def generate_cache_key(
request: Request,
method: str,
varying_headers: typing.List[str],
cache: Cache,
) -> str:
"""
Return a cache key generated from the request full URL and varying
response headers.
Note that the given `method` may be different from that of the request, e.g.
because we're trying to find a response cached from a previous GET request
while this one is a HEAD request. (This is OK because web servers will strip content
from responses to a HEAD request before sending them on the wire.)
"""
assert method in CACHABLE_METHODS
ctx = hashlib.md5()
for header in varying_headers:
value = request.headers.get(header)
if value is not None:
ctx.update(value.encode())
absolute_url = str(request.url)
url = hashlib.md5(absolute_url.encode("ascii"))
return cache.make_key(
f"cache_page.{method}.{url.hexdigest()}.{ctx.hexdigest()}")
def generate_varying_headers_cache_key(request: Request, cache: Cache) -> str:
"""
Return a cache key generated from the requested absolute URL, suitable for
associating varying headers to a requested URL.
"""
url = request.url.path
url_hash = hashlib.md5(url.encode("ascii"))
return cache.make_key(f"varying_headers.{url_hash.hexdigest()}")
def test_cache_version_kwarg_overrides_version_set_in_url():
cache = Cache("dummy://null?version=2019", version="2020")
key = cache.make_key("test")
assert "2019" not in key
assert "2020" in key
assert "test" in key
def test_cache_key_prefix_kwarg_overrides_key_prefix_be_set_in_url():
cache = Cache("dummy://null?key_prefix=prod", key_prefix="beta")
key = cache.make_key("test")
assert key.startswith("beta")
assert "prod" not in key
assert "test" in key
def test_cache_version_can_be_set_in_url():
cache = Cache("dummy://null?version=2019")
key = cache.make_key("test")
assert "2019" in key
assert "test" in key
def test_cache_key_prefix_can_be_set_in_url():
cache = Cache("dummy://null?key_prefix=prod")
key = cache.make_key("test")
assert key.startswith("prod")
assert "test" in key
def test_cache_created_key_includes_prefix_and_version():
cache = Cache("dummy://null", key_prefix="prod", version="2019")
key = cache.make_key("test")
assert key.startswith("prod")
assert "2019" in key
assert "test" in key
def test_cache_key_default_version_can_be_overridded():
cache = Cache("dummy://null", version="beta")
key = cache.make_key("test", "custom")
assert "beta" not in key
assert "custom" in key
assert "test" in key
def test_cache_created_key_includes_default_version():
cache = Cache("dummy://null", version="beta")
key = cache.make_key("test")
assert "beta" in key
assert "test" in key
def test_cache_created_key_includes_prefix():
cache = Cache("dummy://null", key_prefix="prod")
key = cache.make_key("test")
assert key.startswith("prod")
assert "test" in key