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import socket
import struct
import json
def pack_str(data: str):
encoded = data.encode()
return struct.pack('I', len(encoded)) + encoded
def pack_bytes(data: bytes):
return struct.pack('I', len(data)) + data
def handle_request(data, connection):
request = json.loads(data)
# Хотя метод только один, но все равно лучше
# сразу написать расширяемое приложение
if request['method'] == 'get':
path = request['path']
try:
with open(path, 'rb') as f:
file_data = f.read()
except FileNotFoundError:
header = json.dumps({'status': 1, 'reason': 'Файл не найден'})
connection.sendall(pack_str(header))
except PermissionError:
header = json.dumps({'status': 1, 'reason': 'Файл не доступен для чтения'})
connection.sendall(pack_str(header))
# Я знаю, что это плохо, но сервер не должен падать,
# а других ошибок я не смог вспомнить
except Exception as e:
header = json.dumps({'status': 2, 'reason': str(e)})
connection.sendall(pack_str(header))
else:
length = len(file_data)
header = json.dumps({'status': 0, 'size': length, 'path': request['path']})
connection.sendall(pack_str(header))
i = 0
while i < length:
packet = pack_bytes(file_data[i: i + CHUNK_SIZE])
connection.sendall(packet)
i += CHUNK_SIZE
def get_data(connection):
buffer = b''
while len(buffer) < 4:
data = connection.recv(4 - len(buffer))
if not data:
raise ConnectionError('Connection was closed')
buffer += data
size_packed, buffer = buffer[:4], buffer[4:]
if not size_packed:
raise ConnectionError('Connection was closed')
(size,) = struct.unpack('I', size_packed)
data = connection.recv(size - len(buffer))
return buffer + data
def handle_connection(connection, address):
while True:
try:
data = get_data(connection)
except ConnectionResetError:
print(f'Connection with {address[0]} was unexpectedly closed')
break
except ConnectionError:
print(f'Connection with {address[0]} was ended')
break
except KeyboardInterrupt:
raise KeyboardInterrupt()
else:
if not data:
print(f'Connection with {address[0]} was ended')
break
handle_request(data.decode(), connection)
HOST, PORT = ADDR = '0.0.0.0', 6000
CHUNK_SIZE = 4096
sock = socket.socket()
sock.bind(ADDR)
sock.listen(5)
while True:
print('Listening for new connections...')
try:
connection, address = sock.accept()
print(f'Got a connection from {address[0]}')
handle_connection(connection, address)
except KeyboardInterrupt:
print('Stopping server...')
sock.close()
print('Server stopped')
break
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