Python py3compat.BytesIO类代码示例

    def __init__(self, content=None):
        """
        Create a new SSH2 message.

        :param str content:
            the byte stream to use as the message content (passed in only when
            decomposing a message).
        """
        if content is not None:
            self.packet = BytesIO(content)
        else:
            self.packet = BytesIO()

    def write(self, data):
        """
        Write data to the file.  If write buffering is on (``bufsize`` was
        specified and non-zero), some or all of the data may not actually be
        written yet.  (Use `flush` or `close` to force buffered data to be
        written out.)

        :param str data: data to write
        """
        data = b(data)
        if self._closed:
            raise IOError("File is closed")
        if not (self._flags & self.FLAG_WRITE):
            raise IOError("File not open for writing")
        if not (self._flags & self.FLAG_BUFFERED):
            self._write_all(data)
            return
        self._wbuffer.write(data)
        if self._flags & self.FLAG_LINE_BUFFERED:
            # only scan the new data for linefeed, to avoid wasting time.
            last_newline_pos = data.rfind(linefeed_byte)
            if last_newline_pos >= 0:
                wbuf = self._wbuffer.getvalue()
                last_newline_pos += len(wbuf) - len(data)
                self._write_all(wbuf[: last_newline_pos + 1])
                self._wbuffer = BytesIO()
                self._wbuffer.write(wbuf[last_newline_pos + 1 :])
            return
        # even if we're line buffering, if the buffer has grown past the
        # buffer size, force a flush.
        if self._wbuffer.tell() >= self._bufsize:
            self.flush()
        return

 def flush(self):
     """
     Write out any data in the write buffer.  This may do nothing if write
     buffering is not turned on.
     """
     self._write_all(self._wbuffer.getvalue())
     self._wbuffer = BytesIO()
     return

class LoopbackFile (BufferedFile):
    """
    BufferedFile object that you can write data into, and then read it back.
    """
    def __init__(self, mode='r', bufsize=-1):
        BufferedFile.__init__(self)
        self._set_mode(mode, bufsize)
        self.buffer = BytesIO()
        self.offset = 0

    def _read(self, size):
        data = self.buffer.getvalue()[self.offset:self.offset+size]
        self.offset += len(data)
        return data

    def _write(self, data):
        self.buffer.write(data)
        return len(data)

 def __init__(self):
     self.newlines = None
     self._flags = 0
     self._bufsize = self._DEFAULT_BUFSIZE
     self._wbuffer = BytesIO()
     self._rbuffer = bytes()
     self._at_trailing_cr = False
     self._closed = False
     # pos - position within the file, according to the user
     # realpos - position according the OS
     # (these may be different because we buffer for line reading)
     self._pos = self._realpos = 0
     # size only matters for seekable files
     self._size = 0

class BufferedFile(ClosingContextManager):
    """
    Reusable base class to implement Python-style file buffering around a
    simpler stream.
    """

    _DEFAULT_BUFSIZE = 8192

    SEEK_SET = 0
    SEEK_CUR = 1
    SEEK_END = 2

    FLAG_READ = 0x1
    FLAG_WRITE = 0x2
    FLAG_APPEND = 0x4
    FLAG_BINARY = 0x10
    FLAG_BUFFERED = 0x20
    FLAG_LINE_BUFFERED = 0x40
    FLAG_UNIVERSAL_NEWLINE = 0x80

    def __init__(self):
        self.newlines = None
        self._flags = 0
        self._bufsize = self._DEFAULT_BUFSIZE
        self._wbuffer = BytesIO()
        self._rbuffer = bytes()
        self._at_trailing_cr = False
        self._closed = False
        # pos - position within the file, according to the user
        # realpos - position according the OS
        # (these may be different because we buffer for line reading)
        self._pos = self._realpos = 0
        # size only matters for seekable files
        self._size = 0

    def __del__(self):
        self.close()

    def __iter__(self):
        """
        Returns an iterator that can be used to iterate over the lines in this
        file.  This iterator happens to return the file itself, since a file is
        its own iterator.

        :raises ValueError: if the file is closed.
        """
        if self._closed:
            raise ValueError("I/O operation on closed file")
        return self

    def close(self):
        """
        Close the file.  Future read and write operations will fail.
        """
        self.flush()
        self._closed = True

    def flush(self):
        """
        Write out any data in the write buffer.  This may do nothing if write
        buffering is not turned on.
        """
        self._write_all(self._wbuffer.getvalue())
        self._wbuffer = BytesIO()
        return

    if PY2:

        def next(self):
            """
            Returns the next line from the input, or raises
            `~exceptions.StopIteration` when EOF is hit.  Unlike Python file
            objects, it's okay to mix calls to `next` and `readline`.

            :raises StopIteration: when the end of the file is reached.

            :return: a line (`str`) read from the file.
            """
            line = self.readline()
            if not line:
                raise StopIteration
            return line

    else:

        def __next__(self):
            """
            Returns the next line from the input, or raises `.StopIteration` when
            EOF is hit.  Unlike python file objects, it's okay to mix calls to
            `.next` and `.readline`.

            :raises StopIteration: when the end of the file is reached.

            :returns: a line (`str`) read from the file.
            """
            line = self.readline()
            if not line:
                raise StopIteration
            return line

#.........这里部分代码省略.........

class Message (object):
    """
    An SSH2 message is a stream of bytes that encodes some combination of
    strings, integers, bools, and infinite-precision integers (known in Python
    as longs).  This class builds or breaks down such a byte stream.

    Normally you don't need to deal with anything this low-level, but it's
    exposed for people implementing custom extensions, or features that
    paramiko doesn't support yet.
    """

    big_int = long(0xff000000)

    def __init__(self, content=None):
        """
        Create a new SSH2 message.

        :param str content:
            the byte stream to use as the message content (passed in only when
            decomposing a message).
        """
        if content is not None:
            self.packet = BytesIO(content)
        else:
            self.packet = BytesIO()

    def __str__(self):
        """
        Return the byte stream content of this message, as a string/bytes obj.
        """
        return self.asbytes()

    def __repr__(self):
        """
        Returns a string representation of this object, for debugging.
        """
        return 'paramiko.Message(' + repr(self.packet.getvalue()) + ')'

    def asbytes(self):
        """
        Return the byte stream content of this Message, as bytes.
        """
        return self.packet.getvalue()

    def rewind(self):
        """
        Rewind the message to the beginning as if no items had been parsed
        out of it yet.
        """
        self.packet.seek(0)

    def get_remainder(self):
        """
        Return the bytes (as a `str`) of this message that haven't already been
        parsed and returned.
        """
        position = self.packet.tell()
        remainder = self.packet.read()
        self.packet.seek(position)
        return remainder

    def get_so_far(self):
        """
        Returns the `str` bytes of this message that have been parsed and
        returned. The string passed into a message's constructor can be
        regenerated by concatenating ``get_so_far`` and `get_remainder`.
        """
        position = self.packet.tell()
        self.rewind()
        return self.packet.read(position)

    def get_bytes(self, n):
        """
        Return the next ``n`` bytes of the message (as a `str`), without
        decomposing into an int, decoded string, etc.  Just the raw bytes are
        returned. Returns a string of ``n`` zero bytes if there weren't ``n``
        bytes remaining in the message.
        """
        b = self.packet.read(n)
        max_pad_size = 1 << 20  # Limit padding to 1 MB
        if len(b) < n < max_pad_size:
            return b + zero_byte * (n - len(b))
        return b

    def get_byte(self):
        """
        Return the next byte of the message, without decomposing it.  This
        is equivalent to `get_bytes(1) <get_bytes>`.

        :return:
            the next (`str`) byte of the message, or ``'\000'`` if there aren't
            any bytes remaining.
        """
        return self.get_bytes(1)

    def get_boolean(self):
        """
        Fetch a boolean from the stream.
        """
        b = self.get_bytes(1)
#.........这里部分代码省略.........

 def __init__(self, mode='r', bufsize=-1):
     BufferedFile.__init__(self)
     self._set_mode(mode, bufsize)
     self.buffer = BytesIO()
     self.offset = 0