In autoreload mode, only reprocess modified files

pelican/__init__.py

@@ -141,7 +141,7 @@ class Pelican(object):
                 )
                 self.settings[old] = self.settings[new]
 
-    def run(self):
+    def run(self, modified=None):
         """Run the generators and return"""
         start_time = time.time()
 
@@ -164,11 +164,13 @@ class Pelican(object):
         # explicitly asked
         if (self.delete_outputdir and not
                 os.path.realpath(self.path).startswith(self.output_path)):
-            clean_output_dir(self.output_path, self.output_retention)
+            clean_output_dir(self.output_path,
+                             self.output_retention,
+                             files_to_clean=modified)
 
         for p in generators:
             if hasattr(p, 'generate_context'):
-                p.generate_context()
+                p.generate_context(modified=modified)
 
         signals.all_generators_finalized.send(generators)
 
@@ -462,7 +464,9 @@ def main():
                             logger.warning('Empty theme folder. Using `basic` '
                                            'theme.')
 
-                        pelican.run()
+                        modified_files = [v for vals in list(modified.values())
+                                          for v in vals]
+                        pelican.run(modified=modified_files)
 
                 except KeyboardInterrupt:
                     logger.warning("Keyboard interrupt, quitting.")
@@ -484,6 +488,8 @@ def main():
             if next(watchers['theme']) is None:
                 logger.warning('Empty theme folder. Using `basic` theme.')
 
+            modified_files = [val for vals in list(modified.values())
+                              for val in vals]
             pelican.run()
 
     except Exception as e:

pelican/generators.py

@@ -94,6 +94,19 @@ class Generator(object):
                         name, self._templates_path))
         return self._templates[name]
 
+    def _filter_child_paths(self, ancestor_paths, child_paths):
+        """Return set of elements in child_paths which are children of at least
+        one of ancestor_paths.
+        """
+        paths = set()
+        for ancestor_path in ancestor_paths:
+            ancestor_path = os.path.join(self.path, ancestor_path)
+            paths.update(
+                filter(lambda p: os.path.realpath(p).startswith(ancestor_path),
+                       child_paths)
+            )
+        return paths
+
     def _include_path(self, path, extensions=None):
         """Inclusion logic for .get_files(), returns True/False
 
@@ -501,14 +514,17 @@ class ArticlesGenerator(CachingGenerator):
         self.generate_authors(write)
         self.generate_drafts(write)
 
-    def generate_context(self):
+    def generate_context(self, modified=None):
         """Add the articles into the shared context"""
 
         all_articles = []
         all_drafts = []
-        for f in self.get_files(
-                self.settings['ARTICLE_PATHS'],
-                exclude=self.settings['ARTICLE_EXCLUDES']):
+        files = self.get_files(
+            (self.settings['ARTICLE_PATHS'] if modified is None
+             else self._filter_child_paths(self.settings['ARTICLE_PATHS'],
+                                           modified)),
+            exclude=self.settings['ARTICLE_EXCLUDES'])
+        for f in files:
             article_or_draft = self.get_cached_data(f, None)
             if article_or_draft is None:
                 # TODO needs overhaul, maybe nomad for read_file
@@ -611,12 +627,15 @@ class PagesGenerator(CachingGenerator):
         super(PagesGenerator, self).__init__(*args, **kwargs)
         signals.page_generator_init.send(self)
 
-    def generate_context(self):
+    def generate_context(self, modified=None):
         all_pages = []
         hidden_pages = []
-        for f in self.get_files(
-                self.settings['PAGE_PATHS'],
-                exclude=self.settings['PAGE_EXCLUDES']):
+        files = self.get_files(
+            (self.settings['PAGE_PATHS'] if modified is None
+             else self._filter_child_paths(self.settings['PAGE_PATHS'],
+                                           modified)),
+            exclude=self.settings['PAGE_EXCLUDES'])
+        for f in files:
             page = self.get_cached_data(f, None)
             if page is None:
                 try:
@@ -697,11 +716,15 @@ class StaticGenerator(Generator):
                      os.path.join(output_path, destination, path),
                      self.settings['IGNORE_FILES'])
 
-    def generate_context(self):
+    def generate_context(self, modified=None):
         self.staticfiles = []
-        for f in self.get_files(self.settings['STATIC_PATHS'],
-                                exclude=self.settings['STATIC_EXCLUDES'],
-                                extensions=False):
+        files = self.get_files(
+            (self.settings['STATIC_PATHS'] if modified is None
+             else self._filter_child_paths(self.settings['STATIC_PATHS'],
+                                           modified)),
+            exclude=self.settings['STATIC_EXCLUDES'],
+            extensions=False)
+        for f in files:
 
             # skip content source files unless the user explicitly wants them
             if self.settings['STATIC_EXCLUDE_SOURCES']:
@@ -735,7 +758,8 @@ class StaticGenerator(Generator):
 
 class SourceFileGenerator(Generator):
 
-    def generate_context(self):
+    def generate_context(self, modified=None):
+        """`modified` is unused; only here for consistency."""
         self.output_extension = self.settings['OUTPUT_SOURCES_EXTENSION']
 
     def _create_source(self, obj):

pelican/tests/test_utils.py

@@ -286,22 +286,22 @@ class TestUtils(LoggedTestCase):
         file_watcher = utils.file_watcher(path)
 
         # first check returns True
-        self.assertEqual(next(folder_watcher), True)
-        self.assertEqual(next(file_watcher), True)
+        self.assertTrue(next(folder_watcher))
+        self.assertTrue(next(file_watcher))
 
         # next check without modification returns False
-        self.assertEqual(next(folder_watcher), False)
-        self.assertEqual(next(file_watcher), False)
+        self.assertFalse(next(folder_watcher))
+        self.assertFalse(next(file_watcher))
 
         # after modification, returns True
         t = time.time()
         os.utime(path, (t, t))
-        self.assertEqual(next(folder_watcher), True)
-        self.assertEqual(next(file_watcher), True)
+        self.assertTrue(next(folder_watcher))
+        self.assertTrue(next(file_watcher))
 
         # file watcher with None or empty path should return None
-        self.assertEqual(next(utils.file_watcher('')), None)
-        self.assertEqual(next(utils.file_watcher(None)), None)
+        self.assertIsNone(next(utils.file_watcher('')))
+        self.assertIsNone(next(utils.file_watcher(None)))
 
         empty_path = os.path.join(os.path.dirname(__file__), 'empty')
         try:
@@ -309,9 +309,9 @@ class TestUtils(LoggedTestCase):
             os.mkdir(os.path.join(empty_path, "empty_folder"))
             shutil.copy(__file__, empty_path)
 
-            # if no files of interest, returns None
+            # if no files of interest, returns empty list
             watcher = utils.folder_watcher(empty_path, ['rst'])
-            self.assertEqual(next(watcher), None)
+            self.assertEqual(next(watcher), [])
         except OSError:
             self.fail("OSError Exception in test_files_changed test")
         finally:

pelican/utils.py

@@ -398,8 +398,11 @@ def copy_file_metadata(source, destination):
                        source, destination, e)
 
 
-def clean_output_dir(path, retention):
-    """Remove all files from output directory except those in retention list"""
+def clean_output_dir(path, retention, files_to_clean=None):
+    """Remove all files from output directory except those in retention list.
+    If files_to_clean is provided, only clean these files (but still skip over
+    the ones in retention list).
+    """
 
     if not os.path.exists(path):
         logger.debug("Directory already removed: %s", path)
@@ -414,6 +417,8 @@ def clean_output_dir(path, retention):
 
     # remove existing content from output folder unless in retention list
     for filename in os.listdir(path):
+        if files_to_clean is not None and filename not in files_to_clean:
+            continue
         file = os.path.join(path, filename)
         if any(filename == retain for retain in retention):
             logger.debug("Skipping deletion; %s is on retention list: %s",
@@ -727,11 +732,13 @@ def process_translations(content_list, order_by=None):
 def folder_watcher(path, extensions, ignores=[]):
     '''Generator for monitoring a folder for modifications.
 
-    Returns a boolean indicating if files are changed since last check.
+    Returns a list indicating the files that were changed since last check.
     Returns None if there are no matching files in the folder'''
 
-    def file_times(path):
-        '''Return `mtime` for each file in path'''
+    def file_times(path, after=0):
+        '''Return a (`mtime`, `file_path`) tuple for each file in path.
+        If `after` kwarg is provided, only return files with `mtime` > `after`.
+        '''
 
         for root, dirs, files in os.walk(path, followlinks=True):
             dirs[:] = [x for x in dirs if not x.startswith(os.curdir)]
@@ -740,21 +747,24 @@ def folder_watcher(path, extensions, ignores=[]):
                 if f.endswith(tuple(extensions)) and \
                    not any(fnmatch.fnmatch(f, ignore) for ignore in ignores):
                         try:
-                            yield os.stat(os.path.join(root, f)).st_mtime
+                            mtime = os.stat(os.path.join(root, f)).st_mtime
+                            if mtime > after:
+                                yield (mtime, os.path.join(root, f))
                         except OSError as e:
                             logger.warning('Caught Exception: %s', e)
 
     LAST_MTIME = 0
     while True:
         try:
-            mtime = max(file_times(path))
-            if mtime > LAST_MTIME:
-                LAST_MTIME = mtime
-                yield True
+            modified_files = sorted(file_times(path, after=LAST_MTIME),
+                                    reverse=True)
+            if modified_files:
+                LAST_MTIME = modified_files[0][0]
+                yield [mf[1] for mf in modified_files]
         except ValueError:
             yield None
         else:
-            yield False
+            yield []
 
 
 def file_watcher(path):
@@ -770,9 +780,9 @@ def file_watcher(path):
 
             if mtime > LAST_MTIME:
                 LAST_MTIME = mtime
-                yield True
+                yield path
             else:
-                yield False
+                yield ''
         else:
             yield None