package/python-diskcache: new package

The package imports itself in setup.py to get the package-name and
version number. Dping this during the buildroot build would require
buisling host-python with sqlite support, which we are currently not set
up for. It also seems wasteful for just extracting the version number
and package name, so instead we replace the import by using a hardcoded
package-name and the version number stored in buildroot.

Signed-off-by: Marcus Hoffmann <buildroot@bubu1.eu>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

DEVELOPERS

@@ -2263,6 +2263,7 @@ F:	package/picotool/
 F:	package/python-annotated-doc/
 F:	package/python-apscheduler/
 F:	package/python-crc/
+F:	package/python-diskcache/
 F:	package/python-django/
 F:	package/python-gpiod/
 F:	package/python-immutabledict/
@@ -2280,6 +2281,7 @@ F:	package/python-waitress/
 F:	package/python-whitenoise/
 F:	support/testing/tests/package/test_python_apscheduler.py
 F:	support/testing/tests/package/test_python_crc.py
+F:	support/testing/tests/package/test_python_diskcache.py
 F:	support/testing/tests/package/test_python_django.py
 F:	support/testing/tests/package/test_python_fastapi.py
 F:	support/testing/tests/package/test_python_pydantic.py
@@ -2293,6 +2295,7 @@ F:	support/testing/tests/package/test_python_waitress.py
 F:	support/testing/tests/package/test_python_whitenoise.py
 F:	support/testing/tests/package/sample_python_apscheduler.py
 F:	support/testing/tests/package/sample_python_crc.py
+F:	support/testing/tests/package/sample_python_diskcache.py
 F:	support/testing/tests/package/sample_python_django.py
 F:	support/testing/tests/package/sample_python_fastapi.py
 F:	support/testing/tests/package/sample_python_pydantic.py

package/Config.in

@@ -1084,6 +1084,7 @@ menu "External python modules"
 	source "package/python-dictdiffer/Config.in"
 	source "package/python-dicttoxml/Config.in"
 	source "package/python-dicttoxml2/Config.in"
+	source "package/python-diskcache/Config.in"
 	source "package/python-distro/Config.in"
 	source "package/python-django/Config.in"
 	source "package/python-django-enumfields/Config.in"

package/python-diskcache/Config.in

@@ -0,0 +1,8 @@
+config BR2_PACKAGE_PYTHON_DISKCACHE
+	bool "python-diskcache"
+	select BR2_PACKAGE_PYTHON3_SQLITE # runtime
+	select BR2_PACKAGE_PYTHON3_ZLIB # runtime
+	help
+	  Disk Cache -- Disk and file backed persistent cache.
+
+	  http://www.grantjenks.com/docs/diskcache/

package/python-diskcache/python-diskcache.hash

@@ -0,0 +1,5 @@
+# md5, sha256 from https://pypi.org/pypi/diskcache/json
+md5  d92b4afa944bb70ed38c84a622f7abb5  diskcache-5.6.3.tar.gz
+sha256  2c3a3fa2743d8535d832ec61c2054a1641f41775aa7c556758a109941e33e4fc  diskcache-5.6.3.tar.gz
+# Locally computed sha256 checksums
+sha256  583546baa3fd93607d845126570677a401f508e228b5044fefbc3949af179672  LICENSE

package/python-diskcache/python-diskcache.mk

@@ -0,0 +1,26 @@
+################################################################################
+#
+# python-diskcache
+#
+################################################################################
+
+PYTHON_DISKCACHE_VERSION = 5.6.3
+PYTHON_DISKCACHE_SOURCE = diskcache-$(PYTHON_DISKCACHE_VERSION).tar.gz
+PYTHON_DISKCACHE_SITE = https://files.pythonhosted.org/packages/3f/21/1c1ffc1a039ddcc459db43cc108658f32c57d271d7289a2794e401d0fdb6
+PYTHON_DISKCACHE_SETUP_TYPE = setuptools
+PYTHON_DISKCACHE_LICENSE = Apache-2.0
+PYTHON_DISKCACHE_LICENSE_FILES = LICENSE
+
+# diskcache imports itself during the build to get its own version,
+# which doesn't work in the Buildroot context, so we inject the
+# package name and version manually.
+define PYTHON_DISKCACHE_REMOVE_SELF_IMPORT
+	sed -i -e '/import diskcache/d' \
+		-e 's/diskcache.__title__/"diskcache"/' \
+		-e 's/diskcache.__version__/"$(PYTHON_DISKCACHE_VERSION)"/' \
+		$(@D)/setup.py
+endef
+
+PYTHON_DISKCACHE_POST_PATCH_HOOKS += PYTHON_DISKCACHE_REMOVE_SELF_IMPORT
+
+$(eval $(python-package))

support/testing/tests/package/sample_python_diskcache.py

@@ -0,0 +1,9 @@
+from diskcache import Cache
+
+cache = Cache()
+
+cache['test'] = 123
+assert cache['test'] == 123
+del cache['test']
+assert 'test' not in cache
+cache.close()

support/testing/tests/package/test_python_diskcache.py

@@ -0,0 +1,12 @@
+from tests.package.test_python import TestPythonPackageBase
+
+
+class TestPythonPy3DiskCache(TestPythonPackageBase):
+    __test__ = True
+    config = TestPythonPackageBase.config + \
+        """
+        BR2_PACKAGE_PYTHON3=y
+        BR2_PACKAGE_PYTHON_DISKCACHE=y
+        """
+    sample_scripts = ["tests/package/sample_python_diskcache.py"]
+    timeout = 10