The clean command removes the future positions from the queue

from __future__ import division, with_statement

import pdb

import time

import shelve

import operator

            answer += ",%s" %param

        else:

            answer += closers[0]

        self.history.clean()

        return [answer.replace('@', '?'), answer]

    def getspar(self, cmd_num, *params):

            self.history.sort(key=operator.itemgetter(0))

            self.history = self.history[-2**15:] # Last 2**15 positions

    def clean(self, since=0):

        target_time = since if since else Servo.ctime()

        with History.lock:

            idx = len(self.history)

            self.history.sort(key=operator.itemgetter(0))

            for idx, item in enumerate(self.history):

                timestamp = item[0]

                if timestamp > target_time:

                    break

            self.history = self.history[:idx] 

    def get(self, target_time=None):

        """Return the position @target_time as [timestamp, axisA, ..., axisN]"""

        if target_time is None:

                        continue

                else:

                    return self.history[-size]

        pdb.set_trace()