我正在尝试使用Python和龙卷风开发websocket服务器。这个websocket服务器将一个大型数据库结果流式传输到客户端进行一些可视化。
我面临的问题是，在长进程（import time
import random
import json
import datetime
import os
import sys
import cx_Oracle
import string
import re
import subprocess
import asyncio
from tornado import websocket, web, ioloop, escape
from datetime import timedelta
from random import randint
from pprint import pprint
from tornado.web import RequestHandler
os.environ['ORACLE_HOME'] = 'pathToOracleHome'
os.environ['LD_LIBRARY_PATH'] = "$ORACLE_HOME/lib"
def is_hex(a):
printable = set(string.printable) - set("\x0b\x0c")
return any(c not in printable for c in a)
def json_print(d):
print(json.dumps(d, indent=4))
def printf (format,*args):
sys.stdout.write (format % args)
def db(database_name='localhost/database'):
return cx_Oracle.connect('user', 'pwd', database_name)
def query_db(query, args=(), one=False):
cur = db().cursor()
cur.arraysize = 1500
cur.execute(query, args)
return cur
class SummaryWebSocketHandler(websocket.WebSocketHandler):
clients = []
def check_origin(self, origin):
return True
def on_message(self, message):
print ('message received')
def closeDbConn(self,cur):
cur.connection.close()
def query(self, sql):
cursor = query_db(sql)
self.send_data(cursor)
### THIS IS THE LONG PROCESS ###
def send_data(self, cur):
results = {}
columns = [column[0] for column in cur.description]
total = 0
while True:
Res = []
rows = cur.fetchmany()
if rows == []:
print('no more rows')
break;
for row in rows:
results = {}
for i, value in enumerate(row):
if value == None:
value = '-'
results[cur.description[i][0]] = value
Res.append(results)
self.write_message(json.dumps(Res))
total = total + len(rows)
print('total rows send', total)
self.write_message("finished sending all data")
self.on_close(cur)
def open(self, table):
print ('Connection established. \n')
print ('Query string '+table+'\n')
p = re.compile(r'fields=')
m = p.match(table)
matches = table.split("&")
print (matches)
param_string = ''
params = []
if matches:
for m in matches:
print('m', m);
param = ''
items = m.split('=')
if items[1] != '':
param = '--'+items[0]+' '+items[1]
params.append(param)
param_string = " ".join(params)
script = "php getStmt.php "+param_string
print (script)
proc = subprocess.Popen(script, shell=True,stdout=subprocess.PIPE)
sql = proc.stdout.read()
print (sql)
self.query(sql)
def on_close(self, cursor):
print ('Connection closed.')
cursor.close()
settings = {'auto_reload': True, 'debug': True}
if __name__ == "__main__":
print ("Starting websocket server program. Awaiting client requests to open websocket ...")
application = web.Application([(r"/\/table\/(.*)",SummaryWebSocketHandler),
]
,**settings)
application.listen(3001)
ioloop.IOLoop.instance().start()
）完成之前，没有客户端可以连接。就好像一次只能连接一个客户端。
websocket是否已经是异步进程，还是我应该实现异步进程？
以下是我的代码：
Format()