69 lines
2.1 KiB
Python
69 lines
2.1 KiB
Python
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class BufferOverflow(Exception):
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def __init__(self):
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super().__init__("Buffer overflow")
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class LineBuffer():
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__slots__ = 'buf', 'offset',
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BUFFER_SIZE = 4096
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def __init__(self, size: int=BUFFER_SIZE):
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self.buf: bytearray = bytearray(size)
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self.offset: int = 0
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def readline(self, sock: socket.socket) -> bytes:
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while True:
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#
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# Check and see if there is already a line in the
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# internal buffer.
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#
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offset = self.buf.find(b'\n', self.offset, self.count)
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if offset < 0:
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#
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# There is no line in the buffer. Check and see if
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# there is more room in the buffer to continue
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# reading.
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#
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if offset == self.BUFFER_SIZE - 1:
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#
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# There is no room left in the buffer; the line
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# must be too long. Panic.
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#
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raise BufferOverflow()
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#
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# Read from the socket to attempt to fill the buffer
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# more.
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#
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data = sock.recv(self.BUFFER_SIZE - self.offset)
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#
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# Check to see if recv() returned any data. If not,
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# the socket is closed. Return an empty string.
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#
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if data == b'':
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return ''
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count = len(data)
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#
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# Now, fill the buffer. The next iteration of the
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# loop will be used to check for a newline.
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#
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self.buf[self.offset:self.offset+count] = data
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else:
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#
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# There is a line in the buffer. Prepare to return
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# it.
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#
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ret = self.buf[self.offset:offset]
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#
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# Advance the offset to one character beyond the
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# newline.
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#
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self.offset = offset + 1
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return str(ret, 'ascii')
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