Fix swallowed falsy values in all cache backends

Author: FormJani

django_prometheus/cache/backends/django_memcached_consul.py

@@ -1,20 +1,10 @@
 from django_memcached_consul import memcached
 
-from django_prometheus.cache.metrics import (
-    django_cache_get_total,
-    django_cache_hits_total,
-    django_cache_misses_total,
-)
+from django_prometheus.cache.backends.utils import cache_get_with_metrics
 
 
 class MemcachedCache(memcached.MemcachedCache):
     """Inherit django_memcached_consul to add metrics about hit/miss ratio"""
 
     def get(self, key, default=None, version=None):
-        django_cache_get_total.labels(backend="django_memcached_consul").inc()
-        cached = super().get(key, default=None, version=version)
-        if cached is not None:
-            django_cache_hits_total.labels(backend="django_memcached_consul").inc()
-        else:
-            django_cache_misses_total.labels(backend="django_memcached_consul").inc()
-        return cached or default
+        return cache_get_with_metrics(func=super().get, key=key, backend_name="django_memcached_consul", default=default, version=version)

django_prometheus/cache/backends/filebased.py

@@ -1,20 +1,10 @@
 from django.core.cache.backends import filebased
 
-from django_prometheus.cache.metrics import (
-    django_cache_get_total,
-    django_cache_hits_total,
-    django_cache_misses_total,
-)
+from django_prometheus.cache.backends.utils import cache_get_with_metrics
 
 
 class FileBasedCache(filebased.FileBasedCache):
     """Inherit filebased cache to add metrics about hit/miss ratio"""
 
     def get(self, key, default=None, version=None):
-        django_cache_get_total.labels(backend="filebased").inc()
-        cached = super().get(key, default=None, version=version)
-        if cached is not None:
-            django_cache_hits_total.labels(backend="filebased").inc()
-        else:
-            django_cache_misses_total.labels(backend="filebased").inc()
-        return cached or default
+        return cache_get_with_metrics(func=super().get, key=key, backend_name="filebased", default=default, version=version)

django_prometheus/cache/backends/locmem.py

@@ -1,20 +1,9 @@
 from django.core.cache.backends import locmem
-
-from django_prometheus.cache.metrics import (
-    django_cache_get_total,
-    django_cache_hits_total,
-    django_cache_misses_total,
-)
+from django_prometheus.cache.backends.utils import cache_get_with_metrics
 
 
 class LocMemCache(locmem.LocMemCache):
     """Inherit filebased cache to add metrics about hit/miss ratio"""
 
     def get(self, key, default=None, version=None):
-        django_cache_get_total.labels(backend="locmem").inc()
-        cached = super().get(key, default=None, version=version)
-        if cached is not None:
-            django_cache_hits_total.labels(backend="locmem").inc()
-        else:
-            django_cache_misses_total.labels(backend="locmem").inc()
-        return cached or default
+        return cache_get_with_metrics(func=super().get, key=key, backend_name="locmem", default=default, version=version)

django_prometheus/cache/backends/memcached.py

@@ -1,22 +1,11 @@
 from django.core.cache.backends import memcached
 
-from django_prometheus.cache.metrics import (
-    django_cache_get_total,
-    django_cache_hits_total,
-    django_cache_misses_total,
-)
+from django_prometheus.cache.backends.utils import cache_get_with_metrics
 
 
 class MemcachedPrometheusCacheMixin:
     def get(self, key, default=None, version=None):
-        django_cache_get_total.labels(backend="memcached").inc()
-        cached = super().get(key, default=None, version=version)
-        if cached is not None:
-            django_cache_hits_total.labels(backend="memcached").inc()
-            return cached
-
-        django_cache_misses_total.labels(backend="memcached").inc()
-        return default
+        return cache_get_with_metrics(func=super().get, key=key, backend_name="memcached", default=default, version=version)
 
 
 class PyLibMCCache(MemcachedPrometheusCacheMixin, memcached.PyLibMCCache):

django_prometheus/cache/backends/utils.py

@@ -4,13 +4,15 @@
     django_cache_misses_total,
 )
 
+from typing import Callable, Optional, Any
 
-def cache_get_with_metrics(*, key, backend_name, default=None, version=None):
-        django_cache_get_total.labels(backend=backend_name).inc()
-        cached = super().get(key, default=None, version=version)
-        if cached is not None:
-            django_cache_hits_total.labels(backend=backend_name).inc()
-            return cached
 
-        django_cache_misses_total.labels(backend=backend_name).inc()
-        return default
+def cache_get_with_metrics(*, func: Callable, key: str, backend_name: str, default: Optional[Any]=None, version: Optional[int]=None):
+    django_cache_get_total.labels(backend=backend_name).inc()
+    cached = func(key, default=default, version=version)
+    if cached is not None:
+        django_cache_hits_total.labels(backend=backend_name).inc()
+        return cached
+
+    django_cache_misses_total.labels(backend=backend_name).inc()
+    return default