From a1f8e96ae48e428fac1e12a82674f5fcb5a237f7 Mon Sep 17 00:00:00 2001
From: krateng <git.noreply@krateng.ch>
Date: Tue, 15 Feb 2022 05:52:44 +0100
Subject: [PATCH] Reimplemented cache limitation

---
 maloja/__pkginfo__.py      |  2 +-
 maloja/database/dbcache.py | 25 +++++++++++++++++++++----
 maloja/globalconf.py       |  3 ++-
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/maloja/__pkginfo__.py b/maloja/__pkginfo__.py
index 36b33e3..bf5cf8a 100644
--- a/maloja/__pkginfo__.py
+++ b/maloja/__pkginfo__.py
@@ -4,7 +4,7 @@
 # you know what f*ck it
 # this is hardcoded for now because of that damn project / package name discrepancy
 # i'll fix it one day
-VERSION = "3.0.0-alpha.1"
+VERSION = "3.0.0-alpha.2"
 HOMEPAGE = "https://github.com/krateng/maloja"
 
 
diff --git a/maloja/database/dbcache.py b/maloja/database/dbcache.py
index d1508f2..ac01dab 100644
--- a/maloja/database/dbcache.py
+++ b/maloja/database/dbcache.py
@@ -3,26 +3,37 @@
 # that changes very infrequently or not at all
 
 import lru
+import psutil
 import json
 from doreah.regular import runhourly
 from doreah.logging import log
 
+from ..globalconf import malojaconfig
 
 USE_CACHE = True
-cache = lru.LRU(300000)
+HIGH_NUMBER = 1000000
+
+cache = lru.LRU(HIGH_NUMBER)
+hits, misses = 0, 0
 
 @runhourly
 def print_stats():
-	log(f"Cache Size: {len(cache)}")
+	log(f"Cache Size: {len(cache)}, RAM Utilization: {psutil.virtual_memory().percent}%, Cache Hits: {hits}/{hits+misses}")
+	trim_cache()
+
 
 def cached_wrapper(inner_func):
+
 	def outer_func(**kwargs):
+		global hits, misses
 		key = (serialize(kwargs), inner_func, kwargs.get("since"), kwargs.get("to"))
 
 		if USE_CACHE and key in cache:
+			hits += 1
 			return cache.get(key)
 
 		else:
+			misses += 1
 			result = inner_func(**kwargs)
 			cache[key] = result
 			return result
@@ -38,8 +49,14 @@ def invalidate_caches(scrobbletime):
 
 
 
-
-
+def trim_cache():
+	ramprct = psutil.virtual_memory().percent
+	if ramprct > malojaconfig["DB_MAX_MEMORY"]:
+		log(f"{ramprct}% RAM usage, reducing caches!",module="debug")
+		ratio = (malojaconfig["DB_MAX_MEMORY"] / ramprct) ** 3
+		targetsize = max(int(len(cache) * ratio),100)
+		c.set_size(targetsize)
+		c.set_size(HIGH_NUMBER)
 
 
 def serialize(obj):
diff --git a/maloja/globalconf.py b/maloja/globalconf.py
index 87f610b..c70d541 100644
--- a/maloja/globalconf.py
+++ b/maloja/globalconf.py
@@ -148,7 +148,8 @@ malojaconfig = Configuration(
 		},
 		"Technical":{
 			"cache_expire_positive":(tp.Integer(),								"Image Cache Expiration", 							300,	"Days until images are refetched"),
-			"cache_expire_negative":(tp.Integer(),								"Image Cache Negative Expiration",					30,		"Days until failed image fetches are reattempted")
+			"cache_expire_negative":(tp.Integer(),								"Image Cache Negative Expiration",					30,		"Days until failed image fetches are reattempted"),
+			"db_max_memory":(tp.Integer(min=0,max=100),							"Database Cache RAM Percentage soft limit",			80,		"How much of your total memory Maloja should use for caching. If you don't run the application in a container or dedicated VM, you might want to set this lower.")
 		},
 		"Fluff":{
 			"scrobbles_gold":(tp.Integer(),										"Scrobbles for Gold",			250,				"How many scrobbles a track needs to be considered 'Gold' status"),