[Sugar-devel] [PATCH] fix journal scan of external media, dev.laptop.org #10140

[James Cameron]

Update the progress bar regularly and prevent the UI from stalling
during a scan.  Avoid following recursive symlinks, and symlinks that
point outside the filesystem being scanned.  Do not check for MIME type
if file is excluded for other filter reasons.  Do not report permission
denied errors.

Tested on Sugar 0.88 using Ubuntu Sugar Remix (maverick).
---
 src/jarabe/journal/model.py |  150 ++++++++++++++++++++++++++++---------------
 1 files changed, 97 insertions(+), 53 deletions(-)

diff --git a/src/jarabe/journal/model.py b/src/jarabe/journal/model.py
index 81ca7d4..5ba3a76 100644
--- a/src/jarabe/journal/model.py
+++ b/src/jarabe/journal/model.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2007-2008, One Laptop Per Child
+# Copyright (C) 2007-2010, One Laptop per Child
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -16,10 +16,11 @@
 
 import logging
 import os
+import errno
 from datetime import datetime
 import time
 import shutil
-from stat import S_IFMT, S_IFDIR, S_IFREG
+from stat import S_IFLNK, S_IFMT, S_IFDIR, S_IFREG
 import re
 from operator import itemgetter
 
@@ -220,7 +221,9 @@ class InplaceResultSet(BaseResultSet):
         BaseResultSet.__init__(self, query, page_size)
         self._mount_point = mount_point
         self._file_list = None
-        self._pending_directories = 0
+        self._pending_directories = []
+        self._visited_directories = []
+        self._pending_files = []
         self._stopped = False
 
         query_text = query.get('query', '')
@@ -247,7 +250,10 @@ class InplaceResultSet(BaseResultSet):
 
     def setup(self):
         self._file_list = []
-        self._recurse_dir(self._mount_point)
+        self._pending_directories = [self._mount_point]
+        self._visited_directories = []
+        self._pending_files = []
+        gobject.idle_add(self._scan)
 
     def stop(self):
         self._stopped = True
@@ -287,62 +293,100 @@ class InplaceResultSet(BaseResultSet):
 
         return entries, total_count
 
-    def _recurse_dir(self, dir_path):
-        self._pending_directories += 1
-        gobject.idle_add(self._idle_recurse_dir, dir_path)
-
-    def _idle_recurse_dir(self, dir_path):
-        try:
-            self._real_recurse_dir(dir_path)
-        finally:
-            self._pending_directories -= 1
-            if self._pending_directories == 0:
-                self.setup_ready()
-
-    def _real_recurse_dir(self, dir_path):
+    def _scan(self):
         if self._stopped:
+            return False
+
+        self.progress.send(self)
+
+        if self._pending_files:
+            self._scan_a_file()
+            return True
+
+        if self._pending_directories:
+            self._scan_a_directory()
+            return True
+
+        self.setup_ready()
+        self._visited_directories = []
+        return False
+
+    def _scan_a_file(self):
+        full_path = self._pending_files.pop(0)
+
+        try:
+            stat = os.lstat(full_path)
+        except OSError, e:
+            if e.errno != errno.ENOENT:
+                logging.exception(
+                    'Error reading metadata of file %r', full_path)
+            return
+
+        if S_IFMT(stat.st_mode) == S_IFLNK:
+            try:
+                link = os.readlink(full_path)
+            except OSError, e:
+                logging.exception(
+                    'Error reading target of link %r', full_path)
+                return
+
+            if not os.path.abspath(link).startswith(self._mount_point):
+                return
+
+            try:
+                stat = os.stat(full_path)
+
+            except OSError, e:
+                if e.errno != errno.ENOENT:
+                    logging.exception(
+                        'Error reading metadata of linked file %r', full_path)
+                return
+
+        if S_IFMT(stat.st_mode) == S_IFDIR:
+            id_tuple = stat.st_ino, stat.st_dev
+            if not id_tuple in self._visited_directories:
+                self._visited_directories.append(id_tuple)
+                self._pending_directories.append(full_path)
             return
 
+        if S_IFMT(stat.st_mode) != S_IFREG:
+            return
+
+        if self._regex is not None and \
+                not self._regex.match(full_path):
+            return
+
+        if self._date_start is not None and self.st_mtime < self._date_start:
+            return
+
+        if self._date_end is not None and self.st_mtime > self._date_end:
+            return
+
+        if self._mime_types:
+            mime_type = gio.content_type_guess(filename=full_path)
+            if mime_type not in self._mime_types:
+                return
+
+        file_info = (full_path, stat, int(stat.st_mtime), stat.st_size)
+        self._file_list.append(file_info)
+
+        return
+
+    def _scan_a_directory(self):
+        dir_path = self._pending_directories.pop(0)
+
         try:
-            dirs = os.listdir(dir_path)
-        except Exception:
-            logging.exception('Error reading directory %r', dir_path)
-            dirs = []
+            entries = os.listdir(dir_path)
+        except OSError, e:
+            if e.errno != errno.EACCES:
+                logging.exception('Error reading directory %r', dir_path)
+            return
 
-        for entry in dirs:
+        for entry in entries:
             if entry.startswith('.'):
                 continue
-            full_path = dir_path + '/' + entry
-            try:
-                stat = os.stat(full_path)
-                if S_IFMT(stat.st_mode) == S_IFDIR:
-                    self._recurse_dir(full_path)
-
-                elif S_IFMT(stat.st_mode) == S_IFREG:
-                    add_to_list = True
-
-                    if self._regex is not None and \
-                            not self._regex.match(full_path):
-                        add_to_list = False
-
-                    if None not in [self._date_start, self._date_end] and \
-                            (stat.st_mtime < self._date_start or
-                             stat.st_mtime > self._date_end):
-                        add_to_list = False
-
-                    if self._mime_types:
-                        mime_type = gio.content_type_guess(filename=full_path)
-                        if mime_type not in self._mime_types:
-                            add_to_list = False
-
-                    if add_to_list:
-                        file_info = (full_path, stat, int(stat.st_mtime), stat.st_size)
-                        self._file_list.append(file_info)
-
-                    self.progress.send(self)
-
-            except Exception:
-                logging.exception('Error reading file %r', full_path)
+            self._pending_files.append(dir_path + '/' + entry)
+        return
 
 def _get_file_metadata(path, stat):
     client = gconf.client_get_default()
-- 
1.7.1

-- 
James Cameron
http://quozl.linux.org.au/