prefetch init

cache.py

@@ -56,7 +56,8 @@ class BaselineCache(Cache):
             evict = True
         
         self.cache[key] = val
-        self.cache.move_to_end(key)
+        # no need for this since this op appends key-val by default
+        # self.cache.move_to_end(key)
 
         return evict
 

prefetch_cache.py

@@ -0,0 +1,28 @@
+from cache import BaselineCache
+
+class PrefetchCache(BaselineCache):
+    key_relations = None
+    
+    def __init__(self):
+        super()
+        self.key_relations = dict()
+        
+    def put(self, key: str, val: str) -> bool:
+        # LRU evict
+        evict = False
+        if len(self.cache) >= self.limit:
+            self.cache.popitem(last = False)
+            evict = True
+        self.cache[key] = val   
+        self.prefetch(key, val)
+        
+        return evict
+    
+    def prefetch(self, key: str, val: str) -> bool:
+        if len(self.cache) >= self.limit and key in self.key_relations:
+            self.cache[self.key_relations[key][0]] = self.key_relations[key][1]
+            return True
+        return False
+
+    def set_relations(self):
+        return