From 8328c6e61037fa49015292a0ecade0cc204c3c0d Mon Sep 17 00:00:00 2001
From: isha28-uclaCS <ishapardikar28@cs.ucla.edu>
Date: Mon, 17 Feb 2025 20:21:08 -0800
Subject: [PATCH] Eviction Seive Algorithm
---
app/cache/eviction_seive.py | 122 ++++++++++++++++++++++++++++++++++++
app/config.yaml | 2 +-
app/main.py | 3 +
3 files changed, 126 insertions(+), 1 deletion(-)
create mode 100644 app/cache/eviction_seive.py
diff --git a/app/cache/eviction_seive.py b/app/cache/eviction_seive.py
new file mode 100644
index 0000000..f0c61e9
--- /dev/null
+++ b/app/cache/eviction_seive.py
@@ -0,0 +1,122 @@
+from .cache import Cache
+
+class Node:
+ def __init__(self, key, value):
+ self.key = key
+ self.value = value
+ self.visited = False
+ self.next = None
+ self.prev = None
+
+class SeiveCache(Cache):
+ def __init__(self, limit: int):
+ super().__init__(limit)
+ self.limit = limit # Fix: Store limit properly
+ self.cache = {} # Hash map for O(1) access
+ self.head = None
+ self.tail = None
+ self.hand = None
+
+ def print_cache_state(self):
+ print("Current cache state:")
+ node = self.head
+ if not node:
+ print("Cache is empty.")
+ return
+ for _ in range(len(self.cache)):
+ print(f"Key: {node.key}, Value: {node.value}, Visited: {node.visited}")
+ node = node.next
+ if node == self.head:
+ break
+
+ def get(self, key: str) -> str:
+ if key in self.cache:
+ node = self.cache[key]
+ node.visited = True
+ print(f"GET {key}: {node.value}")
+ self.print_cache_state()
+ return node.value
+ print(f"GET {key}: MISS")
+ self.print_cache_state()
+ return None
+
+ def put(self, key: str, val: str) -> bool:
+ print(f"PUT {key}: {val}")
+ if key in self.cache:
+ node = self.cache[key]
+ node.value = val
+ node.visited = True
+ self.print_cache_state()
+ return False # No eviction needed
+
+ new_node = Node(key, val)
+ if len(self.cache) >= self.limit:
+ self.evict()
+
+ if not self.head:
+ self.head = self.tail = new_node
+ new_node.next = new_node.prev = new_node
+ else:
+ new_node.prev = self.tail
+ new_node.next = self.head
+ self.tail.next = new_node
+ self.head.prev = new_node
+ self.tail = new_node
+
+ self.cache[key] = new_node
+ if not self.hand:
+ self.hand = self.head
+ self.print_cache_state()
+ return False
+
+ def invalidate(self, key: str) -> bool:
+ print(f"INVALIDATE {key}")
+ if key in self.cache:
+ node = self.cache.pop(key)
+ if node == self.head:
+ self.head = node.next
+ if node == self.tail:
+ self.tail = node.prev
+ if node.next:
+ node.next.prev = node.prev
+ if node.prev:
+ node.prev.next = node.next
+ self.print_cache_state()
+ return True
+ print("INVALIDATE FAILED: Key not found")
+ return False
+
+ def next_hand(self):
+ self.hand = self.hand.next if self.hand.next else self.head
+
+ def evict(self):
+ print("EVICTION START")
+ while self.hand.visited:
+ self.hand.visited = False
+ self.next_hand()
+ obj_to_evict = self.hand
+ self.next_hand()
+
+ if obj_to_evict == self.head:
+ self.head = obj_to_evict.next
+ if obj_to_evict == self.tail:
+ self.tail = obj_to_evict.prev
+ if obj_to_evict.next:
+ obj_to_evict.next.prev = obj_to_evict.prev
+ if obj_to_evict.prev:
+ obj_to_evict.prev.next = obj_to_evict.next
+
+ del self.cache[obj_to_evict.key]
+ print(f"EVICTED {obj_to_evict.key}")
+ self.print_cache_state()
+
+# Basic API demo for future testing
+if __name__ == "__main__":
+ cache = SeiveCache(3)
+ cache.put("a", "1")
+ cache.put("b", "2")
+ cache.put("c", "3")
+ cache.get("a")
+ cache.put("d", "4") # Should evict "b"
+ assert "b" not in cache.cache, f"Eviction failed, cache contents: {cache.cache.keys()}"
+ print("SeiveCache eviction test passed.")
diff --git a/app/config.yaml b/app/config.yaml
index ab73f0a..add1fa1 100644
--- a/app/config.yaml
+++ b/app/config.yaml
@@ -1,3 +1,3 @@
-cache_strategy: "Baseline" # Change this to "Prefetch" or "Tiered"
+cache_strategy: "Baseline" # Change this to "Prefetch" or "Tiered" or "Seive"
cache_limit: 10
l2_cache_limit: 100
diff --git a/app/main.py b/app/main.py
index 7f22e25..2dca0ab 100644
--- a/app/main.py
+++ b/app/main.py
@@ -3,6 +3,7 @@ from database import get_user_profile, update_user_profile
from cache.cache import BaselineCache
from cache.prefetch_cache import PrefetchCache
from cache.tiered_cache import TieredCache
+from cache.eviction_seive import SeiveCache
from config import CACHE_STRATEGY, CACHE_LIMIT, L2_CACHE_LIMIT
import time
@@ -15,6 +16,8 @@ elif CACHE_STRATEGY == "Prefetch":
cache = PrefetchCache()
elif CACHE_STRATEGY == "Tiered":
cache = TieredCache(limit=CACHE_LIMIT, l2_limit=L2_CACHE_LIMIT)
+elif CACHE_STRATEGY == "Seive":
+ cache = SeiveCache(limit=CACHE_LIMIT)
else:
raise ValueError(f"Invalid CACHE_STRATEGY: {CACHE_STRATEGY}")