mirror of
https://github.com/python/cpython.git
synced 2024-11-24 17:47:13 +01:00
122 lines
4.2 KiB
Plaintext
122 lines
4.2 KiB
Plaintext
Filesystem, RCS and CVS client and server classes
|
|
=================================================
|
|
|
|
*** See the security warning at the end of this file! ***
|
|
|
|
This directory contains various modules and classes that support
|
|
remote file system operations.
|
|
|
|
CVS stuff
|
|
---------
|
|
|
|
rcvs Script to put in your bin directory
|
|
rcvs.py Remote CVS client command line interface
|
|
|
|
cvslib.py CVS admin files classes (used by rrcs)
|
|
cvslock.py CVS locking algorithms
|
|
|
|
RCS stuff
|
|
---------
|
|
|
|
rrcs Script to put in your bin directory
|
|
rrcs.py Remote RCS client command line interface
|
|
|
|
rcsclient.py Return an RCSProxyClient instance
|
|
(has reasonable default server/port/directory)
|
|
|
|
RCSProxy.py RCS proxy and server classes (on top of rcslib.py)
|
|
|
|
rcslib.py Local-only RCS base class (affects stdout &
|
|
local work files)
|
|
|
|
FSProxy stuff
|
|
-------------
|
|
|
|
sumtree.py Old demo for FSProxy
|
|
cmptree.py First FSProxy client (used to sync from the Mac)
|
|
FSProxy.py Filesystem interface classes
|
|
|
|
Generic client/server stuff
|
|
---------------------------
|
|
|
|
client.py Client class
|
|
server.py Server class
|
|
|
|
security.py Security mix-in class (not very secure I think)
|
|
|
|
Other generic stuff
|
|
-------------------
|
|
|
|
cmdfw.py CommandFrameWork class
|
|
(used by rcvs, should be used by rrcs as well)
|
|
|
|
|
|
Client/Server operation
|
|
-----------------------
|
|
|
|
The Client and Server classes implement a simple-minded RPC protocol,
|
|
using Python's pickle module to transfer arguments, return values and
|
|
exceptions with the most generality. The Server class is instantiated
|
|
with a port number on which it should listen for requests; the Client
|
|
class is instantiated with a host name and a port number where it
|
|
should connect to. Once a client is connected, a TCP connection is
|
|
maintained between client and server.
|
|
|
|
The Server class currently handles only one connection at a time;
|
|
however it could be rewritten to allow various modes of operations,
|
|
using multiple threads or processes or the select() system call as
|
|
desired to serve multiple clients simultaneously (when using select(),
|
|
still handling one request at a time). This would not require
|
|
rewriting of the Client class. It may also be possible to adapt the
|
|
code to use UDP instead of TCP, but then both classes will have to be
|
|
rewritten (and unless extensive acknowlegements and request serial
|
|
numbers are used, the server should handle duplicate requests, so its
|
|
semantics should be idempotent -- shrudder).
|
|
|
|
Even though the FSProxy and RCSProxy modules define client classes,
|
|
the client class is fully generic -- what methods it supports is
|
|
determined entirely by the server. The server class, however, must be
|
|
derived from. This is generally done as follows:
|
|
|
|
from server import Server
|
|
from client import Client
|
|
|
|
# Define a class that performs the operations locally
|
|
class MyClassLocal:
|
|
def __init__(self): ...
|
|
def _close(self): ...
|
|
|
|
# Derive a server class using multiple inheritance
|
|
class MyClassServer(MyClassLocal, Server):
|
|
def __init__(self, address):
|
|
# Must initialize MyClassLocal as well as Server
|
|
MyClassLocal.__init__(self)
|
|
Server.__init__(self, address)
|
|
def _close(self):
|
|
Server._close()
|
|
MyClassLocal._close()
|
|
|
|
# A dummy client class
|
|
class MyClassClient(Client): pass
|
|
|
|
Note that because MyClassLocal isn't used in the definition of
|
|
MyClassClient, it would actually be better to place it in a separate
|
|
module so the definition of MyClassLocal isn't executed when we only
|
|
instantiate a client.
|
|
|
|
The modules client and server should probably be renamed to Client and
|
|
Server in order to match the class names.
|
|
|
|
|
|
*** Security warning: this version requires that you have a file
|
|
$HOME/.python_keyfile at the server and client side containing two
|
|
comma- separated numbers. The security system at the moment makes no
|
|
guarantees of actuallng being secure -- however it requires that the
|
|
key file exists and contains the same numbers at both ends for this to
|
|
work. (You can specify an alternative keyfile in $PYTHON_KEYFILE).
|
|
Have a look at the Security class in security.py for details;
|
|
basically, if the key file contains (x, y), then the security server
|
|
class chooses a random number z (the challenge) in the range
|
|
10..100000 and the client must be able to produce pow(z, x, y)
|
|
(i.e. z**x mod y).
|