Implemented request-local DB cache

maloja/database/dbcache.py

@@ -10,16 +10,22 @@ from doreah.logging import log
 
 from ..globalconf import malojaconfig
 
-USE_CACHE = True
 HIGH_NUMBER = 1000000
 
 cache = lru.LRU(HIGH_NUMBER)
 hits, misses = 0, 0
 
 
+if malojaconfig['USE_GLOBAL_CACHE']:
+	log("Using global DB Cache")
+if malojaconfig['USE_REQUEST_CACHE']:
+	log("Using request-local DB Cache")
+
+
 
 @runhourly
 def maintenance():
+	if malojaconfig['USE_GLOBAL_CACHE']:
 		print_stats()
 		trim_cache()
 
@@ -29,7 +35,7 @@ def print_stats():
 
 def cached_wrapper(inner_func):
 
-	if not USE_CACHE: return inner_func
+	if not malojaconfig['USE_GLOBAL_CACHE']: return inner_func
 	def outer_func(*args,**kwargs):
 		if 'dbconn' in kwargs:
 			conn = kwargs.pop('dbconn')
@@ -53,6 +59,7 @@ def cached_wrapper(inner_func):
 
 
 def invalidate_caches(scrobbletime):
+	if malojaconfig['USE_GLOBAL_CACHE']:
 		cleared, kept = 0, 0
 		for k in cache.keys():
 			# VERY BIG TODO: differentiate between None as in 'unlimited timerange' and None as in 'time doesnt matter here'!

maloja/database/jinjaview.py

@@ -1,12 +1,19 @@
-
 from .. import database
 from . sqldb import engine
 
+from .dbcache import serialize
+
+from ..globalconf import malojaconfig
+
 
 # this is a wrapper object that provides a DB connection so that one jinja page
 # (with all its included partials) can use it for all functions
 # it also translates the non-unpacked calls to unpacked calls that the DB wants
+# it also maintains a request-local cache since many webpages use the same stats
+# several times
 class JinjaDBConnection:
+	def __init__(self):
+		self.cache = {}
 	def __enter__(self):
 		self.conn = engine.connect()
 		return self
@@ -19,6 +26,17 @@ class JinjaDBConnection:
 			kwargs = {}
 			for k in keys:
 				kwargs.update(k)
-			return originalmethod(**kwargs,dbconn=self.conn)
+			if malojaconfig['USE_REQUEST_CACHE']:
+				cachekey = serialize((id(originalmethod),kwargs))
+				if cachekey in self.cache:
+					return self.cache[cachekey]
+				else:
+					result = originalmethod(**kwargs,dbconn=self.conn)
+					self.cache[cachekey] = result
+					return result
+			else:
+				result = originalmethod(**kwargs,dbconn=self.conn)
+				return result
+
 
 		return packedmethod

maloja/globalconf.py

@@ -149,7 +149,9 @@ malojaconfig = Configuration(
 		"Technical":{
 			"cache_expire_positive":(tp.Integer(),								"Image Cache Expiration", 				60,		"Days until images are refetched"),
 			"cache_expire_negative":(tp.Integer(),								"Image Cache Negative Expiration",		5,		"Days until failed image fetches are reattempted"),
-			"db_max_memory":(tp.Integer(min=0,max=100),							"RAM Percentage soft limit",			80,		"RAM Usage in percent at which Maloja should no longer increase its database cache.")
+			"db_max_memory":(tp.Integer(min=0,max=100),							"RAM Percentage soft limit",			80,		"RAM Usage in percent at which Maloja should no longer increase its database cache."),
+			"use_request_cache":(tp.Boolean(),									"Use request-local DB Cache",			True),
+			"use_global_cache":(tp.Boolean(),									"Use global DB Cache",					True)
 		},
 		"Fluff":{
 			"scrobbles_gold":(tp.Integer(),										"Scrobbles for Gold",			250,				"How many scrobbles a track needs to be considered 'Gold' status"),