twisted.pair.testing.MemoryIOSystem

class documentation

class MemoryIOSystem: (source)

Implements interfaces: twisted.pair.tuntap._IInputOutputSystem

An in-memory implementation of basic I/O primitives, useful in the context of unit testing as a drop-in replacement for parts of the os module.

Method	`__init__`	Undocumented
Method	`close`	Discard the in-memory buffer and other in-memory state for the given file descriptor.
Method	`getTunnel`	Get the `Tunnel` object associated with the given `TuntapPort`.
Method	`ioctl`	Perform some configuration change to the in-memory state for the given file descriptor.
Method	`open`	A replacement for `os.open`. This initializes state in this `MemoryIOSystem` which will be reflected in the behavior of the other file descriptor-related methods (eg `MemoryIOSystem.read`, `MemoryIOSystem.write`...
Method	`read`	Try to read some bytes out of one of the in-memory buffers which may previously have been populated by `write`.
Method	`receiveUDP`	Get a socket-like object which can be used to receive a datagram sent from the given address.
Method	`registerSpecialDevice`	Specify a class which will be used to handle I/O to a device of a particular name.
Method	`sendUDP`	Write an ethernet frame containing an ip datagram containing a udp datagram containing the given payload, addressed to the given address, to a tunnel device previously opened on this I/O system.
Method	`write`	Try to add some bytes to one of the in-memory buffers to be accessed by a later `read` call.
Constant	`O_CLOEXEC`	No summary
Constant	`O_NONBLOCK`	No summary
Constant	`O_RDWR`	No summary
Instance Variable	`permissions`	No summary
Instance Variable	`_counter`	No summary
Instance Variable	`_devices`	No summary
Instance Variable	`_openFiles`	No summary

def __init__(self): (source) ¶

Undocumented

def close(self, fd): (source) ¶

from twisted.pair.tuntap._IInputOutputSystem

Discard the in-memory buffer and other in-memory state for the given file descriptor.

See Also
`os.close`

def getTunnel(self, port): (source) ¶

Get the Tunnel object associated with the given TuntapPort.

Parameters
port	A `TuntapPort` previously initialized using this `MemoryIOSystem`.

Returns
`Tunnel`	The tunnel object created by a prior use of `open` on this object on the tunnel special device file.

@_privileged

def ioctl(self, fd, request, args): (source) ¶

from twisted.pair.tuntap._IInputOutputSystem

Perform some configuration change to the in-memory state for the given file descriptor.

See Also
`fcntl.ioctl`

@_privileged

def open(self, name, flags, mode=None): (source) ¶

from twisted.pair.tuntap._IInputOutputSystem

A replacement for os.open. This initializes state in this MemoryIOSystem which will be reflected in the behavior of the other file descriptor-related methods (eg MemoryIOSystem.read, MemoryIOSystem.write, etc).

Parameters
name:`bytes`	A string giving the name of the file to open.
flags:`int`	The flags with which to open the file.
mode:`int`	The mode with which to open the file.

Returns
`int`	A file descriptor associated with the newly opened file description.

Raises
`OSError`	With `ENOSYS` if the file is not a recognized special device file.

def read(self, fd, limit): (source) ¶

from twisted.pair.tuntap._IInputOutputSystem

Try to read some bytes out of one of the in-memory buffers which may previously have been populated by write.

See Also
`os.read`

def receiveUDP(self, fileno, host, port): (source) ¶

from twisted.pair.tuntap._IInputOutputSystem

Get a socket-like object which can be used to receive a datagram sent from the given address.

Parameters
fileno:`int`	A file descriptor representing a tunnel device which the datagram will be received via.
host:`bytes`	The IPv4 address to which the datagram was sent.
port:`int`	The UDP port number to which the datagram was sent. received.

Returns
A `socket.socket`-like object which can be used to receive the specified datagram.

def registerSpecialDevice(self, name, cls): (source) ¶

Specify a class which will be used to handle I/O to a device of a particular name.

Parameters
name:`bytes`	The filesystem path name of the device.
cls	A class (like `Tunnel`) to instantiated whenever this device is opened.

def sendUDP(self, datagram, address): (source) ¶

from twisted.pair.tuntap._IInputOutputSystem

Write an ethernet frame containing an ip datagram containing a udp datagram containing the given payload, addressed to the given address, to a tunnel device previously opened on this I/O system.

Parameters
datagram:`bytes`	A UDP datagram payload to send.
address:`tuple` of (`bytes`, `int`)	The destination to which to send the datagram.

Returns
`tuple` of (`bytes`, `int`)	A two-tuple giving the address from which gives the address from which the datagram was sent.

def write(self, fd, data): (source) ¶

from twisted.pair.tuntap._IInputOutputSystem

Try to add some bytes to one of the in-memory buffers to be accessed by a later read call.

See Also
`os.write`

O_CLOEXEC = (source) ¶

from twisted.pair.tuntap._IInputOutputSystem

See Also
`os.O_CLOEXEC`

Value

1 << 2

O_NONBLOCK = (source) ¶

from twisted.pair.tuntap._IInputOutputSystem

See Also
`os.O_NONBLOCK`

Value

1 << 1

O_RDWR = (source) ¶

from twisted.pair.tuntap._IInputOutputSystem

See Also
`os.O_RDWR`

Value

1 << 0

permissions: set[str] = (source) ¶

_counter: int = (source) ¶

_devices: dict = (source) ¶

_openFiles: dict = (source) ¶