""" # TOP2049 Open Source programming suite # # Generic command queue. # # Copyright (c) 2012 Michael Buesch # # 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.