Restore and test DictCache

Author: alexprengere

README.md

@@ -92,7 +92,7 @@ def view():
 ### Cache example
 
 Flask-Compress can be integrated with caching mechanisms to serve compressed responses directly from the cache. This can significantly reduce server load and response times.
-Here is an example of how to configure Flask-Compress with caching using Flask-Caching.
+Here is an example of how to configure Flask-Compress with caching using [Flask-Caching](https://pypi.org/project/Flask-Caching/).
 The example demonstrates how to create a simple cache instance with a 1-hour timeout, and use it to cache compressed responses for incoming requests.
 
 ```python
@@ -122,6 +122,8 @@ compress.cache = cache
 compress.cache_key = get_cache_key
 ```
 
+If you do not want to pull an external dependency, you can use a simple in-memory cache using `compress.cache = flask_compress.DictCache()`.
+
 ## Options
 
 Within your Flask application's settings you can provide the following settings to control the behavior of Flask-Compress. None of the settings are required.

flask_compress/__init__.py

@@ -1,4 +1,4 @@
-from .flask_compress import Compress
+from .flask_compress import Compress, DictCache
 
 # _version.py is generated by setuptools_scm when building the package.
 # It is not version-controlled, so if it is missing, this likely means that
@@ -9,4 +9,4 @@
     __version__ = "0"
 
 
-__all__ = ("Compress",)
+__all__ = ("Compress", "DictCache")

flask_compress/flask_compress.py

@@ -18,6 +18,18 @@
 from flask import after_this_request, current_app, request
 
 
+class DictCache:
+
+    def __init__(self):
+        self.data = {}
+
+    def get(self, key):
+        return self.data.get(key)
+
+    def set(self, key, value):
+        self.data[key] = value
+
+
 @lru_cache(maxsize=128)
 def _choose_algorithm(enabled_algorithms, accept_encoding):
     """

tests/test_flask_compress.py

@@ -6,7 +6,7 @@
 from flask import Flask, render_template
 from flask_caching import Cache
 
-from flask_compress import Compress
+from flask_compress import Compress, DictCache
 from flask_compress.flask_compress import _choose_algorithm
 
 
@@ -476,6 +476,7 @@ def test_disabled_stream(self):
 
 class CachingCompressionTests(unittest.TestCase):
     def setUp(self):
+        # We keep track of the number of times the view is called
         self.view_calls = 0
         self.tmpdir = tempfile.TemporaryDirectory()
 
@@ -530,5 +531,44 @@ def test_compression(self):
         _ = gzip.decompress(response.data)
 
 
+class DictCacheTests(unittest.TestCase):
+    def setUp(self):
+        # We keep track of the number of times the cache key function is called
+        self.cache_key_calls = 0
+        self.app = Flask(__name__)
+        self.app.testing = True
+
+        def get_cache_key(request):
+            self.cache_key_calls += 1
+            return request.url
+
+        compress = Compress()
+        compress.init_app(self.app)
+
+        compress.cache = DictCache()
+        compress.cache_key = get_cache_key
+
+        @self.app.route("/route/")
+        def view():
+            return render_template("large.html")
+
+    def test_compression(self):
+        client = self.app.test_client()
+
+        headers = [("Accept-Encoding", "deflate")]
+        response = client.get("/route/", headers=headers)
+        self.assertEqual(response.status_code, 200)
+        self.assertIn("Content-Encoding", response.headers)
+        self.assertEqual(response.headers.get("Content-Encoding"), "deflate")
+        self.assertEqual(self.cache_key_calls, 1)
+
+        headers = [("Accept-Encoding", "deflate")]
+        response = client.get("/route/", headers=headers)
+        self.assertEqual(response.status_code, 200)
+        self.assertIn("Content-Encoding", response.headers)
+        self.assertEqual(response.headers.get("Content-Encoding"), "deflate")
+        self.assertEqual(self.cache_key_calls, 2)
+
+
 if __name__ == "__main__":
     unittest.main()