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"""
# TOP2049 Open Source programming suite
#
# Generic command queue.
#
# Copyright (c) 2012 Michael Buesch <m@bues.ch>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
"""
from util import *
import time
class CommandQueue(object):
"Generic hardware-command queue. Needs to be subclassed."
def __init__(self, maxPacketBytes, synchronous=False):
self.maxPacketBytes = maxPacketBytes
self.synchronous = synchronous
self.commandQueue = []
def queueCommand(self, command):
"""Queue a raw command for transmission."""
assert(len(command) <= self.maxPacketBytes)
if self.synchronous:
self.send(command)
else:
self.commandQueue.append(command)
def runCommandSync(self, command):
"""Run a command synchronously.
This is slow. Don't use it without a very good reason."""
self.flushCommands()
self.queueCommand(command)
self.flushCommands()
def flushCommands(self, sleepSeconds=0):
"""Flush the command queue."""
command = b""
for oneCommand in self.commandQueue:
assert(len(oneCommand) <= self.maxPacketBytes)
if len(command) + len(oneCommand) > self.maxPacketBytes:
self.send(command)
command = b""
command += oneCommand
if command:
self.send(command)
self.commandQueue = []
if sleepSeconds:
time.sleep(sleepSeconds)
def send(self, data):
raise NotImplementedError # Reimplement in subclass.
def receive(self, size):
raise NotImplementedError # Reimplement in subclass.
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