.use_tdir_in_cache:
+            self._tdir = tdir_in_cache('ev')
+        else:
+            self._tdir = PersistentTemporaryDirectory('_ebook_iter')
+        self.base  = os.path.realpath(self._tdir)
         self.book_format, self.pathtoopf, input_fmt = run_extract_book(
             self.pathtoebook, self.base, only_input_plugin=only_input_plugin, view_kepub=view_kepub, processed=processed)
         self.opf = OPF(self.pathtoopf, os.path.dirname(self.pathtoopf))
@@ -226,7 +231,7 @@ class EbookIterator(BookmarksMixin):
                         item.verified_links.add((path, p.fragment))
 
     def __exit__(self, *args):
-        self._tdir.__exit__(*args)
+        remove_dir(self._tdir)
         for x in self.delete_on_exit:
             try:
                 os.remove(x)
diff --git a/src/calibre/gui2/viewer/main.py b/src/calibre/gui2/viewer/main.py
index 6e0a98f8c2..0a8c30135a 100644
--- a/src/calibre/gui2/viewer/main.py
+++ b/src/calibre/gui2/viewer/main.py
@@ -960,7 +960,7 @@ class EbookViewer(MainWindow):
         if self.iterator is not None:
             self.save_current_position()
             self.iterator.__exit__()
-        self.iterator = EbookIterator(pathtoebook, copy_bookmarks_to_file=self.view.document.copy_bookmarks_to_file)
+        self.iterator = EbookIterator(pathtoebook, copy_bookmarks_to_file=self.view.document.copy_bookmarks_to_file, use_tdir_in_cache=True)
         self.history.clear()
         self.open_progress_indicator(_('Loading e-book...'))
         worker = Worker(target=partial(self.iterator.__enter__, view_kepub=True))