Drop multiprocessing in rendervariations command

.bandit

@@ -1,2 +1,2 @@
 [bandit]
-exclude: tests
+exclude: ./tests

.github/dependabot.yml

@@ -0,0 +1,6 @@
+version: 2
+updates:
+- package-ecosystem: github-actions
+  directory: "/"
+  schedule:
+    interval: daily

.github/workflows/tests.yml

@@ -1,30 +1,45 @@
-name: Tests
+name: CI
 
-on: [push]
+on:
+  push:
+    branches:
+      - master
+  pull_request:
 
 jobs:
-  build:
 
+  dist:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Install gettext
+        run: sudo apt-get install gettext -y
+      - uses: actions/setup-python@v2
+      - run: python -m pip install --upgrade pip setuptools wheel twine readme-renderer
+      - uses: actions/checkout@v2
+      - run: python setup.py sdist bdist_wheel
+      - run: python -m twine check dist/*
+
+  pytest:
     runs-on: ubuntu-latest
     strategy:
-      max-parallel: 4
       matrix:
-        python-version: [3.5, 3.6, 3.7]
-        django-version: [1.11.*, 2.2.*]
-
+        python-version:
+          - "3.7"
+          - "3.8"
+          - "3.9"
+        django-version:
+          - "2.2"
+          - "3.1"
     steps:
-    - uses: actions/checkout@v1
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v1
       with:
         python-version: ${{ matrix.python-version }}
+    - uses: actions/checkout@v1
     - name: Install dependencies
       run: |
-        python -m pip install --upgrade pip setuptools
-        pip install django==${{ matrix.django-version }}
+        python -m pip install --upgrade pip setuptools codecov
+        pip install django~=${{ matrix.django-version }}
     - name: Test with pytest
       run: python setup.py test
-    - name: Codecov
-      uses: codecov/codecov-action@v1.0.2
-      with:
-        token: ${{secrets.CODECOV_TOKEN}}
+    - run: codecov

README.md

@@ -12,7 +12,6 @@ Django Field that implement the following features:
 * Access thumbnails on model level, no template tags required
 * Preserves original image
 * Asynchronous rendering (Celery & Co)
-* Multi threading and processing for optimum performance
 * Restrict accepted image dimensions
 * Rename files to a standardized name (using a callable upload_to)
 
@@ -195,12 +194,3 @@ The `replace` option will replace all existing files.
 The `ignore-missing` option will suspend missing source file errors and keep
 rendering variations for other files. Othervise command will stop on first
 missing file.
-
-### Multi processing
-Since version 2 stdImage supports multiprocessing.
-Every image is rendered in separate process.
-It not only increased performance but the garbage collection
-and therefore the huge memory footprint from previous versions.
-
-**Note:** PyPy seems to have some problems regarding multiprocessing,
-for that matter all multiprocessing is disabled in PyPy.

setup.cfg

@@ -26,14 +26,14 @@ classifier =
 include_package_data = True
 packages = stdimage
 install_requires =
-    Django>=1.11
+    Django>=2.2
     pillow>=2.5
     progressbar2>=3.0.0
 setup_requires =
     setuptools_scm
     pytest-runner
 tests_require =
-    pytest>=4.0,<5.0
+    pytest
     pytest-cov
     pytest-django
 

stdimage/management/commands/rendervariations.py

@@ -1,6 +1,3 @@
-from concurrent.futures import ProcessPoolExecutor
-from multiprocessing import cpu_count
-
 import progressbar
 from django.apps import apps
 from django.core.files.storage import get_storage_class
@@ -75,14 +72,12 @@ def render(field, images, count, replace, ignore_missing, do_render):
         )
         with progressbar.ProgressBar(max_value=count, widgets=(
             progressbar.RotatingMarker(),
-            ' | CPUs: {}'.format(cpu_count()),
             ' | ', progressbar.AdaptiveETA(),
             ' | ', progressbar.Percentage(),
             ' ', progressbar.Bar(),
         )) as bar:
-            with ProcessPoolExecutor() as executor:
-                for _ in executor.map(render_field_variations, kwargs_list):
-                    bar += 1
+            for _ in map(render_field_variations, kwargs_list):
+                bar += 1
 
 
 def render_field_variations(kwargs):