def update(self, doc, process=None):
        if process is None:
            pk = 'id'
            id = doc.id
            doc.synced = False
            set = doc
        elif process == UPDATE_PROCESS:
            if self.db.docs.find({'sid': doc.sid}).count() == 0:
                return self.insert(doc, synced=True)
            pk = 'sid'
            id = doc.sid
            doc.synced = not doc.merged() # must be commited if was merged
            doc.merged(False)
            set = {'tid': doc.tid, 'data': doc.data, 'user': doc.user,
                   'public': doc.public, 'synced': doc.synced}
        elif process == COMMIT_PROCESS:
            pk = 'id'
            id = doc.id
            doc.synced = True
            set = {'sid': doc.sid, 'tid': doc.tid, 'synced': doc.synced}
        else:
            raise DatabaseException('Incorrect update process')

        try:
            rs = self.db.docs.update({pk: id}, {'$set': set}, safe=True)
            assert rs['n'] == 1
        except Exception as e:
            raise DatabaseException(e)
        return doc
def setPPSS(self, p1, p3, lenp1, lenp3):
        temp = []
        self.p1 = p1
        self.p3 = p3
        self.lenp1 = lenp1
        self.lenp3 = lenp3

        #bp3 is the angle beside p3 point, cp3 is the angle for line23, p2 is the output
        line31 = Line(p3, p1)
        self.lenp2 = line31.getR()
        #self.lenp2 = self.p3.distance(self.p1)
        #這裡是求角3
        ap3 = math.acos(((self.lenp1 * self.lenp1 + self.lenp2 * self.lenp2) - self.lenp3 * self.lenp3) / (2 * self.lenp1 * self.lenp2))
        #ap3 = math.acos(((self.lenp1 * self.lenp1 + self.lenp3 * self.lenp3) - self.lenp2 * self.lenp2) / (2 * self.lenp1 * self.lenp3))
        bp3 = line31.getT()
        cp3 = bp3 - ap3
        temp.append(p3.x + self.lenp1*math.cos(cp3))#p2.x
        temp.append(p3.y + self.lenp1*math.sin(cp3))#p2.y
        return temp