Since the C-terminal system to upload pictures sometimes does not receive the message, you need to do a synchronization. When the C-terminal loaded picture gallery but without requesting remote loading local images, the equivalent of doing a cache, greatly reducing the time to load the C-terminus of the picture, improving the user experience.
A functional role
mqtt is a plug-in rabbitmq server, you can use it to publish and subscribe topic.
This synchronization feature, in fact, is to use one of the rabbitmq application scenarios asynchronous processing.
Second, the process steps
1, a unique ID is provided mqtt, because the client id can not be repeated, so that the current time is a unique ID is selected from
The time.strftime = client_id ( ' % D the Y% m%%% M% S H ' , time.localtime (the time.time ())) Client = mqtt.Client (client_id) # the ClientId can not be reused, so the current time
2, set rabbitmq server user name and password
client.username_pw_set("dev", "YTc4Mj")
3, subscribe to topics
client.subscribe("sync")
4, receives the message
recvmsg = msg.payload.decode("utf-8")
5, the message processing
Three, demo source code
1, mqtt server connected rabbitmq
import paho.mqtt.client as mqtt import time import socketclient import logger import demjson import common import syncfile log = logger.Logger("info") HOST = "127.0.0.1" PORT = 1883 def client_loop(): client_id = time.strftime('%Y%m%d%H%M%S', time.localtime(time.time())) client = mqtt.Client(client_id) # ClientId不能重复，所以使用当前时间 client.username_pw_set(" Dev " , " YTc4Mj " ) # must be set, otherwise it will return "Connected with result code 4" client.on_connect = on_connect client.on_message = ON_MESSAGE log.info ( ' start connecting the MQTT ' + HOST + ' : ' + str ( PORT)) the client.connect (the HOST, PORT, 60 ) log.info ( ' MQTT connection completion ' + the HOST + ' : ' + STR (PORT)) client.loop_forever () DEF on_connect(client, userdata, flags, rc): log.info("Connected with result code " + str(rc)) client.subscribe("projector-remote-control") log.info("订阅消息 projector-remote-control") client.subscribe("holo-file-sync") log.info("订阅消息 holo-file-sync") client.subscribe("sync") log.info("订阅消息 sync") client.subscribe("Work-SINGLE-Sync " ) log.info ( " subscribe message Work-SINGLE-Sync " ) DEF ON_MESSAGE (Client, UserData, MSG): recvmsg = msg.payload.decode ( " UTF-. 8 " ) log.info ( " receive the message " + recvmsg + " , executes the command " ) Print (msg.topic + " " + recvmsg) IF (msg.topic == ' Sync-SINGLE-Work ' ): common.insert_sql (recvmsg) elif (MSG == .topic 'sync'): common.insert_sql(recvmsg) elif(msg.topic=='holo-file-sync'): common.insert_sql(recvmsg) elif(msg.topic=='projector-remote-control'): text = demjson.decode(msg) command = text['command'] projectors = text['projectors'] #socketclient.sendSocket(recvmsg) socketclient.handlerMsg(command,projectors) if __name__ == '__main__': syncfile.scheduletask() syncfile.scheduleuncompletedtask() client_loop()
2, the message processing
Import Logger from Threading Import the Timer Import OS Import Requests from IO Import BytesIO from the PIL Import Image Import Common log = logger.Logger ( " info " ) DEF scheduletask (): T = the Timer (10 , scheduletask) t.start () # Print ( 'timer task is turned on, waiting to receive parameters ...') List common.select_sql = (. 3 ) IF (List == None): return getimagesize(list[0],list[2]) def scheduleuncompletedtask(): t = Timer(10,scheduleuncompletedtask) t.start() #print('定时任务已开启，等待接收参数中...') list = common.select_sql(2) if(list == None): return getimagesize(list[0],list[2]) def getimagesize(id,url): savepath = common.readJson()['holoImageUrl'] try: response = requests.get(url) except: common.delete_sql(id) return tmpIm = BytesIO(response.content) im = Image.open(tmpIm) imgpath = url[url.index('.com/')+5:] dirpath = imgpath[:imgpath.rindex('/')].replace('/','\\') filename= imgpath[imgpath.rfind('/')+1:] targetpath = savepath+'\\'+dirpath+'\\' filename1 = filename[:filename.find('!')] if (os.path.exists(targetpath)):pass else:os.makedirs(targetpath) im.save(targetpath+filename1) if(os.path.exists(targetpath + filename)): os.remove(targetpath + filename) os.rename(targetpath + filename1, targetpath + filename) #localfilesize = os.path.getsize(targetpath+filename) #remotefilesize = dict(response.headers).get('Content-Length', 0) #IF (localfilesize == remotefilesize): if(os.path.exists (TargetPath + filename) and os.path.getsize (TargetPath + filename) =! 0): common.delete_sql (the above mentioned id) log.info ( " incremental image to download complete ... " ) the else : common.update_sql (the above mentioned id) log.info ( " incremental part of the picture to download ... " ) IF __name__ == ' __main__ ' : scheduletask ()
Third, the common module
import json import sqlite3 import re from threading import Timer import logger log = logger.Logger("info") def readJson(): with open('config.json', 'rt') as jsonFile: val = jsonFile.read() Config = json.loads(val) return Config def create_table(): conn = sqlite3.connect('imagesnyc.xs') curs=conn.cursor() # 获取游标 try: create_tb_cmd=''' CREATE TABLE IF NOT EXISTS image_sync(id INTEGER PRIMARY KEY AUTOINCREMENT,imgsize INTEGER,url TEXT,status INTEGER) ''' #主要就是上面的语句 curs.execute(create_tb_cmd) conn.commit() except: log.info('Create table failed') return False finally: return conn def insert_sql(url): conn =the create_table () CURS = conn.cursor () # Get cursor imgurls re.split = ( ' , ' , URL) for ImageUrl in imgurls: curs.execute ( " the INSERT the INTO image_sync (ImgSize, URL, Status) the VALUES ( '{} ',' {} ',' {} '); " .format (0, ImageUrl,. 3)) # add records conn.commit () log.info ( " insertion completion " ) DEF select_sql (Status): Conn = the create_table () CURS = conn.cursor () # get a cursor curs.execute ( "* Status from image_sync WHERE SELECT = '% S' Order ID by the ASC. 1 the LIMIT " % Status) # query log List = curs.fetchone () conn.commit () return List DEF update_sql (ID): Conn = the create_table () CURS conn.cursor = () # Get the cursor the try : curs.execute ( " update Status image_sync SET = 2 WHERE ID = '% S' " % ID) # update record conn.commit () the except : log.info ( ' primary key update failure id ' ) the finally: Print ( ' the Continue ' ) DEF delete_sql (the above mentioned id): conn = create_table () CURS = conn.cursor () # get a cursor curs.execute ( " the Delete from the WHERE image_sync the above mentioned id = '% S' " % the above mentioned id) # delete records conn.commit () # log.info ( 'completed successfully deleted the downloaded records')