Function to expire actor cache entries

cache.py

@@ -31,26 +31,46 @@ def storePersonInCache(baseDir: str,personUrl: str,personJson: {},personCache: {
         with open(cacheFilename, 'w') as fp:
             commentjson.dump(personJson, fp, indent=4, sort_keys=False)
 
+def getPersonFromCache(baseDir: str,personUrl: str,personCache: {}) -> {}:
+    """Get an actor from the cache
+    """
+    # if the actor is not in memory then try to load it from file
+    if not personCache.get(personUrl):
+        cacheFilename=baseDir+'/cache/actors/'+personUrl.replace('/','#')+'.json'
+        if os.path.isfile(cacheFilename):
+            with open(cacheFilename, 'r') as fp:
+                personJson=commentjson.load(fp)
+                storePersonInCache(baseDir,personUrl,personJson,personCache)
+        
+    if personCache.get(personUrl):
+        # update the timestamp for the last time the actor was retrieved
+        currTime=datetime.datetime.utcnow()
+        personCache[personUrl]['timestamp']=currTime.strftime("%Y-%m-%dT%H:%M:%SZ")
+        return personCache[personUrl]['actor']
+    return None
+
+def expirePersonCache(personCache: {}):
+    """Expires old entries from the cache in memory
+    """
+    currTime=datetime.datetime.utcnow()
+    removals=[]
+    for personUrl,cacheJson in personCache.items():
+        cacheTime= \
+            datetime.datetime.strptime(cacheJson['timestamp'], \
+                                       "%Y-%m-%dT%H:%M:%SZ")
+        daysSinceCached=(currTime - cacheTime).days
+        if daysSinceCached > 2:
+            removals.append(personUrl)
+    if len(removals)>0:
+        for personUrl in removals:
+            del personCache[personUrl]
+        print(str(len(removals))+' actors were expired from the cache')
+
 def storeWebfingerInCache(handle: str,wf,cachedWebfingers: {}) -> None:
     """Store a webfinger endpoint in the cache
     """
     cachedWebfingers[handle]=wf
 
-def getPersonFromCache(personUrl: str,personCache: {}) -> {}:
-    """Get an actor from the cache
-    """
-    if personCache.get(personUrl):
-        # how old is the cached data?
-        currTime=datetime.datetime.utcnow()
-        cacheTime= \
-            datetime.datetime.strptime(personCache[personUrl]['timestamp'], \
-                                       "%Y-%m-%dT%H:%M:%SZ")
-        daysSinceCached=(currTime - cacheTime).days
-        # return cached value if it has not expired
-        if daysSinceCached <= 2:
-            return personCache[personUrl]['actor']        
-    return None
-
 def getWebfingerFromCache(handle: str,cachedWebfingers: {}) -> {}:
     """Get webfinger endpoint from the cache
     """

inbox.py

@@ -95,7 +95,7 @@ def getPersonPubKey(baseDir: str,session,personUrl: str, \
         if debug:
             print('DEBUG: Obtaining public key for shared inbox')
         personUrl=personUrl.replace('/users/inbox','/inbox')        
-    personJson = getPersonFromCache(personUrl,personCache)
+    personJson = getPersonFromCache(baseDir,personUrl,personCache)
     if not personJson:
         if debug:
             print('DEBUG: Obtaining public key for '+personUrl)

posts.py

@@ -146,7 +146,7 @@ def getPersonBox(baseDir: str,session,wfRequest: {},personCache: {}, \
     personUrl = getUserUrl(wfRequest)
     if not personUrl:
         return None,None,None,None,None,None,None,None
-    personJson = getPersonFromCache(personUrl,personCache)
+    personJson = getPersonFromCache(baseDir,personUrl,personCache)
     if not personJson:
         personJson = getJson(session,personUrl,asHeader,None, \
                              projectVersion,httpPrefix,domain)

tests.py

@@ -147,7 +147,7 @@ def testCache():
     personJson={ "id": 123456, "test": "This is a test" }
     personCache={}
     storePersonInCache(None,personUrl,personJson,personCache)
-    result=getPersonFromCache(personUrl,personCache)
+    result=getPersonFromCache(None,personUrl,personCache)
     assert result['id']==123456
     assert result['test']=='This is a test'
 

webinterface.py

@@ -36,10 +36,10 @@ from config import getConfigParam
 from skills import getSkills
 from cache import getPersonFromCache
 
-def getPersonAvatarUrl(personUrl: str,personCache: {}) -> str:
+def getPersonAvatarUrl(baseDir: str,personUrl: str,personCache: {}) -> str:
     """Returns the avatar url for the person
     """
-    personJson = getPersonFromCache(personUrl,personCache)
+    personJson = getPersonFromCache(baseDir,personUrl,personCache)
     if personJson:
         if personJson.get('icon'):
             if personJson['icon'].get('url'):
@@ -947,7 +947,7 @@ def individualFollowAsHtml(baseDir: str,session,wfRequest: {}, \
     nickname=getNicknameFromActor(followUrl)
     domain,port=getDomainFromActor(followUrl)
     titleStr='@'+nickname+'@'+domain
-    avatarUrl=getPersonAvatarUrl(followUrl,personCache)
+    avatarUrl=getPersonAvatarUrl(baseDir,followUrl,personCache)
     if not avatarUrl:
         avatarUrl=followUrl+'/avatar.png'
     if domain not in followUrl:
@@ -1093,7 +1093,7 @@ def individualPostAsHtml(baseDir: str, \
                             attachmentCtr+=1
 
     if not avatarUrl:
-        avatarUrl=getPersonAvatarUrl(postJsonObject['actor'],personCache)
+        avatarUrl=getPersonAvatarUrl(baseDir,postJsonObject['actor'],personCache)
     if not avatarUrl:
         avatarUrl=postJsonObject['actor']+'/avatar.png'
 
@@ -1321,7 +1321,7 @@ def htmlTimeline(pageNumber: int,itemsPerPage: int,session,baseDir: str, \
     for item in timelineJson['orderedItems']:
         if item['type']=='Create' or item['type']=='Announce':
             itemCtr+=1
-            avatarUrl=getPersonAvatarUrl(item['actor'],personCache)
+            avatarUrl=getPersonAvatarUrl(baseDir,item['actor'],personCache)
             tlStr+=individualPostAsHtml(baseDir,session,wfRequest,personCache, \
                                         nickname,domain,port,item,avatarUrl,True, \
                                         allowDeletion, \
@@ -1668,7 +1668,7 @@ def htmlProfileAfterSearch(baseDir: str,path: str,httpPrefix: str, \
             if profileJson['icon'].get('url'):
                 avatarUrl=profileJson['icon']['url']
         if not avatarUrl:
-            avatarUrl=getPersonAvatarUrl(personUrl,personCache)
+            avatarUrl=getPersonAvatarUrl(baseDir,personUrl,personCache)
         preferredName=searchNickname
         if profileJson.get('preferredUsername'):
             preferredName=profileJson['preferredUsername']