Day30--Python--struct, socketserver

1. struct 
    struct.pack 打包

def pack(fmt, *args): # known case of _struct.pack
    """
    pack(fmt, v1, v2, ...) -> bytes

    Return a bytes object containing the values v1, v2, ... packed according
    to the format string fmt.  See help(struct) for more on format strings.
    """
    return b""

    struct.unpack 解包

def unpack(fmt, string): # known case of _struct.unpack
    """
    unpack(fmt, buffer) -> (v1, v2, ...)

    Return a tuple containing values unpacked according to the format string
    fmt.  The buffer's size in bytes must be calcsize(fmt). See help(struct)
    for more on format strings.
    """
    pass

fmt 长度表

# 粘包解决方案_3_服务端     struct.pack  打包

import socket
import struct
import subprocess
import time

server = socket.socket()
ip_port = ('192.168.15.87', 8001)
server.bind(ip_port)
server.listen(3)

while 1:
    print('等待连接中...')
    conn, addr = server.accept()
    print('连接成功!')
    while 1:
        print('等待接收命令...')
        cmd = conn.recv(1024).decode('utf-8')
        if cmd == 'exit':
            break
        sub_obj = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)  # 调用控制台, stdout标准输出,返回信息 stderr 标准错误,返回错误信息
        content = sub_obj.stdout.read()  # 读取标准输出,获取到是gbk编码的bytes
        error = sub_obj.stderr.read()　　# 读取标准错误, 也是gbk编码的bytes
        len_of_content = len(content)　　 # 获取标准输出长度
        len_packed = struct.pack('i', len_of_content)   # 'i'表示打包成4个字节长度. 此处将数据长度打包成4个字节长度的数据 

        len_of_err = len(error)　　# 获取标准错误长度
        len_err_packed = struct.pack('i', len_of_err)    # 'i' 表示打包成4个字节长度. 此处将错误信息长度打包成4个字节长度的数据
        # print(len_packed)  # 显示的是字节 b'\xaf\x01\x00\x00'
        if len_of_content == 0: 　　# 当标准输出长度是零,也就是返回错误信息的时候
            conn.send(len_err_packed)　　# 发送打包后的错误信息的长度
            print('数据长度发送成功!')
            conn.sendall(error)　　　　　　# 循环着发送错误信息数据,防止数据过大造成缓冲区溢出   # 缓冲区大小 8kb  MTU 最大传输单元 1518b, 每次发送数据最好不超过这个数
            print('数据发送成功!')
        else:
            conn.send(len_packed)　　　　# 发送打包后的标准输出信息长度
            print('数据长度发送成功!')　　# 循环着发送标准输出信息数据,防止数据过大造成缓冲区溢出
            conn.sendall(content)
            print('数据发送成功!')
    conn.close()
    print('连接已断开!')
    time.sleep(3)

# 粘包解决方案_3_客户端        struct.unpack 解包

import socket
import struct

client = socket.socket()
serverip_port = ('192.168.15.87', 8001)
client.connect(serverip_port)

while 1:
    cmd = input('请输入命令>>>')
    client.send(cmd.encode('utf-8'))
    if cmd == 'exit':
        break
    msg_len_return = client.recv(4)　　　　# 先接收4个字节长度的打包信息
    msg_return_unpacked = struct.unpack('i', msg_len_return)[0]   # 拆包, 获取数据长度
    # print(msg_return_unpacked)   # struct.unpack('i', msg_len_return)返回一个元组 (431,),  取[0]得到长度431

    total_len = 0
    total_data = b''

    while total_len < msg_return_unpacked:
        data_splited = client.recv(1024)     # 分段接收信息,一次最多接收1024,防止超过MTU
        total_data += data_splited　　　　　　 # 把接收到的数据拼接到一起
        total_len += len(data_splited)　　　　 #  计算接收到的数据总长度

    print(total_data.decode('gbk'))　　　　　　# 接收到的信息都是gbk编码的bytes,需要进行解码

client.close()

2. FTP 简单上传

   127.0.0.1 本机回环地址

# 服务端

import socket
import struct
import json

# 用户上传文件储存位置
file_storage_catalogue = r"D:\python_work\Day030 struct, socketserver, ftp上传文件\uploads"

server = socket.socket()
ip_port = ('127.0.0.1', 8001)
server.bind(ip_port)
server.listen()
print('等待连接中...')
conn, addr = server.accept()
print('连接成功!')
file_info_len = struct.unpack('i', conn.recv(4))[0]
file_info = conn.recv(file_info_len).decode('utf-8')
file_info = json.loads(file_info)
print(file_info)
print(type(file_info))

full_file_path = file_storage_catalogue + '\\' + file_info['file_name']
total_data_size = 0
with open(full_file_path, 'wb') as f:
    while total_data_size < file_info['file_size']:
        data_slice = conn.recv(1024)
        total_data_size += len(data_slice)
        f.write(data_slice)

conn.send('文件上传成功!'.encode('utf-8'))
conn.close()
server.close()

# 客户端

import socket
import json
import struct
import os

client = socket.socket()
server_ip_port = ('127.0.0.1', 8001)
client.connect(server_ip_port)
read_size = 1024
file_info = {
    'file_path': r'D:\老男孩IT\课件\day30 粘包解决方案2+ftp上传+socketserver\视频\03 socketserver模块.mp4',
    'file_name': '03 socketserver模块.mp4',
    'file_size': None
}

file_info['file_size'] = os.path.getsize(file_info['file_path'])
print('上传文件大小为:%sb' % file_info['file_size'])

file_info_json = json.dumps(file_info, ensure_ascii=False).encode('utf-8')
len_of_info = len(file_info_json)
info_len_packed = struct.pack('i', len_of_info)
client.send(info_len_packed)
print(file_info_json)
client.sendall(file_info_json)

# total_data = b''
total_data_len = 0
with open(file_info['file_path'], 'rb') as f:
    while total_data_len < file_info['file_size']:
        data_slice = f.read(read_size)
        # total_data += data_slice
        total_data_len += len(data_slice)
        client.send(data_slice)

ack = client.recv(1024).decode('utf-8')
print(ack)
client.close()

3. socketserver 套接字服务器

# 服务端同时接待多个客户端

import socketserver

class MyServer(socketserver.BaseRequestHandler):

    def handle(self):  # 重新定义父类BaseRequestHandler中的handle方法. (约束)
        print('Connected From:', self.cliend_address)  # 获取客户端地址和端口
        while 1:
            data_received = self.request.recv(1024)  # self.request 相当于 conn 连接通道
            if data_received == b'':      """ 当连接的客户端关close时,通道仍然没有关闭,里面没有内容,会循环打印b'', 此处判断如果对面关闭了,服务端对应的通道也关闭. 
当对面直接敲回车或者发空字符串或者空字节b''过来,而且对方的通道没有关闭时,此处是收不到任何信息的,甚至不会有空字节b''过来,因为字节为空就是没有东西,没传东西就什么也过不来"""               
 　　　　　　     self.request.close()
                break
            print('妲己宝宝说:%s' % data_received.decode('utf-8'))

            reply = input('亚瑟说>>>')
            self.request.send(reply.encode('utf-8'))

if __name__ == '__main__':
    ip_port = ('127.0.0.1', 8001)
    socketserver.TCPServer.allow_reuse_address = True
    socketserver.TCPServer.request_queue_size = 10          # 设置监听数量,默认是5,可修改
    server = socketserver.ThreadingTCPServer(ip_port, MyServer)  # 绑定IP地址和端口,并启动刚才定义的MyServer类
    server.serve_forever()  # 永久的执行下去, 相当于accept()一直等待连接
    print('这里是测试')

# 客户端

import socket

client = socket.socket()
server_ip_port = ('127.0.0.1', 8001)
client.connect(server_ip_port)
while 1:
    msg = input('发送消息, 按Q退出>>>')
    if msg.upper() == 'Q':
        break
    elif msg == '':     # 此处需要判断,如果输入的是空字符串'',空字节b'',或者直接敲回车,通道内不会存在任何数据,服务端不会收到任何消息,也就没法回复消息,客户端接不到回复,
　　　　　　　　　　　　　　　　　　                                  程序会阻塞住
        print('内容不能为空!')
        continue
    client.send(msg.encode('utf-8'))
    reply = client.recv(1024).decode('utf-8')
    print('亚瑟说: %s' % reply)

client.close()

class TCPServer(BaseServer) 中的类变量,可以修改
request_queue_size = 5
allow_reuse_address = False
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
ThreadingTCPServer(ip_port, MyServer)  # 要找__init__
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
class ThreadingTCPServer(ThreadingMixIn, TCPServer): pass   # 自己类中没有__init__,根据MRO顺序找父类
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
class TCPServer(BaseServer):   # ThreadingMixIn 类中没有,继续在TCPServer中找到__init__
    def __init__(self, server_address, RequestHandlerClass, bind_and_activate=True):  # 找到了ip_port和MyServer对应的形参
        """Constructor.  May be extended, do not override."""
        BaseServer.__init__(self, server_address, RequestHandlerClass)  # 里面还有__init__, 找到了对应的形参
        self.socket = socket.socket(self.address_family,
                                    self.socket_type)
        if bind_and_activate:
            try:
                self.server_bind()                                      # 调用server_bind()方法
                self.server_activate()
            except:
                self.server_close()
                raise

    def server_bind(self):
        """Called by constructor to bind the socket.

        May be overridden.

        """
        if self.allow_reuse_address:                                     # allow_reuse_address = True的条件下
            self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.socket.bind(self.server_address)                            # 绑定IP地址
        self.server_address = self.socket.getsockname()

    def server_activate(self):
        """Called by constructor to activate the server.

        May be overridden.

        """
        self.socket.listen(self.request_queue_size)                      # 监听. request_queue_size 类变量给了值,可修改

    def server_close(self):
        """Called to clean-up the server.

        May be overridden.

        """
        self.socket.close()                                             # 关闭
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

serve_forever() ==> _handle_request_noblock(self)

class BaseServer:
def _handle_request_noblock(self):
    """Handle one request, without blocking.

    I assume that selector.select() has returned that the socket is
    readable before this function was called, so there should be no risk of
    blocking in get_request().
    """
    try:
        request, client_address = self.get_request()                # 同conn, addr   此处get_request()相当于accept()

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
class BaseRequestHandler:                                           # 重新 定义 handle方法,调用handle方法
    def handle(self):
        pass

View 梳理流程

class BaseRequestHandler:

    """Base class for request handler classes.

    This class is instantiated for each request to be handled.  The
    constructor sets the instance variables request, client_address
    and server, and then calls the handle() method.  To implement a
    specific service, all you need to do is to derive a class which
    defines a handle() method.

    The handle() method can find the request as self.request, the
    client address as self.client_address, and the server (in case it
    needs access to per-server information) as self.server.  Since a
    separate instance is created for each request, the handle() method
    can define other arbitrary instance variables.

    """

    def __init__(self, request, client_address, server):
        self.request = request
        self.client_address = client_address
        self.server = server
        self.setup()
        try:
            self.handle()
        finally:
            self.finish()

    def setup(self):
        pass

    def handle(self):
        pass

    def finish(self):
        pass

View class BaseRequestHandler

class ThreadingMixIn:
    """Mix-in class to handle each request in a new thread."""

    # Decides how threads will act upon termination of the
    # main process
    daemon_threads = False

    def process_request_thread(self, request, client_address):
        """Same as in BaseServer but as a thread.

        In addition, exception handling is done here.

        """
        try:
            self.finish_request(request, client_address)
        except Exception:
            self.handle_error(request, client_address)
        finally:
            self.shutdown_request(request)

    def process_request(self, request, client_address):
        """Start a new thread to process the request."""
        t = threading.Thread(target = self.process_request_thread,
                             args = (request, client_address))
        t.daemon = self.daemon_threads
        t.start()

View class ThreadingMixIn

class TCPServer(BaseServer):

    """Base class for various socket-based server classes.

    Defaults to synchronous IP stream (i.e., TCP).

    Methods for the caller:

    - __init__(server_address, RequestHandlerClass, bind_and_activate=True)
    - serve_forever(poll_interval=0.5)
    - shutdown()
    - handle_request()  # if you don't use serve_forever()
    - fileno() -> int   # for selector

    Methods that may be overridden:

    - server_bind()
    - server_activate()
    - get_request() -> request, client_address
    - handle_timeout()
    - verify_request(request, client_address)
    - process_request(request, client_address)
    - shutdown_request(request)
    - close_request(request)
    - handle_error()

    Methods for derived classes:

    - finish_request(request, client_address)

    Class variables that may be overridden by derived classes or
    instances:

    - timeout
    - address_family
    - socket_type
    - request_queue_size (only for stream sockets)
    - allow_reuse_address

    Instance variables:

    - server_address
    - RequestHandlerClass
    - socket

    """

    address_family = socket.AF_INET

    socket_type = socket.SOCK_STREAM

    request_queue_size = 5

    allow_reuse_address = False

    def __init__(self, server_address, RequestHandlerClass, bind_and_activate=True):
        """Constructor.  May be extended, do not override."""
        BaseServer.__init__(self, server_address, RequestHandlerClass)
        self.socket = socket.socket(self.address_family,
                                    self.socket_type)
        if bind_and_activate:
            try:
                self.server_bind()
                self.server_activate()
            except:
                self.server_close()
                raise

    def server_bind(self):
        """Called by constructor to bind the socket.

        May be overridden.

        """
        if self.allow_reuse_address:
            self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.socket.bind(self.server_address)
        self.server_address = self.socket.getsockname()

    def server_activate(self):
        """Called by constructor to activate the server.

        May be overridden.

        """
        self.socket.listen(self.request_queue_size)

    def server_close(self):
        """Called to clean-up the server.

        May be overridden.

        """
        self.socket.close()

    def fileno(self):
        """Return socket file number.

        Interface required by selector.

        """
        return self.socket.fileno()

    def get_request(self):
        """Get the request and client address from the socket.

        May be overridden.

        """
        return self.socket.accept()

    def shutdown_request(self, request):
        """Called to shutdown and close an individual request."""
        try:
            #explicitly shutdown.  socket.close() merely releases
            #the socket and waits for GC to perform the actual close.
            request.shutdown(socket.SHUT_WR)
        except OSError:
            pass #some platforms may raise ENOTCONN here
        self.close_request(request)

    def close_request(self, request):
        """Called to clean up an individual request."""
        request.close()

View TCPServer

class BaseServer:

    """Base class for server classes.

    Methods for the caller:

    - __init__(server_address, RequestHandlerClass)
    - serve_forever(poll_interval=0.5)
    - shutdown()
    - handle_request()  # if you do not use serve_forever()
    - fileno() -> int   # for selector

    Methods that may be overridden:

    - server_bind()
    - server_activate()
    - get_request() -> request, client_address
    - handle_timeout()
    - verify_request(request, client_address)
    - server_close()
    - process_request(request, client_address)
    - shutdown_request(request)
    - close_request(request)
    - service_actions()
    - handle_error()

    Methods for derived classes:

    - finish_request(request, client_address)

    Class variables that may be overridden by derived classes or
    instances:

    - timeout
    - address_family
    - socket_type
    - allow_reuse_address

    Instance variables:

    - RequestHandlerClass
    - socket

    """

    timeout = None

    def __init__(self, server_address, RequestHandlerClass):
        """Constructor.  May be extended, do not override."""
        self.server_address = server_address
        self.RequestHandlerClass = RequestHandlerClass
        self.__is_shut_down = threading.Event()
        self.__shutdown_request = False

    def server_activate(self):
        """Called by constructor to activate the server.

        May be overridden.

        """
        pass

    def serve_forever(self, poll_interval=0.5):
        """Handle one request at a time until shutdown.

        Polls for shutdown every poll_interval seconds. Ignores
        self.timeout. If you need to do periodic tasks, do them in
        another thread.
        """
        self.__is_shut_down.clear()
        try:
            # XXX: Consider using another file descriptor or connecting to the
            # socket to wake this up instead of polling. Polling reduces our
            # responsiveness to a shutdown request and wastes cpu at all other
            # times.
            with _ServerSelector() as selector:
                selector.register(self, selectors.EVENT_READ)

                while not self.__shutdown_request:
                    ready = selector.select(poll_interval)
                    if ready:
                        self._handle_request_noblock()

                    self.service_actions()
        finally:
            self.__shutdown_request = False
            self.__is_shut_down.set()

    def shutdown(self):
        """Stops the serve_forever loop.

        Blocks until the loop has finished. This must be called while
        serve_forever() is running in another thread, or it will
        deadlock.
        """
        self.__shutdown_request = True
        self.__is_shut_down.wait()

    def service_actions(self):
        """Called by the serve_forever() loop.

        May be overridden by a subclass / Mixin to implement any code that
        needs to be run during the loop.
        """
        pass

    # The distinction between handling, getting, processing and finishing a
    # request is fairly arbitrary.  Remember:
    #
    # - handle_request() is the top-level call.  It calls selector.select(),
    #   get_request(), verify_request() and process_request()
    # - get_request() is different for stream or datagram sockets
    # - process_request() is the place that may fork a new process or create a
    #   new thread to finish the request
    # - finish_request() instantiates the request handler class; this
    #   constructor will handle the request all by itself

    def handle_request(self):
        """Handle one request, possibly blocking.

        Respects self.timeout.
        """
        # Support people who used socket.settimeout() to escape
        # handle_request before self.timeout was available.
        timeout = self.socket.gettimeout()
        if timeout is None:
            timeout = self.timeout
        elif self.timeout is not None:
            timeout = min(timeout, self.timeout)
        if timeout is not None:
            deadline = time() + timeout

        # Wait until a request arrives or the timeout expires - the loop is
        # necessary to accommodate early wakeups due to EINTR.
        with _ServerSelector() as selector:
            selector.register(self, selectors.EVENT_READ)

            while True:
                ready = selector.select(timeout)
                if ready:
                    return self._handle_request_noblock()
                else:
                    if timeout is not None:
                        timeout = deadline - time()
                        if timeout < 0:
                            return self.handle_timeout()

    def _handle_request_noblock(self):
        """Handle one request, without blocking.

        I assume that selector.select() has returned that the socket is
        readable before this function was called, so there should be no risk of
        blocking in get_request().
        """
        try:
            request, client_address = self.get_request()
        except OSError:
            return
        if self.verify_request(request, client_address):
            try:
                self.process_request(request, client_address)
            except Exception:
                self.handle_error(request, client_address)
                self.shutdown_request(request)
            except:
                self.shutdown_request(request)
                raise
        else:
            self.shutdown_request(request)

    def handle_timeout(self):
        """Called if no new request arrives within self.timeout.

        Overridden by ForkingMixIn.
        """
        pass

    def verify_request(self, request, client_address):
        """Verify the request.  May be overridden.

        Return True if we should proceed with this request.

        """
        return True

    def process_request(self, request, client_address):
        """Call finish_request.

        Overridden by ForkingMixIn and ThreadingMixIn.

        """
        self.finish_request(request, client_address)
        self.shutdown_request(request)

    def server_close(self):
        """Called to clean-up the server.

        May be overridden.

        """
        pass

    def finish_request(self, request, client_address):
        """Finish one request by instantiating RequestHandlerClass."""
        self.RequestHandlerClass(request, client_address, self)

    def shutdown_request(self, request):
        """Called to shutdown and close an individual request."""
        self.close_request(request)

    def close_request(self, request):
        """Called to clean up an individual request."""
        pass

    def handle_error(self, request, client_address):
        """Handle an error gracefully.  May be overridden.

        The default is to print a traceback and continue.

        """
        print('-'*40, file=sys.stderr)
        print('Exception happened during processing of request from',
            client_address, file=sys.stderr)
        import traceback
        traceback.print_exc()
        print('-'*40, file=sys.stderr)

    def __enter__(self):
        return self

    def __exit__(self, *args):
        self.server_close()

View BaseServer