【发布时间】：2016-03-25 07:14:30
【问题描述】：
我正在尝试从 Matlab 创建一个连接，以通过 WebSocket 流式传输 JSON 帧。我已经测试了我的高速公路 python 安装并使用以下方法进行了扭曲。
工作示例
Matlab 代码
使用JSONlab 工具箱将Matlab 数据转换为JSON 格式然后我compress 和Base64 对数据进行编码的示例驱动程序代码。由于我还没有让 RPC 工作，所以我使用需要压缩和 Base64 编码的命令行来避免行长和 shell 转义问题。
clear all
close all
python = '/usr/local/bin/python'
bc = '/Users/palmerc/broadcast_client.py'
i = uint32(1)
encoder = org.apache.commons.codec.binary.Base64
while true
tic;
packet = rand(100, 100);
json_packet = uint8(savejson('', packet));
compressed = CompressLib.compress(json_packet);
b64 = char(encoder.encode(compressed));
message = sprintf('%s %s %s', python, bc, b64);
status = system(message);
i = i + 1;
toc;
end
广播客户端代码
客户端代码有两种调用方式。您可以通过命令行传递消息或创建 BroadcastClient 实例并调用 sendMessage。
#!/usr/bin/env python
import sys
from twisted.internet import reactor
from txjsonrpc.web.jsonrpc import Proxy
class BroadcastClient():
def __init__(self, server=None):
self.proxy = Proxy(server)
def errorMessage(self, value):
print 'Error ', value
def sendMessage(self, message):
rc = self.proxy.callRemote('broadcastMessage', message).addCallback(lambda _: reactor.stop())
rc.addErrback(self.errorMessage)
def main(cli_arguments):
if len(cli_arguments) > 1:
message = cli_arguments[1]
broadcastClient = BroadcastClient('http://127.0.0.1:7080/')
broadcastClient.sendMessage(message)
reactor.run()
if __name__ == '__main__':
main(sys.argv)
广播服务器代码
服务器使用 TXJSONRPC、Twisted 和 Autobahn 在 7080 上提供 RPC 客户端、在 8080 上提供 Web 客户端和在 9080 上提供 WebSocket。 Autobahn Web Client 对调试很有用，应与服务器代码放在同一目录中。
#!/usr/bin/env python
import sys
from twisted.internet import reactor
from twisted.python import log
from twisted.web.server import Site
from twisted.web.static import File
from txjsonrpc.web import jsonrpc
from autobahn.twisted.websocket import WebSocketServerFactory, \
WebSocketServerProtocol, \
listenWS
class BroadcastServerProtocol(WebSocketServerProtocol):
def onOpen(self):
self.factory.registerClient(self)
def onMessage(self, payload, isBinary):
if not isBinary:
message = "{} from {}".format(payload.decode('utf8'), self.peer)
self.factory.broadcastMessage(message)
def connectionLost(self, reason):
WebSocketServerProtocol.connectionLost(self, reason)
self.factory.unregisterClient(self)
class BroadcastServerFactory(WebSocketServerFactory):
"""
Simple broadcast server broadcasting any message it receives to all
currently connected clients.
"""
def __init__(self, url, debug=False, debugCodePaths=False):
WebSocketServerFactory.__init__(self, url, debug=debug, debugCodePaths=debugCodePaths)
self.clients = []
def registerClient(self, client):
if client not in self.clients:
print("registered client {}".format(client.peer))
self.clients.append(client)
def unregisterClient(self, client):
if client in self.clients:
print("unregistered client {}".format(client.peer))
self.clients.remove(client)
def broadcastMessage(self, message):
print("broadcasting message '{}' ..".format(message))
for client in self.clients:
client.sendMessage(message.encode('utf8'))
print("message sent to {}".format(client.peer))
class BroadcastPreparedServerFactory(BroadcastServerFactory):
"""
Functionally same as above, but optimized broadcast using
prepareMessage and sendPreparedMessage.
"""
def broadcastMessage(self, message):
print("broadcasting prepared message '{}' ..".format(message))
preparedMessage = self.prepareMessage(message.encode('utf8'), isBinary=False)
for client in self.clients:
client.sendPreparedMessage(preparedMessage)
print("prepared message sent to {}".format(client.peer))
class MatlabClient(jsonrpc.JSONRPC):
factory = None
def jsonrpc_broadcastMessage(self, message):
if self.factory is not None:
print self.factory.broadcastMessage(message)
if __name__ == '__main__':
if len(sys.argv) > 1 and sys.argv[1] == 'debug':
log.startLogging(sys.stdout)
debug = True
else:
debug = False
factory = BroadcastPreparedServerFactory(u"ws://127.0.0.1:9000",
debug=debug,
debugCodePaths=debug)
factory.protocol = BroadcastServerProtocol
listenWS(factory)
matlab = MatlabClient()
matlab.factory = factory
reactor.listenTCP(7080, Site(matlab))
webdir = File(".")
web = Site(webdir)
reactor.listenTCP(8080, web)
reactor.run()
问题 - 尝试失败
首先请注意，如果您在从 Matlab 中运行 python 时遇到问题，您需要确保使用 pyversion 命令在您的系统上指向正确版本的 Python，并且您可以使用 pyversion('/path/to/python') 更正它
Matlab 无法运行反应器
clear all
close all
i = uint32(1)
while true
tic;
packet = rand(100, 100);
json_packet = uint8(savejson('', packet));
compressed = CompressLib.compress(json_packet);
b64 = char(encoder.encode(compressed));
bc.sendMessage(py.str(b64.'));
py.twisted.internet.reactor.run % This won't work.
i = i + 1;
toc;
end
Matlab POST
另一个尝试涉及使用 Matlab 的 webwrite POST 到服务器。结果webwrite 只需传递正确的weboptions 即可将数据转换为JSON。
options = weboptions('MediaType', 'application/json');
data = struct('Matrix', rand(100, 100));
webwrite(server, data, options);
这行得通，但结果证明每条消息很慢（约 0.1 秒）。我应该提到，矩阵不是我发送的真实数据，真实数据序列化为每条消息大约 280000 个字节，但这提供了一个合理的近似值。
我怎样才能调用bc.sendMessage，以便它正确地设法让反应器运行或以另一种更快的方式解决这个问题？
【问题讨论】：
标签： python matlab websocket twisted autobahn