class CouchDB:
lock = Lock()
def __init__(self):
self.write_db = Database(Constants.WRITE_URL)
self.read_db = Database(Constants.READ_URL)
self.cache = OrderedDict()
def getDoc(self, id):
document = None
try:
self.lock.acquire()
if id not in self.cache.keys(): #document not in cache
document = self.read_db.get(id)
if self.cache.__len__() == Constants.CACHE_SIZE:
self.cache.popitem(False) #remove the oldest entry from cache
self.cache.__setitem__(id, document)
else: #get from cache
document = self.cache.__getitem__(id)
return document
finally:
self.lock.release()
return document
def createDoc(self, json):
return self.write_db.create(json)
def deleteDoc(self, id):
try:
self.lock.acquire()
doc = self.getDoc(id)
if id in self.cache:
self.cache.pop(id) #clear document from cache
self.write_db.delete(doc)
finally:
self.lock.release()
def saveDoc(self, doc):
self.db.save(doc)
def updateDoc(self, doc):
try:
self.lock.acquire()
if doc[Constants.DOCUMENT_ID] in self.cache:
self.cache.pop(doc[Constants.DOCUMENT_ID]) #clear document from cache
self.write_db.update(doc)
finally:
self.lock.release()
