pyqtgraph/multiprocess/remoteproxy.py

938 lines
38 KiB
Python

import os, __builtin__, time, sys, traceback, weakref
import cPickle as pickle
class ExitError(Exception):
pass
class NoResultError(Exception):
pass
class RemoteEventHandler(object):
"""
This class handles communication between two processes. One instance is present on
each process and listens for communication from the other process. This enables
(amongst other things) ObjectProxy instances to look up their attributes and call
their methods.
This class is responsible for carrying out actions on behalf of the remote process.
Each instance holds one end of a Connection which allows python
objects to be passed between processes.
For the most common operations, see _import(), close(), and transfer()
To handle and respond to incoming requests, RemoteEventHandler requires that its
processRequests method is called repeatedly (this is usually handled by the Process
classes defined in multiprocess.processes).
"""
handlers = {} ## maps {process ID : handler}. This allows unpickler to determine which process
## an object proxy belongs to
def __init__(self, connection, name, pid):
self.conn = connection
self.name = name
self.results = {} ## reqId: (status, result); cache of request results received from the remote process
## status is either 'result' or 'error'
## if 'error', then result will be (exception, formatted exceprion)
## where exception may be None if it could not be passed through the Connection.
self.proxies = {} ## maps {weakref(proxy): proxyId}; used to inform the remote process when a proxy has been deleted.
## attributes that affect the behavior of the proxy.
## See ObjectProxy._setProxyOptions for description
self.proxyOptions = {
'callSync': 'sync', ## 'sync', 'async', 'off'
'timeout': 10, ## float
'returnType': 'auto', ## 'proxy', 'value', 'auto'
'autoProxy': False, ## bool
'deferGetattr': False, ## True, False
'noProxyTypes': [ type(None), str, int, float, tuple, list, dict, LocalObjectProxy, ObjectProxy ],
}
self.nextRequestId = 0
self.exited = False
RemoteEventHandler.handlers[pid] = self ## register this handler as the one communicating with pid
@classmethod
def getHandler(cls, pid):
try:
return cls.handlers[pid]
except:
print pid, cls.handlers
raise
def getProxyOption(self, opt):
return self.proxyOptions[opt]
def setProxyOptions(self, **kwds):
"""
Set the default behavior options for object proxies.
See ObjectProxy._setProxyOptions for more info.
"""
self.proxyOptions.update(kwds)
def processRequests(self):
"""Process all pending requests from the pipe, return
after no more events are immediately available. (non-blocking)
Returns the number of events processed.
"""
if self.exited:
raise ExitError()
numProcessed = 0
while self.conn.poll():
try:
self.handleRequest()
numProcessed += 1
except ExitError:
self.exited = True
raise
except IOError as err:
if err.errno == 4: ## interrupted system call; try again
continue
else:
raise
except:
print "Error in process %s" % self.name
sys.excepthook(*sys.exc_info())
return numProcessed
def handleRequest(self):
"""Handle a single request from the remote process.
Blocks until a request is available."""
result = None
try:
cmd, reqId, optStr = self.conn.recv() ## args, kwds are double-pickled to ensure this recv() call never fails
except EOFError:
## remote process has shut down; end event loop
raise ExitError()
except IOError:
raise ExitError()
#print os.getpid(), "received request:", cmd, reqId
try:
if cmd == 'result' or cmd == 'error':
resultId = reqId
reqId = None ## prevents attempt to return information from this request
## (this is already a return from a previous request)
opts = pickle.loads(optStr)
#print os.getpid(), "received request:", cmd, reqId, opts
returnType = opts.get('returnType', 'auto')
if cmd == 'result':
self.results[resultId] = ('result', opts['result'])
elif cmd == 'error':
self.results[resultId] = ('error', (opts['exception'], opts['excString']))
elif cmd == 'getObjAttr':
result = getattr(opts['obj'], opts['attr'])
elif cmd == 'callObj':
obj = opts['obj']
fnargs = opts['args']
fnkwds = opts['kwds']
if len(fnkwds) == 0: ## need to do this because some functions do not allow keyword arguments.
#print obj, fnargs
result = obj(*fnargs)
else:
result = obj(*fnargs, **fnkwds)
elif cmd == 'getObjValue':
result = opts['obj'] ## has already been unpickled into its local value
returnType = 'value'
elif cmd == 'transfer':
result = opts['obj']
returnType = 'proxy'
elif cmd == 'import':
name = opts['module']
fromlist = opts.get('fromlist', [])
mod = __builtin__.__import__(name, fromlist=fromlist)
if len(fromlist) == 0:
parts = name.lstrip('.').split('.')
result = mod
for part in parts[1:]:
result = getattr(result, part)
else:
result = map(mod.__getattr__, fromlist)
elif cmd == 'del':
LocalObjectProxy.releaseProxyId(opts['proxyId'])
#del self.proxiedObjects[opts['objId']]
elif cmd == 'close':
if reqId is not None:
result = True
returnType = 'value'
exc = None
except:
exc = sys.exc_info()
if reqId is not None:
if exc is None:
#print "returnValue:", returnValue, result
if returnType == 'auto':
result = self.autoProxy(result, self.proxyOptions['noProxyTypes'])
elif returnType == 'proxy':
result = LocalObjectProxy(result)
try:
self.replyResult(reqId, result)
except:
sys.excepthook(*sys.exc_info())
self.replyError(reqId, *sys.exc_info())
else:
self.replyError(reqId, *exc)
elif exc is not None:
sys.excepthook(*exc)
if cmd == 'close':
if opts.get('noCleanup', False) is True:
os._exit(0) ## exit immediately, do not pass GO, do not collect $200.
## (more importantly, do not call any code that would
## normally be invoked at exit)
else:
raise ExitError()
def replyResult(self, reqId, result):
self.send(request='result', reqId=reqId, callSync='off', opts=dict(result=result))
def replyError(self, reqId, *exc):
print "error:", self.name, reqId, exc[1]
excStr = traceback.format_exception(*exc)
try:
self.send(request='error', reqId=reqId, callSync='off', opts=dict(exception=exc[1], excString=excStr))
except:
self.send(request='error', reqId=reqId, callSync='off', opts=dict(exception=None, excString=excStr))
def send(self, request, opts=None, reqId=None, callSync='sync', timeout=10, returnType=None, **kwds):
"""Send a request or return packet to the remote process.
Generally it is not necessary to call this method directly; it is for internal use.
(The docstring has information that is nevertheless useful to the programmer
as it describes the internal protocol used to communicate between processes)
========== ====================================================================
Arguments:
request String describing the type of request being sent (see below)
reqId Integer uniquely linking a result back to the request that generated
it. (most requests leave this blank)
callSync 'sync': return the actual result of the request
'async': return a Request object which can be used to look up the
result later
'off': return no result
timeout Time in seconds to wait for a response when callSync=='sync'
opts Extra arguments sent to the remote process that determine the way
the request will be handled (see below)
returnType 'proxy', 'value', or 'auto'
========== ====================================================================
Description of request strings and options allowed for each:
============= ============= ========================================================
request option description
------------- ------------- --------------------------------------------------------
getObjAttr Request the remote process return (proxy to) an
attribute of an object.
obj reference to object whose attribute should be
returned
attr string name of attribute to return
returnValue bool or 'auto' indicating whether to return a proxy or
the actual value.
callObj Request the remote process call a function or
method. If a request ID is given, then the call's
return value will be sent back (or information
about the error that occurred while running the
function)
obj the (reference to) object to call
args tuple of arguments to pass to callable
kwds dict of keyword arguments to pass to callable
returnValue bool or 'auto' indicating whether to return a proxy or
the actual value.
getObjValue Request the remote process return the value of
a proxied object (must be picklable)
obj reference to object whose value should be returned
transfer Copy an object to the remote process and request
it return a proxy for the new object.
obj The object to transfer.
import Request the remote process import new symbols
and return proxy(ies) to the imported objects
module the string name of the module to import
fromlist optional list of string names to import from module
del Inform the remote process that a proxy has been
released (thus the remote process may be able to
release the original object)
proxyId id of proxy which is no longer referenced by
remote host
close Instruct the remote process to stop its event loop
and exit. Optionally, this request may return a
confirmation.
result Inform the remote process that its request has
been processed
result return value of a request
error Inform the remote process that its request failed
exception the Exception that was raised (or None if the
exception could not be pickled)
excString string-formatted version of the exception and
traceback
============= =====================================================================
"""
#if len(kwds) > 0:
#print "Warning: send() ignored args:", kwds
if opts is None:
opts = {}
assert callSync in ['off', 'sync', 'async'], 'callSync must be one of "off", "sync", or "async"'
if reqId is None:
if callSync != 'off': ## requested return value; use the next available request ID
reqId = self.nextRequestId
self.nextRequestId += 1
else:
## If requestId is provided, this _must_ be a response to a previously received request.
assert request in ['result', 'error']
if returnType is not None:
opts['returnType'] = returnType
#print "send", opts
## double-pickle args to ensure that at least status and request ID get through
try:
optStr = pickle.dumps(opts)
except:
print "==== Error pickling this object: ===="
print opts
print "======================================="
raise
request = (request, reqId, optStr)
self.conn.send(request)
if callSync == 'off':
return
req = Request(self, reqId, description=str(request), timeout=timeout)
if callSync == 'async':
return req
if callSync == 'sync':
try:
return req.result()
except NoResultError:
return req
def close(self, callSync='off', noCleanup=False, **kwds):
self.send(request='close', opts=dict(noCleanup=noCleanup), callSync=callSync, **kwds)
def getResult(self, reqId):
## raises NoResultError if the result is not available yet
#print self.results.keys(), os.getpid()
if reqId not in self.results:
#self.readPipe()
try:
self.processRequests()
except ExitError:
pass
if reqId not in self.results:
raise NoResultError()
status, result = self.results.pop(reqId)
if status == 'result':
return result
elif status == 'error':
#print ''.join(result)
exc, excStr = result
if exc is not None:
print "===== Remote process raised exception on request: ====="
print ''.join(excStr)
print "===== Local Traceback to request follows: ====="
raise exc
else:
print ''.join(excStr)
raise Exception("Error getting result. See above for exception from remote process.")
else:
raise Exception("Internal error.")
def _import(self, mod, **kwds):
"""
Request the remote process import a module (or symbols from a module)
and return the proxied results. Uses built-in __import__() function, but
adds a bit more processing:
_import('module') => returns module
_import('module.submodule') => returns submodule
(note this differs from behavior of __import__)
_import('module', fromlist=[name1, name2, ...]) => returns [module.name1, module.name2, ...]
(this also differs from behavior of __import__)
"""
return self.send(request='import', callSync='sync', opts=dict(module=mod), **kwds)
def getObjAttr(self, obj, attr, **kwds):
return self.send(request='getObjAttr', opts=dict(obj=obj, attr=attr), **kwds)
def getObjValue(self, obj, **kwds):
return self.send(request='getObjValue', opts=dict(obj=obj), **kwds)
def callObj(self, obj, args, kwds, **opts):
opts = opts.copy()
noProxyTypes = opts.pop('noProxyTypes', None)
if noProxyTypes is None:
noProxyTypes = self.proxyOptions['noProxyTypes']
autoProxy = opts.pop('autoProxy', self.proxyOptions['autoProxy'])
if autoProxy is True:
args = tuple([self.autoProxy(v, noProxyTypes) for v in args])
for k, v in kwds.iteritems():
opts[k] = self.autoProxy(v, noProxyTypes)
return self.send(request='callObj', opts=dict(obj=obj, args=args, kwds=kwds), **opts)
def registerProxy(self, proxy):
ref = weakref.ref(proxy, self.deleteProxy)
self.proxies[ref] = proxy._proxyId
def deleteProxy(self, ref):
proxyId = self.proxies.pop(ref)
try:
self.send(request='del', opts=dict(proxyId=proxyId), callSync='off')
except IOError: ## if remote process has closed down, there is no need to send delete requests anymore
pass
def transfer(self, obj, **kwds):
"""
Transfer an object by value to the remote host (the object must be picklable)
and return a proxy for the new remote object.
"""
return self.send(request='transfer', opts=dict(obj=obj), **kwds)
def autoProxy(self, obj, noProxyTypes):
## Return object wrapped in LocalObjectProxy _unless_ its type is in noProxyTypes.
for typ in noProxyTypes:
if isinstance(obj, typ):
return obj
return LocalObjectProxy(obj)
class Request(object):
"""
Request objects are returned when calling an ObjectProxy in asynchronous mode
or if a synchronous call has timed out. Use hasResult() to ask whether
the result of the call has been returned yet. Use result() to get
the returned value.
"""
def __init__(self, process, reqId, description=None, timeout=10):
self.proc = process
self.description = description
self.reqId = reqId
self.gotResult = False
self._result = None
self.timeout = timeout
def result(self, block=True, timeout=None):
"""
Return the result for this request.
If block is True, wait until the result has arrived or *timeout* seconds passes.
If the timeout is reached, raise NoResultError. (use timeout=None to disable)
If block is False, raise NoResultError immediately if the result has not arrived yet.
"""
if self.gotResult:
return self._result
if timeout is None:
timeout = self.timeout
if block:
start = time.time()
while not self.hasResult():
time.sleep(0.005)
if timeout >= 0 and time.time() - start > timeout:
print "Request timed out:", self.description
import traceback
traceback.print_stack()
raise NoResultError()
return self._result
else:
self._result = self.proc.getResult(self.reqId) ## raises NoResultError if result is not available yet
self.gotResult = True
return self._result
def hasResult(self):
"""Returns True if the result for this request has arrived."""
try:
self.result(block=False)
except NoResultError:
pass
return self.gotResult
class LocalObjectProxy(object):
"""
Used for wrapping local objects to ensure that they are send by proxy to a remote host.
Note that 'proxy' is just a shorter alias for LocalObjectProxy.
For example::
data = [1,2,3,4,5]
remotePlot.plot(data) ## by default, lists are pickled and sent by value
remotePlot.plot(proxy(data)) ## force the object to be sent by proxy
"""
nextProxyId = 0
proxiedObjects = {} ## maps {proxyId: object}
@classmethod
def registerObject(cls, obj):
## assign it a unique ID so we can keep a reference to the local object
pid = cls.nextProxyId
cls.nextProxyId += 1
cls.proxiedObjects[pid] = obj
#print "register:", cls.proxiedObjects
return pid
@classmethod
def lookupProxyId(cls, pid):
return cls.proxiedObjects[pid]
@classmethod
def releaseProxyId(cls, pid):
del cls.proxiedObjects[pid]
#print "release:", cls.proxiedObjects
def __init__(self, obj, **opts):
"""
Create a 'local' proxy object that, when sent to a remote host,
will appear as a normal ObjectProxy to *obj*.
Any extra keyword arguments are passed to proxy._setProxyOptions()
on the remote side.
"""
self.processId = os.getpid()
#self.objectId = id(obj)
self.typeStr = repr(obj)
#self.handler = handler
self.obj = obj
self.opts = opts
def __reduce__(self):
## a proxy is being pickled and sent to a remote process.
## every time this happens, a new proxy will be generated in the remote process,
## so we keep a new ID so we can track when each is released.
pid = LocalObjectProxy.registerObject(self.obj)
return (unpickleObjectProxy, (self.processId, pid, self.typeStr, None, self.opts))
## alias
proxy = LocalObjectProxy
def unpickleObjectProxy(processId, proxyId, typeStr, attributes=None, opts=None):
if processId == os.getpid():
obj = LocalObjectProxy.lookupProxyId(proxyId)
if attributes is not None:
for attr in attributes:
obj = getattr(obj, attr)
return obj
else:
proxy = ObjectProxy(processId, proxyId=proxyId, typeStr=typeStr)
if opts is not None:
proxy._setProxyOptions(**opts)
return proxy
class ObjectProxy(object):
"""
Proxy to an object stored by the remote process. Proxies are created
by calling Process._import(), Process.transfer(), or by requesting/calling
attributes on existing proxy objects.
For the most part, this object can be used exactly as if it
were a local object::
rsys = proc._import('sys') # returns proxy to sys module on remote process
rsys.stdout # proxy to remote sys.stdout
rsys.stdout.write # proxy to remote sys.stdout.write
rsys.stdout.write('hello') # calls sys.stdout.write('hello') on remote machine
# and returns the result (None)
When calling a proxy to a remote function, the call can be made synchronous
(result of call is returned immediately), asynchronous (result is returned later),
or return can be disabled entirely::
ros = proc._import('os')
## synchronous call; result is returned immediately
pid = ros.getpid()
## asynchronous call
request = ros.getpid(_callSync='async')
while not request.hasResult():
time.sleep(0.01)
pid = request.result()
## disable return when we know it isn't needed
rsys.stdout.write('hello', _callSync='off')
Additionally, values returned from a remote function call are automatically
returned either by value (must be picklable) or by proxy.
This behavior can be forced::
rnp = proc._import('numpy')
arrProxy = rnp.array([1,2,3,4], _returnType='proxy')
arrValue = rnp.array([1,2,3,4], _returnType='value')
The default callSync and returnType behaviors (as well as others) can be set
for each proxy individually using ObjectProxy._setProxyOptions() or globally using
proc.setProxyOptions().
"""
def __init__(self, processId, proxyId, typeStr='', parent=None):
object.__init__(self)
## can't set attributes directly because setattr is overridden.
self.__dict__['_processId'] = processId
self.__dict__['_typeStr'] = typeStr
self.__dict__['_proxyId'] = proxyId
self.__dict__['_attributes'] = ()
## attributes that affect the behavior of the proxy.
## in all cases, a value of None causes the proxy to ask
## its parent event handler to make the decision
self.__dict__['_proxyOptions'] = {
'callSync': None, ## 'sync', 'async', None
'timeout': None, ## float, None
'returnType': None, ## 'proxy', 'value', 'auto', None
'deferGetattr': None, ## True, False, None
'noProxyTypes': None, ## list of types to send by value instead of by proxy
}
self.__dict__['_handler'] = RemoteEventHandler.getHandler(processId)
self.__dict__['_handler'].registerProxy(self) ## handler will watch proxy; inform remote process when the proxy is deleted.
def _setProxyOptions(self, **kwds):
"""
Change the behavior of this proxy. For all options, a value of None
will cause the proxy to instead use the default behavior defined
by its parent Process.
Options are:
============= =============================================================
callSync 'sync', 'async', 'off', or None.
If 'async', then calling methods will return a Request object
which can be used to inquire later about the result of the
method call.
If 'sync', then calling a method
will block until the remote process has returned its result
or the timeout has elapsed (in this case, a Request object
is returned instead).
If 'off', then the remote process is instructed _not_ to
reply and the method call will return None immediately.
returnType 'auto', 'proxy', 'value', or None.
If 'proxy', then the value returned when calling a method
will be a proxy to the object on the remote process.
If 'value', then attempt to pickle the returned object and
send it back.
If 'auto', then the decision is made by consulting the
'noProxyTypes' option.
autoProxy bool or None. If True, arguments to __call__ are
automatically converted to proxy unless their type is
listed in noProxyTypes (see below). If False, arguments
are left untouched. Use proxy(obj) to manually convert
arguments before sending.
timeout float or None. Length of time to wait during synchronous
requests before returning a Request object instead.
deferGetattr True, False, or None.
If False, all attribute requests will be sent to the remote
process immediately and will block until a response is
received (or timeout has elapsed).
If True, requesting an attribute from the proxy returns a
new proxy immediately. The remote process is _not_ contacted
to make this request. This is faster, but it is possible to
request an attribute that does not exist on the proxied
object. In this case, AttributeError will not be raised
until an attempt is made to look up the attribute on the
remote process.
noProxyTypes List of object types that should _not_ be proxied when
sent to the remote process.
============= =============================================================
"""
self._proxyOptions.update(kwds)
def _getValue(self):
"""
Return the value of the proxied object
(the remote object must be picklable)
"""
return self._handler.getObjValue(self)
def _getProxyOption(self, opt):
val = self._proxyOptions[opt]
if val is None:
return self._handler.getProxyOption(opt)
return val
def _getProxyOptions(self):
return {k: self._getProxyOption(k) for k in self._proxyOptions}
def __reduce__(self):
return (unpickleObjectProxy, (self._processId, self._proxyId, self._typeStr, self._attributes))
def __repr__(self):
#objRepr = self.__getattr__('__repr__')(callSync='value')
return "<ObjectProxy for process %d, object 0x%x: %s >" % (self._processId, self._proxyId, self._typeStr)
def __getattr__(self, attr, **kwds):
"""
Calls __getattr__ on the remote object and returns the attribute
by value or by proxy depending on the options set (see
ObjectProxy._setProxyOptions and RemoteEventHandler.setProxyOptions)
If the option 'deferGetattr' is True for this proxy, then a new proxy object
is returned _without_ asking the remote object whether the named attribute exists.
This can save time when making multiple chained attribute requests,
but may also defer a possible AttributeError until later, making
them more difficult to debug.
"""
opts = self._getProxyOptions()
for k in opts:
if '_'+k in kwds:
opts[k] = kwds.pop('_'+k)
if opts['deferGetattr'] is True:
return self._deferredAttr(attr)
else:
#opts = self._getProxyOptions()
return self._handler.getObjAttr(self, attr, **opts)
def _deferredAttr(self, attr):
return DeferredObjectProxy(self, attr)
def __call__(self, *args, **kwds):
"""
Attempts to call the proxied object from the remote process.
Accepts extra keyword arguments:
_callSync 'off', 'sync', or 'async'
_returnType 'value', 'proxy', or 'auto'
If the remote call raises an exception on the remote process,
it will be re-raised on the local process.
"""
opts = self._getProxyOptions()
for k in opts:
if '_'+k in kwds:
opts[k] = kwds.pop('_'+k)
return self._handler.callObj(obj=self, args=args, kwds=kwds, **opts)
## Explicitly proxy special methods. Is there a better way to do this??
def _getSpecialAttr(self, attr):
## this just gives us an easy way to change the behavior of the special methods
return self._deferredAttr(attr)
def __getitem__(self, *args):
return self._getSpecialAttr('__getitem__')(*args)
def __setitem__(self, *args):
return self._getSpecialAttr('__setitem__')(*args, _callSync='off')
def __setattr__(self, *args):
return self._getSpecialAttr('__setattr__')(*args, _callSync='off')
def __str__(self, *args):
return self._getSpecialAttr('__str__')(*args, _returnType='value')
def __len__(self, *args):
return self._getSpecialAttr('__len__')(*args)
def __add__(self, *args):
return self._getSpecialAttr('__add__')(*args)
def __sub__(self, *args):
return self._getSpecialAttr('__sub__')(*args)
def __div__(self, *args):
return self._getSpecialAttr('__div__')(*args)
def __mul__(self, *args):
return self._getSpecialAttr('__mul__')(*args)
def __pow__(self, *args):
return self._getSpecialAttr('__pow__')(*args)
def __iadd__(self, *args):
return self._getSpecialAttr('__iadd__')(*args, _callSync='off')
def __isub__(self, *args):
return self._getSpecialAttr('__isub__')(*args, _callSync='off')
def __idiv__(self, *args):
return self._getSpecialAttr('__idiv__')(*args, _callSync='off')
def __imul__(self, *args):
return self._getSpecialAttr('__imul__')(*args, _callSync='off')
def __ipow__(self, *args):
return self._getSpecialAttr('__ipow__')(*args, _callSync='off')
def __rshift__(self, *args):
return self._getSpecialAttr('__rshift__')(*args)
def __lshift__(self, *args):
return self._getSpecialAttr('__lshift__')(*args)
def __floordiv__(self, *args):
return self._getSpecialAttr('__pow__')(*args)
def __irshift__(self, *args):
return self._getSpecialAttr('__rshift__')(*args, _callSync='off')
def __ilshift__(self, *args):
return self._getSpecialAttr('__lshift__')(*args, _callSync='off')
def __ifloordiv__(self, *args):
return self._getSpecialAttr('__pow__')(*args, _callSync='off')
def __eq__(self, *args):
return self._getSpecialAttr('__eq__')(*args)
def __ne__(self, *args):
return self._getSpecialAttr('__ne__')(*args)
def __lt__(self, *args):
return self._getSpecialAttr('__lt__')(*args)
def __gt__(self, *args):
return self._getSpecialAttr('__gt__')(*args)
def __le__(self, *args):
return self._getSpecialAttr('__le__')(*args)
def __ge__(self, *args):
return self._getSpecialAttr('__ge__')(*args)
def __and__(self, *args):
return self._getSpecialAttr('__and__')(*args)
def __or__(self, *args):
return self._getSpecialAttr('__or__')(*args)
def __xor__(self, *args):
return self._getSpecialAttr('__xor__')(*args)
def __iand__(self, *args):
return self._getSpecialAttr('__iand__')(*args, _callSync='off')
def __ior__(self, *args):
return self._getSpecialAttr('__ior__')(*args, _callSync='off')
def __ixor__(self, *args):
return self._getSpecialAttr('__ixor__')(*args, _callSync='off')
def __mod__(self, *args):
return self._getSpecialAttr('__mod__')(*args)
def __radd__(self, *args):
return self._getSpecialAttr('__radd__')(*args)
def __rsub__(self, *args):
return self._getSpecialAttr('__rsub__')(*args)
def __rdiv__(self, *args):
return self._getSpecialAttr('__rdiv__')(*args)
def __rmul__(self, *args):
return self._getSpecialAttr('__rmul__')(*args)
def __rpow__(self, *args):
return self._getSpecialAttr('__rpow__')(*args)
def __rrshift__(self, *args):
return self._getSpecialAttr('__rrshift__')(*args)
def __rlshift__(self, *args):
return self._getSpecialAttr('__rlshift__')(*args)
def __rfloordiv__(self, *args):
return self._getSpecialAttr('__rpow__')(*args)
def __rand__(self, *args):
return self._getSpecialAttr('__rand__')(*args)
def __ror__(self, *args):
return self._getSpecialAttr('__ror__')(*args)
def __rxor__(self, *args):
return self._getSpecialAttr('__ror__')(*args)
def __rmod__(self, *args):
return self._getSpecialAttr('__rmod__')(*args)
class DeferredObjectProxy(ObjectProxy):
"""
This class represents an attribute (or sub-attribute) of a proxied object.
It is used to speed up attribute requests. Take the following scenario::
rsys = proc._import('sys')
rsys.stdout.write('hello')
For this simple example, a total of 4 synchronous requests are made to
the remote process:
1) import sys
2) getattr(sys, 'stdout')
3) getattr(stdout, 'write')
4) write('hello')
This takes a lot longer than running the equivalent code locally. To
speed things up, we can 'defer' the two attribute lookups so they are
only carried out when neccessary::
rsys = proc._import('sys')
rsys._setProxyOptions(deferGetattr=True)
rsys.stdout.write('hello')
This example only makes two requests to the remote process; the two
attribute lookups immediately return DeferredObjectProxy instances
immediately without contacting the remote process. When the call
to write() is made, all attribute requests are processed at the same time.
Note that if the attributes requested do not exist on the remote object,
making the call to write() will raise an AttributeError.
"""
def __init__(self, parentProxy, attribute):
## can't set attributes directly because setattr is overridden.
for k in ['_processId', '_typeStr', '_proxyId', '_handler']:
self.__dict__[k] = getattr(parentProxy, k)
self.__dict__['_parent'] = parentProxy ## make sure parent stays alive
self.__dict__['_attributes'] = parentProxy._attributes + (attribute,)
self.__dict__['_proxyOptions'] = parentProxy._proxyOptions.copy()
def __repr__(self):
return ObjectProxy.__repr__(self) + '.' + '.'.join(self._attributes)
def _undefer(self):
"""
Return a non-deferred ObjectProxy referencing the same object
"""
return self._parent.__getattr__(self._attributes[-1], _deferGetattr=False)