add StringCache

Author: Fabien Coelho

CacheToolsUtils.py

@@ -511,7 +511,7 @@ def full_hash_key(*args, **kwargs) -> str:
 #
 # Encrypted Cache
 #
-class EncryptedCache(_KeyMutMapMix):
+class EncryptedCache(_KeyMutMapMix, _StatsMix, MutableMapping):
     """Encrypted Bytes Key-Value Cache.
 
     :param secret: bytes of secret, at least 16 bytes.
@@ -556,6 +556,21 @@ def __getitem__(self, key):
         return self._cipher.new(key=vkey, nonce=vnonce).decrypt(self._cache[hkey])
 
 
+class StringCache(_KeyMutMapMix, _StatsMix, MutableMapping):
+
+    def __init__(self, cache):
+        self._cache = cache
+
+    def _key(self, key):
+        return key.encode("UTF-8")
+
+    def __setitem__(self, key, val):
+        self._cache.__setitem__(self._key(key), val.encode("UTF-8"))
+
+    def __getitem__(self, key):
+        return self._cache.__getitem__(key).decode("UTF-8")
+
+
 #
 # MEMCACHED
 #

README.md

@@ -42,6 +42,7 @@ with `cachetools`.
 - `TwoLevelCache` allows to combine two caches.
 - `DebugCache` to trace cache calls using `logging`.
 - `EncryptedCache` a cache with key hashing and value encryption.
+- `StringCache` maps strings to bytes.
 
 ### Cache utilities
 

test.py

@@ -547,9 +547,15 @@ def test_cache_key():
 
 def test_encrypted_cache():
     SECRET = b"incredible secret key for testing encrypted cache..."
+    # bytes
     cache = ctu.EncryptedCache(ctu.DictCache(), SECRET)
     cache[b"Hello"] = b"World!"
     assert b"Hello" in cache
     assert cache[b"Hello"] == b"World!"
     del cache[b"Hello"]
     assert b"Hello" not in cache
+    scache = ctu.StringCache(cache)
+    scache["Hello"] = "World!"
+    assert "Hello" in scache
+    assert scache["Hello"] == "World!"
+    del scache["Hello"]