Merge pull request #4523 from tk0miya/4230_tuning_sphinx

Fix #4230: slowdown in writing document with sphinx 1.6

CHANGES

@@ -32,6 +32,7 @@ Bugs fixed
 * #4493: recommonmark raises AttributeError if AutoStructify enabled
 * #4209: intersphinx: In link title, "v" should be optional if target has no
   version
+* #4230: slowdown in writing pages with sphinx 1.6
 
 Testing
 --------

sphinx/builders/html.py

@@ -23,7 +23,7 @@
 from docutils.frontend import OptionParser
 from docutils.io import DocTreeInput, StringOutput
 from docutils.readers.doctree import Reader as DoctreeReader
-from docutils.utils import new_document, relative_path
+from docutils.utils import relative_path
 from six import iteritems, text_type, string_types
 from six.moves import cPickle as pickle
 
@@ -41,7 +41,7 @@
 from sphinx.theming import HTMLThemeFactory
 from sphinx.util import jsonimpl, logging, status_iterator
 from sphinx.util.console import bold, darkgreen  # type: ignore
-from sphinx.util.docutils import is_html5_writer_available
+from sphinx.util.docutils import is_html5_writer_available, new_document
 from sphinx.util.fileutil import copy_asset
 from sphinx.util.i18n import format_date
 from sphinx.util.inventory import InventoryFile

sphinx/builders/latex.py

@@ -15,7 +15,6 @@
 from docutils import nodes
 from docutils.frontend import OptionParser
 from docutils.io import FileOutput
-from docutils.utils import new_document
 from six import text_type
 
 from sphinx import package_dir, addnodes, highlighting
@@ -27,6 +26,7 @@
 from sphinx.locale import _
 from sphinx.util import texescape, logging, status_iterator
 from sphinx.util.console import bold, darkgreen  # type: ignore
+from sphinx.util.docutils import new_document
 from sphinx.util.fileutil import copy_asset_file
 from sphinx.util.nodes import inline_all_toctrees
 from sphinx.util.osutil import SEP, make_filename

sphinx/builders/texinfo.py

@@ -15,7 +15,6 @@
 from docutils import nodes
 from docutils.frontend import OptionParser
 from docutils.io import FileOutput
-from docutils.utils import new_document
 
 from sphinx import addnodes
 from sphinx.builders import Builder
@@ -25,6 +24,7 @@
 from sphinx.util import logging
 from sphinx.util import status_iterator
 from sphinx.util.console import bold, darkgreen  # type: ignore
+from sphinx.util.docutils import new_document
 from sphinx.util.fileutil import copy_asset_file
 from sphinx.util.nodes import inline_all_toctrees
 from sphinx.util.osutil import SEP, make_filename

sphinx/transforms/__init__.py

@@ -15,12 +15,13 @@
 from docutils.transforms import Transform, Transformer
 from docutils.transforms.parts import ContentsFilter
 from docutils.transforms.universal import SmartQuotes
-from docutils.utils import new_document, normalize_language_tag
+from docutils.utils import normalize_language_tag
 from docutils.utils.smartquotes import smartchars
 
 from sphinx import addnodes
 from sphinx.locale import _
 from sphinx.util import logging
+from sphinx.util.docutils import new_document
 from sphinx.util.i18n import format_date
 from sphinx.util.nodes import apply_source_workaround, is_smartquotable
 

sphinx/util/docutils.py

@@ -17,6 +17,7 @@
 from distutils.version import LooseVersion
 
 import docutils
+from docutils import nodes
 from docutils.languages import get_language
 from docutils.parsers.rst import directives, roles, convert_directive_function
 from docutils.statemachine import StateMachine
@@ -32,7 +33,6 @@
 if False:
     # For type annotation
     from typing import Any, Callable, Generator, Iterator, List, Tuple  # NOQA
-    from docutils import nodes  # NOQA
     from docutils.statemachine import State, ViewList  # NOQA
     from sphinx.environment import BuildEnvironment  # NOQA
     from sphinx.io import SphinxFileInput  # NOQA
@@ -221,3 +221,30 @@ def switch_source_input(state, content):
     finally:
         # restore the method
         state.memo.reporter.get_source_and_line = get_source_and_line
+
+
+# cache a vanilla instance of nodes.document
+# Used in new_document() function
+__document_cache__ = None  # type: nodes.document
+
+
+def new_document(source_path, settings=None):
+    # type: (unicode, Any) -> nodes.document
+    """Return a new empty document object.  This is an alternative of docutils'.
+
+    This is a simple wrapper for ``docutils.utils.new_document()``.  It
+    caches the result of docutils' and use it on second call for instanciation.
+    This makes an instantiation of document nodes much faster.
+    """
+    global __document_cache__
+    if __document_cache__ is None:
+        __document_cache__ = docutils.utils.new_document(source_path)
+
+    if settings is None:
+        # Make a copy of ``settings`` from cache to accelerate instansiation
+        settings = copy(__document_cache__.settings)
+
+    # Create a new instance of nodes.document using cached reporter
+    document = nodes.document(settings, __document_cache__.reporter, source=source_path)
+    document.note_source(source_path, -1)
+    return document