From 293a50d75c9c18f74ebca757cbc6776f9dbc75ff Mon Sep 17 00:00:00 2001
From: Alexander Schepanovski <suor.web@gmail.com>
Date: Thu, 12 Sep 2019 22:10:16 +0700
Subject: [PATCH] perf: use fast entry points on non-wheel install

This avoids importing `pkg_resources` on startup, which saves around 200
ms.

NOTE: wheel installer uses its own entry points template, which is the same
fastentrypoints.py script provides, so no gain there.
---
 MANIFEST.in        |   2 +
 fastentrypoints.py | 122 +++++++++++++++++++++++++++++++++++++++++++++
 setup.py           |   5 ++
 3 files changed, 129 insertions(+)
 create mode 100644 MANIFEST.in
 create mode 100644 fastentrypoints.py

diff --git a/MANIFEST.in b/MANIFEST.in
new file mode 100644
index 000000000..03d2f17a9
--- /dev/null
+++ b/MANIFEST.in
@@ -0,0 +1,2 @@
+include fastentrypoints.py
+include LICENSE
diff --git a/fastentrypoints.py b/fastentrypoints.py
new file mode 100644
index 000000000..932500886
--- /dev/null
+++ b/fastentrypoints.py
@@ -0,0 +1,122 @@
+# noqa: D300,D400
+# Copyright (c) 2016, Aaron Christianson
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+# TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"""
+Monkey patch setuptools to write faster console_scripts with this format:
+
+    import sys
+    from mymodule import entry_function
+    sys.exit(entry_function())
+
+This is better.
+
+(c) 2016, Aaron Christianson
+http://github.com/ninjaaron/fast-entry_points
+"""
+from setuptools.command import easy_install
+import re
+
+TEMPLATE = r"""
+# -*- coding: utf-8 -*-
+# EASY-INSTALL-ENTRY-SCRIPT: '{3}','{4}','{5}'
+__requires__ = '{3}'
+import re
+import sys
+
+from {0} import {1}
+
+if __name__ == '__main__':
+    sys.argv[0] = re.sub(r'(-script\.pyw?|\.exe)?$', '', sys.argv[0])
+    sys.exit({2}())
+""".lstrip()
+
+
+@classmethod
+def get_args(cls, dist, header=None):  # noqa: D205,D400
+    """
+    Yield write_script() argument tuples for a distribution's
+    console_scripts and gui_scripts entry points.
+    """
+    if header is None:
+        # pylint: disable=E1101
+        header = cls.get_header()
+    spec = str(dist.as_requirement())
+    for type_ in "console", "gui":
+        group = type_ + "_scripts"
+        for name, ep in dist.get_entry_map(group).items():
+            # ensure_safe_name
+            if re.search(r"[\\/]", name):
+                raise ValueError("Path separators not allowed in script names")
+            script_text = TEMPLATE.format(
+                ep.module_name,
+                ep.attrs[0],
+                ".".join(ep.attrs),
+                spec,
+                group,
+                name,
+            )
+            # pylint: disable=E1101
+            args = cls._get_script_args(type_, name, header, script_text)
+            for res in args:
+                yield res
+
+
+# pylint: disable=E1101
+easy_install.ScriptWriter.get_args = get_args
+
+
+def main():
+    import os
+    import re
+    import shutil
+    import sys
+
+    dests = sys.argv[1:] or ["."]
+    filename = re.sub(r"\.pyc$", ".py", __file__)
+
+    for dst in dests:
+        shutil.copy(filename, dst)
+        manifest_path = os.path.join(dst, "MANIFEST.in")
+        setup_path = os.path.join(dst, "setup.py")
+
+        # Insert the include statement to MANIFEST.in if not present
+        with open(manifest_path, "a+") as manifest:
+            manifest.seek(0)
+            manifest_content = manifest.read()
+            if "include fastentrypoints.py" not in manifest_content:
+                manifest.write(
+                    ("\n" if manifest_content else "")
+                    + "include fastentrypoints.py"
+                )
+
+        # Insert the import statement to setup.py if not present
+        with open(setup_path, "a+") as setup:
+            setup.seek(0)
+            setup_content = setup.read()
+            if "import fastentrypoints" not in setup_content:
+                setup.seek(0)
+                setup.truncate()
+                setup.write("import fastentrypoints\n" + setup_content)
diff --git a/setup.py b/setup.py
index 19a29b0be..2598b51b3 100644
--- a/setup.py
+++ b/setup.py
@@ -3,6 +3,11 @@ from setuptools.command.build_py import build_py as _build_py
 import os
 import sys
 
+# Prevents pkg_resources import in entry point script,
+# see https://github.com/ninjaaron/fast-entry_points.
+# This saves about 200 ms on startup time for non-wheel installs.
+import fastentrypoints  # noqa: F401
+
 
 # https://packaging.python.org/guides/single-sourcing-package-version/
 pkg_dir = os.path.dirname(__file__)